An Evaluation of the in Vivo Debridement Efficacy of 3.0% Naocl Vs. 6.0% Naocl Ultrasound After Hand and Rotary Instrumentation in Human Mandibular Molars

AN EVALUATION OF THE IN VIVO DEBRIDEMENT EFFICACY OF 3.0% NAOCL VS. 6.0% NAOCL ULTRASOUND AFTER HAND AND ROTARY INSTRUMENTATION IN HUMAN MANDIBULAR MOLARS

A Thesis

Presented in Partial Fulfillment of the Requirements for

the Degree Master of Science in the

Graduate School of The Ohio State University

Aaron Douglass Aue, D.D.S.

Dentistry Graduate Program

The Ohio State University

2009

Master’s Examination Committee:

John Nusstein, D.D.S., M.S., Adviser

Alfred Reader, D.D.S., M.S.

F. Michael Beck, D.D.S., M.A.

Aaron Douglass Aue, D.D.S.

2009

ABSTRACT

This study histologically compared the in vivo debridement efficacy of a hand and rotary preparation followed by passive ultrasonic irrigation using a continuous flow of

3% sodium hypochlorite (NaOCl) versus a hand/rotary/ultrasound technique using 6%

NaOCl in mesial root canals of vital human mandibular molars. Group 1 consisted of 15 teeth prepared with a hand/rotary technique followed by 1 min of ultrasonic irrigation, per canal, utilizing an ultrasonic needle in a MiniEndo™ unit expressing 15 mL of 3.0%

NaOCl per canal. This was compared to Group 2 which was an existing sample collected and evaluated as part of a previous study. Group 2 consisted of 16 teeth prepared with the same hand/rotary/ultrasonic irrigation technique using 6.0% sodium hypochlorite.

Following extraction and histologic preparation 5 !m cross-sections from the 1- to 3 mm apical levels were evaluated for percentage of tissue removal from canals and isthmuses using a Neurolucida Image Analysis Program version 7.0. In Group 1, 15 out of the 16 teeth were determined to be severely curved which was significantly more than Group 2.

Nonparametric testing between samples from severely curved canals revealed no statistically significant differences between Groups 1 and 2 in mean percent canal and isthmus cleanliness values. Sample values at the 1-, 2-, and 3-mm levels for the 3%

NaOCl and 6% NaOCl techniques, respectively, were: canal, 81.8% versus 99.3%, 91.1% versus 100%, and 98.6% versus 96.9%; isthmus, 6.4% versus 92.9%, 19.5% versus

ii 89.2%, and 27.8% versus 98.9%. In conclusion, hand/rotary instrumentation followed by passive ultrasonic irrigation using 6% NaOCl was not significantly different from corresponding values observed using 3% NaOCl.

iii

DEDICATION

For my beautiful wife Tamara, thank you for your love, support and most of all your laughter, which never fails to keep me smiling.

For my parents John and Mary Ann, who have given me my sense of compassion, the most important trait one must possess in a career devoted to helping others.

And to my big sister Jennifer, you are a true inspiration. I will always look up to you.

ACKNOWLEDGMENTS

A sincere thank you to:

Dr. John Nusstein, my advisor, for your dedication, leadership and encouragement throughout this process. It was an immensely educational and enriching experience that has completely changed the way I read scientific papers and make clinical decisions. I feel immense gratitude for having had the opportunity to make a contribution to such an incredible program.

Dr. Al Reader, for the example you have set for so many people like myself by approaching every day and every patient as an opportunity to make the world a better place.

Dr. William Meyers, for your ability to a give anyone a sense perspective regardless of their former knowledge of a subject, for being the ultimate pragmatist, and of course for you endless wit and humor.

Dr. Melissa Drum, for always being there to give me the confidence to succeed. Whether it was in a clinical or didactic setting, you being there has helped me to do things I once didn’t think were possible.

Dr. Michael Beck, for helping me begin to understand what was really going on behind the mere numbers of this project and to appreciate the interplay occurring between them.

Dr. Susan Travers for your knowledge, assistance and generosity in helping me to produce and interpret every photomicrograph used in this study.

Mary Lloyd for always accommodating the needs of this study by devoting the many hours necessary to take a tooth and transform it into interpretable information.

Our staff past and present, Chantal, Laura, Soraya, Stacey Ann, Adria, Jonda, Jen, Mary-Ann, Kelly, Cheryl, Vicky, Sheri, Vanessa, Jan, Betty, Marie, Gloria, and all of the student workers for their assistance, camaraderie, and friendship.

My fellow residents Micah Nuzum, Mayes McEntire, and Mark Oleson who I look forward to seeing grow and succeed in their respective careers. You are all such talented people; it was a pleasure getting to spend these last 27 months with you. I extend my sincere thanks and gratitude to you.

VITA

December 6, 1978 ...... Born – Columbus, Ohio

1997-2000 ...... Undergraduate, The Ohio State University

2000-2004...... …D.D.S., The Ohio State University

2004-2005 ...... General Practice Residency Saint Barnabas Hospital, Bronx, NY

2007-2009...... …Endodontic Resident, The Ohio State University College of Dentistry

FIELDS OF STUDY

Major Field: Dentistry

TABLE OF CONTENTS

Page

Abstract...... ii

Dedication...... iv

Acknowledgments...... v

Vita...... vi

List of Tables ...... ix

List of Figures...... xi

Chapters:

1. Introduction...... 1

2. Literature Review...... 6

2.1 Root Canal Anatomy of Mandibular Molars ...... 6

2.2 Rotary File Canal Preparation/Cleanliness ...... 9

2.3 Sodium Hypochlorite as an Irrigating Solution ...... 16

2.4 Tissue dissolving properties of sodium hypochlorite ...... 18

2.5 Ultrasonics ...... 25

2.6 Introduction of Ultrasonics in Endodontics ...... 27

2.7 Mechanisms of Action of Ultrasonic Instrumentation...... 30

vii 2.7 Passive Ultrasonic Irrigation...... 38

2.8 Summary...... 49

3. Materials and Methods...... 50

4. Results...... 65

5. Discussion...... 71

5.1 Materials and Methods...... 71

5.2 Results...... 94

6. Summary and Conclusions ...... 119

Tables...... 123

Figures...... 139

Appendices

A. Patient Consent Form ...... 149

B. Patient Medical History Sheet...... 155

C. HIPAA Form ...... 158

D. Raw Data ...... 163

E. Biomedical Submission Forms...... 209

F. Advertisement ...... 234

List of References ...... 235

viii

LIST OF TABLES

TABLE PAGE

1. Curvature, Canal Type, and Tooth Type for Group 1 (3%NaOCl) and Group 2 (6%

NaOCl)...... 124

2. Gender and Age for Group 1 and 2...... 125

3. Mean Canal Cleanliness Analysis by Level and Irrigant Concentration in Severely

Curved Canals...... 126

4. Median Canal Cleanliness Analysis by Level and Irrigant Concentration in Severely

Curved Canals...... 127

5. Mean Isthmus Cleanliness Analysis by Level and Irrigant Concentration in Severely

Curved Canals...... 128

6. Median Isthmus Cleanliness Analysis by Level and Irrigant Concentration in Severely

Curved Canals...... 129

7. Mean Common Canal Cleanliness Analysis by Level and Irrigant Concentration in

Severely Curved Canals...... 130

8. Median Common Canal Cleanliness Analysis by Level and Irrigant Concentration in

Severely Curved Canals...... 131

9. Mean Canal Cleanliness Analysis by Level and Method Comparing Data from this

Study and the Gutarts (20) Control Group (Hand/Rotary/No Ultrasonic) in Severely

ix Curved Canals...... 132

10. Median Canal Cleanliness Analysis by Level and Method Comparing Data from this

Study and the Gutarts (20) Control Group (Hand/Rotary/No Ultrasonic) in Severely

Curved Canals...... 133

11. Mean Isthmus Cleanliness Analysis by Level and Method Comparing Group 1 and

the Gutarts (20) Control Group (Hand/Rotary/No Ultrasonic) in Severely Curved

Canals...... 134

12. Median Isthmus Cleanliness Analysis by Level and Method Comparing Group 1 and

the Gutarts (20) Control Group (Hand/Rotary/No Ultrasonic) in Severely Curved

Canals...... 135

13. Percent Needle Penetration Values in Group 1...... 136

14. Comparison of Canal Mean Percent Cleanliness...... 137

15. Comparison of Isthmus Mean Percent Cleanliness ...... 138

LIST OF FIGURES

FIGURE PAGE

1. Perspective view of ultrasonic device...... 140

2. Perspective view of ultrasonic device during ultrasonic instrumentation within a root

canal ...... 141

3. Mean Percen Clean by Method and Level for Common Curved Canals...... 142

4. Mean Percent Clean by Method and Level for Isthmuses of Curved Canals ...... 143

5. Mean Percent Clean by Method and Level for Cingle Curved Canals...... 144

6. Photomicrograph of cross section at the 1.0 mm level - Group 1, (Specimen

#389596), 89.9% cleanliness in the mesiolingual canal and 53.8% cleanliness in the

mesiobuccal canal, magnification: 100x...... 145

7. Photomicrograph of cross section at the 1.0 mm level - Group 2 collected by Gutarts

et al. (20), (Specimen #859590), 100% cleanliness in the mesiolingual canal and

100% cleanliness in the mesiobuccal canal, with isthmus cleanliness of 99.8%,

magnification: 40x ...... 145

8. Photomicrograph of cross section at the 2.0 mm level - Group 1, (Specimen

#370451), 100% cleanliness in the mesiolingual canal and 100% cleanliness in the

mesiobuccal canal, with isthmus cleanliness of 16.9%, magnification: 40x...... 146

9. Photomicrograph of cross section at the 2.0 mm level - Group 2 collected by Gutarts

xi et al. (20), (Specimen #480660), 100% cleanliness in the mesiolingual canal and

100% cleanliness in the mesiobuccal canal, with isthmus cleanliness of 100%,

magnification: 40x ...... 146

10. Photomicrograph of cross section at the 3.0 mm level - Group 1, (Specimen

#991863), 100% cleanliness in the mesiolingual canal and 100% cleanliness in the

mesiobuccal canal, with isthmus cleanliness of 11.7%, magnification: 100x...... 147

11. Photomicrograph of cross section at the 3.0 mm level - Group 2 collected by Gutarts

et al. (20), (Specimen #402105), 100% cleanliness in the mesiolingual canal and

100% cleanliness in the mesiobuccal canal, with isthmus cleanliness of 90.2%,

magnification: 100x ...... 147

12. Photomicrograph of cross section at the 1.0 mm level - Group 3, (Specimen

#458056), 16.9% cleanliness in the common canal, magnification: 100x...... 148

13. Photomicrograph of cross section at the 3.0 mm level - Group 3, (Specimen

#765709), 0.0% cleanliness in the mesiolingual canal and 0.0% cleanliness in the

mesiobuccal canal, with isthmus cleanliness of 0.0%, magnification: 100x...... 148

xii

CHAPTER 1

INTRODUCTION

Endodontic success relies on thorough chemomechanical preparation of the root canal system (1-3). Adequate canal debridement is necessary to eliminate potential contaminants such as microorganisms, microbial by-products, and pulp tissue from the root canal system. Failure to eliminate these irritants from the root canal system is recognized as a primary reason for failure of endodontic therapy (4).

The intricate nature of root canal anatomy complicates the instrumentation procedure (5-13). Fins, webs, anastomoses, isthmuses and other irregularities within the root canal system harbor tissue, microorganisms, and microbial by-products that may lead to failure of root canal therapy (9-11). These areas were demonstrated to be inaccessible to conventional hand and rotary instrumentation (15-27).

The use of ultrasonics provides a possible solution to the problem of debriding and disinfecting the intricate root canal system. Weller et al. (14) found that serialized hand preparation and the addition of ultrasound were more effective in cleaning canals than either method alone. Goodman et al. (15) used a compensating polar planimeter to compare the tissue removing capability of a step-back/ultrasound method. Using extracted mandibular molars, the authors found the combination method was more

1 effective in removing tissue at the 1 mm and 3 mm levels as well as the isthmuses.

However, this study utilized a modified piezoelectric ultrasonic dental unit that was not commercially available.

Using the same method to measure tissue removal as Goodman et al. (15), Lev et al. (16) compared a step-back/ultrasound technique using the Cavitron® Cavi-Endo® ultrasonic unit for 1 and 3 minutes versus a step-back technique alone. The three-minute step-back/ultrasound group had significantly cleaner isthmuses at both the 1 mm and 3 mm apical levels than the other groups. Haidet et al. (17) used the Cavitron® Cavi-Endo® dental unit to histologically compare the tissue removal of step-back versus step- back/ultrasound instrumentation in the mesial roots of mandibular molars. This in vivo study used the same method of tissue removal evaluation as Goodman et al. (15) and evaluated the 1 mm and 3 mm apical levels along with isthmuses. At the 1 mm level, canals and isthmuses were both significantly cleaner with the combination method.

Metzler and Montgomery (18) compared the effectiveness of ultrasonics using a

Cavitron® dental unit with a Cavi-Endo® insert and calcium hydroxide for the debridement of extracted human mandibular molars. The results showed ultrasonics and calcium hydroxide were equally effective in debriding the root canal system, and both methods were significantly better than hand instrumentation alone in the isthmuses at the

1 mm apical level.

Archer et al. (19) used the Osada Enac piezoelectric ultrasonic system to histologically compare tissue removal of step-back instrumentation versus step-back plus ultrasound instrumentation in the mesial roots of mandibular molars. Canal and isthmus

2 cleanliness values were significantly higher at all apical levels evaluated for the step- back/ultrasound group.

Gutarts et al. (20) examined the in vivo debridement efficacy of an ultrasonic irrigating needle activating 15 mL of 6% NaOCl for 1 minute as an adjunct to hand/rotary instrumentation in teeth with irreversible pulpitis and determined that significantly less pulpal tissue was present using the ultrasonic irrigating needle regardless of canal type, canal curvature, or apical level. Burleson et al. (21) performed the same study on necrotic teeth and found that ultrasonic irrigation using 15 mL 6% NaOCl for 1 minute provided significantly greater cleanliness at all levels examined. Studies by Goodman et al. (15),

Lev et al. (16), Haidet et al. (17), and Archer et al. (19) utilized a three-minute ultrasonic cleaning cycle per canal using endodontic file inserts. These methods resulted in file breakage when subjected to the higher range of ultrasonic energy. Therefore, the files were energized at low settings resulting in an inordinate amount of time to clean the root canals. By using an irrigating tip that can withstand the higher range of energy settings, the cleaning time was reduced from 3 minutes to 1 minute per canal. A one-minute cycle per canal may be more clinically acceptable for endodontic treatment. Additionally, the sodium hypochlorite irrigating solution can be delivered directly through the tip at a controlled rate. This method of delivering irrigating solution offers an advantage over previous methods where the solution was added at the coronal location using a separate syringe.

Sodium hypochlorite (NaOCl) is a well-established endodontic irrigant. However, contradictions exist in the literature and a consensus has not been established regarding its appropriate applied concentration. It has been demonstrated that the cytotoxicity and 3 effectiveness of NaOCl are both directly related to its concentration (22). Sodium hypochlorite is utilized clinically because it; effectively facilitates chemomechanical debridement of the root canal system, it provides lubrication for endodontic instrumentation, removes smear layer, is an effective antimicrobial agent and can dissolve necrotic and vital tissues (23).

The concentration of NaOCl delivered in previous ultrasonic irrigation studies has been questioned as potentially excessive, mainly due to potential cytotoxicity which can cause tissue injury if accidentally expressed into periapical tissues or leaked through the rubber dam (24,25). However, a recently completed study by Pafford (26) found that when using full strength NaOCl with an ultrasonic irrigating technique no procedural accidents occurred and there was no increase in operative or postoperative pain with the use of a 6% solution of NaOCl. Higher concentrations of sodium hypochlorite (!5.25%) also possess a strong odor and may corrode and weaken stainless steel endodontic instruments (27). Reducing the concentration of the irrigant in order to minimize risk to the patient has been suggested (25,28), however it has been shown that as the concentration of NaOCl is reduced, its antibacterial and tissue dissolving properties diminish. Hand and coworkers (29) showed significantly greater necrotic tissue dissolving properties of 5.25% NaOCl when compared to 2.5%, 1% and 0.5% NaOCl.

Baumgartner et al. (23) showed complete removal of pulpal remnants and predentin from uninstrumented canal surfaces in the middle third of roots with NaOCl irrigant concentrations of 5.25%, 2.5%, and 1%. Unfortunately, no study to date has investigated the impact of reducing the concentration of NaOCl on canal and isthmus cleanliness when utilized with ultrasonic irrigation. Therefore, the aim of this follow-up study is to

4 determine if there is a difference in the cleanliness of root canals and isthmuses after rotary/ultrasonic instrumentation with 3.0% sodium hypochlorite compared to the same technique using 6.0% sodium hypochlorite delivered at a rate of 15 mL/min in the mesial roots of vital mandibular molars.

CHAPTER 2

LITERATURE REVIEW

Selected portions of the following literature review have been adapted from previous theses by Gutarts (30), Carver (31) and Burelson (32) from the Division of

Endodontics at The Ohio State University.

ROOT CANAL ANATOMY OF MANDIBULAR MOLARS

“Hess (10), in 1925, described the internal anatomy of 2,800 extracted human teeth by using corrosion preparations and histologic sections. The complex nature of root canal anatomy was described using unaided visual and microscopic analysis. The author concluded that apical ramifications were often observed in the roots of upper molars and the mesial roots of lower first and second molars. He also reported that in mesial roots of lower molars a fine connecting canal or fissure was found between the two main canals.

Skidmore and Bjorndal (9) investigated the anatomy of mandibular molars by making plastic casts of 45 extracted teeth. They found that 59.5% of the mesial canals remained separate throughout the length of the canal, while 40.5% joined in a common apical foramen. In this study, 60% of the roots with two canals were found to have some form of transverse communication. This communication was most commonly observed in the apical third of the root. The authors noted that an operator attempting to remove the

6 pulp tissue must be aware of these transverse connections.

Pineda and Kuttler (5) examined 859 extracted mandibular molars with a magnifying glass. They found ramifications (offshoots) of the main canal in the mesial root in 48.3% of first molars, 27.8% of second molars, and 19.0 % of third molars. It was also observed that the majority of these ramifications were located in the apical third of the root.

Cambruzzi and Marshall (33), using 108 extracted mandibular molars, studied canal anatomy by resecting 3 mm of the apical root. A bevelled cut was made to simulate an apicoectomy, and methylene blue dye was placed into the opened canals. It was determined in the mesial root that an isthmus joined the two canals 60% of the time. Two mesial canals existed without an isthmus in only 18% of the cases.

Vertucci (11) used a hematoxylin dye and clearing technique to study the anatomy of 200 extracted mandibular first and second molars. In the mesial root, 63% of first molars and 31% of second molars were found to have a transverse communication. In approximately 75% of first and second molars this communication was found in the middle third of the root” (32).

“Manning et al. (12) studied the root canal anatomy of 149 mandibular second molars using a technique in which the pulp was removed, the canal space filled with black ink and the roots demineralized and made transparent. Transverse anastomoses were found in 33% of roots, most commonly in the middle third of the root. Lateral canals were found in 72% of roots, most commonly in the apical third of the root. Apical deltas were found in 35% of the apices. The patient's age and race affected canal shape, with more round canals present in patients over 35 years of age, and more C-shaped

7 canals in Asians. The sex of the patient and the side of the mouth affected the presence of apical deltas, with more being found in males and on the left side. Single-rooted teeth had more complex root canal systems than two-rooted teeth, with more lateral canals, transverse anastomoses, apical deltas and C-shaped canals.

Yesilsoy et al. (13) observed sixty freshly extracted, mandibular first and second molars. The patency and the presence of two mesial canals was established with a #10 file. A vinyl polysiloxane impression material was injected into the pulp chambers, and the teeth were centrifuged. The impressions were carefully removed and then measured using a dissecting microscope and a transparent millimeter ruler. The ruler, at zero, placed at the mid-floor area of the impression and viewed from the mesial, measured (to the nearest 0.5 mm) the depth of the mesial groove between the mesiolingual and mesiobuccal canals. Due to imperfect impressions, 50 teeth were actually included in the study. The average recorded depth was 1.0 mm. Some of the impressions had depths measuring 3.5 mm. This could be a significant space when considering the limitations of instrumentation techniques. The authors brought up the question of whether this area may remain undebrided after instrumentation thereby affecting the prognosis of treatment in both vital and nonvital teeth. They believed that modifications in access preparation and/or an increased emphasis on irrigation and intracanal medication may be needed”

(32).

Cunningham and Senia (34) studied the degree and configuration of canal curvature in 100 extracted human mandibular first and second molars. Radiographs were exposed in the buccolingual (clinical) and mesiodistal (proximal) directions with #8 K files placed inside the canals. One hundred percent of specimens were found to have

8 curvatures in both dimensions. Secondary curvatures were found more frequently in the proximal view.

Mannocci et al. (35) investigated the presence of isthmuses in the mesial roots of mandibular molars using micro-computed tomography (MCT). The mesial roots of twenty extracted mandibular first molars were examined at 40 levels throughout the apical 5mm using a high-resolution MCT scanner. The presence or absence of an isthmus was recorded in each section and the data was analyzed. The authors found the presence of isthmuses at all levels with a prevalence of 17-50%. Isthmuses were present most frequently at the level 3mm from the apex. It is stated that these apical ramifications would likely affect the results of clinical endodontic procedures.

Other studies using micro-computed tomography in mandibular molars have also found a high prevalence of isthmuses in the apical third of the mesial root. Gu et al. (36) investigated 36 extracted mandibular first molars in a Chinese population. The prevalence of isthmuses was evaluated and grouped according to age. The presence of isthmuses was found to be inversely proportional to age. However, isthmuses were present frequently, between 24 and 50% of the time. Again, it was noted that these complexities may affect endodontic treatment outcomes.

“Skillen (37) stated that due to the complexities of form of the root canal, it is practically impossible to remove the pulp in its entirety. The high percentage of fins, isthmuses, and accessory canals found by the above authors supports this statement” (32).

ROTARY FILE CANAL PREPARATION/CLEANLINESS

“Past studies (38,39,43) have examined the effectiveness of biomechanical

9 preparation using rotary instrumentation in removing the contents of the root canal.

These investigations have reported advantages over hand filing however these techniques also fall short of the goal of 100% canal cleanliness.

Schafer and Zapke (38) investigated the cleaning effectiveness of automated and manual root canal instrumentation with the aid of a scanning electron microscope. Hand instrumentation was performed with K-Flexofiles used in a reaming working motion and the step-back technique and with Hedström files used in a filing motion. Automated preparation was performed using torque-limited rotation with K-Flexofiles, as well as rotary nickel-titanium instruments (ProFile® system). After cracking the roots longitudinally (n =120), the amount of debris and smear layer was quantified on the basis of a numerical evaluation scale (1 through 5). Comparison of manual instrumentation with the automated KaVo-Endo Flash resulted in an equivalent degree of canal cleaning.

Complete cleanliness was not achieved by any of the techniques or devices investigated.

Best instrumentation results, especially in curved canals, were obtained with rotary

ProFile® instruments.

Several parameters of root canal preparation were compared by Versumer et al.

(39) using two different rotary nickel-titanium instruments: ProFile® .04 (Dentsply/

Maillefer, Ballaigues, Switzerland) and LightSpeed® (LightSpeed Technology Inc., San

Antonio, TX). Fifty extracted mandibular molars with root canal curvatures between 20 degrees and 40 degrees were divided into two similar groups having equal mean curvatures. All root canals were prepared using ProFile® .04 or LightSpeed Ni-Ti instruments to size 45 following the manufacturers' instructions. The LightSpeed® system was used in a step-back technique. The ProFile® .04 instruments were used in a crown-

10 down technique. The following parameters were evaluated: straightening of curved root canals (superimposition of pre- and postoperative radiographs), postoperative root canal diameter (superimposition of pre- and postoperative photographs of root canal cross- sections), safety issues (file fractures, perforations, apical blockages, loss of working length), cleaning ability (SEM-evaluation of root canal walls using a five-score system for debris and smear layer), and working time. Both Ni-Ti systems maintained the original canal curvature well; the mean degree of straightening was less than 1 degree for both ProFile® .04 and LightSpeed® with no statistical significance between the groups.

Most procedural incidents occurred with Profile® .04 instruments (three fractures), while

LightSpeed® preparation was completed without instrument fractures. Loss of working length, perforations or apical blockage did not occur with either instrument. Following preparation with Profile® .04, 64.0% of the root canals had a round, 30.7% an oval, and

5.3% an irregular cross-section. LightSpeed® preparation resulted in a round cross- section in 41.3% of cases; an oval shape in 45.3% of cases and 13.3% of cases had an irregular cross-section. No significant differences were found between the two systems.

LightSpeed® instruments enlarged the root canal more uniformly with no specimen showing 50% or more contact between pre- and postoperative diameter. For debris removal LightSpeed® achieved the best results (68% scores of 1 and 2), followed by

Profile® .04 (48.4% scores of 1 and 2) with no significant differences between the systems. The results for remaining smear layer were similar: the lowest amount of smear layer on the root canal walls was found after preparation with LightSpeed® (30.7% scores of 1 and 2) followed by Profile® .04 (23.1% scores of 1 and 2). In the coronal third of the root canals LightSpeed® performed significantly better than Profile® .04 (p = 0.029): in

11 the middle and apical third the differences were not significant” (32).

Loizides et al. (40) compared root canal transportation of the crown-down technique performed with rotary the Profile® system and with step-back technique using stainless steel K-Flexofiles. Thirty resin blocks with simulated root canals were divided into two groups. Group one was instrumented with the ProFile® system in a crown-down manner and group two was instrumented with hand K-Flexofiles. The blocks were then scanned and evaluated for canal transportation using computer software. Statistically significant differences between the groups were shown at 1, 2, 4, 5, and 6 mm from the apical foramen. It was concluded that the ProFile® rotary technique caused less transportation while creating more standardized preparations.

Schafer et al. (41) compared the effect of hand instruments and rotary nickel titanium Flex-Master files used in vivo on the extent of straightening of curved root canals. Eight experienced dentists in private practice prepared 110 canals using

FlexMaster instruments and 84 canals using hand techniques. The canals were obturated and comparisons were made between preoperative and postoperative radiographs taken using customized bite blocks. It was found that the rotary Flex-Master files created significantly less straightening in a shorter preparation time compared with hand instrumentation.

“Mayer et al. (42) evaluated debris and smear layer scores after two types of instruments manufactured from different alloys were used to ultrasonically activate irrigants during canal preparation. The influence of two rotary preparation techniques on cleanliness of the shaped canals was also studied. Apical stops were prepared to size 45 in 42 single-canal extracted premolars and canines. Groups 1, 2 and 3 were prepared by

12 ProFile® .04 (PF), while groups 4, 5 and 6 were prepared by LightSpeed® (LS). All groups were irrigated using 5.25% NaOCl and 17% EDTA. Irrigants in groups 2 and 5 were ultrasonically activated using a size 15 K-file and by a blunt flexible nickel-titanium wire in groups 3 and 6. Groups 2, 3, 5, and 6 received a 1 min. ultrasonic treatment while the EDTA and NaOCl were left in the canals. Groups 1 and 4 served as negative controls.

Roots were split and canal walls examined at 15x, 200x and 400x magnification with a

SEM. Smear layer and debris scores were recorded at 3, 6 and 9 mm levels using a 5- step scoring scale and a 200 micron grid. Although all groups had significantly higher smear layer and debris scores at the 3 mm levels compared to the 9 mm levels (p < 0.05), no significant differences (improvements) were recorded due to the ultrasonic energy transmitted by the two alloys. Ultrasonically activated irrigants did not reduce debris or smear layer scores. This finding was not influenced by the material or by the design of the instrument used to transmit ultrasonic activation.

Tan and Messer (43) compared the quality of apical enlargement of mesiobuccal canals of mandibular molars using conventional stainless steel hand files (K-files) and nickel-titanium (Ni-Ti) rotary instruments (LightSpeed®). Thirty freshly extracted mandibular molars were randomly assigned to three equal groups (n = 10 each group).

The mesiobuccal canals were instrumented with K-files using step-back technique without coronal flaring (control; group 1), K-file using step-back technique after coronal flaring (group 2), and LightSpeed® (LS) instrumentation (group 3). Specific criteria for apical enlargement based on initial apical size were used. Canal cleanliness, canal transportation, and final canal shapes were determined histologically at 1 mm and 3 mm levels short of the working length. Canals were prepared to significantly larger sizes

13 using LS instrumentation than with either hand instrumentation techniques (15-17 ISO units, p < 0.001). LightSpeed® instrumentation allowed greater apical enlargement with significantly cleaner canals, less apical transportation, and better canal shape than both hand instrumentation groups at both levels (p < 0.05). None of the three techniques were totally effective in cleaning the apical canal space. It was concluded that greater apical enlargement using LS rotary instruments is beneficial as an attempt to further debride the apical third region in mesiobuccal canals of mandibular molars. Instrument designs, alloy properties, and canal curvature are important factors that determine the feasibility of greater apical enlargement in narrow canals” (31).

Siqueira et al. (44) histologically evaluated the effectiveness of five different instrumentation techniques for cleaning of the apical third of root canals. The mesial canals of freshly extracted human mandibular molars were prepared using step-back technique with stainless steel files, step-back using nickel-titanium files, an ultrasonic filing technique, a balanced force technique and the Canal Master U rotary technique.

After preparation, the teeth were cross-sectioned, analyzed microscopically, and graded on a scale of 0-3. Although all of the techniques were relatively effective in debriding the main canal systems, total cleansing was not frequently observed. The authors noted significant tissue remnants in the isthmuses and branches of the canal system. The authors concluded that none of the five techniques tested were effective in completely removing debris within the root canal system.

Peters et al. (45) conducted a series of studies using micro-computed tomography to evaluate the geometric changes that occur in root canals during different instrumentation techniques (45-47). They found that, in vitro, 35% or more of the canal

14 surface area in maxillary molars was entirely unchanged when using NiTi K-Files,

Lightspeed® instruments, Profile® .04 or GT® rotary instruments. There was no significant difference found between technique and amount of uninstrumented canal surface area (45).

Peters et al. (46) also investigated the effect of using ProTaper® instruments on canal final shape in extracted maxillary molars. This instrumentation technique was found to leave untouched canal areas ranging from 43-49% in wide canals. The observation was made that smaller, constricted canals have a larger percentage of instrumented surface area and may be better suited for this file system.

Peters et al. (47) continued to analyze the shapes created within canals after preparation with rotary files. In this study, eleven extracted human maxillary molars were scanned before and after instrumentation using FlexMaster® rotary files and analyzed for

“volume, surface area, thickness, canal transportation and prepared surface” (47). Again, the authors frequently observed unprepared surfaces of canal walls, especially in larger canals. Between 42 and 61% of wide canals were untouched. Because of these high percentages of untouched canal surfaces, it was concluded that effective irrigation was necessary. These studies (45-47) show that although rotary instrumentation techniques and systems debride canals superiorly compared to hand instrumentation with K-Files, significant portions of the complex canal system are left uninstrumented.

Gutarts et al. (20) compared the in vivo debridement efficacy of hand and rotary instrumentation with .04 taper Profile® GT® versus hand and rotary instrumentation with

.04 taper Profile® GT® followed by passive ultrasonic irrigation in the mesial canals of human mandibular molars with a pulpal diagnosis of irreversible pulpitis. In this study 36

15 teeth were prepared to an apical size of 30/.04. Fifteen teeth were treated with ultrasonic irrigation using NaOCl administered through a 25-gauge ultrasonic needle for one minute per mesial canal. The teeth were extracted and histologically evaluated for percentage of tissue removal. The investigators found that when using the hand and rotary technique, mean canal cleanliness values were similar to those reported by other investigators who prepared vital teeth using the hand step-back technique (15-17).

Burleson et al. (21) performed a similar study evaluating the cleaning efficacy of hand/rotary and hand/rotary/ultrasonic techniques on necrotic pulp tissue. They reported similar mean canal cleanliness values to Gutarts et al. (20) when using the hand/rotary technique and better cleaning than those reported by Goodman et al. (15), Lev et al. (16), or Haidet et al. (17). They speculated that their values were better because there is less tissue to remove when cleaning necrotic canals.

Rotary instrumentation has been shown to be an effective method of removing soft tissue from the root canal while also keeping with the curvature of the canal, and having a uniform and rounded preparation. However, as the studies have shown, it does not remove all of the debris from the complex root canal system.

SODIUM HYPOCHLORITE AS AN IRRIGATING SOLUTION

“Sodium hypochlorite has long been recognized as an effective irrigating solution.

In 1915, Dakin (48) first used sodium hypochlorite as an antiseptic in open wounds.

Walker (49) introduced sodium hypochlorite as a root canal irrigant in 1936. He described double-strength chlorinated soda to be an organic solvent and powerful germicide. In 1941, Grossman and Meiman (50) studied the tissue dissolving capability

16 of various irrigating solutions. The authors found double-strength chlorinated soda to be the most effective solvent of pulp tissue.

Lewis (51) introduced the use of Clorox as a source of sodium hypochlorite in

1954. Currently, Clorox (Ultra) comes in a concentration of 6% sodium hypochlorite and

94% inert ingredients. Sodium hypochlorite is manufactured by bubbling chlorine gas into sodium hydroxide, forming sodium hypochlorite and sodium chloride (52). Chlorine is the bactericidal agent in sodium hypochlorite. It inhibits metabolic reactions of

- microbial enzymes by reacting with amino groups (NH2 ) and sulfydryl groups (SH) of bacterial enzymes (cystein).

The physico-chemical characteristics of sodium hypochlorite (NaOCl) are important in explaining its mechanism of action. The saponification, amino acid neutralization and chloramination reactions that occur when microorganisms and organic tissue are exposed to NaOCl are the cause for the antimicrobial and tissue dissolution properties. The antimicrobial activity is due to irreversible inactivation by hydroxyl ions and the chloramination reaction of bacterial essential enzymatic sites. The organic dissolution action can be observed in the saponification reaction when sodium hypochlorite degrades lipids and fatty acids resulting in the formation soap and glycerol

(53)” (30).

“Mentz (54) stated that sodium hypochlorite has three important properties when used as an endodontic irrigant: 1) it kills microbes; 2) it dissolves pulp remnants; 3) it is only slightly irritating to vital tissue. Bactericidal effects increase with a lower pH, a higher temperature, and a higher solution concentration. Tissue dissolving properties depend on the ratio of solution to substrate, condition of the tissue to be dissolved, and

17 amount of mechanical agitation of the solution. The author supported the enlargement of the canal with Gates Glidden burs and files, enabling the solution to penetrate the confined areas in the canal. Enlarged canals also allowed the irrigant to return -flow, preventing extrusion beyond the apex” (32).

TISSUE DISSOLVING PROPERTIES OF SODIUM HYPOCHLORITE

The variables influencing the tissue dissolving characteristics of sodium hypochlorite have been studied by many investigators. This property has been found to rely on several factors including concentration, volume, temperature and pH.

Unfortunately, as the effectiveness of sodium hypochlorite is increased, so is its toxicity and severe irritations may result when high concentration NaOCl is introduced to periapical tissues. (22)

“Senia et al. (55) evaluated the solvent action of 5.25% sodium hypochlorite.

They instrumented the mesial roots of extracted mandibular molars to a size #25 file apically, using saline as an irrigant. One canal of each root was then irrigated for either

15 or 30 minutes with 5.25% sodium hypochlorite. The other canal in the root was irrigated with a saline control. After histologic preparation, sections were microscopically examined at the 1 mm, 3 mm, and 5 mm levels. Sodium hypochlorite was found to remove more tissue than saline in the larger portion of the canal (5 mm level). However, there was no appreciable difference in tissue removal in the constricted apical portion of the canal. Therefore, the potential of sodium hypochlorite to dissolve tissue is limited by its ability to make direct contact with the tissue in small canal systems.

Baker et al. (56) instrumented extracted teeth with different volumes of 24

18 irrigating solutions including varying concentrations and combinations of saline, sodium hypochlorite, hydrogen peroxide, glyoxide, EDTA, and sodium fluoride. Using a scanning electron microscope, they determined that more debris was removed with an increased volume of irrigant, regardless of the type of solution used.

McComb and Smith (57) used a scanning electron microscope to evaluate the effects of different irrigating solutions on the removal of debris. Instrumentation was found to leave a smear layer with superficial debris. Six percent sodium hypochlorite was found to leave very little debris in the canal. The 6% solution left less debris in the apical region when compared to a 1% solution, however the smear layer was still present and all irrigating solutions performed poorly in the apical portion of the canals” (30).

“Svec and Harrison (58) microscopically evaluated the effectiveness of chemomechanical preparation with normal saline solution versus a combination of sodium hypochlorite and hydrogen peroxide. Forty extracted single rooted teeth were prepared using irrigant between each instrument. Histologic analysis revealed that the combination solution removed significantly more tissue at the 1 mm and 3 mm levels, while no difference existed at the 5 mm level. However, tissue debris remained in the canals regardless of the solution used.

Trepagnier, Madden, and Lazzari (59) studied the effectiveness of various dilutions of sodium hypochlorite at different time intervals. Hydroxyproline content of the irrigant, which reflects the amount of collagen-containing tissues dissolved, was used to measure the effectiveness of the irrigant. They found that there was no significant difference between the 2.5% and 5% concentrations, strongly supporting the use of the diluted solution.

19 Koskinen et al. (60) also used a hydroxyproline assay to measure the effectiveness of various concentrations of sodium hypochlorite. They used fresh frozen bovine tissue which was incubated at 37º C with the test solutions. Sodium hypochlorite at 5% and

2.5% showed the strongest solvent capacity, as measured by mean weight change of the samples. In contrast to Trepagnier et al. (59), the authors could not measure hydroxyproline in the sodium hypochlorite extracts. They postulated that the sodium hypochlorite disturbed the assay, causing a decomposition of the hydroxyproline.

Rosenfeld et al. (61) compared 5.25% sodium hypochlorite versus physiologic saline by measuring tissue dissolution. Uninstrumented and instrumented teeth were studied in vivo. Using microscopic analysis, they determined that 5.25% sodium hypochlorite was effective in exerting a nonspecific, surface acting solvent action on intact vital pulp tissue. The solvent action was limited by the size of the lumen, and was therefore more effective in the middle and occlusal thirds” (30).

“Cunningham and Balekjian (62) exposed bovine tendon collagen to 2.5% and

5% sodium hypochlorite at both room and body temperature. Measuring the amount of collagen dissolved, they determined that the 2.5% solution at the higher temperature was equally as effective as the 5% solution at either temperature.

Abou-Rass and Oglesby (63) studied the effects of varying concentration and temperature on the tissue dissolution properties of sodium hypochlorite. They also attempted to determine if the condition of tissue (fresh, fixed, or necrotic) influenced dissolution effectiveness. Using the dermal connective tissue of rats, they measured the time needed to completely dissolve tissue specimens. Results showed that the 5.25% concentration was more effective than the 2.5% concentration regardless of tissue

20 condition or temperature” (32).

Sirtes et al. (64) compared the dissolving properties of varying concentrations and temperatures of sodium hypochlorite by calculating the percent of initial pulp tissue weight remaining after irrigation using vital human pulp specimens. They reported that raising the temperature of 1% NaOCl from 20˚C to 45˚C significantly improved its tissue dissolving properties and that at 60˚C the tissue dissolving properties were again significantly improved. They also found that a solution of 1% NaOCl at 45˚C was equally effective as 5.25% NaOCl at 20˚C.

“Gordon et al. (65) exposed vital and necrotic bovine tooth pulp to various concentrations of sodium hypochlorite for two to ten minutes. Both 3% and 5% solutions dissolved three quarters of the vital pulp equally after 2 minutes of exposure. Solutions of

1%, 3%, and 5% were equally effective in dissolving 90% of the necrotic pulp after exposure for five minutes. They also found that increasing the amount of surface area of pulp tissue exposed to the sodium hypochlorite solution had a positive effect on the amount of tissue dissolved” (30).

Hand et al. (66) compared the tissue dissolution properties of various concentrations of sodium hypochlorite on necrotic tissue in rat pulps. Sixty-three specimens of necrotic tissue were obtained and exposed to 5.25%, 2.5%, 1.0%, or 0.5%

NaOCl, normal saline, distilled water, and 3% hydrogen peroxide. The 5.25% NaOCl was shown to be significantly more effective as a tissue solvent than any of the other tested solutions.

“Wayman et al. (67) measured the amount of hydroxyproline and calcium removed from extracted teeth by various irrigants. Hydroxyproline values showed that

21 5.25% sodium hypochlorite significantly dissolved more tissue than citric acid or lactic acid. The acid irrigants were found to dissolve more inorganic material (calcium) than the sodium hypochlorite. The authors therefore recommended a combination of sodium hypochlorite and citric acid to remove both organic and inorganic components.

Goldman et al. (68) reamed and filed extracted teeth, using either Roth’s ethylenediaminetetraacetic acid (REDTA) or 5.25% sodium hypochlorite as an irrigating solution. A safety-ended, perforated, needle was used to deliver irrigant 1 mm short of the working length. One mL was deposited between instruments and a 20 mL flush was deposited at the completion of instrumentation. Using a scanning electron microscope they found that sodium hypochlorite cleaned the canal more effectively than REDTA when used during instrumentation. When sodium hypochlorite was used as a final flush, the smear layer was more effectively removed. The authors concluded that there might be an organic component to the smear layer.

Baumgartner et al. (69) used a scanning electron microscope to statistically evaluate the amount of superficial debris and smeared layer that remained on the canal wall following root canal preparation with six different debridement regimens. Distal roots of mandibular molars were serially instrumented using 3 mL of irrigant between file sizes. It was found that sodium hypochlorite was significantly better than citric acid in removing superficial debris from the apical third of the canals. Citric acid was more effective in removing the smear layer.

Nakamura et al. (70) attempted to determine the optimum temperature and concentration of sodium hypochlorite required to dissolve bovine tendon collagen, pulp, and gingiva. Using a hydroxyproline assay to measure dissolution effectiveness, they

22 determined that a 10% solution at 37°C was the most effective” (30).

“Johnson and Remeikis (71) investigated the variables of time on the tissue- dissolving capacity of three different concentrations of sodium hypochlorite. Fresh frozen human umbilical cord were dissolved at time intervals ranging from 1 day to 10 weeks in

5.25%, 2.62%, and 1.0% solutions of sodium hypochlorite. The tissue-dissolving ability of 5.25% sodium hypochlorite remained stable for at least 10 weeks. The tissue- dissolving ability of 2.62% and 1.0% sodium hypochlorite remained relatively stable for

1 week after mixing, then exhibited a significant decrease in tissue-dissolving ability at 2 weeks and beyond.

Yang et al. (72) evaluated and compared dissolving properties of calcium hydroxide and sodium hypochlorite on bovine pulp tissue in aerobic and anaerobic environments. Results showed the following: (a) both chemicals partially dissolved pulp tissue, (b) anaerobic environment did not alter tissue-dissolving properties of Ca(OH)2 or

NaOCl, and (c) Ca(OH)2 and NaOCl were equal and more effective than water in dissolving tissue.

Gambarini et al. (73) investigated the effect of heating sodium hypochlorite to

50°C on the stability of the solution. An iodometric titration test was used to evaluate the decomposition rates of heated and nonheated solutions over 30 days. Results showed that all specimens exhibited a minimal, gradual degradation versus time. However, no statistically significant difference (p < 0.05) was noted between the two groups. After 30 days, both heated and non-heated solutions maintained high available chlorine content and pH values consistent with excellent tissue-dissolving and antibacterial properties.

These studies show that sodium hypochlorite is an effective solvent of organic tissue”

23 (30).

“Moorer and Wesselink (74) examined the effect of ultrasonics on the tissue dissolving effects of sodium hypochlorite. In experiments in which specimens of necrotic rabbit tissue were dissolved in different concentrations of sodium hypochlorite, it was found that available chlorine was an important variable in tissue dissolution. Low concentrations of sodium hypochlorite (0.6% and 1.2%) were rapidly depleted of available chlorine. Three percent sodium hypochlorite more effectively dissolved the tissue. When ultrasonic power was added to the tissue/sodium hypochlorite system, the solution was agitated violently, causing rapid dispersion and dissolution of tissue. The authors concluded that the most important factor influencing tissue dissolution was the physical agitation caused by the ultrasound” (30).

Christensen, McNeal, and Eleazer (75) compared the tissue dissolving effects of various pHs and concentrations of NaOCl on porcine muscle tissue. Five and a quarter percent NaOCl with pH 12, 9, and 6 were compared to 2.6% NaOCl with pH 12, 9, and 6.

Tissue samples were weighed before and after submersion in 10 mL of each solution for

5, 15, and 30 minutes. Higher concentration solutions were shown to have significantly higher tissue dissolving properties. The results of this study showed that higher concentration, longer time in contact with solution, and higher pH levels were all important factors for increasing tissue dissolution.

Türkün and Cengiz (76) conducted an in vitro study on the effects of NaOCl and

Calcium Hydroxide tissue dissolution and root canal cleanliness. Concentrations of 0.5% and 5% NaOCl were tested for dissolving properties on necrotic bovine tissue by weighing samples before and after exposure to the different solutions. It was shown that

24 the 5% NaOCl solution was significantly more effective as a solvent of necrotic tissue versus the 0.5% solution.

ULTRASONICS

“Generally, ultrasonic means the sound that is not audible because it has frequencies above those of audible sound, and the sound that we also do not try to hear.

It’s very difficult to define the threshold frequency that each person hears. Commonly, we define it as the sound under the frequency of 30 Hz and over 20 KHz (77). We can hear the sound within but not beyond this range. A sound frequency of under 30 Hz is defined as ultra low frequency, and a frequency of over 20 KHz is defined as the ultrasonic range (77).

Ultrasonic cleaning is powered by ultrasonic wave energy. When an ultrasonic wave is projected in liquid, negative pressure is created and causes the liquid to fracture, a process known as cavitation. Cavitation creates bubbles that oscillate in the projected ultrasonic waves (77). As the ultrasonic waves continue, these bubbles grow larger and become very unstable, eventually collapsing in a violent implosion. The implosions radiate high-powered shockwaves that dissipate repeatedly at a rate of 25,000-30,000 times per second (77). Additionally, the implosion of cavitation bubbles creates temperatures that exceed 10,000º F and pressures that exceed 10,000 psi (77). Ultrasonic cleaning uses this cavitation implosion effect to clean.

Cleaning an object requires dissolving a contaminant and then displacing the saturated layer of the contaminant so that fresh cleaning solvent can come in contact with the unsaturated surface of the contaminant. The Ultrasonic Cavitation Implosion Effect

25 (UCIE) is incredibly effective in doing this (77). The UCIE is especially effective on unsmooth and out of reach surfaces that are normally inaccessible through conventional means of such cleaning as brushing or irrigation alone (77).

Throughout the evolution of the use of ultrasonics in endodontics, most technical changes have dealt primarily with ultrasonic energy generators. There are two main types of generators that differ in their mode of operations. The magnetostrictive generator utilizes the principle of magnetostriction in which certain materials expand and contract when placed in an alternating magnetic field (77). Alternating electrical current (AC) from the ultrasonic generator is first converted into an alternating magnetic field through the use of a copper coil of wire (77). The alternating magnetic field is then used to induce mechanical vibrations at the ultrasonic frequency in resonant strips of nickel or other magnetostrictive material that are attached to the surface or tip to be vibrated (78). Since magnetostrictive materials behave identically to a magnetic field of either polarity, the frequency of the electrical energy applied to the transducer (coiled wire) is half of the desired output frequency (77)” (32). Magnetostrictive technology requires energy to be converted twice: electrical energy to magnetic energy and then to mechanical energy.

This relatively inefficient way of producing ultrasonic energy results in a greater amount of heat. Due to this, the use of water as a coolant is required while the unit runs and the frequencies produced are considered only in the low-end of ultrasonic energy, around 20 kHz. “Magnetostrictive transducers have difficulty operating at frequencies higher than

20 kHz since the amount of the electrical energy needed and size of the wire coils are limited by the clinical usefulness/size of the handpieces they are located in” (31).

Attempting to increase the frequency would result in a device too cumbersome to use

26 clinically.

“The piezoelectric generator, on the other hand, converts AC electrical energy directly into mechanical energy through the use of the piezoelectric effect. This occurs when certain materials change dimension when an electric charge is applied to them (77).

When electrical energy is applied to ceramic piezoelectric materials (i.e. lead zirconate titanate) there is a conversion and amplification of electrical energy into mechanical energy that is then directly transmitted into the ultrasonic tip (77). This methodology allows piezoelectric transducers to operate higher into the megahertz frequency range.

Piezoelectric generators are more efficient than magnetostrictive units due to the fact that magnetostrictive units require two separate conversions of energy. Energy is lost each time one type of energy is converted into another (77). The piezoelectric units convert electrical energy directly into mechanical energy (77)” (31).

INTRODUCTION OF ULTRASONICS IN ENDODONTICS

“The first application of ultrasonics in endodontics was reported by Richman (79) in 1957. He used a Cavitron ultrasonic dental unit to clean, dry, and obturate root canals in over 50 cases. Richman concluded that since these cases were treated without untoward postoperative sequelae, the use of ultrasonics in root canal therapy held great promise.

In a series of articles published in the endodontic literature from 1976 to 1985,

Martin and Cunningham reported on the use of ultrasound as a primary method of debridement in root canal therapy. The studies evaluated the efficacy of the endosonic method, its ability to eliminate bacteria from the canal, its effect on extrusion, and its

27 effect on postoperative pain.

In order to evaluate the efficacy of the use of ultrasound, Martin, Cunningham et al. (80) compared the ability of K-type files to remove dentin when powered by either hand manipulation or ultrasound. Two groups of seven standard canals in extracted teeth were each prepared by one operator, using the two techniques. Using a Litton LT:200

(maximum output 50 watts at 18 KHz) as an ultrasonic source, and tap water as an irrigant, they found ultrasound significantly superior to hand filing in total dentin removal. In a similar study, using the same ultrasonic source, Martin, Cunningham et al.

(81) compared the ability of diamond files and K -type files to remove dentin when powered by either ultrasound or hand manipulation. Using the same methods and materials as the previous study (80), they found that regardless of whether hand manipulation or ultrasound was used, the diamond files effectively removed more dentin than the K-type files. They also found that ultrasonically energized diamonds were significantly superior to hand manipulated diamonds. In 1982, Cunningham, Martin and

Forrest (82) compared ultrasonic filing to conventional hand filing, evaluating root canal debridement. They instrumented canals from extracted human teeth for three minutes, using 2.5% sodium hypochlorite. After histologic preparation, sections from the 1 mm, 3 mm, and 5 mm levels were paired and subjectively evaluated for debris removal.

Evaluating eleven pairs of teeth, ultrasound was found to significantly remove more debris than hand instrumentation at all levels. In a similar study, Cunningham and Martin

(83) used a scanning electron microscope to evaluate root canal debridement. Comparing a conventional hand method to an ultrasound technique, they found that the ultrasound method produced cleaner canals at the midroot and apical levels in all cases. They went

28 on to report that the smear layer was "much less apparent" in the ultrasonically cleaned canals” (31).

“In a study to evaluate the antibacterial effect of ultrasonic instrumentation,

Martin (84) used 5.5% sodium hypochlorite, 1% acid pentanedial, or a neutral buffer solution in conjunction with ultrasound. Extracted human molars were instrumented, sterilized, apically sealed, and inoculated with one of four test organisms. Ultrasound was found to reduce the number of bacteria when used alone, but the method became significantly more bactericidal when it was combined with the sodium hypochlorite or acid pentanedial. Cunningham et al. (85) evaluated the effect of endosonic and hand filing techniques in reducing the number of bacterial spores in artificially contaminated root canals. Comparing different combinations of instrumentation techniques and irrigating solutions, the number of remaining organisms was measured. It was found that when using saline as an irrigating solution, the hand filed group had a 62% reduction in microbial spores, while the ultrasonically instrumented group had a 86% reduction.

When using sodium hypochlorite, the hand instrumented group showed a 99.3% reduction, while the ultrasonically instrumented group showed a 99.8% reduction.

Therefore, it was shown that the use of a sodium hypochlorite irrigating solution had more of an effect on bacterial reduction than the use of ultrasound.

Martin and Cunningham (86) measured the effect of the endosonic system on the amount of root canal material extruded. Using 38 extracted teeth, they compared ultrasound preparation versus hand preparation by desiccating and weighing the amount of material extruded. It was found that the ultrasonically prepared teeth produced less extruded material whether instrumented short or past the apex. In both groups less

29 extruded material was produced when instrumentation was short of the foramen” (31).

“Martin and Cunningham (87) evaluated the effect of endosonic instrumentation on postoperative pain by comparing it against conventional root canal therapy. Each group had 164 patients, which were treated identically, except for the use of the endosonic system. Pain was defined as a patient request for an analgesic other than aspirin. No significant difference was noted between the groups.

In an overview of their technique, Martin and Cunningham (88) concluded that endosonic root canal preparation was superior to hand preparation in mechanical and chemical debridement, disinfection, and final canal shaping. The ultrasonically energized file was reported to rapidly instrument the canal wall more efficiently with less operator fatigue. The ultrasonically activated irrigant facilitated cleansing and disinfecting actions within the root canal system.

These studies by Martin and Cunningham (80-88) laid the foundation for future investigations of the use of ultrasound in endodontics. These investigations centered on the various aspects of the application of ultrasound. Studies involved the mechanisms of action of ultrasonic instrumentation the use of ultrasound as a primary method of instrumentation, and the use of ultrasound as an adjunct to hand and/or rotary instrumentation. Each of these areas of investigation will be reviewed” (31).

MECHANISMS OF ACTION OF ULTRASONIC INSTRUMENTATION

“Martin and Cunningham (88) attributed the success of ultrasonic instrumentation to the interaction of the ultrasonic energy and the irrigating solution. They called this interaction the synergistic system. The irrigating solution achieves its active biological-

30 chemical effects when it undergoes ultrasonation. The authors defined the primary effects of ultrasound as being cavitation and acoustic streaming. Transient cavitation was said to occur when the ultrasonic energy creates a bubble, which grows to a certain point and then collapses. This collapse creates a pressure-vacuum effect which cleans irregularities in canals and kills microorganisms. The oscillatory effect, which vigorously agitates the irrigating solution, is defined as resonant or stable cavitation. Combined with these effects of cavitation is a dispersal of physical energy which leads to physical acoustic streaming. Acoustic streaming is the creation of intense circular fluid movement or flow patterns around files known as eddies (89). This acoustic streaming enhances cleansing and disinfection.

Martin and Cunningham (90) went on to describe the production of an "ultrasonic bath." Their endosonic system contains a flow through, high volume delivery of irrigating solution. Hydrodynamic action is created as this high volume of irrigant is continually aspirated. The authors concluded that this multidimensional synergistic system results in a significantly cleaner root canal system” (30).

Mitic et al. (91) showed the synergistic nature of ultrasound and irrigant by comparing smear layer removal after rotary instrumentation and ultrasonic irrigation with either distilled water or 2.5% NaOCl. 35 single-canalled extracted human teeth were instrumented and then subjected to either ultrasound without irrigation, ultrasound with irrigation using distilled water, or ultrasound with irrigation using 2.5% NaOCl solution.

The authors stated that without irrigant, smear layer remained unaltered on the dentin walls. With the addition of distilled water, the dentin walls were cleaner but smear layer remained. Finally, they found that the ultrasound treatment using 2.5% NaOCl provided a

31 clean dentin surface without a smear layer.

“In order to gain an insight into the mechanisms involved in ultrasonic instrumentation, Ahmad et al. (92) investigated the phenomena of cavitation and acoustic streaming. The authors combine the phenomenon of resonant or stable cavitation, as described by Martin and Cunningham (88), with the phenomenon of acoustic streaming.

These terms were combined because the rapid vortex-like motion associated with the vibrating file can also be associated with small gas bubbles set into oscillation by the fluctuating pressure field generated by the file. Transient cavitation was evaluated using a photometric-sensitive image intensification system. This detection system could monitor the light produced by the violent collapse of cavitation bubbles. A rectangular container filled with methylene blue dye and a dispersed film of polystyrene spheres was used to detect acoustic streaming. These spheres were illuminated so that patterns of acoustic streaming could be detected. In this study, 40 extracted maxillary anterior teeth were divided into four groups and instrumented either by hand or ultrasonically (Cavi-Endo), using either water or 2.5% sodium hypochlorite as an irrigating solution. The teeth were then split longitudinally and evaluated for presence of a smear layer using a scanning electron microscope. It was determined that transient cavitation did not occur with the

Cavi-Endo unit and Endosonic files. However, cavitation was produced when a scaler tip was inserted into the unit. Acoustic streaming was produced by the Endosonic files.

When the amount of remaining debris was evaluated, there was no statistically significant difference between ultrasonic and hand instrumentation when either water or sodium hypochlorite was used as an irrigating solution. The groups using the sodium hypochlorite always had less debris, regardless of type of instrumentation. Ultrasound

32 with either water or sodium hypochlorite significantly reduced the smear layer, but this reduction was of unequal distribution and thickness. The authors concluded that acoustic streaming was more important to cleaning than cavitation. It was also concluded that the recommended technique of ultrasonic instrumentation did not produce sufficient acoustic streaming to effectively clean the canal. The limitation in the production of acoustic streaming was caused by damping of the files in the constricted canal system.

Ahmad et al. (93) continued the investigation of ultrasonic debridement by examining acoustic streaming generated by the Cavi-Endo unit. Using the same method to detect acoustic streaming as described in the previous study (92), different size

Endosonic files were studied at different power settings. The power generated by the files was estimated by measuring the transverse displacement amplitudes that were produced.

Transverse displacement amplitude is defined as half of the total distance moved by the pinpoint of light which appears as a thin transverse line when a file oscillates. Twenty extracted maxillary central incisors or canines were divided into 2 groups and instrumented either according to manufacturer's instructions or with a modified technique. With the modified technique, a #15 Endosonic file was allowed to freely vibrate at working length at a power setting of 2.5 for 5 minutes. The results showed that the smaller files generated relatively greater acoustic streaming, the velocity of which increased with increased power. Canals instrumented with the modified method were found to exhibit cleaner surfaces. The authors concluded that this increase in canal cleaning was due to an increase in acoustic streaming with the modified method.

In another investigation into the mechanisms of ultrasound, Ahmad et al. (94) examined the effects of acoustic cavitation in debridement of root canals. In a preliminary

33 study, a range of power settings in the Enac were evaluated to determine if cavitation was produced. Using a #15 file, it was determined that cavitation could be produced at a minimum power setting of 3.5, and that a minimum displacement amplitude of 135 microns was required for the file to oscillate freely (without binding) in a canal prepared up to a #40 file. Twenty extracted maxillary canines were instrumented to a #40. In 10 teeth, a #15 file was allowed to freely vibrate at a setting of 3.5 for 5 minutes. A continuous flow of 2.5% sodium hypochlorite was provided during the period of instrumentation. In the other 10 teeth, a power setting of 1.0 was used. Cleanliness was determined by evaluating the remaining smear layer using a scanning electron microscope. Using this method of evaluation, it was found that there was no difference between the two groups. It was also noted that cavitation may have produced small pits on the canal wall. The authors concluded that cavitation should not be regarded as an important mechanism in root canal debridement.

Walmsley (95) also investigated the mechanisms of ultrasound in root canal treatment. Agreeing with Ahmad et al. (94), he concluded that cavitation had little if any bearing on the debridement activity of ultrasound. This conclusion was based on his postulation that although the displacement amplitudes of the vibrating file were adequate to produce cavitation, the streamlined shape of the endosonic file was not conducive to generating a sound pressure field large enough to produce cavitation. Walmsley also concluded that because of the transverse nature of the vibration pattern of the activated file, the effectiveness of ultrasonic instrumentation is limited by the damping of the file against the root canal wall. Acoustic streaming is an effective mechanism in disrupting debris within the canals, but is reduced when loading occurs against canal walls. Also,

34 the synergistic activity of ultrasound and the irrigating solution does not take place when the file is not allowed to vibrate freely” (30).

“Walmsley and Williams (96) studied the effect of constraint on the oscillatory pattern of endosonic files. The displacement amplitudes of various files were measured, using a Cavi-Endo as an ultrasonic source. A model system utilizing pins in an acrylic block was used to simulate the effects of damping which would occur during routine instrumentation. The constraining influence was found to be the greatest near the tip of the file, and increased if the file was angled. This constraint resulted in inefficiency of the ultrasonic system, especially in the apical third of a curved root canal. The authors recommended that a small diameter file should be used in a step-down technique to minimize the effects of constraint.

Lumley et al. (97) used slow setting plaster to demonstrate the activity of streaming around both ultrasonically and sonically activated files. For ultrasonic files, streaming occurred mainly in front of and behind the file, in contrast to the sonic file, where the plaster was disturbed evenly around it. With both types of file most activity occurred around the file tip, and became reduced towards the driver. Streaming patterns associated with the ultrasonic device were found to be dependent on the power setting of the instrument and whether the side of the file was constrained or lightly touched. The sonic device produced a large disturbance around the freely oscillating tip. Under load, this streaming occurred along the whole length of the file and was unaffected by constraint.

Ahmad et al. (98) found that the ultrasonic files can generate acoustic streaming both in the free field and in the small channel. Higher velocity streaming was observed

35 when smaller size files were employed and when the file was precurved. Light file-wall contact did not totally inhibit streaming while severe file-wall contact inhibited movement of the file and, as a result, no streaming was observed. The positions and length scales of the streaming vortices appeared to be influenced by the presence of boundaries. In the free field, two rows of vortices were situated along the sides of the file while in the small channel, the vortices were positioned above the surface of the file.

These results indicated that it is possible for acoustic streaming to occur in a confined space, as in a root canal, provided that severe file-wall contact is avoided. They recommended that light filing or allowing the file to freely vibrate during some stage of treatment should be carried out in order to generate streaming in the root canal.

The pattern of oscillation of a Piezon-Master 400 (piezoelectric transducer) ultrasonic file was studied in air and on water by Ahmad et al. (99). Displacement amplitudes of the files were also measured. It was observed that the files vibrated such that a standing wave was formed and it exhibited points of maximum deflection

(antinode) and points of minimum deflection (node) with the largest deflection occurring at the file tip. This pattern of oscillation was similar to that exhibited by the Cavi-Endo file which employed a magnetostrictive transducer. However, the displacement amplitudes were much higher than those exhibited by the Cavi-Endo. They figured that the 120 degree angle of the file holder, inherent in the Piezon-Master 400 unit, and the more effective power transmission with the piezoelectric transducer may have contributed to the large amplitudes.

Ahmad et al. (100) also studied the Piezon-Master 400 ultrasonic to see if there was variability in its power out put when driven using different generators, tranducers

36 and file holders. The displacement amplitude of the oscillating tip of the file in air was used as a measure of the power output. The results showed that there was considerable variability in the power output of Piezon-Master 400 ultrasonic files of similar size and length when driven using different generators, transducers and file holders. In consideration of this, it was recommended that a calibration device be incorporated in the ultrasonic unit so that the operator will have some knowledge of when the unit is working at its maximum efficiency.

Roy et al. (101) used sonoluminescence as an indicator of transient cavitation activity and photographic analysis was utilized as a means for detecting steady streaming, microstreaming, and stable cavitation with ultrasonic files. Measurements failed to indicate any strong correlation between registered driving power and the propensity to produce transient cavitation. Files that were pitted or possessed salient edges were very effective at generating transient cavitation. When observed, transient cavitation activity generally occurred near the tip of the straight file, provided the wall-loading did not inhibit file motion. In all cases studied, steady streaming and stable cavitation were observed to varying degrees, depending on the amount of file to wall contact. Stable cavitation was probably enhanced by the addition of moderate amounts of dissolved gas into the irrigant. Although the imposition of file-wall contact served to inhibit the production of transient cavitation, this action had relatively little effect on the ability of a file to produce a nominal level of streaming, microstreaming, and stable cavitation.

Observations suggested that it was not prudent to ascribe enhanced cleaning effects to any one phenomenon, for it is likely that several factors are involved to varying degrees depending on the local conditions of application.

37 These studies (92-101) show that damping of the vibrating file limits the effectiveness of ultrasound. Therefore, an instrumentation method must be used which does not constrain the file in the canal” (30).

PASSIVE ULTRASONIC IRRIGATION

Ultrasound as the primary method of instrumentation has not been shown to present any clinical advantage over conventional techniques (102-107). However, investigators have found that when ultrasonic irrigation is used as an adjunct to step-back preparation or to hand/rotary techniques it may have advantages including improved cleanliness of the complex canal system. The term “passive activation” implies that the activated ultrasonic instrument is not used to instrument, plane, or contact the canal walls

(89). Therefore, smooth wires or needles have been recommended since they will not cut into the dentin walls of the canal (108). Current literature also suggests that in order for the ultrasonic instrument to agitate the irrigant it must have an unobstructed range of movement which is allowed by initial canal preparation and enlargement. Free oscillation of the instrument causes more ultrasonic effects in the irrigating solution and may improve debridement of the canal system (22).

“Weller et al. (14) compared the efficacy of ultrasonics as a primary method of instrumentation and as an adjunct to hand instrumentation versus hand instrumentation alone. Thirty extracted single rooted teeth and 30 resin blocks were prefilled with radioactive gelatin and canal cleaning was based on the loss of radioactivity after instrumentation. The ultrasonic source consisted of a Cavitron unit with an insert, which was spot welded to a 25 mm #15 stainless steel finger plugger. Sodium hypochlorite

38 (5.25%) was used as an irrigating solution. In both the extracted teeth and the resin blocks, it was determined that when the ultrasonic technique was applied after completion of hand instrumentation and irrigation, radioactivity reduction was significantly superior to either hand or ultrasonic instrumentation used alone. Therefore, the authors concluded that ultrasonic instrumentation is not an alternative to hand cleaning, but acts as an aid to increase debridement efficacy after hand instrumentation.

Goodman et al. (15) compared the effect of a step-back preparation versus a preparation which utilized ultrasound after step-back on the tissue removal from the mesial root canals of 60 extracted human mandibular molars. Two operators performed identical procedures. The ultrasonic source consisted of a Buffalo piezoelectric dental unit with a #15 finger plugger soldered to the ultrasonic tip. Three minutes of ultrasound was added per canal after completion of hand instrumentation. Continuous irrigation was provided utilizing 2.62% sodium hypochlorite. An additional 3 minutes of irrigation was applied to the hand instrumentation group to equalize the amounts of irrigant used in each group. Tissue removal in the canals and isthmuses was measured from transverse sections taken from the 1 mm and 3 mm levels, using a polar planimeter to measure the areas of the canals and remaining tissue debris. Results showed that the step-back/ultrasonic technique cleaned canals at the 1 mm level and isthmuses at both levels better than the step-back technique. No difference was found in canal cleanliness at the 3 mm level.

Using hand instrumentation alone, a difference in canal cleanliness was observed between operators. However, in the step-back ultrasound group, no difference was observed between operators.

In a similar study, Lev et al. (16) also compared the step-back technique to a step-

39 back/ultrasound technique. This investigation used the same methods and materials as

Goodman's study (31), except that a Cavi-Endo unit with a size #20 Endosonic file was used as an ultrasound source. A 1 minute ultrasound group was added in addition to the 3 minute ultrasound group. Results showed no statistically significant difference between the groups at either the 1 mm or 3 mm level. However, the step-back/ultrasound 3 minute group significantly cleaned the isthmuses at both levels more effectively than the other techniques.

Haidet et al. (17) also compared a step-back technique to a step-back/ultrasound technique in the mesial canals of human mandibular molars. This investigation was performed in vivo, with the teeth being extracted immediately after instrumentation. A

Cavi-Endo unit with a #20 Endosonic file was used for 3 minutes in the step-back/ultrasound group. Equal amounts of irrigating solution (5.25% sodium hypochlorite) were used in both groups as was reported by Goodman et al. (15). At the 3 mm level, it was found that there was no difference in canal or isthmus cleaning between the 2 groups. At the 1 mm level, the step-back/ultrasound technique was superior to the step-back technique in canal (99.6% versus 88%) and isthmus (86% versus 10%) cleanliness.

Similar results were obtained by Metzler and Montgomery (18) who compared the effectiveness of passive ultrasonics and calcium hydroxide for the debridement of extracted human mandibular molars. Two minutes of ultrasound was used following hand instrumentation (step-back technique). A Cavitron unit with a Cavi-Endo insert was used as the ultrasonic source. Continuous irrigation with 2.6% sodium hypochlorite was supplied by an intravenous bag connected to the insert in the handpiece. In the second

40 group, calcium hydroxide was allowed to remain in the canals for one week after hand instrumentation. Sections were made similar to those used by Goodman et al. (15), however an Olympus CUE-2 Image Analysis Program was used to evaluate the remaining tissue within the canal. Results showed that ultrasonics and calcium hydroxide were equally effective in debriding the root canal system, and that both techniques were significantly better than hand instrumentation alone in the isthmuses at the 1 mm level.

The authors recommended that if multiple treatment appointments are required for root canal therapy, calcium hydroxide should be placed in the canals between appointments.

If single visit treatment is used, then the addition of ultrasonics is advised at the conclusion of hand instrumentation. However, if multiple appointments are used, ultrasonics could also be utilized prior to obturation.

Archer et al. (19) also compared the in vivo debridement efficacy of the step-back preparation versus a step-back/ultrasound preparation in the mesial root canals of vital mandibular molars. Group 1 consisted of 17 teeth prepared with a step-back technique using intermittent irrigation with 5.25% sodium hypochlorite. Group 2 consisted of 17 teeth prepared with a step-back technique as in group 1 followed by 3 min of ultrasonic instrumentation per canal utilizing a #15 Endosonic file in an Enac unit set at 3.5. An additional 6 mL/canal of 5.25% sodium hypochlorite was used during the ultrasonic preparation. Eight uninstrumented mandibular molars served as histologic controls.

Following extraction and histologic preparation, 0.4 micron cross-sections from the 1- to

3 mm apical levels of the canal and isthmus were evaluated for percentage of tissue removal using an Olympus CUE-2 Image Analysis System. Factorial analysis of variance indicated canal and isthmus cleanliness values were significantly higher, at all 11 apical

41 levels, with the ultrasonic technique. Sample values at the 1-, 2-, and 3 mm levels for the step-back and step-back/ultrasonic techniques, respectively, were: canal, 64% versus

92%, 81% versus 97%, and 90% versus 99.9%; isthmus, 2% versus 46%, 15% versus

60%, and 16% versus 83%.

Cameron (109) studied 4% sodium hypochlorite and 15% ethylenediaminetetraacetic acid with centrimide (EDTAC), either alone or in conjunction, as irrigants during hand instrumentation and ultrasonic irrigation of the root canal. Thirty- six extracted human teeth, each with a single, 21-25 mm long straight root were hand- instrumented through a clinical access cavity to file size 40. One milliliter of the test irrigant was used after each instrument size. Canal debridement was completed with an intermittent flush irrigation technique with one or both of the test irrigants activated by ultrasound at a medium power output. The specimens were sectioned longitudinally, viewed in a scanning electron microscope and scored for the presence or absence of debris and smear layer at levels less than 1 mm, 5 mm, and 10 mm from the apical seat.

Under the conditions of this experiment the most effective regime was irrigation with 1 mL EDTAC after each instrument size, followed by two 30 second exposures to ultrasound+EDTAC then four 30 second exposures to ultrasound and 4% sodium hypochlorite. The specimens in this group were free of retained pulp tissue and superficial smear layer, had the lowest debris scores at the < 1 mm and 5 mm levels, and the lowest total debris score. All of the techniques tested produced smear-free canals at the 10 mm level.

Jensen et al. (110) compared the cleaning efficacy of passive ultrasonic activation with that of passive sonic activation after hand instrumentation. Sixty curved molar

42 canals were hand-instrumented to size 35 and divided into three groups. Group 1 received no further treatment. Group 2 received 3 min of passive sonic activation. Group 3 received 3 min. of passive ultrasonic activation. The roots were split and photomicrographs (x20) were made of the apical 6 mm of canal. A transparent grid was placed over projected images, and the total number of squares covering the apical 6 mm of the canal space and the number of squares containing debris were counted. The mean debris scores were 31.6% for hand instrumentation only, 15.1% for the sonic group, and

16.7% for the ultrasonic group. The debris scores for the sonic and ultrasonic activation groups were significantly lower than that for the hand instrumentation only group (p <

0.01); however, there was no significant difference between the sonic and ultrasonic activation groups. Passive sonics after hand instrumentation produce a cleaner canal than hand instrumentation alone and is comparable with that of passive ultrasonics.

Cameron (111) investigated the synergistic relationship between sodium hypochlorite and ultrasound. Twenty–eight extracted teeth were instrumented to clinical standards with water used as an irrigating solution. Canals were given a final irrigation with either 4% sodium hypochlorite, ultrasonically activated sodium hypochlorite, or ultrasonically activated water. Evaluation with a scanning electron microscope revealed that 4% sodium hypochlorite, or ultrasound with water did not remove the smear layer inside the canal. However, 2% or 4% sodium hypochlorite did remove the smear layer when activated by ultrasound. Therefore, it was concluded that a clinically significant synergistic relationship does exist between ultrasound and sodium hypochlorite” (20).

“Gutarts et al. (20) studied the effects of an ultrasonic irrigating needle as an adjunct to hand and rotary instrumentation in the mesial root canals of 36 mandibular

43 molars with a clinical diagnosis of irreversible pulpitis. Teeth were placed into 2 groups.

Group 1 consisted of the mesial root canals of mandibular molars prepared using hand and rotary instrumentation and intermittent irrigation with 6% NaOCl. Group 2 consisted of the mesial root canals of mandibular molars prepared using hand and rotary instrumentation with intermittent irrigation using 6% NaOCl followed by a 1 minute ultrasonic application using an irrigating needle connected to a MiniEndo™ ultrasonic unit and IV tubing through which passed 6% sodium hypochlorite. The irrigating needle was placed passively into each canal for 1 minute. Following access into the pulp chamber and electronic and radiographic verification of working length, crown-down instrumentation of the mesial root canals was performed as follows: (1) a #20 K-file was inserted to working length, (2) a #5 Gates-Glidden drill was used to facilitate instrumentation with rotary files, (3) ProFile® GT® rotary instruments in sizes 30/.10,

30/.08, 30/.06, and 30/.04 were taken to resistance, (4) ProFile® GT® orifice shapers in sizes 70/.12, 50/.12, and 35/.12 were used to further enlarge the coronal aspect of the canals, and (5) a #30 K-file was used to verify apical enlargement to a size #30. Two mL of 6% sodium hypochlorite was used as an irrigant after every third hand and rotary file.

Ultrasonic instrumentation was then performed in a random set of these patients.

Following instrumentation, each tooth was extracted; the apical 3 mm of each mesial root sectioned, and analyzed histologically using a Neurolucida Image Analysis Program version 5.0 for canal cleanliness. The authors found significantly (p< 0.05) less dentinal debris and pulp tissue remaining following the use of the ultrasonic irrigating needle regardless of canal type, canal curvature, or apical level. Canal isthmuses were also significantly cleaner (p< 0.05) following the use of the ultrasonic irrigating needle. The

44 authors concluded that the use of the ultrasonic irrigating needle with 6% NaOCl for 1 minute was clinically applicable and was able to better debride the root canal system than hand and rotary instrumentation alone” (31).

“Burleson et al. (21) histologically examined hand/rotary/ultrasonic instrumentation in necrotic, human mandibular molars. Mesial canal systems of mandibular molars are known to have isthmus bacterial contamination which hand/rotary techniques cannot mechanically access. This in vivo, prospective, randomized, single- blinded study histologically compared biofilm/necrotic debridement efficiency of a hand/rotary technique versus a hand/rotary/1 minute ultrasound technique in the mesial root of necrotic, mandibular molars. Following extraction, the roots and isthmus were histologically stained at 0.2 !m cross-sections from the 1- to 3 mm apical levels and evaluated for cleanliness. Statistical analysis revealed mean percent canal and isthmus cleanliness values to be significantly higher for hand/rotary/ultrasound technique at all levels evaluated. The authors concluded that 1-minute of ultrasonic activated irrigation has been shown to greatly reduce or completely remove canal and isthmus necrotic debris/biofilm contamination” (112).

In another study histologically evaluating tissue removal, Passarinho-Neto et al.

(113) compared the in vitro effectiveness of rotary instrumentation coupled with ultrasonic irrigation in extracted human mandibular incisors. Thirty-six extracted teeth were prepared using the crown-down technique to an apical size of 30/.04 using Profile®

GT® files. The teeth were divided into four random and equal groups to be treated with various final irrigations. Group one was irrigated with 100 mL of 1% NaOCl from a syringe. Groups two, three and four had final irrigation with 100 mL of 1% NaOCl

45 energized by ultrasound for 1, 3, and 5 minutes respectively. The apical thirds of the teeth were then analyzed at 40x magnification for percentage of debris. Group one was found to have statistically (p < 0.01) more debris than all other groups. Group two had a mean percentage of 27.3%, Group three resulted in 24.4%, and Group four was found to be the cleanest with only 18.5% debris remaining. The authors attributed the results to increasing time of ultrasonic activation allowing for more cleaning activity and higher intracanal temperatures.

Al-Jadaa and Zehnder (114) used resin blocks with simulated main and accessory canals to compare the tissue dissolving properties of 2.5% NaOCl on necrotic tissue.

Transparent resin models were filled with necrotic bovine tissue and then flushed using passive ultrasonic irrigation five times in1 minute intervals. Debris removal was evaluated and temperature of the NaOCl during ultrasonic activation was measured. The resin blocks were again filled with tissue and flushed with 2.5% NaOCl this time without ultrasonic activation but heated to the temperatures recorded in the ultrasonic group.

Irrigation using passive ultrasonics was shown to dissolve significantly more debris

(p<0.05) than heated NaOCl showing that there is an ultrasonic effect on tissue removal beyond that of increasing the temperature of the irrigant.

Munley et al. (89) compared fluted and non-fluted instruments when used for passive ultrasonic debridement of extracted straight human teeth. Eighty-five teeth were decoronated and prepared using a crown-down technique with ProFile® rotary instruments to an apical size of 40/.04. Teeth were then randomly divided into 4 experimental groups and a control group. All experimental groups were irrigated with 5 mL of 6% NaOCl and then passively ultrasonically activated for 1 or 3 minutes using

46 either a size #15 K file or a yellow stainless steel finger spreader. The teeth were then split, photographed and evaluated for remaining debris in the apical, middle and coronal thirds. The addition of one minute of ultrasonic irrigation was found to improve debris removal at all levels. When comparing overall cleanliness, Group 1 (#15 file, 3 min.) was shown to be significantly cleaner than Group 4 (Finger spreader, 1 min.). It was concluded that non-fluted finger spreaders did not improve debris removal. The authors also speculated that continuous irrigation or increased volume of irrigant may have improved the removal of canal debris.

“Carver et al. (115) studied the in vivo antibacterial efficacy of ultrasonic activation of sodium hypochlorite after hand and rotary instrumentation in human mandibular molars. Study groups were divided consisting of 16 mesial roots prepared with hand/rotary technique, and 15 mesial roots prepared similarly, followed by 1 minute of ultrasonic irrigation per canal with an ultrasonic needle in a MiniEndo unit and 15 mL/canal of 6.0% sodium hypochlorite. Each canal was sampled before and after hand/rotary instrumentation and after ultrasonic irrigation. Samples were incubated in an anaerobic chamber, and colony forming units were counted. The addition of 1 minute of ultrasonic irrigation resulted in significant reduction of positive cultures. Logistic regression analysis indicated the addition of ultrasonic irrigation was 7 times more likely to yield a negative culture” (112).

Imperial et al. (112) evaluated antibacterial efficacy by means of microbial culture method, of a hand and rotary instrumentation technique plus one-minute of 15 mL/minute

6% NaOCl, and 30 seconds 15 mL/min 2% Chlorhexidine via passive ultrasonic irrigation using an ultrasonic irrigating needle connected to a MiniEndo™ piezoelectric

47 ultrasonic system in the mesial roots of infected, necrotic, human mandibular molars.

Canals were sampled prior to treatment (sample S1), after hand and rotary instrumentation (sample S2), after ultrasonic irrigation with 30 mL 6% NaOCl (sample

S3), and after ultrasonic irrigation with 15 mL 2% Chlorhexidine (sample S4). The samples were incubated anaerobically for 7 days at 37°C. The bacteria from each sample were quantified, and the mean and median CFU count and log10 CFU count were used for statistical analysis. All samples were positive for initial growth (sample S1). The analysis revealed a statistical difference between samples S1 vs. S2 (p = 0.0005), S1 vs. S3 (p =

0.0005), and S1 vs. S4 (p = 0.0005). A trend toward significant reduction in mean CFU count was seen between samples S2 vs. S3 (p = 0.08). The number of positive cultures was observed to decrease after each step of treatment. The median and median log bacterial counts showed a decreasing trend from S1-S4 with both reaching 0 at S4.

Between-sample differences were seen with S2 vs. S4 (p = 0.06), and between samples

S3 vs. S4 (p = 0.06). Although not statistically significant, the addition of ultrasonic irrigation with 30 mL of NaOCl and 15 mL of 2% Chlorhexidine showed a decreasing trend in bacterial growth.

“As previously described by Carver (115) and Burleson (21), ultrasound activated NaOCl irrigation with hand/rotary instrumentation significantly improved root canal cleanliness. Many of these studies (14-18,20,21,42,109,115) show that when ultrasound was added after hand instrumentation, at least one of the evaluated areas of the root canal was cleaner than when hand instrumentation was used alone” (26).

48 SUMMARY

Taken collectively, numerous studies have demonstrated the complexity of the root canal system and the relative ineffectiveness of current instrumentation procedures to completely debride and disinfect all areas of the root canal. The use of ultrasound following hand and rotary instrumentation may be a helpful adjunct in the removal of soft tissue and in the elimination of the microbial population within the root canal. However, further research is required to determine the effects of lowering the concentration of sodium hypochlorite during passive ultrasonic irrigation.

CHAPTER 3

MATERIALS AND METHODS

Selected portions of the following Materials and Methods have been adapted from previous theses by Gutarts (30), and Burleson (32) from the Division of Endodontics at

The Ohio State University.

Sixteen volunteer subjects participated in this study. All patients were questioned orally and with a written health questionnaire to ensure that they were in good health and not taking any medications that would complicate endodontic or extraction procedures.

This study was approved by The Ohio State University Human Subjects and Maternal-

Fetal Committees. All participants signed a consent form for treatment and participation in the study. Participants were not used if they had contraindications or were sensitive to the local anesthetic injections or solution used in this study. All teeth used were diagnosed as requiring extraction for periodontal or prosthetic reasons, non-restorability, or patient refusal of endodontic therapy in order to save and/or restore the tooth.

Tooth vitality was initially established with Green Endo-Ice® refrigerant spray

(Hygenic, Akron, OH). The experimental tooth was dried with 2x2 inch cotton gauze.

The Green Endo Ice® refrigerant spray was sprayed onto a cotton pellet held by cotton forceps until the pellet was saturated. This pellet was then applied to the middle one third 50 of the buccal enamel surface (or lingual if buccal was missing). The pellet was removed when the patient indicated a feeling of cold or pain by raising their hand. This positive vital response was then confirmed with a Kerr Vitality Scanner (Kerr Dental, West

Collins Orange, CA) digital electric pulp tester. After drying the tooth with 2x2 inch cotton gauze, a small amount of Colgate Total toothpaste (The Colgate-Palmolive

Company, New York, NY) was used (enough to cover the electrode of the pulp tester) as a conducting medium between the pulp tester and tooth. The electrode was placed on sound enamel in the middle third of the buccal surface (or lingual if buccal was missing) of the crown (116). The electrode was not placed on exposed dentin, cementum, or restorations. Pulp testing was started when the electrode made contact with the tooth and when the patient indicated sensation in the tooth with a raised hand. The digital value from the pulp tester was recorded. The “cold test” and “electric pulp test” was only done until a definite positive response of vitality or non-vitality was established. On average this was approximately two times per test, per experimental tooth. Only teeth with vital pulps were included in this study.

Prior to injection, topical anesthesia (20% benzocaine gel; Patterson Brand Dental

Supply, Inc., St. Paul, MN) was administered with a cotton swab in the area of the inferior alveolar nerve block injection. The cotton swab was left in place for thirty seconds and then removed. Two 1.8 mL cartridges of 2% lidocaine with 1:100,000 epinephrine (AstraZeneca LP, York, PA) were administered, using an inferior alveolar nerve block and long buccal injection technique. The inferior alveolar and long buccal nerve blocks were administered using a 27-gauge 21 mm short needle (Kendall

Monoject, Mansfield, MA). All injections were given by the principal investigator. The

51 conventional inferior alveolar injection technique as described by Fischer (117) and modified by Jorgensen and Hayden (118) was used. The injection site was the soft tissue overlying the medial surface of the ramus, lateral to the pterygomandibular raphe, at a height determined by the coronoid notch on the anterior border of the ramus. With the subjects mouth wide open, the thumb of the non-injecting hand was placed over the pterygomandibular triangle and then pulled laterally until the deepest depression in the anterior border of the ramus was felt. The first or second finger of the non-injecting hand palpated the posterior portion of the ramus, finding a slight depression. The line between the thumb and the finger was used to establish the vertical height of the injection site. The direction of needle insertion was from the contralateral mandibular premolars and directed parallel to the occlusal plane. The needle was advanced over a time period of ten seconds to the target site until bone was gently contacted at a depth of penetration of approximately 16 to 20 mm. After contact with bone was made, the needle was withdrawn 1 mm, aspiration performed, and the solution was deposited at a rate of approximately 1 mL every 30 seconds. After all of the anesthetic solution was deposited the needle was fully withdrawn.

The conventional long buccal injection technique as described by Malamed (119) was also used. The area of insertion was the mucous membrane distal and buccal to the most distal mandibular molar, and the target was the buccal nerve as it passed over the anterior border of the ramus. With the subject's mouth wide open, the index finger of the non-injecting hand was used to pull the buccal soft tissues in the area of injection laterally so that visibility was improved. The syringe was directed toward the injection site with the bevel facing down toward the bone and the syringe aligned parallel to the

52 occlusal plane on side of injection but buccal to it. The mucous membrane was penetrated at the injection site, distal and buccal to the last molar. The needle was advanced slowly until the mucoperiosteum was gently contacted. After contact with bone was made and aspiration performed, the solution was deposited at a rate of approximately 0.5 mL/15 seconds. After all of the anesthetic solution was deposited the needle was fully withdrawn. Approximately 2.3 mL was used for the inferior alveolar injection and about

0.5 mL of anesthetic was used for the long buccal injection.

When required, additional anesthesia was provided with an intraosseous injection, using the Stabident System (Fairfax Dental Inc., Miami, FL). The intraosseous injection was given using 1.8 mL cartridges of 2% lidocaine with 1:100,000 epinephrine. The injection was given distal to the tooth intended to be anesthetized except for second and third molars in which case the injections were given on the mesial. The area of cortical plate perforation was determined by the horizontal line of the buccal gingival margins of the experimental and adjacent teeth and a vertical line that passed through the interdental papilla. A point approximately 2 mm below the intersection of these lines, in the attached gingiva, was used as the perforation site.

An infiltration injection of approximately 0.1 mL of 2% lidocaine with 1:100,000 epinephrine was deposited using a 27-gauge ultra-short Stabident needle at the site of perforation. The cortical bone was then perforated, approximately 30-60 seconds later, using the Stabident perforator in a contra-angle, slow-speed handpiece. The intraosseous injection followed as the Stabident needle was placed in the perforation to the hub and the anesthetic solution was deposited at a rate of 1.8 mL/min. If any additional pulpal anesthesia was required, an intrapulpal injection was given using 2% lidocaine with

53 1:100,000 epinephrine and a 27-gauge needle placed directly into the pulp chamber or the root canal that remained painful to instrumentation. The injection was given under back- pressure to ensure successful anesthesia.

The experimental teeth were randomly divided into two groups. Group 1 consisted of teeth prepared using a manual hand file technique and rotary instrumentation, immediately followed by 1 minute of ultrasonic instrumentation with

3% sodium hypochlorite per canal at a rate of 15 mL/min. Group 2 consisted of uninstrumented teeth which served as histologic controls, and were obtained from the

Oral Surgery Department at The Ohio State University. This group was made up of freshly extracted teeth with a vital pulp diagnosis. These molars were extracted for periodontal or prosthetic reasons, non-restorability, or patient refusal of endodontic therapy in order to save and/or restore the tooth. In order to compare these groups to the variable of sodium hypochlorite concentration, data from a study previously completed by Gutarts (30) was referenced to form a third group which consisted of teeth instrumented in the same manner as Group 1 except 6% sodium hypochlorite was used to irrigate the samples.

The original design of this study intended to compare 3.0% and 6.0% NaOCl ultrasonic irrigation using a new single-use ultrasonic tip that was developed in conjunction with a large US dental manufacturer. This device replicated the setup originally described by Gutarts (30) but simplified the system making for easier use. The needle and hub assembly was combined in a plastic housing and coupled with a short length of IV tubing. The hub/needle portion screwed directly onto the ultrasonic handpiece and the short IV tubing, which fed solution into the needle, was then attached

54 to a long section of tubing that was connected to a 30 mL syringe of irrigant secured in a mechanical pump. The device could have been marketed to clinicians who wanted to use ultrasonic irrigation more conveniently.

The first 20 patients of this study were treated using this new device in conjunction with either 3.0% or 6.0% sodium hypochlorite however evaluation of these samples revealed that effective cleaning of the canals did not occur. The reason for large amounts of remaining tissue in the canals and especially isthmuses was believed to be because the new device was not effectively transmitting ultrasonic energy into the solution and the benefit of acoustic streaming was not occurring. It was hypothesized by the engineers who produced the new ultrasonic needle that the EIE ultrasonic unit used in this study did not synchronize with the new tip and therefore did not produce the proper frequency of vibration of the needle. This was measured with an oscilloscope. Due to this, none of the samples were be effectively cleaned and could not show a true comparison of ultrasonic cleaning between 3.0% and 6.0% sodium hypochlorite. It was at this time that we decided to employ the ultrasonic needle setup used by Gutarts (30) and compare the variable of sodium hypochlorite concentration to their previously collected data.

Two 10 mL syringes and one 30 mL syringe were prepared and given to the principal investigator for use immediately before treatment. The 3% solution was created by mixing equal parts tap water and 6% sodium hypochlorite in a plastic container before drawing the solution into the syringes. Both canals of the mesial root of the experimental tooth received the same treatment.

GROUP 1 - HAND/ROTARY INSTRUMENTATION WITH ONE MINUTE

OF PASSIVE ULTRASONIC IRRIGATION USING 3% SODIUM

HYPOCHLORITE

Experimental teeth were isolated with a rubber dam. A standard access opening was then made using a #4 round bur in a high-speed handpiece. Canal orifices were located and the presence of pulpal hemorrhage was noted as a confirmation of pulpal vitality. If necrotic tissue was found upon access the patient was excluded from the study.

Prior to file insertion, the pulp chamber was irrigated with approximately 5 mL of sodium hypochlorite solution (Clorox Co., Oakland, CA). The concentration of sodium hypochlorite (3.0%) was consistent throughout the procedure. All intermittent irrigation was performed using a 25-gauge 5/8 inch needle with a Luer-Lok attachment (Becton-

Dickinson & Co., Rutherford, NJ), connected to a 10 mL disposable plastic syringe. The irrigating solution was aspirated with a high-speed suction directed toward the distal aspect of the pulp chamber.

K-type hand files (Dentsply Maillefer, Tulsa, OK) and rotary ProFile® GT® files

(Dentsply Tulsa Dental, Tulsa, OK) were used for the canal preparation. A provisional working length was determined by measuring the approximate canal length on the preoperative radiograph. A #10 K-file was placed into each mesial canal using a one- quarter turn, push-pull motion, until the end of the file was approximately 1 mm from the radiographic apex. This was used for initial canal exploration, and then followed by a #15

K-file, to approximately 1 mm from the radiographic apex. The Root ZX Apex Locator

(J. Morita, Irvine, CA) was used with a #10 K-file to determine the working length

56 approximately 0.5 mm (apical constriction) from the actual apex. A digital radiograph was exposed with a slight mesial angulation (approximately 15° from perpendicular) to determine the position of each file, and to confirm the working length determined by the

Root ZX Apex Locator. Teeth with a mesial canal configuration of Type I, II, and III

(117) were used in the study. Files were removed, measured with an endodontic ruler, and the lengths were recorded. The working length was adjusted to the level of 1 mm from the radiographic apex.

After working length was established for each mesial canal and each canal was filed up to a size #20 hand-file, a crown down technique was used to enlarge the coronal portion of the canal, then the mid root, and finally the apical third with rotary files. Each canal was irrigated with approximately 2 mL of sodium hypochlorite following the use of every third hand and rotary file, and after the #5 Gates-Glidden bur (Pulpdent Corp.,

Brookline Village, MA) had been used in the root canal. Each rotary file was used with

Glyde® lubricant (Dentsply International, York, PA) during instrumentation of each canal. The following instrumentation sequence was used:

Step #1: #10 K-file (canal exploration)

Step #2: #15 K-file

Step #3: #10 K-file used with Root ZX (establish working length)

Step #4: #15 K-file, radiograph taken (confirm working length)

Step #5: #20 K-file

Step #6: #5 Gates-Glidden

Step #5: ProFile® GT® (30/.10)

57 Step #6: ProFile® GT® (30/.08)

Step #7: ProFile® GT® (30/.06)

Step #8: ProFile® GT® (30/.04)

Step #9: ProFile® GT® (70/.12)

Step #10: ProFile® GT® (50/.12)

Step #11: ProFile® GT® (35/.12)

Step #13: #30 K-file, to confirm apical portion enlargement to a size #30

The largest size K-file, equivalent (#30) to the largest size rotary ProFile® GT® used at working length, was inserted to ensure that the initial working length had been maintained, and a radiograph was exposed to verify its location. If the placement of the final file was short of the calculated working length, an alternating procedure (79-81) was used with a #10 through #25 K-file, which attempted to get the final K-file to the calculated working length.

Following completion of hand and rotary instrumentation the teeth were ultrasonically irrigated with 3% sodium hypochlorite using the same ultrasonic needle and setup utilized by Gutarts (30). (See Appendix for figure) The ultrasonic unit used was a MiniEndo™ (Analytic EIE Inc., San Diego, CA). The power adjustment on the unit was set to full power. The ultrasonic irrigating needle was attached to the MiniEndo handpiece via an ultrasonic tip adaptor and connected, via IV tubing, to a 30 mL syringe containing 30 mL of the test sodium hypochlorite solution (3.0%).

Each canal was filled with 1 mL of 3.0% sodium hypochlorite using the needle and syringe previously described. High-speed suction, using a surgical aspirating tip, was

58 placed at the distal aspect of the tooth and maintained at this position during the ultrasonic irrigation. The ultrasonic needle, connected to the handpiece, was placed in the canal as far apically as possible without binding. Prior to activation, the working length of the needle was determined using a silicone stop and recorded in millimeters. After activation, the needle was moved passively in an up and down motion to ensure it did not bind with the root canal walls. The energized ultrasonic needle was used continuously for

1 minute in each canal. Sodium hypochlorite was delivered from a 30 mL syringe at a rate of 15 mL/min through the IV tubing connected to the ultrasonic tip. High-speed suction was maintained at all times on the distal aspect of the experimental tooth. This procedure was then repeated for the other mesial canal. The same ultrasonic needle was used in both mesial canals and then discarded. After completion of the hand/rotary/ultrasonic preparation, the canals were dried with coarse and medium paper points. A sterile cotton pellet was then sealed in the pulp chamber with temporary filling material (Cavit™, ESPE™, 3M™, Maplewood, MN). All samples were assigned a unique, random, six-digit identification number.

GROUP 2 - HAND/ROTARY INSTRUMENTATION WITH ONE MINUTE OF

PASSIVE ULTRASONIC IRRIGATION USING 6% SODIUM HYPOCHLORITE

The sixteen teeth in this group were prepared by Gutarts et al. (20), using the exact same method used for teeth in Group 1, with the exception of the use of a 6% sodium hypochlorite solution as an irrigant throughout the procedure.

59 GROUP 3 – HISTOLOGIC CONTROL

The 2 teeth in this group were freshly extracted mandibular molars that had been extracted by the Ohio State University Oral Surgery Department. These teeth were treatment planned for extraction due to periodontal or prosthetic reasons, non- restorability, or patient refusal of endodontic therapy in order to save and/or restore the tooth. All pulps were determined to be vital before being included in this study. After the teeth were extracted, access openings were made and the pulp chambers irrigated with 1 mL of 10% formalin. They were then marked with a vertical groove on the buccal surface of the mesial root and placed into randomly numbered, 40 mL vials containing 20 mL of formalin. These uninstrumented teeth served as controls for histologic processing and sectioning procedures. Each sample was assigned a unique, random, six-digit identification number.

HISTOLOGIC PREPARATION

Following fixation, all teeth were decalcified in an aqueous solution of equal parts

50% formic acid and 20% sodium citrate for 10 days. The solution was replaced every 48 hours. The crown and distal root was then removed from each tooth with a single-edged razor blade and the teeth rinsed in running water for approximately 2 hours.

Teeth were then dehydrated and infiltrated using Skinner's method (121). This consisted of a 15 hour submersion of the specimens in 70% ethanol, followed by a 2 hour submersion in 95% ethanol. Teeth were then transferred to 100% ethanol which was replaced every 2 hours, for a total of three 100% ethanol submersions in 6 hours. The specimens were then submerged in methyl salicylate for 15 hours, followed by two 2

60 hour submersions in fresh methyl salicylate solution, for a total of 19 hours. Finally, teeth were placed in Paraplast® (Sherwood Medical Ind. Inc., St. Louis, MO) for 6-hours, with solutions being changed every 2 hours. The specimens were kept in a 56ºC oven to allow the Paraplast® solution to infiltrate the specimens.

Following infiltration, the teeth were placed in an embedding boat containing

Paraplast®. The specimens were oriented in two planes to produce perpendicular sections from the same level in both root canals. Each root was placed horizontally in the embedding boat with the buccal surface facing up. Both mesial root apices were positioned so that they were touching the inside wall of the embedding boat. The specimens were oriented so that the mesial-distal curvature of the apical one third of the root was perpendicular to this wall.

After the Paraplast® had set, 5 micron sections were obtained by an experienced histologic laboratory technologist using an American Optical Model 820 microtome

(American Optical Co., Buffalo, NY) equipped with a stainless steel knife. This knife was sharpened before each specimen was cut. Initial sections were collected from the apex of the specimen and examined with a microscope until the first section was located which contained the entire circumference of the apical foramen. Once the apical foramen was located, eighteen sections were made and the 18th to 22nd sections collected on slide

#1. After cutting sixteen additional sections, the 39th to 42nd sections were collected on slide #2. In this way, four out of every twenty sections were collected per specimen.

Collection of four sections per slide continued in this manner until thirty slides had been collected. The first eight slides were kept but not stained. Starting with slide #9

(representing the 1 mm level from the apical foramen), every slide was stained using

61 Gomori's One-Step Trichrome Method (122). The best, technically error-free section was chosen from each stained slide for evaluation. All slides were labeled with the specimen's six-digit random number, and sequentially numbered according to the order in which they were taken to identify the slide number (#1-#30). These numbers were recorded on the histologic slide.

METHOD OF EVALUATION

Mounted sections from the two groups in this study as well as Gutarts et al.’s (20) specimens were evaluated using a computer (Dell Pentium 4, Windows XP) attached to a

Nikon Eclipse e600 microscope (Nikon, Melville, NY) and a monitor. Neurolucida Image

Analysis Program version 7.0 (MicroBrightField, Inc., Colchester, VT) was used to measure the area of the root canals and isthmuses and all pulp tissue contained within them. Evaluation was done by the chief investigator prior to the random numbers being decoded. This ensured that the evaluator was blinded to the possibility of instrumentation on each specimen. Each canal was focused on and centered in the microscopic field using a 40X, 100X, or 200X power depending on which magnification filled the monitor with the largest possible image without cutting out any part of the canal image. The section was projected onto the monitor screen, using the microscope's video camera, and the digitized image was frozen. Because Gomori's One-Step Trichrome Method was utilized, the following structures were identified by the following colors: vertical dentin-bright red; tangentional dentin-bright blue; odontoblast layer-dark red; fibrous tissue, connective tissue, and nerve bundles-light blue; central pulp tissue and blood vessels-pink (123,124).

A computer mouse was then used to trace the outline of the root canal (tangentional or

62 vertical dentin). The area of the canal space was calculated by the software and displayed on the computer monitor and recorded. The unit of measurement of this readout was in square microns. Anything in the canal system other than dentin (staining bright red) and tangentional dentin (staining bright blue) was considered "remaining tissue". The area of remaining tissue was calculated in the same manner just described. If more than one area of remaining tissue was present within each section being analyzed, the cursor was moved to each separate area and identified it to the computer. The total tissue area was calculated by adding together all the separate "remaining tissue" areas using a calculator.

The isthmuses between canals were traced separately from the primary root canals, and their total area and the area of their remaining pulp tissue recorded as described above. Tracing both the mesiobuccal and mesiolingual canals differentiated the boundaries between the canals and the isthmuses. When tracing canals, the area connected to the isthmus was traced last. In this area, the canal outline was closed by drawing a connecting line which followed the arc formed by the circular shape of the canal. After completion of this step, the remaining canal area was identified as the isthmus.

In order to calculate canal cleanliness, the area of remaining attached pulp tissue was divided by the total area of the canal or isthmus to yield the percentage of remaining pulp tissue. The percentage of the pulp tissue removed, or cleanliness, was determined by subtracting the percentage of remaining pulp tissue from 100%.

Initial digital radiographs of the experimental teeth were analyzed using

Schneider's method (125) to determine the curvature of the mesial root. These radiographs were printed on an 8"” x 11” sheet of white paper using a laser printer. A

63 straight line was drawn through the coronal portion of the mesial canal and through the long axis of the root. A second line connected the apical foramen to the point on the first line where the canal began to deviate from the long axis. A protractor was then used to measure the angle formed and this value were recorded for each specimen.

Teeth having Type I, II, III, IV, and C-shaped mesial canal configurations (120) were allowed in this study. A Type IV canal system splits into two separate canals apically (126). A C-shaped canal may run the whole length of the root like a curtain or ribbon and exit at or near the root apex as a single foramen, or it may divide within the depth of the canal into two or more canals which exit separately (126). The canal configuration was determined when the initial files were placed approximately 1 mm from the radiographic apex of the root. When a periapical radiograph was exposed from a slight mesial angulation, a convergence of the files apically indicated a Type II canal configuration. A Type III canal configuration existed if the files remained separate at the apex. A Type I configuration was determined when only one file was inserted to working length. The determination of canal configuration was later verified during histologic evaluation. The canal configuration of the control specimens was determined during histologic evaluation.

The Mann-Whitney-Wilcoxon test was used to statistically analyze mean cleanliness values for canals and isthmuses (Tables 3,5,7). Method of instrumentation, apical level, and root curvature were the factors which were analyzed. The raw P values were then adjusted by the Bonferroni method of Holm.

CHAPTER 4

RESULTS

A total of 31 patients were evaluated in this study. Group 1 (3% NaOCl ultrasonic irrigation) consisted of 15 patients (48%), and Group 2, which was collected by Gutarts

(30) (6% ultrasonic irrigation), consisted of 16 patients (52%). Only the teeth in Group 1 and the histologic controls were newly collected samples. Table 1 shows a breakdown of the two experimental groups into curvature, canal type, and tooth type. There was a significant difference between the groups when comparing the canal curvature of the samples. In Group 1, fourteen out of fifteen samples (93%) and in Group 2 nine out of sixteen (56%) were classified as severely curved. Since only one sample from Group 1 was classified as moderately curved (less than or equal to 25 degrees), the sample size was not large enough to make valid comparisons between the groups in terms of moderately curved canals. Comparing the two groups as a whole without accounting for canal curvature would possibly favor the group with straighter canals. Therefore comparisons were only made between teeth with severe curvature from both groups. No statistically significant differences were found between Group 1 and Group 2 with regard to tooth type (p = 0.8451). A more complete record of data (sex, age, tooth type, instrumentation method, curvature, working length, needle penetration, canal level, percent cleanliness) is found in the Raw Data (Appendix D). 65 As part of this study, a new ultrasonic irrigating needle was developed and was intended to be used for all teeth. However, after evaluating the first twenty samples using this device, it was concluded that it was not providing effective cleaning. The Raw Data in Appendix D also includes percent cleanliness values from these samples.

A summary of results comparing treatment method by age and gender is presented in Table 2. No significant differences were shown for either of these variables. Results for single canal, isthmus, and common canal cleanliness in severely curved samples are presented in Tables 3 to 8. Reliability in evaluating sample cleanliness was determined for the main evaluator to ensure consistency in his evaluations. The intraclass correlation coefficient was determined to be 0.926 (95% confidence interval 0.844; 0.966), indicating excellent reliability. The inter-rater reliability was also calculated by having the operator in this study measure slides that were used by Gutarts (30) to see if the two evaluators graded the same histologic sections with the same scores. The intra-close correlation coefficient for inter-rater reliability of canals and isthmuses combined was determined to be 0.99 (95% confidence interval 0.94; 1.00), indicating excellent reliability between evaluators.

Mean canal cleanliness values by level and irrigant concentration in severely curved canals are listed in Table 3 and illustrated in Figure 5. Mean isthmus cleanliness values by level and irrigant concentration in severely curved canals are listed in Table 5 and illustrated in Figure 4. Mean common canal cleanliness values by level and irrigant concentration in severely curved canals are listed in Table 7 and illustrated in Figure 3.

The median, minimum, and maximum single canal, isthmus, and common canal cleanliness values by level and irrigant concentration in severely curved canals are listed

66 in Tables 4, 6, and 8 respectively. The canal and isthmus cleanliness values for each experimental sample are listed in Appendix D (Raw Data). The single canal, isthmus, and common canal cleanliness values for the histologic control group are also listed in

Appendix D. Representative photomicrographs of cross sections from each group are presented in Figures 6 through 13.

Table 3 and Figure 5 summarize and illustrate the mean percent single canal cleanliness and standard deviation by level (1-3 mm from the apex) and irrigant concentration in severely curved canals. Group 2 (6% NaOCl) showed consistently cleaner canals at all levels with a low standard deviation, whereas Group 1 (3% NaOCl) showed lower canal cleanliness apically. Cleanliness values improved further from the apex and a general decrease in standard deviation was noted further from the apex. The mean canal cleanliness values were not found to be significant (p > 0.05).

Table 5 and Figure 4 summarize and illustrate mean percent isthmus cleanliness and standard deviation by level (1-3 mm from the apex) and irrigant concentration in severely curved canals. Group 2 showed consistently cleaner isthmuses at all levels, whereas Group 1 showed consistently poor isthmus cleanliness at all levels and a consistently large standard deviation at all levels. Table 5 shows that Group 2 had significantly cleaner isthmuses than the 3% NaOCl group (Group 1) at all levels except 1 mm (p < .05) when the p values were not Bonferroni adjusted. No significant differences were shown when p values were adjusted by the Bonferroni method. However, differences approaching significance were shown at the 2.2, 2.4, 2.6, and 2.8 mm levels.

Table 7 and Figure 3 summarize and illustrate mean percent common canal cleanliness and standard deviation by level (1-3 mm from the apex) and irrigant

67 concentration in severely curved canals. Both groups showed similar cleanliness values at most levels except at the 1.6 and 1.8 mm level where values for the 6% NaOCl group were notably better than the 3% NaOCl group. No significant differences were shown at any level (p = 1.0000) and both groups had consistently high standard deviation values at most levels.

Table 4 shows large minimum and maximum canal cleanliness values which account for a low difference and range for the 6% NaOCl group at all levels. The 3%

NaOCl group showed a large difference between the minimum and maximum canal cleanliness values and a large range at the lower levels, which decreased at the higher levels.

Table 6 shows variability in the differences between the minimum and maximum isthmus cleanliness values and range for the 6% and 3% NaOCl groups at all levels. The

3% NaOCl group showed consistently large differences between the minimum and maximum isthmus cleanliness values and a consistently large range at all the levels examined. All levels except one (1.8 mm) had a minimum value of 0.0% clean in the 3%

NaOCl group.

Table 8 shows variability in the differences between the minimum and maximum common canal cleanliness values and range for the 6% and 3% NaOCl groups at all levels. The median scores are generally higher in Group 2. In the 6% NaOCl group, all levels had a maximum value of 100% whereas Group 1 had 7 out of 11 levels with a

100% maximum cleanliness value.

Table 9 summarizes the mean percent single canal cleanliness and standard deviation by level (1-3 mm from the apex) and instrumentation method in severely

68 curved canals for Group 1 and the control group collected by Gutarts (30) that was instrumented with hand and rotary but received no ultrasonic irrigation. Both groups show a general decrease in standard deviation further from the apex. Group 1 produced cleaner canals than the no ultrasonic group 1.0 to 1.8 mm from the apex.

Table 10 shows the 3% NaOCl with ultrasonic group with a large difference between the minimum and maximum canal cleanliness values and a large range at the lower levels, which decreased at the higher levels. The group using hand and rotary without ultrasonic irrigation also showed large differences between minimum and maximum canal cleanliness values with a decreasing range at higher levels. Median values for the 3% NaOCl group were higher at all levels except at 2.8 mm where both groups had a median of 100%.

Table 11 summarizes the mean percent isthmus cleanliness and standard deviation by level (1-3 mm from the apex) and instrumentation method in severely curved canals for Group 1 and for the control group collected by Gutarts (30) that was instrumented with hand and rotary but no ultrasonic irrigation. Both groups showed minimal cleaning of isthmuses at all levels. The highest mean cleanliness value of 36.6% was recorded in the nonultrasonic group at the 2.8 mm level. No trends in standard deviation or cleanliness were noted in either group.

Table 12 shows variability in the differences between the minimum and maximum isthmus cleanliness values and range for Group 1 and Gutarts’ (30) control group at all levels. Ten out of eleven minimum values (91%) were recorded as 0% in both groups. In Group 1, two out of eleven levels (18%) had a maximum of 100%. In the

Gutarts (30) control group, one out of eleven levels (9%) had a maximum of 100%. The

69 highest median score of 23.6% was recorded in the nonultrasonic group at the 2.8 mm level.

Table 13 summarizes the needle penetration in percent of working length for all samples in Group 1. A comparison of mean canal and isthmus cleanliness values by level and method of instrumentation for Archer et al. (19), Gutarts (30), Haidet et al. (17), and this study are found in tables 14 and 15 respectively. The canal and isthmus cleanliness values for each experimental sample are listed in Appendix D (Raw Data).

CHAPTER 5

DISCUSSION

Selected portions of the following Discussion section have been adapted from previous Theses by Gutarts (30) and Burleson (32) from the Division of Endodontics at

The Ohio State University.

DISCUSSION OF MATERIALS AND METHODS

“An in vivo design was chosen for this study for several reasons. McComb and

Smith (57,127) attempted to correlate results from two studies which evaluated chemomechanical instrumentation. Their methods and materials were similar, except that one study was in vitro and the other in vivo. They concluded that the in vitro design allowed for a more aggressive approach, which increased debridement efficiency as compared to in vivo instrumentation. Walton (128) and Bolanos and Jensen (129) also reported on differences in instrument manipulation which would increase the effectiveness of in vitro instrumentation. Fairbourn et al. (130) stated that the positive apical pressure present in the mouth is difficult to simulate in vitro. They concluded that this difference in apical pressure might alter canal preparation in an in vivo situation.

Vande Visse and Brilliant (131) speculated that the presence of periapical tissue 71 influenced the amount of material extruded from the apex during instrumentation. It was the intentions of this study to have the parameters of the experimental treatment conform as much as possible to a clinical setting. Therefore, an in vivo design was chosen.

Only teeth with vital pulp tissue were included in this study. In an in vivo study,

Salzgeber and Brilliant (132) determined that the presence of vital tissue confined the irrigating solution to the space of instrumentation. In necrotic cases, the solution permeated the canal faster than in vital cases, and extruded into the periapical lesion in a random pattern. Abou-Rass and Oglesby (133) found that the condition of the tissue affected the effectiveness of the irrigant. They concluded that vital tissue was more easily dissolved by sodium hypochlorite than necrotic tissue. Necrotic teeth also contain variable amounts of tissue. Because we wanted to evaluate the effectiveness of ultrasonic irrigation to clean/debride canals, vital teeth were utilized since it would not be possible to determine if the absence of tissue (canal cleanliness) in necrotic teeth was due to the ultrasonic debridement or due to tissue degradation. Also, in order to maintain consistency, vital pulp tissue was needed so that it could be compared to the data collected by Gutarts et al. (20) who also studied only teeth with vital pulps.

Mandibular molars were chosen to serve as experimental teeth because they frequently require endodontic therapy (120). Mesial canals were chosen due to their complex root canal anatomy (5-13). Skidmore and Bjorndal (9) found 60% of mandibular molar roots with two canals had some form of transverse communication. This communication was most commonly observed in the apical third of the root. The authors noted that an operator attempting to remove the pulp tissue must be aware of these transverse connections. Pineda and Kuttler (5) examined 859 extracted mandibular

72 molars with a magnifying glass. They reported ramifications (offshoots) of the main canal in the mesial root in 48.3% of first molars, 27.8% of second molars, and 19.0 % of third molars. It was also observed that the majority of these ramifications were located in the apical third. Cambruzzi and Marshall (33) reported that, in the mesial root of 108 mandibular molars, an isthmus joined two canals 60% of the time. Two mesial canals existed without an isthmus in only 18% of the cases. Vertucci (11) established that 63% of first molars and 31% of second molars had transverse communications in the mesial root. In approximately 75% of first and second molars these communications were found in the middle third of the root. Yesilsoy et al. (13) examined freshly extracted, mandibular first and second molars after injecting vinyl polysiloxane impression material into the pulp chambers and carefully removing and measuring the impressions. The ruler, at zero, placed at the mid-floor area of the impression and viewed from the mesial, measured (to the nearest 0.5 mm) the depth of the mesial groove between the mesiolingual and mesiobuccal canals. The average recorded depth was 1.0 mm. Some of the impressions had depths measuring 3.5 mm. This was a significant space when considering the limitations of instrumentation techniques. The authors brought up the question of whether this area may remain undebrided after instrumentation thereby affecting the prognosis of treatment in both vital and nonvital teeth. They believed that modifications in access preparation and/or an increased emphasis on irrigation and intracanal medication might be needed. Hess (10) concluded that apical ramifications were often observed in the roots of upper molars and the mesial roots of lower first and second molars. He reported that in mesial roots of lower molars a fine connecting canal or fissure was found between the two main canals” (30). More recently Mannocci et al.

73 (35) investigated the presence of isthmuses in the mesial roots of mandibular molars using micro-computed tomography finding a prevalence of 17-50% in the apical 5 mm.

Gu et al. (36) also confirmed the high prevalence of isthmuses in mandibular molars using micro-computed tomography on a Chinese population showing their presence between 24 and 50% of the time.

“Studies on hand and rotary instrumentation of mandibular molar mesial roots have fallen short of the goal of 100% canal system cleanliness (38,39,42,43,56,129,134-

140). Gutierrez and Garcia (134) instrumented canals using reamers or a combination of files and reamers and a variety of irrigation solutions. They found that there was a high incidence of fins which were not touched by instrumentation. Davis, Brayton, and

Goldman (135) instrumented teeth using 2.5% sodium hypochlorite until the operator felt they were clean. The models revealed irregularities, which included fins, webbing, and accessory foramina. Instrument marks were noted on one wall with the opposite wall devoid of marks. Therefore, instrumentation was not complete on all walls of the canal.

Baker et al. (56) instrumented single rooted teeth with various irrigating solutions. They found one wall of the root canal consistently cleaner than the other. It was also discovered that debris was not removed from recesses and cul-de-sacs. Walton (138) histologically compared the cleaning ability of filing, reaming, and step-back techniques.

Step-back was found to be consistently superior to filing and reaming. No method was found to plane more than 85% of the canal walls. Moodnik et al. (139) used a scanning electron microscope to compare teeth instrumented with either K-files or Hedstrom files.

Saline or 2.5% sodium hypochlorite was used as an irrigant. All teeth were shown to have dentin irregularities containing tissue. No portion of the root canal was found to be

74 consistently cleaner than any other portion. They also found that many of the specimens had areas where the instruments never contacted canal walls. Yang et al. (140) used step- back hand-instrumentation with 2.5% NaOCl on the mesial root canals of 75 freshly extracted mandibular molars. The cleanliness of main canals and inaccessible areas

(isthmuses and fins) at the apical, middle, and coronal thirds was examined and scored.

Results showed no significant differences among different groups in either the 1-day or

7-day time intervals in either the main canal or inaccessible areas. Instrumentation combined with NaOCl irrigation alone accounted for the removal of tissue in the main canal. Prolonged contact with Ca(OH)2 and NaOCl was similarly ineffective; neither contributed significantly to canal debridement. Isthmuses and fins were poorly debrided in all groups” (30). Peters et al. (45-47) used micro-computed tomography to evaluate the geometric changes that occur in root canals during different instrumentation techniques and showed a high percentage of uninstrumented canal surfaces. In maxillary molars,

35% of canal surface area was entirely unchanged using NiTi K-Files, Lightspeed® instruments, Profile® .04 or GT® rotary instruments (45). Instrumentation using

ProTaper® instruments in extracted maxillary molars was found to alter more area in smaller, constricted canals while large canals were untouched 43-49% of the time. When using FlexMaster® rotary files in maxillary molars 42-61% of wide canal walls were untouched. Because of these high percentages of untouched canal surfaces, it was concluded that effective irrigation may be necessary to ensure complete debridement.

“Schafer and Zapke (38) investigated the cleaning effectiveness of automated and manual root canal instrumentation with the aid of a scanning electron microscope.

Complete cleanliness was not achieved by any of the techniques or devices investigated.

75 Hulsmann et al. (141) compared two different rotary nickel-titanium instruments: Hero

642® (Micro-Mega, Besancon, France) and Quantec SC® (Tycom, Irvine, CA, USA). For debris, Hero 642® achieved better results (80%) than Quantec SC® (76%). The results for smear layer removal were similar: cleaner root canal walls were found after preparation with Hero 642®, followed by Quantec SC®. Neither system was 100% effective.

Versumer et al. (39) compared two different rotary nickel-titanium instruments: ProFile®

.04 and Lightspeed® for canal debridement. Lightspeed® achieved the best debridement results compared to Profile® .04 but with no significant differences between the systems.

Tan and Messer (43) compared the quality of apical enlargement of mesiobuccal canals of mandibular molars using conventional stainless steel hand files (K-files) and nickel- titanium rotary instruments (LightSpeed®). None of the three techniques were totally effective in cleaning the apical canal space.

Therefore, the high percentage of fins, isthmuses, and accessory canals found in mesial roots of mandibular molars served as an excellent testing ground to see if ultrasonic irrigation would improve on the cleanliness of canals and isthmuses after hand and rotary instrumentation” (30).

The irrigating solution used in this study was 3.0% sodium hypochlorite. “In prior studies (17,104), 5.25% sodium hypochlorite was utilized based on the following research. Koskinen et al. (60) showed that 5.25% sodium hypochlorite had the very strong solvent capacity, as measured by mean weight change of the tissue samples.

Rosenfeld et al. (61) determined that 5.25% sodium hypochlorite was effective in exerting a nonspecific, surface acting solvent action on intact vital pulp tissue. The solvent action was limited by the size of the canal lumen, and was therefore more

76 effective in the middle and occlusal thirds. Abou-Rass and Oglesby (133) showed that the

5.25% concentration was more effective than the 2.5% concentration regardless of tissue condition or temperature. Harrison et al. (142) conducted a clinical study to determine the effect of various endodontic irrigants on interappointment pain. When comparing 5.25% sodium hypochlorite to physiologic saline, they found no difference in the incidence of interappointment pain. Also, Yguel-Henry et al. (143) showed that sodium hypochlorite increased the cutting efficiency of files (+200% for the K-file and +30% for the H-file) due to its lubricating properties” (30). Gutarts et al. (20) used a 6.0% sodium hypochlorite solution because the manufacturer altered the standard formulation of commercially available bleach and 5.25% was no longer available. The authors felt that the small change in concentration would have no appreciable effect and, because it was the only concentration commercially available, was more applicable in a clinical setting.

Although research has shown 6.0% NaOCl to be a safe concentration to use for ultrasonic irrigation techniques (26), full strength 6.0% sodium has been questioned as potentially cytotoxic to tissues, corrosive to instruments, and strong-smelling. This has led to the suggestion of reducing its concentration and thus the risk to the patient (25,28). No study to date has investigated the impact of reducing the concentration of NaOCl on canal and isthmus cleanliness when utilized with ultrasonic irrigation.

“A 25-gauge, 5/8 inch, Luer-Lok hypodermic needle was chosen for non- ultrasonic irrigation due to several considerations. Authors such as Abou-Rass and

Piccinino (144), and Chow (145) felt as though irrigation effectiveness was a function of the depth of placement of the irrigating needle. Therefore, they recommend the use of a

27- or 30- gauge needle. However, Archer et al. (19) found that when a 30-gauge needle

77 was used with 5.25% sodium hypochlorite, the lumen clogged immediately. When a 27- gauge needle was tried with the same solution, it clogged after only a few minutes of use.

A 25-gauge needle was able to express the solution freely during the entire period of instrumentation. The choice of a 25-gauge needle conforms to the recommendation of

Harrison (146), who recommended the use of a 25- to 27-gauge needle. The 5/8-inch length was chosen due to its ability to be easily manipulated in the canals. This length was also chosen because it is more clinically applicable than using the same 25-gauge,

1.5 inch needle for both the ultrasonic and non-ultrasonic groups. The needles were bent at the junction of the hub and needle approximately 45 degrees. This bend allowed the needle to be easily placed in the canal to a point just short of binding. Usually this point was approximately 15 to 17 mm from the coronal aspect of the access opening, and corresponded to the middle third of the canal. The 5/8-inch needle could always be inserted to this point in the canal. Therefore, a longer needle was not required.

During instrumentation, 2 mL of irrigating solution was deposited in each canal after the use of every third hand and rotary file, and after the #5 Gates-Glidden bur had been used in the root canal. This amount was also used in previous studies (15-17,19), and it followed the recommendation of Harrison (146) who recommended 2 to 5 mL of

5.25% sodium hypochlorite after every instrument. This recommendation was based on air bubbles being trapped in the canal system which prevent contact of the irrigant with soft tissue attached to the canal. The mechanical movement of instruments disrupts the air bubbles and allows the irrigant to move throughout the system. The reason we irrigated after every third hand and rotary file, and after the #5 Gates-Glidden bur, instead of irrigating after every instrument was because this was more clinically applicable. This

78 type of protocol would still allow the disruption of any air bubbles and have ample sodium hypochlorite in the canal system to help remove pulpal and dentinal debris.

In this study, after the access opening was made and the canals were located, a combination hand and rotary file instrumentation technique was used. Initially, smaller size #10-20 K-files were used to enlarge the canals to a size #20 K-file. This was done in order to remove the bulk of pulp tissue, determine the working length, and prevent any potential canal blockage that might have occurred if a larger sized #30-rotary file was used initially. These smaller files also gave the operator the ability to explore the canal anatomy by using tactile sense which would have been harder to do using rotary instrumentation alone.

Using the preoperative radiograph, a preliminary working length was determined by making an approximate measurement 0.5mm short of the radiographic apex. The Root

ZX Apex Locator (J. Morita, Irvine, CA) was used with a #10 K-file to determine the actual working length for each root instrumented in the study. The unit was set for 0.5 mm from the apex. After electronic apex location, a radiograph was exposed with a slight mesial angulation (approximately 15° from perpendicular) to determine the position of each #15 K-file, and to confirm the working length determined by the Root ZX Apex

Locator. This radiograph also helped determine canal configuration. The use of the working length of 0.5 mm short of the apex was used due to the work of Kuttler (7). He showed that the greatest canal constriction is located in dentin, 0.507-0.784 mm coronal to the apical cementum. Green (8) reported this canal constriction to be an average of

0.75 mm from the apical opening. He went on to state that the apical opening could be at the true apex of the tooth, or any location up to 2 mm eccentric to this position.

79 The Root ZX Apex Locator was chosen to find the working length because it has been shown to be accurate at finding the working length of a canal (147-153) when a potential error of +/- 0.5 mm from the foramen was used. The Root ZX has been reported to locate the foramen with a clinical accuracy rate of 96.2%, as reported by Shabahang et al. (147); 100%, as found by Pagavino et al. (150); and 83%, as reported by Meares et al.

(153). El Ayouti et al. (152) showed that radiographic working length determination resulted in overestimation of length in 51% of root canals tested, although the measuring file tip was assessed to be 0 to 2 mm short of the radiographic apex. Electronic working length measurements with the Root ZX were shown to be more accurate than radiographic film since it overestimated the working length in only 21% of the canals tested. Additional studies using other apex locators have shown that working lengths determined by electric apex locators were significantly more accurate than working lengths determined by radiographs (154,155). Brunton et al. (154) showed that using the

Analytic A.F.A. electronic apex locator was extremely accurate in locating the apical foramen when 25 (100%) teeth tested within 0.5 mm of the anatomical apex and 11

(44%) teeth at the apical foramen. In contrast, 15 (60%) teeth tested using radiographs alone were within 0.5 mm of the anatomical apex and only 4 (16%) teeth were actually at the anatomical apex. Pratten et al. (155) determined the working length of root canals in human cadaver teeth by positioning an endodontic file at the apical termination point as indicated by the Endex Apex Locator. These same teeth were radiographed at various angles with the file in place. The radiographs were evaluated by five examiners to determine a radiographic termination point for each canal. Teeth were extracted and examined histologically to determine the ideal termination point. The deviations of the

80 two experimental termination points from the ideal termination point were compared. The mean of the absolute value of the deviations from the apical constriction for the apex locator was significantly less (p < 0.05) than that for the radiographic method. Thus, the method using the apex locator was considered more reliable. Consequently, the Root ZX

Apex Locator was used in this study to determine working length along with a radiograph.

After hand instrumentation and working length determination, a #5 Gates-Glidden bur was used to open the coronal aspect of the canal so that rotary files could descend deeper into the canal more easily. By using this instrument, there was less coronal binding and better direct access to the apical third of the canal. Therefore there was less chance for instrument breakage and the rotary files could more easily work at the apex.

Also, a reservoir was formed for the sodium hypochlorite and lubricating solutions.

Toward the end of instrumentation the ProFile® GT® (70/.12), (50/.12), (35/.12) orifice shaper rotary files were used to further enlarge the coronal aspect of the canal, so that the

25-gauge ultrasonic needle could penetrate the canal as deep as possible, and move freely without binding.

Nickel-titanium rotary files, used in a crown down method, were chosen as the primary method of instrumentation because they have been shown to be an effective method of removing soft tissue from the root canal (38,39,42,43,141), while also maintaining the curvature of the canal, and producing uniform and round preparations”

(30). Lozides et al. (40) compared root canal transportation of the crown-down technique performed with the nickel-titanium rotary ProFile® system and with step-back technique using stainless steel K-Flexofiles concluding that the crown-down rotary technique

81 resulted in less transportation and created more standardized preparations. Schafer et al.

(41) compared the effect of hand instruments and rotary NiTi Flex-master files on the extent of straightening of curved root canals. They found that the rotary system created significantly less straightening in a shorter preparation time compared with hand instrumentation. “Tan and Messer (43) compared the quality of apical enlargement of mesiobuccal canals of mandibular molars using conventional stainless steel hand files (K- files) and nickel-titanium (Ni-Ti) rotary instruments. The mesiobuccal canals were instrumented with K-file using step-back technique without coronal flaring (control; group 1), K-files using step-back technique after coronal flaring (group 2), and

LightSpeed Ni-Ti rotary instrumentation (group 3). The Ni-Ti rotary instrumentation allowed for greater apical enlargement with significantly cleaner canals, less apical transportation, and better canal shape than both hand instrumentation groups at both levels (p<0.05). None of the three techniques were totally effective in cleaning the apical canal space. It was concluded that greater apical enlargement using LightSpeed rotary instruments is beneficial as an attempt to further debride the apical third region in mesiobuccal canals of mandibular molars. Instrument designs, alloy properties, and canal curvature were cited as important factors that determine the feasibility of greater apical enlargement in narrow canals.

The ProFile® GT® rotary file system (Tulsa Dentsply Dental, Tulsa, OK) was chosen to do the bulk of the canal preparation because it is a widely used brand throughout the United States. These nickel titanium rotary files have little risk of apical transporting, ledging or perforating the tooth (156). Variable pitched flutes provide reamer-like efficiency at the shank and K-File strength at the tip, virtually eliminating the

82 chance of accidental breakage. The ProFile® GT® Rotary instruments' predefined taper lets the operator create a continuous tapering preparation with just a few instruments

(156). A crown-down method of instrumentation was used with the ProFile® GT® rotary files. This method of instrumentation afforded larger tapered rotary files to open and flare the canals coronally and let each subsequently smaller tapered rotary file to descend apically into the canal in order to debride and shape the apical aspect. Schafer and Zapke

(38) showed that the rotary ProFile® instruments (crown-down technique) had the best debridement results, especially in curved canals, when compared to hand instrumentation performed with K-Flexofiles used in a reaming motion and the step-back technique,

Hedstrom files used in a filing motion, and mechanical rotary preparation using K-

Flexofiles. Vansan et al. (157) showed how important crown-down instrumentation was for decreasing the apical extrusion of debris. They instrumented 40 newly extracted human upper central incisors 1 mm from the apex using four different techniques: standard, step-back, crown-down, and ultrasound, with distilled and deionized water as the irrigating solution. Extrusion was calculated by the determination of the mass of extruded material. Even though all techniques used caused extrusion of material beyond the apical foramen, the step-back technique caused a larger amount of extrusion than the standard technique, which in turn caused greater extrusion than the crown-down and ultrasound techniques. These results agreed with those reported by Ruiz-Hubard et al.

(158) who demonstrated a better performance of the crown-down technique compared to the step-back technique. Iqbal et al. (159) reported that rotary ProFile® instrumentation or

ProFile® GT® preinstrumentation has no effect on canal transportation and loss of working length whether they are used in a crown-down or step-back instrumentation

83 method” (30).

In this study ultrasonic irrigation was added after completion of hand and rotary instrumentation to enhance debridement efficiency. All studies (14-

19,38,39,42,43,109,141) which have used ultrasonic irrigation after hand instrumentation have shown that at least one of the evaluated areas of the root canal has been cleaner as compared to hand instrumentation alone. Ahmad et al. (92-94) and Walmsley (95) postulated that ultrasonic instrumentation was more effective in canal debridement after hand instrumentation as compared to ultrasonic instrumentation alone, because the vibrating ultrasonic tip is better able to freely translate without dampening. Ultrasonic file constriction dampening is thought to cause a loss of energy when the file contacts the root canal wall. Hand and rotary preparation also allowed for a greater volume of irrigating solution to be circulated in the root canal space, thereby increasing debridement efficiency (53,56,146). Krell et al. (160) examined irrigation patterns during ultrasonic canal instrumentation in clear resin blocks. A Cavi-Endo unit was utilized with

Endosonic files. Using a food color dye, they found that the irrigant could not reach the most apical extent of the preparation until the ultrasonic file could vibrate freely within the canal.

The safe, in vivo use of ultrasound was addressed by Jahde et al. (161) in a study which compared short-term periapical responses to hand and ultrasonic file overextension during root canal instrumentation in monkeys. Using either 2.6% sodium hypochlorite or saline as an irrigating solution, #25 files were used one millimeter past the radiographic apex. A Cavi-Endo unit was used in the ultrasonic part of the study. At 48 hours post instrumentation, there was no significant difference in inflammatory reaction among any

84 of the groups. All inflammatory reactions were found to be of low to moderate intensity”

(30). Pafford et al. (26) studied the occurrence of intraoperative and postoperative pain in vital and necrotic teeth with the addition of ultrasonic irrigation following hand/rotary instrumentation in molars and premolars. In that study 13 patients with a pulpal diagnosis of irreversible pulpitis and 10 patients with a pulpal diagnosis of necrotic were treated with 1 minute of continuous ultrasonic irrigation using 6.0% NaOCl. None reported intraoperative pain and statistical analysis showed that, when compared to a group receiving mock ultrasonic irrigation, no statistical difference in postoperative pain or use of analgesics was found. No study using an irrigation flow rate of 15 mL/min utilizing this setup have reported the occurrence of pain during the ultrasonic irrigation phase which could be associated with the accidental extrusion of NaOCl into the periapical tissues (20,21,26,31,112).

“The MiniEndo™ ultrasonic endodontic system was used in this study. The

MiniEndo™ system was chosen as an ultrasonic source due to several factors. Since this device is a piezoelectric unit, it generates minimal heat and does not require an external water coolant supply. The ultrasonic energy is developed when a high frequency alternating current is applied to a piezoelectric material, such as barium titanate or lead zirconate titanate. Corresponding lengthening and shortening of the material then occurs over a minute distance, which produces ultrasonic vibrations which are transferred to the tip of the instrument (162). The MiniEndo™ operates by the action of cavitation following the propogation of ultrasounds in a frequency spectrum between 25 and 32 kHz and amplitudes ranging from 5 to 250 !m at more than 20,000 cycles per second. A computer chip is found in the base of the MiniEndo™ which reads the ultrasonic amplitude at the

85 tip. It checks this amplitude 7 times a second. The computer chip regulates the amplitude at the tip to a constant rate by boosting power to the handpiece, even when resistance is encountered. This feedback mechanism and the constant tip amplitude separate the

MiniEndo™ from other Piezo units (163). (30)” “The MiniEndo™ system is also reported to be more efficient than the Cavi-Endo™ system because the electromechanical conversion efficiency of magnetostrictive units is only about 50%, compared to 70-80% for piezoelectric units. (32)”

A 25-gauge, 1.5 inch needle was chosen for use in the ultrasonic irrigation phase because it was our intention to replicate the technique use by Gutarts et al. (20). In that study it was noted a 25-gauge needle produced superior cavitation and acoustic streaming when compared to 27- and 30-gauge needles. In addition, a 25-gauge needle was shown to be strong enough not to break after one continuous minute of activation with the

MiniEndo Unit set to maximum power. The 1.5-inch length was chosen because it permitted clearance for suctioning and provided an unobstructed view to see inside the access chamber during ultrasonic instrumentation. Unlike an ultrasonic file, a needle can deliver and replenish sodium hypochlorite directly into the canal during activation. No other study before Gutarts et al. (20) had ever done this.

Gutarts et al. (20) also established that activating the 25-gauge needle for one minute per canal was sufficient time to produce superior cleanliness values when compared to studies that had used an ultrasonic file for 3 minutes per canal (15,16).

Because Gutarts et al. (20) showed favorable results using ultrasonic irrigation for only one minute, we wanted to examine the effects of reducing the irrigant concentration under similar conditions, which may potentially be safer.

86 Continuous irrigation (15 mL) was used to deliver 3.0% sodium at a rate of 15 mL/min through IV tubing connected directly to the ultrasonic needle. This type of system was chosen because it easily delivered the solution at a continuous and steady rate without any interruption during intra-canal irrigation. In this study we used a mechanical pump (AL-1000, World Precision Instruments, Sarasota, FL) to precisely deliver the irrigant at a rate of 15 mL/min. Previous studies (20,21,26,112) have shown the effectiveness of the AL-1000 in safely and effectively delivering sodium hypochlorite at this constant rate. “Gutarts et al. (20) did note that mild-to-moderate pain was experienced when a rate of 20 mL/min was used after teeth had been debrided with hand and rotary instrumentation” (32). This device was also chosen because it allowed the operator to deliver irrigant without having to physically depress a syringe plunger during the ultrasonic portion of the procedure.

Investigations have addressed the question of whether or not sodium hypochlorite as an irrigating solution affects the ability of ultrasound to remove debris. After examining the debridement of small straight canals, Cameron (164) felt that ultrasound with sodium hypochlorite was superior to ultrasound with an EDTA/urea peroxide solution. In a study involving extracted teeth, Ahmad et al. (92) found that, regardless of whether hand or ultrasonic instrumentation was used, sodium hypochlorite irrigation resulted in less debris than water irrigation. Griffiths and Stock (165) compared the ability of sodium hypochlorite, water, and Solvidont (a bis-dequalinium acatate based irrigant) to remove debris when used with ultrasound in extracted teeth. Sodium hypochlorite was found to be superior in debris removal as compared to the other irrigating solutions. Van der Sluis (166) compared dentin debris removal in grooves

87 created in the apical portions of extracted canines when ultrasonic irrigation was used after hand and rotary instrumentation. The effectiveness of 2% NaOCl, 6% NaOCl and water using continuous and syringe delivery during passive ultrasonic irrigation was compared. This study concluded that both concentrations of NaOCl were significantly more effective than water in removing dentin debris regardless of delivery type. In addition, water was not effective in removing debris from the artificial grooves.

The decision to use ultrasound for one minute in each canal was based on the desire to confirm the findings of Gutarts et al. (20) that one minute per canal was a sufficient time to effectively clean canals and isthmuses. “Lev et al. (16) showed increased efficacy in isthmus cleaning at the 1 and 3 mm apical levels when ultrasound was used at high power (Cavi-Endo) for three minutes as opposed to one minute. In that study they utilized a #20 ultrasonic file” (30). Gutarts et al. (20), showed that a three- minute time period was not needed if the ultrasonic instrument (in this study - a needle) could be used at the even higher energy, produced by the MiniEndo™ unit. Because of this, the more clinically applicable time period of one-minute was used. No studies prior to Gutarts et al. (20) had used ultrasonic irrigation after hand and/or rotary instrumentation for only a one minute time period per canal.

Root curvature was also considered to be an important factor in this study since it may have an effect on potential canal cleanliness. Gutarts et al. (20) found that the addition of ultrasonic irrigation after hand and rotary instrumentation lead to cleaner canals and isthmuses in severely curved canals compared to hand and rotary instrumentation however the difference was not significant. The authors felt that a small sample size was responsible for this lack of a statistically significant difference. “In a

88 study evaluating the efficacy of root canal preparations, Bolanos and Jensen (129) found that with greater root curvature, round preparations were more difficult to achieve.

Walton (138) found that fewer canal walls were planed in canal preparation when the root curvature increased. Using radiographs exposed from a buccal direction, the Schneider method (125) was used to determine root curvature. Previous studies have also used

Schneider’s method to determine root curvature (15-17,19). In this study, canals with a curvature of 25 degrees or less were designated as curved, and canals with a curvature of

26 degrees or greater were designated as severely curved. These degrees of curvature were chosen in order to have curvature groups of similar difficulty and utilize a classification system used in other studies. However, all teeth collected in this study were classified as severely curved. These classifications closely resembled Schneider’s classifications of moderately curved (less than 25 degrees), and severely curved (25 to 70 degrees) canals (125).

Root configurations were also evaluated in this study. These configurations were described by Weine (3). Canal type was initially determined when the working length radiograph was exposed from a mesial angulation. In mesial roots with a Type I canal configuration, only 1 canal was present. Type II canal configuration existed when two separate canals joined to form a common canal at the apex of the root. In teeth with a

Type II canal configuration, filing was alternated between buccal and lingual canals to avoid blockage of the canals where they joined. Type III canals remained separate throughout the length of the canal. Although our study did not contain any roots with

Type IV or C-shaped canals, these canals may result in decreased cleanliness compared to other canal types. A type IV canal system splits into two separate canals apically, and

89 can be difficult to instrument both canals (3). One canal may go uninstrumented because the operator is unaware of the apical canal bifurcation or is unable to gain access to the canal due to its severe divergence from the main canal. A C-shaped canal can also be difficult to instrument since the ribbon shaped canal may run the whole length of the root like a curtain and exit at or near the root apex as a single foramen or it may divide within the depth of the canal into two or more canals which exit separately (126).

In order to prevent contamination of the root canals during extraction, a sterile cotton pellet was sealed in the tooth with Cavit™ prior to extraction. Immediately after extraction, the temporary fillings were removed and each mesial canal was irrigated with

1 mL of 10% formalin. A vertical groove was placed in the buccal surface of the mesial root of each tooth in order that the orientation of the canals could be identified during microscopic evaluation. Teeth were stored in plastic 40 mL vials containing 20 mL of

10% formalin in order to keep any remaining tissue fixed until histological processing could be accomplished. Tooth fixation, decalcification, and histological processing were done in the same manner as described by Archer et al. (19) and Gutarts et al. (20).

Teeth were kept in the 40 mL vials and decalcified in 37 mL 80% formic acid and

20% sodium citrate for a period of 14 days. The decalcifying solution was replaced with fresh solution every 48 hours in order to keep the pH low and acidic, since the pH of an acid solution goes up or becomes more alkaline as the tooth decalcifies. After 10 days the distal root and crown were removed with a razor blade to facilitate decalcification of the mesial root.

After decalcification, the mesial roots were dehydrated in a series of ethanol baths to remove all decalcifying solution. The specimens were then cleared in methyl

90 salicylate. In a study by Skinner (121), tissue shrinkage was found to be reduced when methyl salicylate was used as a clearing agent instead of xylene. Following the clearing procedure, specimens were infiltrated and embedded in Paraplast ®. Roots were oriented in the embedding boat so that a perpendicular cross section could be obtained from both mesial canals at the same apical level. After the mesial root apices were placed on the inside wall of the embedding boat, the root was oriented so that the apical third was perpendicular to that wall. This was done in order to have proper positioning and orientation in the microtome so that the apical portion of the root would be cut first.

Five micron cross sections were cut from the apical three millimeters of the embedded mesial root. The sample thickness utilized was similar to those of Archer et al. and Gutarts et al. (19,20). Two of these were sectioned at a five micron thickness and two at a seven micron thickness. Archer et al. (19) found that the seven micron sections exhibited more pulp tissue loss than the five micron sections. They felt that this increase in tissue loss might have been caused by the microtome during the cutting procedure. It was also found that the seven micron sections did not adhere as well to the glass slides as the five micron sections.

One slide, with four sections per slide, was obtained from every 0.1 mm level in the apical 3 mm of each sample. Starting at the 1 mm level, every slide was stained using

Gomori's one-step trichrome method (132). The Gomori's one-step trichrome method was also used by Haidet et al. (17), Archer et al. (19), and Gutarts (30). Gutarts (30) compared this method to staining with hematoxylin and eosin as used by Goodman et al. (15). The

Gomori one-step trichrome method was found to be superior than hematoxylin and eosin stain because it was able to differentiate the cross-sectional tissues into many colors. All

91 other slides were kept unstained and they acted as reserves to be used in the future for a serial reconstruction of the apical three millimeters of each root specimen. Approximately

1080 slides were processed.

One section from each stained slide (eleven per specimen) was chosen for evaluation. The evaluated section was the one which had the fewest technical errors

(poorly cut, torn, or folded cross-sections). The identity of the experimental group to which the specimen belonged was not known during the evaluation process. During this study, a total of 393 stained sections were evaluated. A representative sample section from every 0.2 mm from the apex was evaluated for each specimen. Past studies have used sections only from the 1, 3, and 5 mm levels (136,137), or the 1 and 3 mm levels

(15-18,167). By evaluating only two levels in the apical three millimeters, it is possible to misinterpret the true degree of canal cleanliness (15,16). With more levels being evaluated in this study, a more accurate representation of the apical three millimeters was possible.

The selected sections were evaluated using a Neurolucida Image Analysis

Program version 7.0. This system saved time and eliminated the inherent error of making tracings required for analysis with the polar planimeter as used by Goodman et al. (15),

Lev et al. (16), and Haidet et al. (17). Several parts of the analysis process required interpretation. The area of the canal required tracing with the computer mouse and areas of pulp tissue had to be identified by the evaluator. The differentiation of canals and isthmuses also had to be established using the optical mouse. In this study only a single investigator identified the outlines of canals and isthmuses, and identified remaining tissue. In order to control for inherent error and bias future studies may utilize two or

92 more investigators for the evaluation process. In this study, evaluator bias was controlled by labeling the samples with six digit numbers and not study groups, making it hard for the evaluator to decipher or memorize what group the sample was from. Inherent error and reliability of the single evaluator was controlled by determining the intra-class correlation coefficient. The intra-class correlation coefficient was 0.926 (95% confidence interval 0.844; 0.966), indicating excellent reliability of the evaluator.

Ten and 20x power lenses were chosen for the microscope because they provided the largest image which would fit on the computer monitor without cutting off any of the canal space. The 10x lens was used mostly at levels 3-2.2 mm, and the 20x lens was used mostly at levels 2-1 mm. Since the mesiobuccal canal, mesiolingual canal, and isthmuses were evaluated separately, they did not all have to fit on the screen at the same time. The slide could be moved on the microscope stage to center each one individually for analysis. The small cursor size made it easy to make tracings.

Any types of offshoots from the main canal, such as cul-de-sacs or isthmuses, were grouped under the category of isthmuses for the purpose of evaluation. These ramifications off the main canal are usually inaccessible to instrumentation with files as are isthmuses (14-19,38,39,42,43,109,141). We therefore felt they should also be evaluated for cleanliness.

Only three histologic control teeth were processed in this investigation. This small sample number was used because they served only to monitor the amount of tissue present in the canals and isthmuses after histologic processing. They were assumed to contain 100% tissue since they were untreated. These teeth served as negative controls.

Three specimens had to be thrown out of the study. One control specimen was

93 dropped from the study because the slides produced from its root were not technically usable and thus unable to be interpreted. The other two teeth were unable to be instrumented to the desired working length. A total of 15 specimens were used in the experimental group and, and 2 specimens in histologic control group.

The Randomization test was used to statistically analyze mean cleanliness values for both canals and isthmuses (Tables 3,5,8). This test was utilized to evaluate the cleanliness because of skewed distributions (mean cleanliness values), so parametric testing was not possible. Because the mean cleanliness values for canals and isthmuses were related to each other and not independent, the raw P values were adjusted by the

Bonferroni method of Holm to prevent type I error inflation.

DISCUSSION OF RESULTS

Sample distributions for both groups, in terms of canal curvature, canal anatomy, and tooth type are found in Table 1. A total of 15 mandibular molars were used in the 3%

NaOCl group (Group 1), and compared to 16 mandibular molars in the 6% NaOCl group

(Group 2) which came from Gutarts’ study (30). Originally, the second group was also going to be newly collected samples that were irrigated with 6% NaOCl. Both groups would have been irrigated using a newly developed ultrasonic irrigating needle.

However, after the first twenty samples were collected using 3% and 6% NaOCl with this new tip and evaluated, it was found that the teeth were not being adequately cleaned. It was obvious that the ultrasonic energy and cleaning was not equivalent to previous studies (20) when using the new device. The mean cleanliness values for samples prepared using the new irrigating needle are included in the Raw Data (Appendix D). The

94 manufacturer developed the new irrigating tip to be used with the Satelec P5 piezoelectric unit (Dentsply Tulsa, Tulsa, OK) as a source of ultrasonic energy. However we operated the needle in conjunction with a MiniEndo™ piezoelectric unit. After collaboration with the manufacturer regarding our results, the different ultrasonic source was attributed to the lack of effective cleaning we had encountered. Because the manufacturer intended to market this device for use with all piezoelectric ultrasonic units (allowing for more broad-use of the product) they continued to make refinements in its design. The main change they made was in the material that houses the hub and needle assembly. The needle we tested utilized an injection molded polymer, Vectra®, while they used a more rigid polycarbonate material that transmits ultrasonic waves more effectively to the needle. While in vitro demonstrations of the device were promising, gathering two adequately sized groups would not have been possible within the time constraints of this research. It was then decided to use the exact equipment and irrigating needle used by

Gutarts et al. (20). A different irrigant concentration would be used (3% NaOCl) and our results would be compared to those found using ultrasonic irrigation with 6% NaOCl by

Gutarts et al. (20).

In order to have the most statistical power and statistical efficiency between two or more experimental groups, it was important to have an equal and somewhat large sample size for each experimental group. A large sample size may better represent information about each group, while a small sample size may give skewed and/or nonrepresentative information about the same group. It was also important to have similar population sizes (such as-tooth type, canal type, canal curvature type, and patient age) in each experimental group in order to avoid the potential effects of the confounding

95 variables. Confounding variables may influence the results of an experiment even though they are unrelated to the experimental variable (in this study irrigant concentration). In an ideal situation, it would be best to stratify each experimental group with equal populations. However, since this would be extremely difficult to do in a clinical, in vivo experiment, it was important to be aware of potentially modified results due to confounding variables. Therefore, in order to obtain an accurate evaluation of the experiment it was important to have sample and population sizes in the experimental groups be as equal as possible. As shown in Tables 1 and 2, significant differences were not shown between groups with regard to tooth type, gender, or age.

In this study canal curvature was divided into two groups - straight (0-25 degrees) and severely curved (greater than 25 degrees). Schneider's method (125) was used to determine canal curvature. Ninety-three percent (14 out of 15) of the mesial roots in

Group 1 and 56% (9 out of 16) of Group 2 canals were considered severely curved. This difference was found to be statistically significant (p = 0.0373). The average canal curvature of Group 1 was 37.6 degrees and in Group 2 it was 33.3 degrees. Gutarts et al.

(20) had 44% of the mesial roots in the hand/rotary/no ultrasound group, and 56% of mesial roots in the hand/rotary/ultrasound group with severe curvatures. “Haidet et al.

(17) had 47% of the mesial roots in the no ultrasound group and 48% in the ultrasound group categorized as severely (26-52º) curved. Archer et al. (19) had 47% of the mesial roots in the no ultrasound group and 71% in the ultrasound group categorized as 26-52º curved. Canal curvature has been reported to negatively affect canal cleanliness

(43,139,141). During hand and rotary instrumentation, all canal walls may not be instrumented because the curvature of the canal may cause the file to contact some

96 portions of the canal’s walls more than others (43,139,141,168). Nickel-titanium files have the property of remaining straight and will tend to touch the outer wall of a curve and not touch the wall nearest to the curve (inner wall of the curved canal). Furthermore, the cavitation effect caused by an ultrasonic instrument may be hindered by having to go around a curve, or the curvature may dampen the power of an ultrasonic file when the file’s motion is impeded by a curve or a tight canal as described by Ahmad et al. (94)”

(30). Because significant differences were found in this study between Groups 1 and 2 in terms of canal curvature, only those teeth graded as having a severe curvature (greater than 25 degrees) were compared. This led to comparisons being made from 14 of the 15 teeth in Group 1 and 9 of 16 teeth from Group 2.

“This study’s inclusion parameters allowed for mesial roots with canal types I, II,

III, IV, and C-shaped as described by Weine (3). Canal type distribution per Group is found in Table 1. Table 1 shows an equal distribution of canal types between the two study groups. Haidet et al. (17) had 13% Type I, 27% Type II, 53% Type III, and 7% C- shaped in the no ultrasound group, and 9% Type I, 22% Type II, 65% Type III, and 4%

Type IV in the ultrasound group. Archer et al. (19) had 24% Type I, 47% Type II, and

29% Type III, in the no ultrasound group, and 12% Type I, 41% Type II, 41% Type III, and 6% C-shaped in the ultrasound group” (30). “Gutarts et al. (20) had 19% Type II and

81% Type III in the no ultrasound group, and 27% Type II and 73% Type III in the ultrasound group” (32). “Canal anatomy may have an impact on the ability to clean a canal with hand/rotary with or without ultrasonics. Roots with a Type II canal system may result in cleaner apical results than the other canal types since the apical area is actually instrumented twice due to the apical connection of the two canals. Although our

97 study did not contain any roots with Type IV or C-shaped canals, these canals may result in decreased cleanliness compared to other canal types. A Type IV canal system splits into two separate canals apically, and can be difficult to instrument both canals (126).

One canal may go uninstrumented because the operator is unaware of the apical canal bifurcation or is unable to gain access to the canal due to its severe divergence from the main canal. A C-shaped canal can also be difficult to instrument since the ribbon shaped canal may run the whole length of the root like a curtain and exit at or near the root apex as a single foramen or it may divide within the depth of the canal into two or more canals which exit separately (126). Furthermore, it usually contains many isthmuses and crevices (126). Therefore, hand and/or rotary files are unable to reach all aspects of the canal and debris and bacteria may be left within the canal system. Since we did not have any Type IV or C-shaped canals in our study, further studies are needed using the ultrasonic instrument used in the current study on these types of complex canal systems.

This may be difficult to do since these canal types are difficult to find in any appreciable number. Pineda and Kuttler (5) reported a 7.6% occurrence of the Type IV mesial root configuration in a study of 300 mandibular second molars, and Vertucci et al. (11) reported a 9.0% occurrence of Type IV mesial root configuration in a study of 100 mandibular second molars. Sidow et al. (169) reported a 2.2% occurrence of C-shaped root configuration in a study of 150 mandibular third molars, while Weine (170) reported a 7.6% occurrence of C-shaped root configuration in a study of 811 mandibular second molars” (30). If we wanted to study the effects of ultrasonic irrigation on C-shaped root canal systems, we would likely target an Asian population. A higher incidence of C- shaped canals has been reported in mandibular first premolars and second molars of

98 Asian and Far East populations including Japanese, Chinese, Hong Kong Chinese,

Lebanese, and Thai (171). In a Chinese population, Yang et al. (172) reported a 31.5% incidence of C-shaped roots in 581 mandibular second molars.

“Distribution of tooth types in each group is found in Table 1. Tooth type may be an important factor in an in vivo study like this one since access to the canals may impact the ability of the provider to properly instrument the canals. In fact, each molar type (1st,

2nd, and 3rd) may negatively impact canal cleaning in its own way. First mandibular molar mesial canals are generally curved, and have the most branches and ramifications from the main canals than second or third molars (5,126). Second mandibular molar mesial canals tend to always demonstrate curvature in both buccal-lingual and mesial-distal views. Third mandibular molars have the most unpredictable anatomy, poor access for instrumentation, and severely curved roots (126)” (32). This study contained 27% 1st molars, 66% 2nd molars, and 7% 3rd molars in Group 1, and 38% 1st molars, 56% 2nd molars, and 6% 3rd molars in Group 2 which was collected by Gutarts et al. (20). No significant differences were found between groups 1 and 2 with regard to tooth type.

“Haidet et al. (17) collected 13% 1st molars, 47% 2nd molars, and 40% 3rd molars in their no ultrasound group, and 35% 1st molars, 43% 2nd molars, and 22% 3rd molars in the ultrasound group. Archer et al. (19) had 24% 1st molars, 31% 2nd molars, and 45% 3rd molars in the no ultrasound group, and 30% 1st molars, 35% 2nd molars, and 35% 3rd molars in the ultrasound group. Both studies utilized a higher percentage of third molars than this study. This higher percentage of third molars may have decreased their canal cleanliness results due to a potential decrease in accessibility for instrumentation. Also, since 3rd molars have the greatest chance of unpredictable anatomy when compared to

99 other teeth in the mouth (126), one may find more isthmuses and curves which may have a negative impact on canal cleanliness” (32). No significant difference (p > 0.05) in canal or isthmus cleanliness between groups was shown at any level when p values were

Bonferroni adjusted (Tables 3,5,7). Mean cleanliness values approaching significant differences were found in isthmuses at the 2.2, 2.4, 2.6, and 2.8 mm levels. It is likely that no significant differences were shown due to the small sample sizes and high standard deviations at many levels in both groups. Small sample sizes were especially evident in isthmuses and common canals where comparisons were made between groups that only included between 1 and 7 samples. With such small groups, statistically significant differences were not seen when even large differences in mean cleanliness values existed between samples. For example, no significant difference was found between the groups in isthmuses at the 2.2 mm level even when there was an 87.6% difference in the means (6.4% versus 92.9%).

Raw p values showed significant differences (p < 0.05) in isthmuses at levels 1.2 through 3 mm. These raw, unadjusted values were obtained by making the statistical assumption that the mean cleanliness values are all independent of one another. However, this is not true because multiple values were taken from the same teeth. If one level was clean then it is likely the levels around it would also be clean. For example, if a tooth is easier to clean because it has single, straight canals then each level throughout the canal is affected by this condition. The mean cleanliness values would likely be high at most levels because all levels were relatively easy to clean. Bonferroni adjustment allowed the samples to be compared without making this assumption. In addition, the sample sizes were small and the data was therefore not a good representation of the overall population.

100 Because of this, variations in the groups, rather than irrigant concentration could statistically account for the observed differences in the means. Taking this into account, the following will discuss other possible reasons for differences or similarities in cleanliness values between Groups 1 and 2 and also between Group 1 and the Gutarts et al. (20) non-ultrasonic irrigation group. In addition, groups from previous in vivo studies

(17,19,21) evaluating tissue and debris removal that utilized ultrasonic irrigation are discussed to provide perspective on these results. Photomicrographs of representative cross sections from this study are seen in Figures 6 through 13.

CANAL AND ISTHMUS CLEANLINESS

The overall single canal cleanliness values for the 3% NaOCl with ultrasonic irrigation group ranged from 81.8% to 98.6% in severely curved single canals. The mean values in Group 2 ranged from 96.9% to 100%. At the 1 mm level, the mean value in

Group 1 was 81.8% versus 99.3% in Group 2. At 3 mm, the mean value of Group 1 was

98.6% versus 96.9% in Group 2. With the exception of the 3 mm level, the 3% NaOCl group showed consistently less clean single canals at all levels when compared to the 6%

NaOCl group (Table 3, Figure 5). Cleanliness values were mostly higher in Group 1 when compared to the Gutarts et al. (20) control group which used hand and rotary instrumentation without ultrasonic irrigation (Table 9, Figure 5). Cleanliness values for single canals in Group 1 mostly fell between Group 2 and the Gutarts et al. (20) control group (Figure 5).

In comparing single canal cleanliness values of other in vivo studies at the 1 mm and 3 mm level, Haidet et al. (17) reported 99.6% and 100%, Archer et al. (19) reported

101 92.3% and 99.9%, and Gutarts et al. (20) reported in their non-ultrasonic group 61.6% and 99.6% (Table 9,14). Again, our investigation revealed 81.8% cleanliness at the 1 mm level and 98.6% at the 3 mm level.

Group 1 had a high standard deviation in single canals at levels close to the apex that gradually decreased towards the 3 mm level. This indicated a wider range of cleanliness values and thus higher variances closer to the apex of the tooth. Previous studies histologically evaluating remaining tissue and debris (20,21) have shown this gradual decrease in standard deviation further from the apex in groups using hand and rotary instrumentation without ultrasonic irrigation (Table 9). Group 2 had a consistently low standard deviation at all levels in single canals similar to findings by Burleson (32) in which the standard deviation remained low throughout levels in single canals with the addition of ultrasonic irrigation in necrotic teeth. This would indicate consistent values in all areas and thus low variance. Burleson (32) stated that a low standard deviation in groups receiving ultrasonic irrigation strongly indicated that its addition consistently resulted in improved canal cleanliness. In other words, the canals were cleaner more often when ultrasonic irrigation was used. Haidet et al. (17) and Archer et al. (19) did not report standard deviations of mean cleanliness values. Although not found to be statistically significant, these results suggest that the ultrasonic instrumentation method using 6% NaOCl improved single canal cleanliness at all levels evaluated except 3 mm.

Common canals were encountered when distinct buccal and lingual canals joined somewhere along the length of the root. This is typically seen in a type II canal system where the two canals meet apically creating one main canal. In severely curved common canals, mean cleanliness values were similar between Groups 1 and 2 at many levels.

102 Group 1 ranged from 57.7% to 93.2% clean and group 2 ranged from 72.7% to 100%

(Table 7, Figure 3). Again, statistical significance was not shown due to small sample sizes and very large standard deviations in both groups. Group 1 had only 2 or 3 samples at any given level that were severely curved and had a common canal configuration.

Group 2 had a range of 1 to 5 samples per level that were compared with the values in

Group 1. The similarity in cleanliness may suggest that in larger type I canals, both techniques provided similar cleaning. With such a small number of samples it cannot be proven that these values were not merely due to variability.

When evaluating the 1 mm results of canal cleanliness for the Group 1, our values were lower (less clean) than previous in vivo studies performed using ultrasonics in vital teeth. This investigation found that the hand/rotary with 3% NaOCl ultrasonic irrigation method resulted in 81.8% canal cleanliness at the 1 mm level. At 1 mm, Archer et al. (19) reported 92.3% cleanliness using 5.25% NaOCl, Gutarts et al. (20) reported 99.3% cleanliness using 6% NaOCl, and Haidet et al. (17) reported 99.6% using 5.25% NaOCl

(all full strength solutions at the time of publication) (Table 14). Archer et al. (19),

Gutarts et al. (20) and the current study recorded results every 0.2 mm from 1-3 mm from the apex (total of 11 levels). This study showed lower canal cleanliness at all levels except at the 3 mm level (98.6% vs. 96.9%: current study vs. Gutarts et al. (20)) (Table

14).

Isthmus cleanliness values for Group 1 were lower than Group 2 at all levels evaluated (Table 5, Figure 4). Mean cleanliness values in Group 1 ranged from 6.4% to

27.8% while in Group 2 they were much higher ranging from 87.0% to 98.9%. At the 1 mm level, the mean value in Group 1 was 6.4% versus 92.9% in Group 2. At 3 mm, the

103 mean value of Group 1 was 27.8% versus 98.9% in Group 2. Because of the small sample sizes, statistically significant differences were not shown in these groups after Bonferroni adjustment. However, unadjusted p values showed significant differences at the 1.2 mm through 3.0 mm levels. Both groups had a maximum of only 7 samples from any one of the eleven levels evaluated. Although statistically significant differences are not shown between groups 1 and 2, the results suggest that the ultrasonic instrumentation method using 6% NaOCl improves isthmus cleanliness at all levels evaluated.

In comparing isthmus cleanliness values of other in vivo studies at the 1 mm and 3 mm level, Haidet et al. (17) reported 85.7% and 94.1%, Archer et al. (19) reported 45.6% and 83.0%, and Gutarts et al. (20) reported 7.8% and 28.0% in their non-ultrasonic group.

Our investigation revealed 6.4% cleanliness at the 1 mm level and 27.8% at the 3 mm level. The mean isthmus cleanliness values from the Gutarts et al. (20) control group were much closer to those found in Group 1 and ranged from 0.1% to 36.6% (Table 11,

Figure 4). All of the studies (15-19) found significant improvements in isthmus cleanliness in at least one level when comparing step-back to step-back/ultrasound. The reason for this increase in cleaning efficiency with ultrasound lies in the ability of ultrasonic energy to clean areas which are not accessible to the mechanical action of the file. Again, one would expect isthmuses in the higher levels of the canal to be cleaner than the more apical levels because there is a greater canal diameter at higher levels increasing the chance for irrigant and ultrasonic wave flow. This trend was true in all of the previous studies (16-19) except Gutarts et al. (20). The current study did have the highest isthmus cleanliness value (27.8%) at the 3 mm level with a sample size of 7. A greater sample size is needed to confirm our results. It is difficult to compare the

104 individual values between groups and studies due to the small sample size in each study.

This investigation had a sample size as small as 3 for an isthmus at the 1.2 mm level

(Table 5). Gutarts et al. (20) reported a sample size as low as 1. When the sample sizes are this small, one or two aberrant samples may significantly alter the reported mean.

Overall, the superiority of ultrasonic irrigation in canals and isthmuses, which was shown in the other studies, was not reaffirmed in this investigation (Figures 5,7,9, Tables 3,4,5).

Similar to Gutarts et al. (20), our ultrasonic irrigation time was only one minute per canal.

Our irrigant concentration was 3% compared to 6% used by Gutarts et al. (20) and 5.25% used by Archer et al. (19) and Haidet et al. (17).

Groups 1 and 2 used the same volume of irrigating solution during the ultrasonic irrigation phase of the procedure: 15 mL in each canal. Haidet et al. (17) added 30 mL per minute (90 mL total/3 min.) during continuous ultrasonic instrumentation. Our study also used continuous irrigation but it was only 15 ml total over a 1 minute time period.

Haidet et al. (17) used six times as much irrigation volume and three times as much irrigation time compared to our study and showed cleaner results at the 1 mm and 3 mm levels in isthmuses and canals. Archer et al. (19) used intermittent irrigation during the ultrasonic instrumentation phase and added 1 mL every 30 seconds for a total of 6 ml in three minutes. Intermittent irrigation was used because the Enac unit used in that study did not have a system for delivering continuous irrigation. Archer et al. (19) still achieved higher cleanliness values in all isthmuses when compared to Group 1 of this study. The

6% NaOCl group in this study (Group 2) was shown to have cleaner canals than Archer et al. (19) at all levels except at 3.0 mm from the apex.

Even though Haidet et al. (17) used continuous irrigation, their delivery system

105 delivered the sodium hypochlorite over the top of the canal orifice whereas our delivery system delivered the sodium hypochlorite directly into the canal. This factor may have contributed to higher cleanliness results in Group 2 after only 1 minute of ultrasonic instrumentation. Group 2 of our study indicated that high volumes of irrigant over longer time spans (3 min/canal) are not necessary with the ultrasonic needle system we utilized using 6% NaOCl. Group 2 obtained cleanliness superior to or similar to results obtained with longer time periods and more irrigant.

It is unknown what the optimum volume of irrigation should be in ultrasonic instrumentation after hand and rotary instrumentation however, it would be advantageous to minimize the volume and thus treatment time during these procedures leading to more efficient use of time with the patient. The use of a traditional high volume continuous irrigation system (solution delivered at the canal orifice) presents difficulties when used clinically. Three studies (15,16,18) were performed in vitro where the irrigating solution was easily evacuated. However, when using the traditional irrigation system in vivo, the evacuation of this solution presents a problem. Haidet et al. (17) reported that it was necessary to reinforce the rubber dam with Cavit™ to prevent leakage. Even with this precaution, irrigating solution leaked into the patient's mouth in two cases. When used in small volumes with delivery directly into the canal, as we used in this study, solution evacuation was easy to control. A mechanical pump was used to express the irrigant instead of the operator expressing it by hand as was done by Gutarts et al. (20) making our system even easier to control by a single operator. No patients reported any leakage during the ultrasonic irrigation phase of this study when 3% NaOCl was used. Even so, the operator in this study used an assistant whenever possible for this phase of the

106 treatment because if it was necessary to stop irrigation due to leakage it was possible to deactivate the pump while evacuation was continuously performed. Cavit™ was also occasionally necessary to prevent leakage around the rubber dam and into the patient’s mouth in this study.

Haidet et al. (17) noted that the reservoir within the Cavi-Endo unit required replenishing between instrumentation of the mesial canals. This step could cause an interruption during a clinical procedure. In our study, the mechanical pump (AL-1000,

World Precision Instruments, Sarasota, FL) controlled flow rate from a large syringe that did not need to be replenished between canals and therefore avoiding any interruption during irrigation of the canals.

Archer et al. (19) and Haidet et al. (17) found that the degree of root curvature in their experimental samples were not significantly different between their two experimental groups. They found that step-back/ultrasound significantly cleaned canals and isthmuses better than step-back instrumentation alone regardless of whether a high or low degree of root curvature was exhibited. It is difficult to statistically compare our results with theirs. The main reason for this is that we looked at canal curvature at each experimental level (nonparametric statistical testing), whereas the other studies (17,19) looked at curvature as a whole (parametric statistical testing-Anova).

Consistently lower values in Group 1 (3% NaOCl) when compared to Group 2

(6% NaOCl) may be associated with a number of technique/study variables. All attempts were made to maintain consistency in all factors except irrigant concentration between

Groups 1 and 2. Many factors were controlled such as tooth type (lower molars), tissue type (vital), instrumentation sequence, canal instrumentation size (30/.04), instrument

107 type (ProFile® GT® ), ultrasonic unit MiniEndo™ (Analytic EIE Inc., San Diego, CA), ultrasonic needle size (25 gauge), time of ultrasonic irrigation (1 minute per canal), and irrigant volume (15 mL/min per canal). In addition, no significant differences were found in other factors such as patient age, gender and tooth type. Because differences were found in canal curvature between the groups, only severely curved canals were compared between groups. Although as many variables as possible were controlled, there is still the possibility that some played a part in differences between the groups. Also, because two separate operators’ results are being compared, differences may be possibly attributed to any number of technique or evaluation differences between them.

Even though the instrumentation procedure was carried out according to the same procedure used by Gutarts et al. (20), operator differences between Groups 1 and 2 may have played a significant role in the differences found in mean cleanliness values. In both groups, the mesial canals were instrumented to a size 20 K-file. The working length of the teeth was verified using radiographs as well as a Root ZX II electronic apex locator

(J. Morita, Irvine, CA). A size 5 Gates Glidden bur was used to open the canal orifices and then Tulsa ProFile® GT® NiTi rotary files were used to clean and shape the canal(s) in a crown-down manner to size 30/.04. The use of NiTi rotary instruments has been shown to create more consistent canal preparations when compared to the step-back technique (38-43) so it is likely that the same canal instrumented to a size 30/.04 by separate operators with similar experience levels would result in a similar preparation.

After this size was achieved, another radiograph was exposed to verify the files had reached the appropriate working length and then the ultrasonic irrigation phase of treatment began. Up to this point, Group 1 used 3% NaOCl irrigation between every third

108 file and Group 2 used 6% NaOCl.

The depth of the orifice opening instruments such as the #5 Gates Glidden, size

70/.12, 50/.12, and 35/.12 rotary files was not predetermined and is an opportunity for differences in operators to potentially effect the canal and isthmus cleanliness. Using these instruments more conservatively would potentially create less space for the ultrasonic needle to vibrate thus creating a dampening effect. The use of orifice openers would have an effect on the ability of the needle to penetrate into the depth of the canals.

Although Gutarts et al. (20) did not measure needle penetration, it was recorded for

Group 1 of this study and also recorded by Burleson et al. (21) in a similar study that instrumented canals to a slightly larger size of 30/.06 using ProFile® GT® instruments but used the same size 25-gauge ultrasonic irrigating needle. The average working length in

Group 1 was 21.0 mm and the average needle penetration depth was 72.8% of that length.

In severely curved teeth (curvature greater than 25 degrees) evaluated by Burleson et al.

(21), the average working length was similarly 21.0 mm and the average needle penetration was 73.7% of working length. Therefore, the canals in Group 1 of this study were instrumented to a size that was likely large enough to allow the ultrasonic needle to vibrate as effectively as previous studies. Although an adequate canal size was likely achieved, the Burleson et al. (21) study obtained higher canal and isthmus cleanliness levels than this study and were closer to the values obtained by previously discussed studies (17,19,20). It should be noted however that Burleson et al. (21) was treating necrotic teeth which have less tissue and debris at initial access. This shows that even though the canal space was instrumented to a size that allowed very similar needle penetration, and likely potential for ultrasonic activation of the irrigating needle, the

109 amount of cleaning taking place was not equal.

“Instrumentation time is another factor which may be considered in the canal cleanliness results. Previous studies have found similar instrumentation times when compared to each other (15-17,19). The two operators in the study by Goodman et al.

(15) had mean instrumentation times of 11.3 and 9.9 minutes for the first operator, and

13.6 and 13.2 minutes for the second operator. Lev et al. (16) reported mean instrumentation times of 9.7, 10.0, and 9.9 minutes for the first operator, and 10.3, 8.7, and 8.4 minutes for the second operator. Haidet et al. (17) reported instrumentation times of 9.1 and 9.2 minutes. Archer et al. (19) reported 10.3 minutes and 10.0 minutes.

Each of these studies reported no significant difference in instrumentation time between the experimental groups (15-17,19). This further supports the finding that the improvement in cleanliness between the two groups was primarily due to the addition of ultrasound after instrumentation and not due to added instrumentation time.

Instrumentation time was not recorded in our study since all the previous studies (15-

17,19), mentioned above, reported instrumentation time not to be a significant factor in canal or isthmus cleanliness. Also, in vivo instrumentation time may vary due to canal complexity, access to canals, patient behavior, and patient tolerance during the procedure.

We did not want our instrumentation regimen compromised by a time factor. This would not have been a clinically applicable treatment scenario” (30).

It is possible that the way in which the ultrasonic needle was used inside the canal space during irrigation of Group 1 was different from Group 2. However, it was noted by

Gutarts (30) that, “clinically, the addition of ultrasonic instrumentation may reduce the impact of the operator's skill following hand instrumentation. In the investigation by

110 Goodman et al. (15), a significant difference was seen in canal cleanliness after hand instrumentation, when two different operators performed the procedure. This finding supports the conclusion of Littman (173) that the operator has more influence on canal cleanliness than the technique. However, when examining the step-back/ultrasound cleanliness values in Goodman's (15) study, no difference was found between the two operators. Therefore, the use of ultrasound after hand instrumentation was shown to reduce the effect of the operator. Lev et al. (16) found no difference between two operators when evaluating either step-back or step-back/ultrasound. These results indicate that in Lev's study the operators may have been equally effective in canal debridement using hand instrumentation and therefore, no effect was shown when ultrasound was added” (30).

Because the operator of Group 1 was able to instrument the teeth to an acceptable degree and ultrasonic irrigation has been shown to reduce differences between operators, the differences in canal and isthmus cleanliness may be attributed to whether sufficient ultrasonic energy was being added to the irrigant in Group 1. This explanation would account for the values of Group 1 being slightly higher in canals than the Gutarts et al.

(20) control group and very similar to the non-ultrasonic group in isthmuses where more ultrasonic energy would be required to provide any benefit. Like Group 2, a MiniEndo™

(Analytic EIE Inc., San Diego, CA) ultrasonic unit was used at full power in Group 1.

This unit produces ultrasonic frequencies ranging from 28-32 kHz at maximum power. It is not known what the optimum frequency for obtaining maximum cleaning is or if any differences would be noted within this range. The specific unit used in this study could have produced a lower maximum energy level as compared to the units used in previous

111 studies. However, subjective observations by the operator of Group 1 concluded that the ultrasonically activated needle appeared to be providing agitation because of the distinctive noise the irrigating needle produced when activated and by the effervescence of the irrigation solution while being activated. In addition, when the activated needle was applied to a dye film created on the surface water in a plastic container, currents and eddies were noted around the needle suggesting that the unit and needle assembly was likely functioning properly.

The relationship between NaOCl concentration and how it is affected by ultrasonic energy may have played a role in this study. Moorer and Wesselink (74) examined the effect of ultrasonics on the tissue dissolving effects of sodium hypochlorite.

In experiments in which specimens of necrotic rabbit tissue were dissolved in different concentrations of sodium hypochlorite, it was found that available chlorine was an important variable in tissue dissolution. Low concentrations of sodium hypochlorite

(0.6% and 1.2%) were rapidly depleted of available chlorine. Three percent sodium hypochlorite dissolved the tissue more effectively. When ultrasonic power was added to the tissue/sodium hypochlorite system, the solution was agitated violently, causing rapid dispersion and dissolution of tissue. The authors concluded that the most important factor influencing tissue dissolution was the physical agitation caused by the ultrasound. If this is true then our results may suggest that Group 1 was not receiving the benefit of effective ultrasonic irrigation.

The main factor of interest in this study was irrigant concentration. If the operators of Groups 1 and 2 were able to prepare similar teeth in a standardized fashion and they were using the same equipment then the only differences in treatment would be

112 the use of different concentrations of sodium hypochlorite. It has been reported that

NaOCl in higher concentrations possesses greater tissue dissolving properties (66,75,76).

It is possible that this property contributed to cleaner canals and isthmuses in Group 2 and those reported by Archer et al. (19) and Haidet et al. (17). Both Archer et al. (19) and

Haidet et al. (17) used 5.25% NaOCl which was considered full strength at the time of their investigations. The dissolving ability of 3% NaOCl throughout the procedure including during ultrasonic irrigation may have not been able to clean as well as the higher concentration solutions.

Van der Sluis (166) showed in an in vitro tooth model that ultrasonically activated saline was not as effective as NaOCl in removing dentin debris from grooves placed in root canal walls. In another in vitro model, Walker and del Rio (174) found that using

2.6% sodium hypochlorite in conjunction with ultrasonic energy was more effective for soft tissue debridement than ultrasonically energized tap water in the middle third of canals. However, both were found to be ineffective in cleaning isthmuses and fins in the apical third of canals. These studies suggest that there is a synergistic relationship between ultrasonic energy and sodium hypochlorite. Alone, each cleans to a limited degree, but when combined, greater cleaning results.

“In Group 2 superior cleanliness values were achieved even in severely curved canals, as compared to previous studies (15,16,18,19). The small diameter and curved morphology of the mesial canals of mandibular molars (5-11) may dictate the limits of apical instrumentation. These canals are usually only instrumented to a #25 or #30 file apically. The activated ultrasonic files used in previous studies (15,16,18,19) may have been dampened when they were taken to within 1 mm of working length resulting in the

113 ultrasonic effect being retarded. Our study utilized a 25-gauge ultrasonic irrigating needle that was used only in the middle to coronal third of the root and did not bend around canal curves. By doing this there was less chance for needle dampening since the needle worked passively in the upper non-curved portion of the root canal. Even by not placing the needle to within 3 mm of the working length, excellent canal debridement resulted in

Group 2” (30).

At the 3 mm level, the step-back/ultrasound values of all the studies (15-18,19) tend to show similar results including this study. At the 3 mm level, the canal diameter is larger and the ultrasonically activated files are better able to freely vibrate without restriction. Therefore, the ultrasound is more effective and cleanliness values are increased. Action of the irrigating solution is also enhanced because it has better access in the larger diameter canal. “In an in vivo experiment, Rosenfeld et al. (61) found that the solvent action of sodium hypochlorite was limited by the size of the lumen of the canal.

Ram (175) felt that canal diameter was the most important factor in determining the effectiveness of irrigation. He felt that canal diameter needed to be equal to the size of a

#40 file (0.40 mm) before irrigation could be effective. Salzgeber and Brilliant (132), however, found that when a step-back preparation was used, the irrigating solution penetrated to the full depth of instrumentation. Studying irrigation patterns during ultrasonic instrumentation, Krell et al. (160) found that the irrigating solution reached the full extent of the canal when the activated file was able to freely vibrate. In the current study, the high cleanliness values in Group 2 were most likely due to both cavitational energy and acoustic streaming created by the ultrasonic needle. The ultrasonic needle was energized in the upper portion of the root, which was prepared to at least a size #70 (0.70

114 mm), the ultrasonic needle (outside diameter = 0.50 mm or #50 file) had at least 0.2 mm of free space to work in. Because the needle was utilized in the upper third to half of the root, the energy used to clean the apical portions (1-3 mm) of the root came from both acoustic streaming waves and cavitational bubbles as described in the ‘ultrasonic mechanism’ portion of the chapter” (30).

“The manner of measuring remaining tissue within canals and isthmuses is a factor which can influence the values of various studies. Whether a polar planimeter (15-

17,167) or image analysis software (18,20,21) was used, determination of canal and isthmus boundary areas was left to subjective interpretation. Canals and isthmuses must be predefined, and tissue and artifacts must be discriminated by the evaluator. Human interpretation of samples plays a role in the values which are recorded. As long as the method of interpretation is consistent throughout the study, as it was in this investigation, then an accurate comparison of experimental groups is possible” (30). As stated earlier in this study, reliability for the data collected (cleanliness evaluation of the histologic sections) was considered to be good showing that there was consistency in the evaluation of samples. The intraclass correlation coefficient was determined to be 0.926 (95% confidence interval 0.844; 0.966), indicating excellent intrarater reliability. The inter- rater reliability was calculated by having the operator in this study measure slides that were evaluated and graded by Gutarts et al. (20) to see if the two evaluators graded the same teeth with the same scores. The intra class correlation coefficient for inter-rater reliability of canals and isthmuses combined was determined to be 0.99 (95% confidence interval 0.94; 1.00), indicating excellent reliability between evaluators. This means there is a very good chance that regardless of evaluator, the cleanliness values assigned to the

115 samples would be very similar.

In the study conducted by Archer et al. (19) and this investigation, eleven apical levels were evaluated (Tables 2 & 3) (Figures 3 & 4). We believed it was important to analyze multiple levels in order to gain a better insight into how well the apical third of the root canal was cleaned. Previous studies (15-17) have been criticized since they only evaluated two apical levels of the root canal. We addressed this criticism by studying multiple levels of the apical third of the root, as mentioned earlier. Our cleanliness levels for the 3% NaOCl group were lower than that of Archer et al. (19) at all eleven levels

(Table 14). This may have been because our ultrasonic instrument was not producing sufficient ultrasonic energy or because of the lower irrigant concentration. Archer et al.

(19) used 5.25% NaOCl.

MECHANISMS OF ULTRASONIC CLEANING

“The postulated reason for the success of Group 2 (with ultrasonics) can be related to the action of the ultrasonic needle. Weller et al. (14) evaluated the use of ultrasound after hand instrumentation. They measured the removal of radioactive gelatin from the root canals of extracted teeth and resin blocks and found that more of this medium was removed using ultrasound after hand instrumentation than when either method was used alone. This study laid the foundation for the methods which were used in the investigations of Goodman et al. (15), Lev et al. (16), Haidet et al. (17), Metzler and Montgomery (18), Archer et al. (19), Gutarts et al. (20), and Burleson et al. (21).

As mentioned earlier, previous studies used #15 or #20 file during the ultrasonic phase of instrumentation (15-18,19). When an ultrasonic file or needle is utilized after

116 hand and/or rotary instrumentation, the canal is already enlarged, thus enabling the energized file to vibrate freely. When the file is able to freely vibrate, the physical effects of ultrasound in a liquid medium are maximized (162). Ahmad et al. (94) believed that the most important of these physical effects was acoustic streaming, and not cavitation.

An Enac unit was utilized in an experimental setting where cavitation would be produced.

They had determined the parameters required for the production of cavitation using a photometric light detection system. First, the Enac unit had to be adjusted to a power setting of at least 3.5 (producing some cavitation). Second and more important, the size

#15 file had to vibrate at a displacement amplitude of at least 135 !m. Apical preparations in a molar are usually prepared to a size #30. Ahmad et al. (94) stated that the size of a #40 file (0.40 mm at the tip) was required in order for the file to have enough room to move around freely enough for cavitation to be produced. If their statement was correct, then in their study, cavitation may have been produced only when the energized file was moved 2-3 mm from the apical extent of the canal preparation, and dampening of the file had to be at a minimum. As the energized file was passively worked in the canal during previous studies (15-18,19), it was moved 2-3 mm from the apical extent of the canal preparation. Therefore, cavitation may have been produced. Working in narrow canals, which cause dampening, the less powerful Cavi-Endo unit may be as effective as the Enac unit. Walmsley (95) believed that cavitation did not play a major role in tissue removal within the root canal. He believed that the thin streamlined shape of the file prevented formation of a large enough pressure field required for cavitation. He believed that acoustic streaming was the primary mechanism for canal debridement.

Ahmad et al. (92-94) had stated that acoustic streaming was produced from the

117 sides of the file while cavitation was produced from the end point of the file. Also, acoustic streaming was produced at low and high power settings while cavitation (a more powerful force) could only be produced at high power settings in order to be effective

(94). Previous studies (15-19) could not use high ultrasonic setting since this caused the files to break. Therefore, the primary ultrasonic mechanism of tissue removal appears to have been acoustic streaming in the previous studies (15-19) as has been postulated by

Ahmad et al. (92-94) and Walmsley (95).

The study by Gutarts et al. (20) was the first to utilize an ultrasonic needle. They believed that the high canal and isthmus cleanliness values obtained (Group 2) were due to cavitation and not acoustic streaming even though they found in a pilot study that both occurred. Because the needle was utilized in the upper third to half of the root and no where close to the apex, the energy used to clean the apical portion of the root had to come from cavitation and not acoustic streaming since cavitation is produced from the file or needle tip (vertical plume) and acoustic streaming from the file or needle sides

(horizontal fashion) (92-94). Further studies need to be done in order to see if this instrument is able to produce the same type of cavitational energy at power settings less than full power” (30). It is likely that both acoustic streaming and cavitation were occurring and contributing to the cleaning of debris from the canals.

118

CHAPTER 6

SUMMARY AND CONCLUSIONS

This in vivo study compared the tissue debridement effectiveness of hand and rotary instrumentation followed by one-minute of ultrasonic irrigation with either 3% or

6% sodium hypochlorite (NaOCl) in vital mesial root canals of human mandibular molars. A MiniEndo™ dental unit was used as the ultrasonic source utilizing the maximum power level.

Experimental teeth were collected and compared to an existing experimental group collected and evaluated by Gutarts et al. (20). Originally, groups were solely prepared by the author of this study using a newly manufactured ultrasonic irrigating needle. However, after evaluation of the first twenty samples using the new irrigating needle, it was concluded that the device was not providing adequate cleaning. It was then decided to use the irrigating needle utilized by Gutarts et al. (20) and make comparisons to the experimental group from the Gutarts et al. (20) study. Group 1 consisted of 15 mesial roots collected by the author of this study. They were initially instrumented with

K-files followed by ProFile® GT® nickel-titanium rotary files using a crown-down technique followed by one minute of continuous ultrasonic irrigation per canal using 3%

NaOCl at a rate of 15 mL per minute. Group 2 was collected by Gutarts et al. (20) and consisted of 15 mesial roots instrumented in the same manner, followed by one minute of 119 continuous ultrasonic irrigation per canal using 6% NaOCl at the same rate. Both groups were irrigated intermittently with 3% or 6% NaOCl during the hand/rotary phase of preparation. A third group of 2 accessed but uninstrumented teeth served as controls for the histologic processing.

Immediately following completion of instrumentation, teeth were extracted and fixed in formalin. Teeth were histologically prepared and 5 micron serial cross sections were made from the apical three millimeters of each root. Starting at the 1 mm level and ending at the 3 mm level, representative sample sections from every 0.2 mm were analyzed for the presence of remaining pulp tissue. Analysis of each mesial canal and isthmus, for presence of pulpal tissue, was made utilizing a Neurolucida Image Analysis

Program version 7.0.

No statistically significant enhancement in debridement of single canals, common canals, and isthmuses was shown after Bonferroni adjustment when ultrasonic irrigation using 3% NaOCl was used following hand and rotary preparation even though trends towards better cleaning were mostly noted. In Group 2 canal cleanliness values were not only cleaner than Group 1, but also showed consistently high values of cleanliness irrespective of the canal level whereas the samples in Group 1 showed improvement in cleanliness farther from the apex of the tooth. Even when large differences in values existed, mean percent canal and isthmus cleanliness values were not significantly different when Bonferroni adjusted at any level evaluated. This was most likely due to small sample sizes and high variability among the samples. Mean canal cleanliness of

Group 1 tended to be less than Group 2 but greater than values of a previously collected group (20) that was instrumented in the same manner but did not receive ultrasonic

120 irrigation. In isthmuses, mean cleanliness values of Group 1 tended to be notably less than those in Group 2 and were similar to values obtained in the previously collected group that was instrumented in the same manner but did not receive ultrasonic irrigation.

Cleanliness values from the uninstrumented controls indicated that a negligible amount of pulp tissue was lost during histologic processing.

Various factors may account for the differences seen in mean cleanliness values between the groups. A 3% NaOCl solution may not be strong enough to dissolve tissues as effectively as 6% NaOCl over the time needed to instrument the canals. Even though steps were taken to ensure consistency between the groups, because they were collected by two different operators, there may be any number of confounding variables that could account for the differences such as sample, technique and equipment differences. For example, the 3% NaOCl group may have been comprised of teeth that were more difficult to clean because of their curvature and anatomy (average curvature in Group 1 was 37.6 degrees and Group 2 was 33.3 degrees). Gutarts (30) may have instrumented the canals in a way that was different from the author of this study that allowed the ultrasonic energy to provide more effective cleaning in the webs, fins, and isthmuses. In addition, although the equipment that was used in the study was meant to be identical, it is possible that it was not functioning as well in Group 1 as it was when Group 2 was collected.

Although this study did not find statistically significant differences between the groups (adjusted values), the author believes that with larger sample sizes, ultrasonic irrigation using 3% NaOCl would be shown to be significantly less effective at cleaning canals and isthmuses in vital mandibular molars than ultrasonic irrigation using a 6%

NaOCl solution. However, no statistically significant differences were shown between

121 the use of constant ultrasonic irrigation using 3% NaOCl after hand and rotary instrumentation versus the same techniques using 6% NaOCl.

122

TABLES

123

(GROUP 1) (GROUP 2)* 3% NaOCl 6% NaOCl P

Curvature

Moderate (0-25º) 1/15 (6%) 7/16 (44%) 0.03731

Severe (26-52º) 14/15 (93%) 9/16 (56%)

Canal Type

I 1/15 (7%) 0/16 (0%)

II 3/15 (20%) 4/16 (25%)

III 11/15 (73%) 12/16 (75%)

IV 0/15 (0%) 0/16 (0%)

C-shaped 0/15 (0%) 0/16 (0%)

Tooth Type

1st Molars 4/15 (27%) 6/16 (38%) 0.84511

2nd Molars 10/15 (66%) 9/16 (56%)

3rd Molars 1/15 (7%) 1/16 (6%) * Group 2 data collected by Gutarts (20). (1) Fisher’s exact test.

Table 1. Curvature, Canal Type, and Tooth Type for Group 1 (3%NaOCl) and Group 2 (6% NaOCl).

124

(GROUP 1) (GROUP 2)* P 3% NaOCl 6% NaOCl

Gender

Male 6/15 (40%) 7/16 (44%) 0.83251

Female 9/15 (60%) 9/16 (56%)

Age

Mean 32.0 29.9 0.60092

SD 12.71 8.76

Min 20 19

Max 63 48 * Group 2 data collected by Gutarts (20). (1) Chi-Square. (2) T-Test.

Table 2. Gender and Age for Group 1 and 2.

125

(GROUP 1) (GROUP 2)*

3% NaOCl 6% NaOCl

Level (mm) N Mean** SD N Mean** SD P (RAW)1 P (ADJ)2

1.0 22 81.8 23.2 8 99.3 0.9 0.0367 0.8441

1.2 20 88.4 20.7 10 99.6 0.6 0.0765 1.0000

1.4 21 90.0 24.0 10 99.7 0.5 0.2097 1.0000

1.6 24 90.4 19.5 10 98.9 3.0 0.1821 1.0000

1.8 24 91.9 14.0 12 98.5 4.9 0.1416 1.0000

2.0 24 91.1 16.6 14 100 0.1 0.0498 1.0000

2.2 24 96.4 7.9 14 99.9 0.3 0.1357 1.0000

2.4 24 96.7 8.3 12 100 0.1 0.2348 1.0000

2.6 24 96.4 9.4 12 100 0.0 0.2120 1.0000

2.8 24 97.6 6.6 11 100 0.0 0.2495 1.0000

3.0 24 98.6 4.6 16 96.9 11.4 0.6708 1.0000 (*) Group 2 data collected by Gutarts (20). (**) Mean percent cleanliness. (1) Randomization test. 2 ( ) Bonferroni adjusted.

Table 3. Mean Canal Cleanliness Analysis by Level and Irrigant Concentration in Severely Curved Canals.

126

(GROUP 1) (GROUP 2)* 3% NaOCl 6% NaOCl Level (mm) h N Median** Min** Max** N Median** Min** Max**

1.0 22 87.6 6.8 100 8 99.8 97.6 100

1.2 20 96.2 14.8 100 10 99.9 98.5 100

1.4 21 100 4.3 100 10 100 98.7 100

1.6 24 100 16.0 100 10 99.9 90.3 100

1.8 24 100 59.0 100 12 100 82.8 100

2.0 24 100 38.3 100 14 100 99.7 100

2.2 24 100 74.4 100 14 100 98.9 100

2.4 24 100 63.0 100 12 100 99.6 100

2.6 24 100 58.5 100 12 100 99.9 100

2.8 24 100 69.7 100 12 100 100 100

3.0 24 100 78.0 100 16 100 54.1 100 (*) Group 2 data collected by Gutarts (20). (**) Percent cleanliness.

Table 4. Median Canal Cleanliness Analysis by Level and Irrigant Concentration in Severely Curved Canals.

127

(GROUP 1) (GROUP 2)*

3% NaOCl 6% NaOCl

Level (mm) N Mean** SD N Mean** SD P (RAW)1 P (ADJ)2

1.0 5 6.4 9.4 1 92.9 . 0.1678 1.0000

1.2 3 9.7 8.6 4 87.4 15.1 0.0296 0.7104

1.4 3 17.1 29.7 5 89.0 19.0 0.0180 0.4500

1.6 4 22.7 21.6 5 87.0 11.1 0.0079 0.2079

1.8 5 26.2 15.0 5 87.5 9.8 0.0077 0.2079

2.0 6 19.5 40.0 7 89.2 13.2 0.0066 0.1848

2.2 6 4.0 9.7 6 91.6 14.5 0.0022 0.0682

2.4 6 14.1 14.8 5 88.2 23.7 0.0019 0.0627

2.6 6 3.2 7.7 5 88.0 22.8 0.0022 0.0682

2.8 6 11.1 15.0 5 98.0 3.5 0.0021 0.0672

3.0 7 27.8 34.5 6 98.9 2.1 0.0050 0.1450 (*) Group 2 data collected by Gutarts (20). (**) Mean percent cleanliness. (1) Randomization test. 2 ( ) Bonferroni adjusted.

Table 5. Mean Isthmus Cleanliness Analysis by Level and Irrigant Concentration in Severely Curved Canals.

128 (GROUP 1) (GROUP 2)* 3% NaOCl 6% NaOCl Level (mm) N Median** Min** Max** N Median** Min** Max**

1.0 5 0.0 0.0 20.7 1 92.9 92.9 92.9

1.2 3 9.7 0.0 16.5 4 90.3 69.0 100

1.4 3 0.0 0.0 51.4 5 99.9 56.1 100

1.6 4 23.4 0.0 43.8 5 82.9 73.1 100

1.8 5 21.3 12.5 45.4 5 86.8 73.5 100

2.0 6 0.0 0.0 100 7 92.6 61.9 100

2.2 6 0.0 0.0 23.7 6 96.9 62.7 100

2.4 6 11.2 0.0 33.7 5 99.3 46.0 100

2.6 6 0.0 0.0 18.9 5 98.7 47.5 100

2.8 6 7.0 0.0 40.0 5 99.8 91.9 100

3.0 7 20.1 0.0 100 6 99.9 94.8 100 (*) Group 2 data collected by Gutarts (20). (**) Percent cleanliness.

Table 6. Median Isthmus Cleanliness Analysis by Level and Irrigant Concentration in Severely Curved Canals.

129

(GROUP 1) (GROUP 2)*

3% NaOCl 6% NaOCl

Level (mm) N Mean** SD N Mean** SD P (RAW)1 P (ADJ)2

1.0 2 84.4 22.1 5 85.7 25.7 1.0000 1.0000

1.2 3 88.6 11.5 4 79.0 35.9 0.9714 1.0000

1.4 3 93.2 11.8 4 79.9 35.1 0.8001 1.0000

1.6 2 57.7 59.9 4 84.8 30.0 0.7344 1.0000

1.8 2 58.3 59.0 3 86.4 23.4 0.6995 1.0000

2.0 2 88.9 15.8 2 81.5 26.2 1.0000 1.0000

2.2 2 91.3 8.3 2 72.7 38.6 1.0000 1.0000

2.4 2 78.3 28.1 3 84.6 26.7 0.8031 1.0000

2.6 2 82.9 23.1 3 86.5 23.3 0.8015 1.0000

2.8 2 82.2 17.3 3 98.1 3.2 0.2000 1.0000

3.0 2 83.3 23.7 1 100 . 1.0000 1.0000 (*) Group 2 data collected by Gutarts (20). (**) Mean percent cleanliness. (1) Randomization test. 2 ( ) Bonferroni adjusted.

Table 7. Mean Common Canal Cleanliness Analysis by Level and Irrigant Concentration in Severely Curved Canals.

130

(GROUP 1) (GROUP 2)* 3% NaOCl 6% NaOCl

Level (mm) N Median** Min** Max** N Median** Min** Max**

1.0 2 84.4 68.7 100 5 96.8 40.1 100

1.2 3 88.8 77.0 100 4 95.3 25.6 100

1.4 3 100 79.5 100 4 96.1 27.5 100

1.6 2 57.7 15.3 100 4 99.7 39.7 100

1.8 2 58.3 16.6 100 3 99.9 59.4 100

2.0 2 88.9 77.7 100 2 81.5 63.0 100

2.2 2 91.3 85.4 97.2 2 72.7 45.4 100

2.4 2 78.3 58.4 98.1 3 100 53.8 100

2.6 2 82.9 66.6 99.2 3 100 59.6 100

2.8 2 82.2 69.9 94.4 3 100 94.4 100

3.0 2 83.3 66.5 100 1 100 100 100 (*) Group 2 data collected by Gutarts (20). (**) Percent cleanliness.

Table 8: Median Common Canal Cleanliness Analysis by Level and Irrigant Concentration in Severely Curved Canals.

131

(GROUP 1) GUTARTS CONTROL* 3% NaOCl (HAND/ROTARY/ NO ULTRASONIC)

Level (mm) N Mean** SD N Mean** SD

1.0 22 81.8 23.2 13 61.6 31.7

1.2 20 88.4 20.7 13 77.8 23.5

1.4 21 90.0 24.0 13 77.3 31.6

1.6 24 90.4 19.5 13 86.8 17.9

1.8 24 91.9 14.0 13 87.9 17.8

2.0 24 91.1 16.6 12 93.6 7.7

2.2 24 96.4 7.9 12 96.8 4.2

2.4 24 96.7 8.3 12 97.4 2.5

2.6 24 96.4 9.4 11 98.4 2.6

2.8 24 97.6 6.6 12 99.3 1.9

3.0 24 98.6 4.6 12 99.6 0.7 (*) Data in this group was collected by Gutarts (20). (**) Mean percent cleanliness.

Table 9. Mean Canal Cleanliness Analysis by Level and Method Comparing Data from this Study and the Gutarts (20) Control Group (Hand/Rotary/No Ultrasonic) in Severely Curved Canals.

132

(GROUP 1) GUTARTS CONTROL* 3% NaOCl (HAND/ROTARY NO ULTRASONIC) Level (mm) h N Median** Min** Max** N Median** Min** Max**

1.0 22 87.6 6.8 100 13 79.1 3.1 98.0

1.2 20 96.2 14.8 100 13 84.0 30.1 100

1.4 21 100 4.3 100 13 89.5 3.7 99.9

1.6 24 100 16.0 100 13 94.1 36.8 100

1.8 24 100 59.0 100 13 90.2 32.5 100

2.0 24 100 38.3 100 12 97.5 76.9 100

2.2 24 100 74.4 100 12 99.5 86.8 100

2.4 24 100 63.0 100 12 97.7 92.3 100

2.6 24 100 58.5 100 11 99.7 92.3 100

2.8 24 100 69.7 100 12 100 93.2 100

3.0 24 100 78.0 100 12 99.9 97.4 100 (*) Control group data collected by Gutarts (20). (**) Percent cleanliness.

Table 10. Median Canal Cleanliness Analysis by Level and Method Comparing Data from this Study and the Gutarts (20) Control Group (Hand/Rotary/No Ultrasonic) in Severely Curved Canals.

133

(GROUP 1) GUTARTS CONTROL* 3% NaOCl (HAND/ROTARY NO ULTRASONIC)

Level (mm) N Mean** SD N Mean** SD

1.0 5 6.4 9.4 4 7.8 15.5

1.2 3 9.7 8.6 3 4.8 8.3

1.4 3 17.1 29.7 2 0.1 0.1

1.6 4 22.7 21.6 2 2.5 3.5

1.8 5 26.2 15.0 2 1.4 1.9

2.0 6 19.5 40.0 3 12.1 20.9

2.2 6 4.0 9.7 3 18.4 31.0

2.4 6 14.1 14.8 3 3.3 4.9

2.6 6 3.2 7.7 3 4.2 6.4

2.8 6 11.1 15.0 5 36.6 43.0

3.0 7 27.8 34.5 4 28.0 48.2 (*) Control group data collected by Gutarts (20). (**) Mean percent cleanliness.

Table 11. Mean Isthmus Cleanliness Analysis by Level and Method Comparing Group 1 and the Gutarts (20) Control Group (Hand/Rotary/No Ultrasonic) in Severely Curved Canals.

134

(GROUP 1) GUTARTS CONTROL* 3% NaOCl (HAND/ROTARY NO ULTRASONIC)

Level (mm) h N Median** Min** Max** N Median** Min** Max**

1.0 5 0.0 0.0 20.7 4 0.0 0.0 31.0

1.2 3 9.7 0.0 16.5 3 0.0 0.0 14.3

1.4 3 0.0 0.0 51.4 2 0.1 0.0 0.2

1.6 4 23.4 0.0 43.8 2 2.5 0.0 5.0

1.8 5 21.3 12.5 45.4 2 1.4 0.0 2.7

2.0 6 0.0 0.0 100 3 0.0 0.0 36.2

2.2 6 0.0 0.0 23.7 3 1.0 0.0 54.1

2.4 6 11.2 0.0 33.7 3 1.0 0.0 9.0

2.6 6 0.0 0.0 18.9 3 0.7 0.3 11.6

2.8 6 7.0 0.0 40.0 5 23.6 0.0 100

3.0 7 20.1 0.0 100 4 6.0 0.0 99.8 (*) Percent cleanliness. (**) Control group data collected by Gutarts (20).

Table 12. Median Isthmus Cleanliness Analysis by Level and Method Comparing Group 1 and the Gutarts (20) Control Group (Hand/Rotary/No Ultrasonic) in Severely Curved Canals.

135

(GROUP 1): NEEDLE PENETRATION (mm) Working Length Needle Penetration Sample (id #) (mm) (mm) % Penetration

191408 20.5 16.5 80.5

511091 22.5 15.5 68.9

991863 21.5 15.5 72.1

596229 20.5 13.0 63.4

253852 19.5 14.0 71.8

572066 20.0 13.0 65.0

677700 22.0 17.0 77.3

370451 19.5 14.5 74.4

389596 21.5 17.0 79.1

856756 21.0 16.5 78.6

999574 21.0 16.0 76.2

624420 20.5 14.0 68.3

850395 21.5 16.0 74.4

662554 22.0 15.0 68.3

943004 22.0 17.0 77.4

859704 21.5 15.0 69.8

Table 13. Percent Needle Penetration Values in Group 1.

136

CANAL INSTRUMENTATION FOLLOWED BY ULTRASOUND

Level (mm) ARCHER (19) GUTARTS (20) HAIDET (17) GROUP 1

1.0 92.3 99.3 99.6 81.8

1.2 94.1 99.6 - 88.4

1.4 96.3 99.7 - 90.0

1.6 94.8 98.9 - 90.4

1.8 96.5 98.5 - 91.9

2.0 97.3 100 - 91.1

2.2 98.6 99.9 - 96.4

2.4 98.9 100 - 96.7

2.6 99.0 100 - 96.4

2.8 99.4 100 - 97.6

3.0 99.9 96.9 100 98.6

Table 14. Comparison of Canal Mean Percent Cleanliness.

137

CANAL INSTRUMENTATION FOLLOWED BY ULTRASOUND

Level (mm) ARCHER (19) GUTARTS (20) HAIDET (17) GROUP 1

1.0 45.6 92.9 85.7 6.4

1.2 63.5 87.4 - 9.7

1.4 63.7 89.0 - 17.1

1.6 74.5 87.0 - 22.7

1.8 62.0 87.5 - 26.2

2.0 59.8 89.2 - 19.5

2.2 65.2 91.6 - 4.0

2.4 73.7 88.2 - 14.1

2.6 80.2 88.0 - 3.2

2.8 77.0 98.0 - 11.1

3.0 83.0 98.9 94.1 27.8

Table 15. Comparison of Isthmus Mean Percent Cleanliness.

138

FIGURES

139

Reference Numerals 102. suhltarfats aosnsiecm dbevlyic e 124. sthhraefat daesdse hmobulsyin g 146. tfhirrseta pdleadn ahro suusrifnagc e 168. fsihrasft tp lanar surface 1280. shhuabf t 202. hseucbo nd planar surface 224. sneeceodnled planar surface 246. ntiepe dle 268. taippe rture 2380. acpoenrnteucreto r 302. ctuobninnegc atosrs embly 324. tfuirbsitn cgo lalsasre mbly 346. fleirnsgt tcho ollfa rtu bing 368. lseencgotnhd o cfo tlulabri n g 3480. seycrionngde collar 402. suyltrriansgoen ic wand 424. uatlttaracshomneicn tw maneadn s 446. atottoatchh ment means

Figure 1: Perspective view of ultrasonic device

140 Reference Numerals 12. shaft assembly 14. threaded housing 16. first planar surface 18. shaft 20. hub 22. second planar surface 24. needle 26. tip 28. aperture 30. connector 32. tubing assembly 34. first collar 36. length of tubing 38. second collar 40. syringe 42. ultrasonic wand 44. attachment means 46. tooth

Figure 2: Perspective view of ultrasonic device during ultrasonic instrumentation within a root canal

141

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Figure 6: Photomicrograph of cross section at the 1.0 mm level - Group 1, (Specimen #389596), 89.9% cleanliness in the mesiolingual canal and 53.8% cleanliness in the mesiobuccal canal, magnification: 100x.

Figure 7: Photomicrograph of cross section at the 1.0 mm level - Group 2 collected by Gutarts et al. (20), (Specimen #859590), 100% cleanliness in the mesiolingual canal and 100% cleanliness in the mesiobuccal canal, with isthmus cleanliness of 99.8%, magnification: 40x.

145

Figure 8: Photomicrograph of cross section at the 2.0 mm level - Group 1, (Specimen #370451), 100% cleanliness in the mesiolingual canal and 100% cleanliness in the mesiobuccal canal, with isthmus cleanliness of 16.9%, magnification: 40x.

Figure 9: Photomicrograph of cross section at the 2.0 mm level - Group 2 collected by Gutarts et al. (20), (Specimen #480660), 100% cleanliness in the mesiolingual canal and 100% cleanliness in the mesiobuccal canal, with isthmus cleanliness of 100%, magnification: 40x.

146

Figure 10: Photomicrograph of cross section at the 3.0 mm level - Group 1, (Specimen #991863), 100% cleanliness in the mesiolingual canal and 100% cleanliness in the mesiobuccal canal, with isthmus cleanliness of 11.7%, magnification: 100x.

Figure 11: Photomicrograph of cross section at the 3.0 mm level - Group 2 collected by Gutarts et al. (20), (Specimen #402105), 100% cleanliness in the mesiolingual canal and 100% cleanliness in the mesiobuccal canal, with isthmus cleanliness of 90.2%, magnification: 100x.

147

Figure 12: Photomicrograph of cross section at the 1.0 mm level - Group 3, (Specimen #458056), 16.9% cleanliness in the common canal, magnification: 100x.

Figure 13: Photomicrograph of cross section at the 3.0 mm level - Group 3, (Specimen #765709), 0.0% cleanliness in the mesiolingual canal and 0.0% cleanliness in the mesiobuccal canal, with isthmus cleanliness of 0.0%, magnification: 100x. 148

APPENDIX A

PATIENT CONSENT FORM

149

The Ohio State University Consent to Participate in Research

An Evaluation of the In Vivo Debridement Efficacy of 3.0% NaOCl Study Title: vs. 6.0% NaOCl Ultrasound After Hand and Rotary Instrumentation in Human Mandibular Molars

Principal Investigator: John Nusstein

Sponsor:

• This is a consent form for research participation. It contains important information about this study and what to expect if you decide to participate. Please consider the information carefully. Feel free to discuss the study with your friends and family and to ask questions before making your decision whether or not to participate. • Your participation is voluntary. You may refuse to participate in this study. If you decide to take part in the study, you may leave the study at any time. No matter what decision you make, there will be no penalty to you. Your decision will not affect your future relationship with The Ohio State University. If you are a student or employee at Ohio State, your decision will not affect your grades or employment status. • You may or may not benefit as a result of participating in this study. Also, as explained below, your participation may result in unintended or harmful effects for you that may be minor or may be serious depending on the nature of the research. • You will be provided with any new information that develops during the study that may affect your decision whether or not to continue to participate. If you decide to participate, you will be asked to sign this form and will receive a copy of the form. You are being asked to consider participating in this study for the reasons explained below.

1. Why is this study being done? The purpose of this study is to compare the cleanliness of root canals after two different concentrations of NaOCl (bleach-disinfecting solution) are used within a tooth. We are trying to see if a lesser concentration of disinfecting solution is as effective as the more concentrated form.

2. How many people will take part in this study? Ninety-Five (95) people will take part in this study. Ninety (90) of these participants will have the experimental procedure performed on their tooth before it is extracted and 5 will be considered ‘control’ subjects. These control subjects will be chosen anonymously at random and will have their tooth simply extracted and evaluated without performing any experimental procedures on it.

3. What will happen if you take part in this study? You will receive injections (shots) of lidocaine with epinephrine (a numbing solution like “novocaine”) in the back of your lower jaw. The numbing solution used is not experimental and would be used if you decided to simply have your tooth extracted. Once your tooth is numb, a rubber dam will be placed over the tooth. The rubber dam is a non-latex square that is routinely used during root canals and fillings to protect patients from swallowing or inhaling any foreign objects or solutions. After the rubber dam is placed, the nerve inside of your tooth will be removed just like during a root canal. This is done by placing a small hole through the top of the tooth and into the inside of the tooth where the nerve is located. Small instruments called files will be used to clean the nerve from the inside of the tooth. If you feel discomfort at any time, more anesthetic will be given to you so that you are comfortable while your tooth is being worked on. While the nerve is being removed, one of two concentrations of root canal irrigants will be used to rinse the inside of the tooth. The concentration used in your tooth will be determined at random (like 150 rolling dice) before you start treatment. The actual irrigating solution and the concentrations we will be using are both routinely used in dental practice and have both been shown to be safe. The only difference is the concentration of the solution. The solution’s function is to remove debris and dissolve pulp tissue. Your doctor will not know which concentration of irrigating solution is being used. After the nerve is removed, the same irrigating solution will be used inside the tooth with an ultrasonic tip. The tip is attached to a handpiece which delivers the ultrasonic energy through the tip and into the irrigating solution. This tip will be placed inside the root canals of the tooth and will express irrigating solution for one minute while making a buzzing noise. The tip will be simply moved in an up-and-down motion as solution is delivered from the tip. A high-speed suction tip will be in place to catch the irrigating fluid. It is intended to further clean the root canal of the tooth and is not painful. Once this is completed your tooth will be removed.

4. How long will you be in the study? You will have one appointment which will last approximately 70 minutes; 45-50 minutes to clean the inside of the tooth and15-20 minutes to extract the tooth. You will only need to return to the office for follow-up if you are having complications from the extraction such as a dry socket.

5. Can you stop being in the study? You may leave the study at any time. If you decide to stop participating in the study, there will be no penalty to you, and you will not lose any benefits to which you are otherwise entitled. Your decision will not affect your future relationship with The Ohio State University.

If you are a student or staff member at OSU and choose to stop participating in this study, your grades and/or employment will not be affected. If you choose to stop, you will then be given the option to have the tooth removed (extracted), or, if possible, have the root canal treatment finished at a later time (another appointment). If you choose to try and save the tooth, you will be charged for the emergency treatment and will be responsible for all future costs involved with preserving the tooth (root canal, filling, crown).

6. What risks, side effects or discomforts can you expect from being in the study? You may have pain associated with the injections (shots) of local anesthetic (numbing solutions). Since conventional local anesthetics will be used, the discomforts and risks would include: possible soreness of the injection site which dissipates in a few days; allergy to the numbing solution (very rare); possible lightheadedness or fainting; a possible infection at the site of injection; an increase in heart rate; a tingling of the tongue, lip and cheek that may persist for a few weeks (very rare); an uncomfortable feeling produced by the numbness sensation; and possible tingling, swelling, or bruising of the injection site for 2- 3 days. Soreness of the extraction site can also be expected for 2-3 days after the procedure. An electronic pulp tester will be used to assess the vitality of your tooth. It may produce a tingling sensation that may be uncomfortable. This feeling can be moderately painful and is no more than one second in duration. If an ice spray is used on your teeth, you may feel pain and the pain may linger for a few minutes. This study will use digital radiography (less radiation exposure) and a double lead shield with a collar. The radiation from the 2 x-rays will be equal to approximately 5 hours of natural environment background radiation that you experience everyday, and it will be limited to your mouth. This is less radiation then found in a one hour airplane ride at 39,000 ft., or a 1 month's consumption of drinking water by a single human (Idaho State University Physics Department. Radiation and Risk: www.physics.isu.edu/radinf/risk.htm).

If an intraosseous injection (shot into the bone) is needed to help achieve adequate numbness in the tooth to be treated, you may experience soreness of the injection site with a small risk of infection; and may feel as if the tooth next to the extraction site is ‘high’ to bite on for a few days (‘high’ meaning the tooth may hurt when biting down on it). The use of an intraosseous injection is not part of the study. It is regularly used in dentistry to help achieve numbness and comfort for the patient. If an intrapulpal injection (shot into my tooth) is given to you, it may cause a 2 second burst of pain.

You may experience some pain during the root canal procedure. More anesthesia may be given (see above) 151 to help eliminate this pain.

The use of 6% sodium hypochlorite with ultrasonic irrigation has been shown not to result in an increase in pain over standard root canal therapy without the use of ultrasonic rinsing. This is assumed to be true of the lesser concentrated 3% solution but has not been studied. The 6% solution may have a strong bleach smell. The solution is more dangerous to cells but has been shown to be clinically safe. 7. What benefits can you expect from being in the study? You will not directly benefit from this study since the study tooth will be extracted. Society may benefit from the results of this study by finding that a lower concentration irrigating solution works as well in cleaning root canals as a more concentrated solution when used with ultrasonic energy.

8. What other choices do you have if you do not take part in the study? You may choose not to participate without penalty or loss of benefits to which you are otherwise entitled. If you are a student or staff member at OSU and choose not to participate in this study, your grades and/or employment will not be affected. If you do not choose to participate you can still have the affected tooth taken out or you can decide to save the tooth after the root canal treatment has been started (if the tooth can be restored). 9. Will your study-related information be kept confidential?

Efforts will be made to keep your study-related information confidential. However, there may be circumstances where this information must be released. For example, personal information regarding your participation in this study may be disclosed if required by state law. Also, your records may be reviewed by the following groups (as applicable to the research):

• Office for Human Research Protections or other federal, state, or international regulatory agencies; • U.S. Food and Drug Administration; • The Ohio State University Institutional Review Board or Office of Responsible Research Practices; • The sponsor supporting the study, their agents or study monitors; and • Your insurance company (if charges are billed to insurance).

If the study involves the use of your protected health information, you may also be asked to sign a separate Health Insurance Portability and Accountability Act (HIPAA) research authorization form.

10. What are the costs of taking part in this study? The study will not pay for the cost of the emergency examination ($30.00) or extraction ($56.00) or parking costs.

11. Will you be paid for taking part in this study? Yes, you will be paid $100 for your participation. You will receive the $100.00 for completing all aspects of the study. If you are unable or unwilling to complete the study, you will not be paid. Payment is to compensate you for time and travel expenses.

By law, payments to subjects are considered taxable income.

12. What happens if you are injured because you took part in this study? If you suffer an injury from participating in this study, you should notify the researcher or study doctor immediately, who will determine if you should obtain medical treatment at The Ohio State University Medical Center. 152

The cost for this treatment will be billed to you or your medical or hospital insurance. The Ohio State University has no funds set aside for the payment of health care expenses for this study. 13. What are your rights if you take part in this study?

If you choose to participate in the study, you may discontinue participation at any time without penalty or loss of benefits. By signing this form, you do not give up any personal legal rights you may have as a participant in this study.

You will be provided with any new information that develops during the course of the research that may affect your decision whether or not to continue participation in the study.

You may refuse to participate in this study without penalty or loss of benefits to which you are otherwise entitled.

An Institutional Review Board responsible for human subjects research at The Ohio State University reviewed this research project and found it to be acceptable, according to applicable state and federal regulations and University policies designed to protect the rights and welfare of participants in research.

14. Who can answer your questions about the study?

For questions, concerns, or complaints about the study you may contact Dr. John Nusstein or Dr. Aaron Aue at 614-292-5399.

For questions about your rights as a participant in this study or to discuss other study-related concerns or complaints with someone who is not part of the research team, you may contact Ms. Sandra Meadows in the Office of Responsible Research Practices at 1-800-678-6251.

If you are injured as a result of participating in this study or for questions about a study-related injury, you may contact Dr. John Nusstein or Dr. Aaron Aue at 614-292-5399.

Signing the consent form

You have read (or someone has read to you) this form and you are aware that you are being asked to participate in a research study. You have had the opportunity to ask questions and have had them answered to my satisfaction. You voluntarily agree to participate in this study.

You are not giving up any legal rights by signing this form. You will be given a copy of this form.

Printed name of subject Signature of subject

AM/PM Date and time

153 Printed name of person authorized to Signature of person authorized to consent for consent for subject (when applicable) subject (when applicable)

AM/PM Relationship to the subject Date and time

Investigator/Research Staff

I have explained the research to the participant or his/her representative before requesting the signature(s) above. There are no blanks in this document. A copy of this form has been given to the participant or his/her representative.

Printed name of person obtaining Signature of person obtaining consent consent

AM/PM Date and time

Witness(es) - May be left blank if not required by the IRB

Printed name of witness Signature of witness

AM/PM Date and time

Printed name of witness Signature of witness

AM/PM Date and time

154

APPENDIX B

PATIENT MEDICAL HISTORY SHEET

155 156 157

APPENDIX C

HIPAA FORM

158

THE OHIO STATE UNIVERSITY

AUTHORIZATION TO USE

PERSONAL HEALTH INFORMATION IN RESEARCH

Title of the Study: An Evaluation of the In Vivo Debridement Efficacy of 3.0% NaOCl vs. 6.0% NaOCl Ultrasound After Hand and Rotary Instrumentation in Human Mandibular Molars

OSU Protocol Number: 2008H0143

Principal Investigator: John Nusstein, DDS, MS

Subject Name______Before researchers use or share any health information about you as part of this study, The Ohio State University is required to obtain your authorization. This helps explain to you how this information will be used or shared with others involved in the study.

• The Ohio State University and its hospitals, clinics, health-care providers and researchers are required to protect the privacy of your health information. • You should have received a Notice of Privacy Practices when you received health care services here. If not, let us know and a copy will be given to you. Please carefully review this information. Ask if you have any questions or do not understand any parts of this notice. • If you agree to take part in this study your health information will be used and shared with others involved in this study. Also, any new health information about you that comes from tests or other parts of this study will be shared with those involved in this study. • Health information about you that will be used or shared with others involved in this study may include your research record and any health care records at the Ohio State University. For example, this may include your medical records, x-ray or laboratory results. Psychotherapy notes in your health records (if any) will not, however, be shared or used. Use of these notes requires a separate, signed authorization. Please read the information carefully before signing this form. Please ask if you have any questions about this authorization, the University’s Notice of Privacy Practices or the study before signing this form.

Initials/Date: ______

159 Those Who May Use, Share And Receive Your Information As Part Of This Study

• Researchers and staff at The Ohio State University will use, share and receive your personal health information for this research study. Other Ohio State University staff not involved in the study but who may become involved in your care for study-related treatment will have access to your information. • Those who oversee the study will have access to your information, including: • Members and staff of the Ohio State University’s Institutional Review Boards, including the Western Institutional Review Board • The Office for Responsible Research Practices • University data safety monitoring committees • The Ohio State University Research Foundation • Your health information may also be shared with federal and state agencies that have oversight of the study or to whom access is required under the law. These may include: • The Food and Drug Administration • The Office for Human Research Protections • The National Institutes of Health • The Ohio Department of Human Services

These researchers, companies and/or organization(s) outside of The Ohio State University may also use, share and receive your health information in connection with this study:

None.

The information that is shared with those listed above may no longer be protected by federal privacy rules.

Initials/Date______

160

Authorization Period

This authorization will not expire unless you change your mind and revoke it in writing. There is no set date at which your information will be destroyed or no longer used. This is because the information used and created during the study may be analyzed for many years, and it is not possible to know when this will be complete.

Signing the Authorization

• You have the right to refuse to sign this authorization. Your health care outside of the study, payment for your health care, and your health care benefits will not be affected if you choose not to sign this form. • You will not be able to take part in this study and will not receive any study treatments if you do not sign this form. • If you sign this authorization, you may change your mind at any time. Researchers may continue to use information collected up until the time that you formally changed your mind. If you change your mind, your authorization must be revoked in writing. To revoke your authorization, please write to: Dr. John Nusstein at the College of Dentistry, 305 West 12th Avenue, The Ohio State University, Columbus, Ohio 43210 or Dr. Stanley Vermilyea at the College of Dentistry, 305 West 12th Avenue, The Ohio State University, Columbus, Ohio 43210. • Signing this authorization also means that you will not be able to see or copy your study- related information until the study is completed. This includes any portion of your medical records that describes study treatment.

Contacts for Questions

• If you have any questions relating to your privacy rights, please contact or Dr. Stanley Vermilyea at the College of Dentistry, 305 West 12th Avenue, The Ohio State University, Columbus, Ohio 43210. (614)292-6983. • I you have any questions relating to the research, please contact Dr. John Nusstein at the College of Dentistry, 305 West 12th Avenue, The Ohio State University, Columbus, Ohio 43210. (614)292-9412.

Signature

I have read (or someone has read to me) this form and have been able to ask questions. All of my questions about this form have been answered to my satisfaction. By signing below, I permit Dr. John Nusstein and the others listed on this form to use and share my personal health information for this study. I will be given a copy of this signed form. 161

Signature______(Subject or Legally Authorized Representative)

Name ______(Print name above) (If legal representative, also print relationship to subject.)

Date______Time ______AM / PM

Page 3 of 3

162

APPENDIX D

RAW DATA

163

SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 191408 31 1 18 3 2 0 . 0.80 1 . 191408 31 1 18 3 2 0 . 0.80 1.2 . 191408 31 1 18 3 2 0 . 0.80 1.4 . 191408 31 1 18 3 2 0 . 0.80 1.6 . 191408 31 1 18 3 2 0 . 0.80 1.8 . 191408 31 1 18 3 2 0 . 0.80 2 . 191408 31 1 18 3 2 0 . 0.80 2.2 3.9 191408 31 1 18 3 2 0 . 0.80 2.4 0 191408 31 1 18 3 2 0 . 0.80 2.6 0 191408 31 1 18 3 2 0 . 0.80 2.8 0 191408 31 1 18 3 2 0 . 0.80 3 0 191408 31 1 18 3 2 1 . 0.80 1 . 191408 31 1 18 3 2 1 . 0.80 1.2 . 191408 31 1 18 3 2 1 . 0.80 1.4 . 191408 31 1 18 3 2 1 . 0.80 1.6 . 191408 31 1 18 3 2 1 . 0.80 1.8 . 191408 31 1 18 3 2 1 . 0.80 2 . 191408 31 1 18 3 2 1 . 0.80 2.2 100 191408 31 1 18 3 2 1 . 0.80 2.4 100 191408 31 1 18 3 2 1 . 0.80 2.6 100 191408 31 1 18 3 2 1 . 0.80 2.8 100 191408 31 1 18 3 2 1 . 0.80 3 100 191408 31 1 18 3 2 2 . 0.80 1 . 191408 31 1 18 3 2 2 . 0.80 1.2 . 191408 31 1 18 3 2 2 . 0.80 1.4 . 191408 31 1 18 3 2 2 . 0.80 1.6 . 191408 31 1 18 3 2 2 . 0.80 1.8 . 191408 31 1 18 3 2 2 . 0.80 2 . 191408 31 1 18 3 2 2 . 0.80 2.2 100 191408 31 1 18 3 2 2 . 0.80 2.4 100 191408 31 1 18 3 2 2 . 0.80 2.6 75.9 191408 31 1 18 3 2 2 . 0.80 2.8 73.8 191408 31 1 18 3 2 2 . 0.80 3 71 191408 31 1 18 3 2 3 . 0.80 1 0 191408 31 1 18 3 2 3 . 0.80 1.2 94 191408 31 1 18 3 2 3 . 0.80 1.4 35.6 191408 31 1 18 3 2 3 . 0.80 1.6 35.5 191408 31 1 18 3 2 3 . 0.80 1.8 27.3 191408 31 1 18 3 2 3 . 0.80 2 49 191408 31 1 18 3 2 3 . 0.80 2.2 . 191408 31 1 18 3 2 3 . 0.80 2.4 . 191408 31 1 18 3 2 3 . 0.80 2.6 . 191408 31 1 18 3 2 3 . 0.80 2.8 . 191408 31 1 18 3 2 3 . 0.80 3 . 511091 63 1 31 2 2 0 37 0.69 1 88 511091 63 1 31 2 2 0 37 0.69 1.2 . 164 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 511091 63 1 31 2 2 0 37 0.69 1.4 100 511091 63 1 31 2 2 0 37 0.69 1.6 100 511091 63 1 31 2 2 0 37 0.69 1.8 59.4 511091 63 1 31 2 2 0 37 0.69 2 66 511091 63 1 31 2 2 0 37 0.69 2.2 100 511091 63 1 31 2 2 0 37 0.69 2.4 100 511091 63 1 31 2 2 0 37 0.69 2.6 100 511091 63 1 31 2 2 0 37 0.69 2.8 94.4 511091 63 1 31 2 2 0 37 0.69 3 94.2 511091 63 1 31 2 2 1 37 0.69 1 92.3 511091 63 1 31 2 2 1 37 0.69 1.2 . 511091 63 1 31 2 2 1 37 0.69 1.4 87.6 511091 63 1 31 2 2 1 37 0.69 1.6 100 511091 63 1 31 2 2 1 37 0.69 1.8 100 511091 63 1 31 2 2 1 37 0.69 2 100 511091 63 1 31 2 2 1 37 0.69 2.2 100 511091 63 1 31 2 2 1 37 0.69 2.4 91.1 511091 63 1 31 2 2 1 37 0.69 2.6 94.7 511091 63 1 31 2 2 1 37 0.69 2.8 99.5 511091 63 1 31 2 2 1 37 0.69 3 100 511091 63 1 31 2 2 2 37 0.69 1 . 511091 63 1 31 2 2 2 37 0.69 1.2 . 511091 63 1 31 2 2 2 37 0.69 1.4 . 511091 63 1 31 2 2 2 37 0.69 1.6 . 511091 63 1 31 2 2 2 37 0.69 1.8 . 511091 63 1 31 2 2 2 37 0.69 2 100 511091 63 1 31 2 2 2 37 0.69 2.2 0 511091 63 1 31 2 2 2 37 0.69 2.4 0 511091 63 1 31 2 2 2 37 0.69 2.6 0 511091 63 1 31 2 2 2 37 0.69 2.8 5 511091 63 1 31 2 2 2 37 0.69 3 1.6 511091 63 1 31 2 2 3 37 0.69 1 . 511091 63 1 31 2 2 3 37 0.69 1.2 88.8 511091 63 1 31 2 2 3 37 0.69 1.4 . 511091 63 1 31 2 2 3 37 0.69 1.6 . 511091 63 1 31 2 2 3 37 0.69 1.8 . 511091 63 1 31 2 2 3 37 0.69 2 . 511091 63 1 31 2 2 3 37 0.69 2.2 . 511091 63 1 31 2 2 3 37 0.69 2.4 . 511091 63 1 31 2 2 3 37 0.69 2.6 . 511091 63 1 31 2 2 3 37 0.69 2.8 . 511091 63 1 31 2 2 3 37 0.69 3 . 991863 20 0 . 3 2 0 1 0.72 1 100 991863 20 0 . 3 2 0 1 0.72 1.2 100 991863 20 0 . 3 2 0 1 0.72 1.4 100 991863 20 0 . 3 2 0 1 0.72 1.6 81.6 991863 20 0 . 3 2 0 1 0.72 1.8 93.5 165 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 991863 20 0 . 3 2 0 1 0.72 2 100 991863 20 0 . 3 2 0 1 0.72 2.2 100 991863 20 0 . 3 2 0 1 0.72 2.4 100 991863 20 0 . 3 2 0 1 0.72 2.6 100 991863 20 0 . 3 2 0 1 0.72 2.8 100 991863 20 0 . 3 2 0 1 0.72 3 100 991863 20 0 . 3 2 1 1 0.72 1 79.7 991863 20 0 . 3 2 1 1 0.72 1.2 89.5 991863 20 0 . 3 2 1 1 0.72 1.4 98.4 991863 20 0 . 3 2 1 1 0.72 1.6 100 991863 20 0 . 3 2 1 1 0.72 1.8 100 991863 20 0 . 3 2 1 1 0.72 2 100 991863 20 0 . 3 2 1 1 0.72 2.2 100 991863 20 0 . 3 2 1 1 0.72 2.4 100 991863 20 0 . 3 2 1 1 0.72 2.6 100 991863 20 0 . 3 2 1 1 0.72 2.8 100 991863 20 0 . 3 2 1 1 0.72 3 100 991863 20 0 . 3 2 2 1 0.72 1 0 991863 20 0 . 3 2 2 1 0.72 1.2 0 991863 20 0 . 3 2 2 1 0.72 1.4 0 991863 20 0 . 3 2 2 1 0.72 1.6 8.7 991863 20 0 . 3 2 2 1 0.72 1.8 38.5 991863 20 0 . 3 2 2 1 0.72 2 0 991863 20 0 . 3 2 2 1 0.72 2.2 0 991863 20 0 . 3 2 2 1 0.72 2.4 4.6 991863 20 0 . 3 2 2 1 0.72 2.6 0 991863 20 0 . 3 2 2 1 0.72 2.8 0 991863 20 0 . 3 2 2 1 0.72 3 11.7 991863 20 0 . 3 2 3 1 0.72 1 . 991863 20 0 . 3 2 3 1 0.72 1.2 . 991863 20 0 . 3 2 3 1 0.72 1.4 . 991863 20 0 . 3 2 3 1 0.72 1.6 . 991863 20 0 . 3 2 3 1 0.72 1.8 . 991863 20 0 . 3 2 3 1 0.72 2 . 991863 20 0 . 3 2 3 1 0.72 2.2 . 991863 20 0 . 3 2 3 1 0.72 2.4 . 991863 20 0 . 3 2 3 1 0.72 2.6 . 991863 20 0 . 3 2 3 1 0.72 2.8 . 991863 20 0 . 3 2 3 1 0.72 3 . 596229 45 0 31 2 2 0 43 0.63 1 . 596229 45 0 31 2 2 0 43 0.63 1.2 . 596229 45 0 31 2 2 0 43 0.63 1.4 . 596229 45 0 31 2 2 0 43 0.63 1.6 . 596229 45 0 31 2 2 0 43 0.63 1.8 . 596229 45 0 31 2 2 0 43 0.63 2 . 596229 45 0 31 2 2 0 43 0.63 2.2 . 596229 45 0 31 2 2 0 43 0.63 2.4 . 166 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 596229 45 0 31 2 2 0 43 0.63 2.6 . 596229 45 0 31 2 2 0 43 0.63 2.8 . 596229 45 0 31 2 2 0 43 0.63 3 . 596229 45 0 31 2 2 1 43 0.63 1 . 596229 45 0 31 2 2 1 43 0.63 1.2 . 596229 45 0 31 2 2 1 43 0.63 1.4 . 596229 45 0 31 2 2 1 43 0.63 1.6 . 596229 45 0 31 2 2 1 43 0.63 1.8 . 596229 45 0 31 2 2 1 43 0.63 2 . 596229 45 0 31 2 2 1 43 0.63 2.2 . 596229 45 0 31 2 2 1 43 0.63 2.4 . 596229 45 0 31 2 2 1 43 0.63 2.6 . 596229 45 0 31 2 2 1 43 0.63 2.8 . 596229 45 0 31 2 2 1 43 0.63 3 . 596229 45 0 31 2 2 2 43 0.63 1 . 596229 45 0 31 2 2 2 43 0.63 1.2 . 596229 45 0 31 2 2 2 43 0.63 1.4 . 596229 45 0 31 2 2 2 43 0.63 1.6 . 596229 45 0 31 2 2 2 43 0.63 1.8 . 596229 45 0 31 2 2 2 43 0.63 2 . 596229 45 0 31 2 2 2 43 0.63 2.2 . 596229 45 0 31 2 2 2 43 0.63 2.4 . 596229 45 0 31 2 2 2 43 0.63 2.6 . 596229 45 0 31 2 2 2 43 0.63 2.8 . 596229 45 0 31 2 2 2 43 0.63 3 . 596229 45 0 31 2 2 3 43 0.63 1 100 596229 45 0 31 2 2 3 43 0.63 1.2 100 596229 45 0 31 2 2 3 43 0.63 1.4 100 596229 45 0 31 2 2 3 43 0.63 1.6 100 596229 45 0 31 2 2 3 43 0.63 1.8 100 596229 45 0 31 2 2 3 43 0.63 2 100 596229 45 0 31 2 2 3 43 0.63 2.2 97.2 596229 45 0 31 2 2 3 43 0.63 2.4 98.1 596229 45 0 31 2 2 3 43 0.63 2.6 99.2 596229 45 0 31 2 2 3 43 0.63 2.8 94.4 596229 45 0 31 2 2 3 43 0.63 3 100 253852 21 0 18 3 2 0 33 0.72 1 81.1 253852 21 0 18 3 2 0 33 0.72 1.2 97.7 253852 21 0 18 3 2 0 33 0.72 1.4 100 253852 21 0 18 3 2 0 33 0.72 1.6 100 253852 21 0 18 3 2 0 33 0.72 1.8 100 253852 21 0 18 3 2 0 33 0.72 2 100 253852 21 0 18 3 2 0 33 0.72 2.2 100 253852 21 0 18 3 2 0 33 0.72 2.4 100 253852 21 0 18 3 2 0 33 0.72 2.6 100 253852 21 0 18 3 2 0 33 0.72 2.8 100 253852 21 0 18 3 2 0 33 0.72 3 100 167 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 253852 21 0 18 3 2 1 33 0.72 1 97.7 253852 21 0 18 3 2 1 33 0.72 1.2 100 253852 21 0 18 3 2 1 33 0.72 1.4 100 253852 21 0 18 3 2 1 33 0.72 1.6 100 253852 21 0 18 3 2 1 33 0.72 1.8 100 253852 21 0 18 3 2 1 33 0.72 2 100 253852 21 0 18 3 2 1 33 0.72 2.2 100 253852 21 0 18 3 2 1 33 0.72 2.4 100 253852 21 0 18 3 2 1 33 0.72 2.6 100 253852 21 0 18 3 2 1 33 0.72 2.8 100 253852 21 0 18 3 2 1 33 0.72 3 100 253852 21 0 18 3 2 2 33 0.72 1 0 253852 21 0 18 3 2 2 33 0.72 1.2 . 253852 21 0 18 3 2 2 33 0.72 1.4 . 253852 21 0 18 3 2 2 33 0.72 1.6 . 253852 21 0 18 3 2 2 33 0.72 1.8 . 253852 21 0 18 3 2 2 33 0.72 2 . 253852 21 0 18 3 2 2 33 0.72 2.2 . 253852 21 0 18 3 2 2 33 0.72 2.4 . 253852 21 0 18 3 2 2 33 0.72 2.6 . 253852 21 0 18 3 2 2 33 0.72 2.8 . 253852 21 0 18 3 2 2 33 0.72 3 . 253852 21 0 18 3 2 3 33 0.72 1 . 253852 21 0 18 3 2 3 33 0.72 1.2 . 253852 21 0 18 3 2 3 33 0.72 1.4 . 253852 21 0 18 3 2 3 33 0.72 1.6 . 253852 21 0 18 3 2 3 33 0.72 1.8 . 253852 21 0 18 3 2 3 33 0.72 2 . 253852 21 0 18 3 2 3 33 0.72 2.2 . 253852 21 0 18 3 2 3 33 0.72 2.4 . 253852 21 0 18 3 2 3 33 0.72 2.6 . 253852 21 0 18 3 2 3 33 0.72 2.8 . 253852 21 0 18 3 2 3 33 0.72 3 . 572066 21 0 18 3 2 0 40 0.65 1 96.4 572066 21 0 18 3 2 0 40 0.65 1.2 100 572066 21 0 18 3 2 0 40 0.65 1.4 100 572066 21 0 18 3 2 0 40 0.65 1.6 100 572066 21 0 18 3 2 0 40 0.65 1.8 100 572066 21 0 18 3 2 0 40 0.65 2 100 572066 21 0 18 3 2 0 40 0.65 2.2 100 572066 21 0 18 3 2 0 40 0.65 2.4 100 572066 21 0 18 3 2 0 40 0.65 2.6 100 572066 21 0 18 3 2 0 40 0.65 2.8 100 572066 21 0 18 3 2 0 40 0.65 3 100 572066 21 0 18 3 2 1 40 0.65 1 . 572066 21 0 18 3 2 1 40 0.65 1.2 . 572066 21 0 18 3 2 1 40 0.65 1.4 . 168 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 572066 21 0 18 3 2 1 40 0.65 1.6 100 572066 21 0 18 3 2 1 40 0.65 1.8 99.3 572066 21 0 18 3 2 1 40 0.65 2 100 572066 21 0 18 3 2 1 40 0.65 2.2 100 572066 21 0 18 3 2 1 40 0.65 2.4 100 572066 21 0 18 3 2 1 40 0.65 2.6 100 572066 21 0 18 3 2 1 40 0.65 2.8 100 572066 21 0 18 3 2 1 40 0.65 3 100 572066 21 0 18 3 2 2 40 0.65 1 . 572066 21 0 18 3 2 2 40 0.65 1.2 . 572066 21 0 18 3 2 2 40 0.65 1.4 . 572066 21 0 18 3 2 2 40 0.65 1.6 . 572066 21 0 18 3 2 2 40 0.65 1.8 . 572066 21 0 18 3 2 2 40 0.65 2 . 572066 21 0 18 3 2 2 40 0.65 2.2 . 572066 21 0 18 3 2 2 40 0.65 2.4 . 572066 21 0 18 3 2 2 40 0.65 2.6 . 572066 21 0 18 3 2 2 40 0.65 2.8 . 572066 21 0 18 3 2 2 40 0.65 3 . 572066 21 0 18 3 2 3 40 0.65 1 . 572066 21 0 18 3 2 3 40 0.65 1.2 . 572066 21 0 18 3 2 3 40 0.65 1.4 . 572066 21 0 18 3 2 3 40 0.65 1.6 . 572066 21 0 18 3 2 3 40 0.65 1.8 . 572066 21 0 18 3 2 3 40 0.65 2 . 572066 21 0 18 3 2 3 40 0.65 2.2 . 572066 21 0 18 3 2 3 40 0.65 2.4 . 572066 21 0 18 3 2 3 40 0.65 2.6 . 572066 21 0 18 3 2 3 40 0.65 2.8 . 572066 21 0 18 3 2 3 40 0.65 3 . 677700 46 1 18 3 2 0 25 0.77 1 100 677700 46 1 18 3 2 0 25 0.77 1.2 100 677700 46 1 18 3 2 0 25 0.77 1.4 . 677700 46 1 18 3 2 0 25 0.77 1.6 . 677700 46 1 18 3 2 0 25 0.77 1.8 . 677700 46 1 18 3 2 0 25 0.77 2 . 677700 46 1 18 3 2 0 25 0.77 2.2 . 677700 46 1 18 3 2 0 25 0.77 2.4 . 677700 46 1 18 3 2 0 25 0.77 2.6 . 677700 46 1 18 3 2 0 25 0.77 2.8 . 677700 46 1 18 3 2 0 25 0.77 3 . 677700 46 1 18 3 2 1 25 0.77 1 94.6 677700 46 1 18 3 2 1 25 0.77 1.2 83.2 677700 46 1 18 3 2 1 25 0.77 1.4 . 677700 46 1 18 3 2 1 25 0.77 1.6 . 677700 46 1 18 3 2 1 25 0.77 1.8 . 677700 46 1 18 3 2 1 25 0.77 2 . 169 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 677700 46 1 18 3 2 1 25 0.77 2.2 . 677700 46 1 18 3 2 1 25 0.77 2.4 . 677700 46 1 18 3 2 1 25 0.77 2.6 . 677700 46 1 18 3 2 1 25 0.77 2.8 . 677700 46 1 18 3 2 1 25 0.77 3 . 677700 46 1 18 3 2 2 25 0.77 1 100 677700 46 1 18 3 2 2 25 0.77 1.2 100 677700 46 1 18 3 2 2 25 0.77 1.4 . 677700 46 1 18 3 2 2 25 0.77 1.6 . 677700 46 1 18 3 2 2 25 0.77 1.8 . 677700 46 1 18 3 2 2 25 0.77 2 . 677700 46 1 18 3 2 2 25 0.77 2.2 . 677700 46 1 18 3 2 2 25 0.77 2.4 . 677700 46 1 18 3 2 2 25 0.77 2.6 . 677700 46 1 18 3 2 2 25 0.77 2.8 . 677700 46 1 18 3 2 2 25 0.77 3 . 677700 46 1 18 3 2 3 25 0.77 1 . 677700 46 1 18 3 2 3 25 0.77 1.2 . 677700 46 1 18 3 2 3 25 0.77 1.4 100 677700 46 1 18 3 2 3 25 0.77 1.6 95.1 677700 46 1 18 3 2 3 25 0.77 1.8 100 677700 46 1 18 3 2 3 25 0.77 2 99 677700 46 1 18 3 2 3 25 0.77 2.2 98.6 677700 46 1 18 3 2 3 25 0.77 2.4 98.8 677700 46 1 18 3 2 3 25 0.77 2.6 100 677700 46 1 18 3 2 3 25 0.77 2.8 100 677700 46 1 18 3 2 3 25 0.77 3 96.6 370451 23 1 30 3 2 0 31 0.74 1 100 370451 23 1 30 3 2 0 31 0.74 1.2 100 370451 23 1 30 3 2 0 31 0.74 1.4 100 370451 23 1 30 3 2 0 31 0.74 1.6 100 370451 23 1 30 3 2 0 31 0.74 1.8 100 370451 23 1 30 3 2 0 31 0.74 2 100 370451 23 1 30 3 2 0 31 0.74 2.2 100 370451 23 1 30 3 2 0 31 0.74 2.4 100 370451 23 1 30 3 2 0 31 0.74 2.6 100 370451 23 1 30 3 2 0 31 0.74 2.8 100 370451 23 1 30 3 2 0 31 0.74 3 100 370451 23 1 30 3 2 1 31 0.74 1 100 370451 23 1 30 3 2 1 31 0.74 1.2 100 370451 23 1 30 3 2 1 31 0.74 1.4 100 370451 23 1 30 3 2 1 31 0.74 1.6 100 370451 23 1 30 3 2 1 31 0.74 1.8 100 370451 23 1 30 3 2 1 31 0.74 2 100 370451 23 1 30 3 2 1 31 0.74 2.2 100 370451 23 1 30 3 2 1 31 0.74 2.4 100 370451 23 1 30 3 2 1 31 0.74 2.6 100 170 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 370451 23 1 30 3 2 1 31 0.74 2.8 100 370451 23 1 30 3 2 1 31 0.74 3 100 370451 23 1 30 3 2 2 31 0.74 1 20.7 370451 23 1 30 3 2 2 31 0.74 1.2 16.5 370451 23 1 30 3 2 2 31 0.74 1.4 0 370451 23 1 30 3 2 2 31 0.74 1.6 0 370451 23 1 30 3 2 2 31 0.74 1.8 12.5 370451 23 1 30 3 2 2 31 0.74 2 16.9 370451 23 1 30 3 2 2 31 0.74 2.2 0 370451 23 1 30 3 2 2 31 0.74 2.4 28.7 370451 23 1 30 3 2 2 31 0.74 2.6 0 370451 23 1 30 3 2 2 31 0.74 2.8 12.8 370451 23 1 30 3 2 2 31 0.74 3 38.7 370451 23 1 30 3 2 3 31 0.74 1 . 370451 23 1 30 3 2 3 31 0.74 1.2 . 370451 23 1 30 3 2 3 31 0.74 1.4 . 370451 23 1 30 3 2 3 31 0.74 1.6 . 370451 23 1 30 3 2 3 31 0.74 1.8 . 370451 23 1 30 3 2 3 31 0.74 2 . 370451 23 1 30 3 2 3 31 0.74 2.2 . 370451 23 1 30 3 2 3 31 0.74 2.4 . 370451 23 1 30 3 2 3 31 0.74 2.6 . 370451 23 1 30 3 2 3 31 0.74 2.8 . 370451 23 1 30 3 2 3 31 0.74 3 . 389596 35 1 31 3 2 0 42 0.79 1 89.9 389596 35 1 31 3 2 0 42 0.79 1.2 94.6 389596 35 1 31 3 2 0 42 0.79 1.4 59 389596 35 1 31 3 2 0 42 0.79 1.6 88.7 389596 35 1 31 3 2 0 42 0.79 1.8 93.1 389596 35 1 31 3 2 0 42 0.79 2 92.8 389596 35 1 31 3 2 0 42 0.79 2.2 94.5 389596 35 1 31 3 2 0 42 0.79 2.4 100 389596 35 1 31 3 2 0 42 0.79 2.6 100 389596 35 1 31 3 2 0 42 0.79 2.8 98.7 389596 35 1 31 3 2 0 42 0.79 3 100 389596 35 1 31 3 2 1 42 0.79 1 53.8 389596 35 1 31 3 2 1 42 0.79 1.2 78.5 389596 35 1 31 3 2 1 42 0.79 1.4 100 389596 35 1 31 3 2 1 42 0.79 1.6 100 389596 35 1 31 3 2 1 42 0.79 1.8 100 389596 35 1 31 3 2 1 42 0.79 2 100 389596 35 1 31 3 2 1 42 0.79 2.2 100 389596 35 1 31 3 2 1 42 0.79 2.4 100 389596 35 1 31 3 2 1 42 0.79 2.6 100 389596 35 1 31 3 2 1 42 0.79 2.8 100 389596 35 1 31 3 2 1 42 0.79 3 100 389596 35 1 31 3 2 2 42 0.79 1 . 171 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 389596 35 1 31 3 2 2 42 0.79 1.2 . 389596 35 1 31 3 2 2 42 0.79 1.4 . 389596 35 1 31 3 2 2 42 0.79 1.6 . 389596 35 1 31 3 2 2 42 0.79 1.8 . 389596 35 1 31 3 2 2 42 0.79 2 . 389596 35 1 31 3 2 2 42 0.79 2.2 . 389596 35 1 31 3 2 2 42 0.79 2.4 . 389596 35 1 31 3 2 2 42 0.79 2.6 . 389596 35 1 31 3 2 2 42 0.79 2.8 . 389596 35 1 31 3 2 2 42 0.79 3 . 389596 35 1 31 3 2 3 42 0.79 1 . 389596 35 1 31 3 2 3 42 0.79 1.2 . 389596 35 1 31 3 2 3 42 0.79 1.4 . 389596 35 1 31 3 2 3 42 0.79 1.6 . 389596 35 1 31 3 2 3 42 0.79 1.8 . 389596 35 1 31 3 2 3 42 0.79 2 . 389596 35 1 31 3 2 3 42 0.79 2.2 . 389596 35 1 31 3 2 3 42 0.79 2.4 . 389596 35 1 31 3 2 3 42 0.79 2.6 . 389596 35 1 31 3 2 3 42 0.79 2.8 . 389596 35 1 31 3 2 3 42 0.79 3 . 856756 41 0 31 2 2 0 45 0.79 1 . 856756 41 0 31 2 2 0 45 0.79 1.2 . 856756 41 0 31 2 2 0 45 0.79 1.4 . 856756 41 0 31 2 2 0 45 0.79 1.6 100 856756 41 0 31 2 2 0 45 0.79 1.8 100 856756 41 0 31 2 2 0 45 0.79 2 100 856756 41 0 31 2 2 0 45 0.79 2.2 100 856756 41 0 31 2 2 0 45 0.79 2.4 100 856756 41 0 31 2 2 0 45 0.79 2.6 100 856756 41 0 31 2 2 0 45 0.79 2.8 100 856756 41 0 31 2 2 0 45 0.79 3 100 856756 41 0 31 2 2 1 45 0.79 1 . 856756 41 0 31 2 2 1 45 0.79 1.2 . 856756 41 0 31 2 2 1 45 0.79 1.4 . 856756 41 0 31 2 2 1 45 0.79 1.6 69.4 856756 41 0 31 2 2 1 45 0.79 1.8 64.4 856756 41 0 31 2 2 1 45 0.79 2 67.3 856756 41 0 31 2 2 1 45 0.79 2.2 74.4 856756 41 0 31 2 2 1 45 0.79 2.4 84.9 856756 41 0 31 2 2 1 45 0.79 2.6 98.4 856756 41 0 31 2 2 1 45 0.79 2.8 100 856756 41 0 31 2 2 1 45 0.79 3 100 856756 41 0 31 2 2 2 45 0.79 1 . 856756 41 0 31 2 2 2 45 0.79 1.2 . 856756 41 0 31 2 2 2 45 0.79 1.4 . 856756 41 0 31 2 2 2 45 0.79 1.6 . 172 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 856756 41 0 31 2 2 2 45 0.79 1.8 . 856756 41 0 31 2 2 2 45 0.79 2 . 856756 41 0 31 2 2 2 45 0.79 2.2 . 856756 41 0 31 2 2 2 45 0.79 2.4 . 856756 41 0 31 2 2 2 45 0.79 2.6 . 856756 41 0 31 2 2 2 45 0.79 2.8 . 856756 41 0 31 2 2 2 45 0.79 3 100 856756 41 0 31 2 2 3 45 0.79 1 68.7 856756 41 0 31 2 2 3 45 0.79 1.2 77 856756 41 0 31 2 2 3 45 0.79 1.4 100 856756 41 0 31 2 2 3 45 0.79 1.6 . 856756 41 0 31 2 2 3 45 0.79 1.8 . 856756 41 0 31 2 2 3 45 0.79 2 . 856756 41 0 31 2 2 3 45 0.79 2.2 . 856756 41 0 31 2 2 3 45 0.79 2.4 . 856756 41 0 31 2 2 3 45 0.79 2.6 . 856756 41 0 31 2 2 3 45 0.79 2.8 . 856756 41 0 31 2 2 3 45 0.79 3 . 999574 41 1 19 3 2 0 36 0.76 1 79.2 999574 41 1 19 3 2 0 36 0.76 1.2 85.7 999574 41 1 19 3 2 0 36 0.76 1.4 100 999574 41 1 19 3 2 0 36 0.76 1.6 100 999574 41 1 19 3 2 0 36 0.76 1.8 100 999574 41 1 19 3 2 0 36 0.76 2 100 999574 41 1 19 3 2 0 36 0.76 2.2 100 999574 41 1 19 3 2 0 36 0.76 2.4 100 999574 41 1 19 3 2 0 36 0.76 2.6 100 999574 41 1 19 3 2 0 36 0.76 2.8 100 999574 41 1 19 3 2 0 36 0.76 3 100 999574 41 1 19 3 2 1 36 0.76 1 87.1 999574 41 1 19 3 2 1 36 0.76 1.2 96.4 999574 41 1 19 3 2 1 36 0.76 1.4 100 999574 41 1 19 3 2 1 36 0.76 1.6 98.7 999574 41 1 19 3 2 1 36 0.76 1.8 100 999574 41 1 19 3 2 1 36 0.76 2 100 999574 41 1 19 3 2 1 36 0.76 2.2 100 999574 41 1 19 3 2 1 36 0.76 2.4 100 999574 41 1 19 3 2 1 36 0.76 2.6 100 999574 41 1 19 3 2 1 36 0.76 2.8 100 999574 41 1 19 3 2 1 36 0.76 3 100 999574 41 1 19 3 2 2 36 0.76 1 . 999574 41 1 19 3 2 2 36 0.76 1.2 . 999574 41 1 19 3 2 2 36 0.76 1.4 . 999574 41 1 19 3 2 2 36 0.76 1.6 . 999574 41 1 19 3 2 2 36 0.76 1.8 21.3 999574 41 1 19 3 2 2 36 0.76 2 0 999574 41 1 19 3 2 2 36 0.76 2.2 23.7 173 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 999574 41 1 19 3 2 2 36 0.76 2.4 33.7 999574 41 1 19 3 2 2 36 0.76 2.6 18.9 999574 41 1 19 3 2 2 36 0.76 2.8 40 999574 41 1 19 3 2 2 36 0.76 3 20.1 999574 41 1 19 3 2 3 36 0.76 1 . 999574 41 1 19 3 2 3 36 0.76 1.2 . 999574 41 1 19 3 2 3 36 0.76 1.4 . 999574 41 1 19 3 2 3 36 0.76 1.6 . 999574 41 1 19 3 2 3 36 0.76 1.8 . 999574 41 1 19 3 2 3 36 0.76 2 . 999574 41 1 19 3 2 3 36 0.76 2.2 . 999574 41 1 19 3 2 3 36 0.76 2.4 . 999574 41 1 19 3 2 3 36 0.76 2.6 . 999574 41 1 19 3 2 3 36 0.76 2.8 . 999574 41 1 19 3 2 3 36 0.76 3 . 624420 23 0 30 3 2 0 31 0.68 1 34 624420 23 0 30 3 2 0 31 0.68 1.2 14.8 624420 23 0 30 3 2 0 31 0.68 1.4 99 624420 23 0 30 3 2 0 31 0.68 1.6 74.1 624420 23 0 30 3 2 0 31 0.68 1.8 66.5 624420 23 0 30 3 2 0 31 0.68 2 38.3 624420 23 0 30 3 2 0 31 0.68 2.2 86.7 624420 23 0 30 3 2 0 31 0.68 2.4 91.6 624420 23 0 30 3 2 0 31 0.68 2.6 81.4 624420 23 0 30 3 2 0 31 0.68 2.8 69.7 624420 23 0 30 3 2 0 31 0.68 3 94.9 624420 23 0 30 3 2 1 31 0.68 1 100 624420 23 0 30 3 2 1 31 0.68 1.2 98.3 624420 23 0 30 3 2 1 31 0.68 1.4 97.9 624420 23 0 30 3 2 1 31 0.68 1.6 94.3 624420 23 0 30 3 2 1 31 0.68 1.8 96.3 624420 23 0 30 3 2 1 31 0.68 2 92.5 624420 23 0 30 3 2 1 31 0.68 2.2 100 624420 23 0 30 3 2 1 31 0.68 2.4 100 624420 23 0 30 3 2 1 31 0.68 2.6 100 624420 23 0 30 3 2 1 31 0.68 2.8 100 624420 23 0 30 3 2 1 31 0.68 3 100 624420 23 0 30 3 2 2 31 0.68 1 0 624420 23 0 30 3 2 2 31 0.68 1.2 . 624420 23 0 30 3 2 2 31 0.68 1.4 . 624420 23 0 30 3 2 2 31 0.68 1.6 38.1 624420 23 0 30 3 2 2 31 0.68 1.8 45.4 624420 23 0 30 3 2 2 31 0.68 2 0 624420 23 0 30 3 2 2 31 0.68 2.2 0 624420 23 0 30 3 2 2 31 0.68 2.4 0 624420 23 0 30 3 2 2 31 0.68 2.6 0 624420 23 0 30 3 2 2 31 0.68 2.8 0 174 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 624420 23 0 30 3 2 2 31 0.68 3 0 624420 23 0 30 3 2 3 31 0.68 1 . 624420 23 0 30 3 2 3 31 0.68 1.2 . 624420 23 0 30 3 2 3 31 0.68 1.4 . 624420 23 0 30 3 2 3 31 0.68 1.6 . 624420 23 0 30 3 2 3 31 0.68 1.8 . 624420 23 0 30 3 2 3 31 0.68 2 . 624420 23 0 30 3 2 3 31 0.68 2.2 . 624420 23 0 30 3 2 3 31 0.68 2.4 . 624420 23 0 30 3 2 3 31 0.68 2.6 . 624420 23 0 30 3 2 3 31 0.68 2.8 . 624420 23 0 30 3 2 3 31 0.68 3 . 850395 27 1 32 1 2 0 46 0.74 1 82.4 850395 27 1 32 1 2 0 46 0.74 1.2 91.3 850395 27 1 32 1 2 0 46 0.74 1.4 . 850395 27 1 32 1 2 0 46 0.74 1.6 . 850395 27 1 32 1 2 0 46 0.74 1.8 . 850395 27 1 32 1 2 0 46 0.74 2 . 850395 27 1 32 1 2 0 46 0.74 2.2 . 850395 27 1 32 1 2 0 46 0.74 2.4 . 850395 27 1 32 1 2 0 46 0.74 2.6 . 850395 27 1 32 1 2 0 46 0.74 2.8 . 850395 27 1 32 1 2 0 46 0.74 3 . 850395 27 1 32 1 2 1 46 0.74 1 69.2 850395 27 1 32 1 2 1 46 0.74 1.2 81.4 850395 27 1 32 1 2 1 46 0.74 1.4 . 850395 27 1 32 1 2 1 46 0.74 1.6 . 850395 27 1 32 1 2 1 46 0.74 1.8 . 850395 27 1 32 1 2 1 46 0.74 2 . 850395 27 1 32 1 2 1 46 0.74 2.2 . 850395 27 1 32 1 2 1 46 0.74 2.4 . 850395 27 1 32 1 2 1 46 0.74 2.6 . 850395 27 1 32 1 2 1 46 0.74 2.8 . 850395 27 1 32 1 2 1 46 0.74 3 . 850395 27 1 32 1 2 2 46 0.74 1 . 850395 27 1 32 1 2 2 46 0.74 1.2 . 850395 27 1 32 1 2 2 46 0.74 1.4 . 850395 27 1 32 1 2 2 46 0.74 1.6 . 850395 27 1 32 1 2 2 46 0.74 1.8 . 850395 27 1 32 1 2 2 46 0.74 2 . 850395 27 1 32 1 2 2 46 0.74 2.2 . 850395 27 1 32 1 2 2 46 0.74 2.4 . 850395 27 1 32 1 2 2 46 0.74 2.6 . 850395 27 1 32 1 2 2 46 0.74 2.8 . 850395 27 1 32 1 2 2 46 0.74 3 . 850395 27 1 32 1 2 3 46 0.74 1 . 850395 27 1 32 1 2 3 46 0.74 1.2 . 175 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 850395 27 1 32 1 2 3 46 0.74 1.4 79.5 850395 27 1 32 1 2 3 46 0.74 1.6 15.3 850395 27 1 32 1 2 3 46 0.74 1.8 16.6 850395 27 1 32 1 2 3 46 0.74 2 77.7 850395 27 1 32 1 2 3 46 0.74 2.2 85.4 850395 27 1 32 1 2 3 46 0.74 2.4 58.4 850395 27 1 32 1 2 3 46 0.74 2.6 66.6 850395 27 1 32 1 2 3 46 0.74 2.8 69.9 850395 27 1 32 1 2 3 46 0.74 3 66.5 662554 29 1 30 3 2 0 37 0.68 1 96.5 662554 29 1 30 3 2 0 37 0.68 1.2 100 662554 29 1 30 3 2 0 37 0.68 1.4 100 662554 29 1 30 3 2 0 37 0.68 1.6 100 662554 29 1 30 3 2 0 37 0.68 1.8 100 662554 29 1 30 3 2 0 37 0.68 2 100 662554 29 1 30 3 2 0 37 0.68 2.2 100 662554 29 1 30 3 2 0 37 0.68 2.4 100 662554 29 1 30 3 2 0 37 0.68 2.6 100 662554 29 1 30 3 2 0 37 0.68 2.8 100 662554 29 1 30 3 2 0 37 0.68 3 100 662554 29 1 30 3 2 1 37 0.68 1 82.7 662554 29 1 30 3 2 1 37 0.68 1.2 94.6 662554 29 1 30 3 2 1 37 0.68 1.4 100 662554 29 1 30 3 2 1 37 0.68 1.6 100 662554 29 1 30 3 2 1 37 0.68 1.8 100 662554 29 1 30 3 2 1 37 0.68 2 100 662554 29 1 30 3 2 1 37 0.68 2.2 100 662554 29 1 30 3 2 1 37 0.68 2.4 100 662554 29 1 30 3 2 1 37 0.68 2.6 100 662554 29 1 30 3 2 1 37 0.68 2.8 100 662554 29 1 30 3 2 1 37 0.68 3 100 662554 29 1 30 3 2 2 37 0.68 1 11.4 662554 29 1 30 3 2 2 37 0.68 1.2 12.5 662554 29 1 30 3 2 2 37 0.68 1.4 51.4 662554 29 1 30 3 2 2 37 0.68 1.6 43.8 662554 29 1 30 3 2 2 37 0.68 1.8 13.2 662554 29 1 30 3 2 2 37 0.68 2 0 662554 29 1 30 3 2 2 37 0.68 2.2 0 662554 29 1 30 3 2 2 37 0.68 2.4 17.7 662554 29 1 30 3 2 2 37 0.68 2.6 0 662554 29 1 30 3 2 2 37 0.68 2.8 8.9 662554 29 1 30 3 2 2 37 0.68 3 22.6 662554 29 1 30 3 2 3 37 0.68 1 . 662554 29 1 30 3 2 3 37 0.68 1.2 . 662554 29 1 30 3 2 3 37 0.68 1.4 . 662554 29 1 30 3 2 3 37 0.68 1.6 . 662554 29 1 30 3 2 3 37 0.68 1.8 . 176 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 662554 29 1 30 3 2 3 37 0.68 2 . 662554 29 1 30 3 2 3 37 0.68 2.2 . 662554 29 1 30 3 2 3 37 0.68 2.4 . 662554 29 1 30 3 2 3 37 0.68 2.6 . 662554 29 1 30 3 2 3 37 0.68 2.8 . 662554 29 1 30 3 2 3 37 0.68 3 . 943004 21 1 31 3 2 0 47 0.77 1 . 943004 21 1 31 3 2 0 47 0.77 1.2 . 943004 21 1 31 3 2 0 47 0.77 1.4 4.3 943004 21 1 31 3 2 0 47 0.77 1.6 16 943004 21 1 31 3 2 0 47 0.77 1.8 86.1 943004 21 1 31 3 2 0 47 0.77 2 68.1 943004 21 1 31 3 2 0 47 0.77 2.2 82.8 943004 21 1 31 3 2 0 47 0.77 2.4 63 943004 21 1 31 3 2 0 47 0.77 2.6 58.5 943004 21 1 31 3 2 0 47 0.77 2.8 90.5 943004 21 1 31 3 2 0 47 0.77 3 99.1 943004 21 1 31 3 2 1 47 0.77 1 6.8 943004 21 1 31 3 2 1 47 0.77 1.2 52.6 943004 21 1 31 3 2 1 47 0.77 1.4 48.7 943004 21 1 31 3 2 1 47 0.77 1.6 58.5 943004 21 1 31 3 2 1 47 0.77 1.8 59 943004 21 1 31 3 2 1 47 0.77 2 68.3 943004 21 1 31 3 2 1 47 0.77 2.2 76 943004 21 1 31 3 2 1 47 0.77 2.4 89.5 943004 21 1 31 3 2 1 47 0.77 2.6 85.8 943004 21 1 31 3 2 1 47 0.77 2.8 90.2 943004 21 1 31 3 2 1 47 0.77 3 78 943004 21 1 31 3 2 2 47 0.77 1 . 943004 21 1 31 3 2 2 47 0.77 1.2 . 943004 21 1 31 3 2 2 47 0.77 1.4 . 943004 21 1 31 3 2 2 47 0.77 1.6 . 943004 21 1 31 3 2 2 47 0.77 1.8 . 943004 21 1 31 3 2 2 47 0.77 2 . 943004 21 1 31 3 2 2 47 0.77 2.2 . 943004 21 1 31 3 2 2 47 0.77 2.4 . 943004 21 1 31 3 2 2 47 0.77 2.6 . 943004 21 1 31 3 2 2 47 0.77 2.8 . 943004 21 1 31 3 2 2 47 0.77 3 . 943004 21 1 31 3 2 3 47 0.77 1 . 943004 21 1 31 3 2 3 47 0.77 1.2 . 943004 21 1 31 3 2 3 47 0.77 1.4 . 943004 21 1 31 3 2 3 47 0.77 1.6 . 943004 21 1 31 3 2 3 47 0.77 1.8 . 943004 21 1 31 3 2 3 47 0.77 2 . 943004 21 1 31 3 2 3 47 0.77 2.2 . 943004 21 1 31 3 2 3 47 0.77 2.4 . 177 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 943004 21 1 31 3 2 3 47 0.77 2.6 . 943004 21 1 31 3 2 3 47 0.77 2.8 . 943004 21 1 31 3 2 3 47 0.77 3 . 859704 24 1 31 3 2 0 34 0.70 1 86.4 859704 24 1 31 3 2 0 34 0.70 1.2 95.9 859704 24 1 31 3 2 0 34 0.70 1.4 97.3 859704 24 1 31 3 2 0 34 0.70 1.6 98 859704 24 1 31 3 2 0 34 0.70 1.8 97.6 859704 24 1 31 3 2 0 34 0.70 2 99.1 859704 24 1 31 3 2 0 34 0.70 2.2 99.1 859704 24 1 31 3 2 0 34 0.70 2.4 100 859704 24 1 31 3 2 0 34 0.70 2.6 94.6 859704 24 1 31 3 2 0 34 0.70 2.8 100 859704 24 1 31 3 2 0 34 0.70 3 100 859704 24 1 31 3 2 1 34 0.70 1 96.1 859704 24 1 31 3 2 1 34 0.70 1.2 97.2 859704 24 1 31 3 2 1 34 0.70 1.4 98.7 859704 24 1 31 3 2 1 34 0.70 1.6 90.6 859704 24 1 31 3 2 1 34 0.70 1.8 91.1 859704 24 1 31 3 2 1 34 0.70 2 94.3 859704 24 1 31 3 2 1 34 0.70 2.2 100 859704 24 1 31 3 2 1 34 0.70 2.4 100 859704 24 1 31 3 2 1 34 0.70 2.6 100 859704 24 1 31 3 2 1 34 0.70 2.8 100 859704 24 1 31 3 2 1 34 0.70 3 100 859704 24 1 31 3 2 2 34 0.70 1 . 859704 24 1 31 3 2 2 34 0.70 1.2 . 859704 24 1 31 3 2 2 34 0.70 1.4 . 859704 24 1 31 3 2 2 34 0.70 1.6 . 859704 24 1 31 3 2 2 34 0.70 1.8 . 859704 24 1 31 3 2 2 34 0.70 2 . 859704 24 1 31 3 2 2 34 0.70 2.2 . 859704 24 1 31 3 2 2 34 0.70 2.4 . 859704 24 1 31 3 2 2 34 0.70 2.6 . 859704 24 1 31 3 2 2 34 0.70 2.8 . 859704 24 1 31 3 2 2 34 0.70 3 . 859704 24 1 31 3 2 3 34 0.70 1 . 859704 24 1 31 3 2 3 34 0.70 1.2 . 859704 24 1 31 3 2 3 34 0.70 1.4 . 859704 24 1 31 3 2 3 34 0.70 1.6 . 859704 24 1 31 3 2 3 34 0.70 1.8 . 859704 24 1 31 3 2 3 34 0.70 2 . 859704 24 1 31 3 2 3 34 0.70 2.2 . 859704 24 1 31 3 2 3 34 0.70 2.4 . 859704 24 1 31 3 2 3 34 0.70 2.6 . 859704 24 1 31 3 2 3 34 0.70 2.8 . 859704 24 1 31 3 2 3 34 0.70 3 . 178 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 303473 27 1 18 3 1 0 26 . 1 100 303473 27 1 18 3 1 0 26 . 1.2 100 303473 27 1 18 3 1 0 26 . 1.4 100 303473 27 1 18 3 1 0 26 . 1.6 100 303473 27 1 18 3 1 0 26 . 1.8 100 303473 27 1 18 3 1 0 26 . 2 100 303473 27 1 18 3 1 0 26 . 2.2 100 303473 27 1 18 3 1 0 26 . 2.4 100 303473 27 1 18 3 1 0 26 . 2.6 100 303473 27 1 18 3 1 0 26 . 2.8 100 303473 27 1 18 3 1 0 26 . 3 100 303473 27 1 18 3 1 1 26 . 1 100 303473 27 1 18 3 1 1 26 . 1.2 100 303473 27 1 18 3 1 1 26 . 1.4 100 303473 27 1 18 3 1 1 26 . 1.6 100 303473 27 1 18 3 1 1 26 . 1.8 100 303473 27 1 18 3 1 1 26 . 2 100 303473 27 1 18 3 1 1 26 . 2.2 100 303473 27 1 18 3 1 1 26 . 2.4 100 303473 27 1 18 3 1 1 26 . 2.6 100 303473 27 1 18 3 1 1 26 . 2.8 100 303473 27 1 18 3 1 1 26 . 3 100 303473 27 1 18 3 1 2 26 . 1 . 303473 27 1 18 3 1 2 26 . 1.2 69 303473 27 1 18 3 1 2 26 . 1.4 100 303473 27 1 18 3 1 2 26 . 1.6 82.3 303473 27 1 18 3 1 2 26 . 1.8 73.5 303473 27 1 18 3 1 2 26 . 2 61.9 303473 27 1 18 3 1 2 26 . 2.2 93 303473 27 1 18 3 1 2 26 . 2.4 46 303473 27 1 18 3 1 2 26 . 2.6 47.5 303473 27 1 18 3 1 2 26 . 2.8 100 303473 27 1 18 3 1 2 26 . 3 100 303473 27 1 18 3 1 3 26 . 1 . 303473 27 1 18 3 1 3 26 . 1.2 . 303473 27 1 18 3 1 3 26 . 1.4 . 303473 27 1 18 3 1 3 26 . 1.6 . 303473 27 1 18 3 1 3 26 . 1.8 . 303473 27 1 18 3 1 3 26 . 2 . 303473 27 1 18 3 1 3 26 . 2.2 . 303473 27 1 18 3 1 3 26 . 2.4 . 303473 27 1 18 3 1 3 26 . 2.6 . 303473 27 1 18 3 1 3 26 . 2.8 . 303473 27 1 18 3 1 3 26 . 3 . 293640 32 1 31 2 1 0 48 . 1 . 293640 32 1 31 2 1 0 48 . 1.2 . 293640 32 1 31 2 1 0 48 . 1.4 . 179 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 293640 32 1 31 2 1 0 48 . 1.6 . 293640 32 1 31 2 1 0 48 . 1.8 100 293640 32 1 31 2 1 0 48 . 2 100 293640 32 1 31 2 1 0 48 . 2.2 100 293640 32 1 31 2 1 0 48 . 2.4 . 293640 32 1 31 2 1 0 48 . 2.6 . 293640 32 1 31 2 1 0 48 . 2.8 . 293640 32 1 31 2 1 0 48 . 3 100 293640 32 1 31 2 1 1 48 . 1 . 293640 32 1 31 2 1 1 48 . 1.2 . 293640 32 1 31 2 1 1 48 . 1.4 . 293640 32 1 31 2 1 1 48 . 1.6 . 293640 32 1 31 2 1 1 48 . 1.8 82.8 293640 32 1 31 2 1 1 48 . 2 100 293640 32 1 31 2 1 1 48 . 2.2 100 293640 32 1 31 2 1 1 48 . 2.4 . 293640 32 1 31 2 1 1 48 . 2.6 . 293640 32 1 31 2 1 1 48 . 2.8 . 293640 32 1 31 2 1 1 48 . 3 100 293640 32 1 31 2 1 2 48 . 1 . 293640 32 1 31 2 1 2 48 . 1.2 . 293640 32 1 31 2 1 2 48 . 1.4 . 293640 32 1 31 2 1 2 48 . 1.6 . 293640 32 1 31 2 1 2 48 . 1.8 92.4 293640 32 1 31 2 1 2 48 . 2 100 293640 32 1 31 2 1 2 48 . 2.2 100 293640 32 1 31 2 1 2 48 . 2.4 . 293640 32 1 31 2 1 2 48 . 2.6 . 293640 32 1 31 2 1 2 48 . 2.8 . 293640 32 1 31 2 1 2 48 . 3 100 293640 32 1 31 2 1 3 48 . 1 96.8 293640 32 1 31 2 1 3 48 . 1.2 90.5 293640 32 1 31 2 1 3 48 . 1.4 92.3 293640 32 1 31 2 1 3 48 . 1.6 99.6 293640 32 1 31 2 1 3 48 . 1.8 . 293640 32 1 31 2 1 3 48 . 2 . 293640 32 1 31 2 1 3 48 . 2.2 . 293640 32 1 31 2 1 3 48 . 2.4 100 293640 32 1 31 2 1 3 48 . 2.6 100 293640 32 1 31 2 1 3 48 . 2.8 100 293640 32 1 31 2 1 3 48 . 3 . 604727 22 1 18 3 1 0 19 . 1 100 604727 22 1 18 3 1 0 19 . 1.2 100 604727 22 1 18 3 1 0 19 . 1.4 100 604727 22 1 18 3 1 0 19 . 1.6 100 604727 22 1 18 3 1 0 19 . 1.8 100 604727 22 1 18 3 1 0 19 . 2 100 180 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 604727 22 1 18 3 1 0 19 . 2.2 100 604727 22 1 18 3 1 0 19 . 2.4 100 604727 22 1 18 3 1 0 19 . 2.6 100 604727 22 1 18 3 1 0 19 . 2.8 100 604727 22 1 18 3 1 0 19 . 3 100 604727 22 1 18 3 1 1 19 . 1 100 604727 22 1 18 3 1 1 19 . 1.2 100 604727 22 1 18 3 1 1 19 . 1.4 100 604727 22 1 18 3 1 1 19 . 1.6 100 604727 22 1 18 3 1 1 19 . 1.8 100 604727 22 1 18 3 1 1 19 . 2 100 604727 22 1 18 3 1 1 19 . 2.2 100 604727 22 1 18 3 1 1 19 . 2.4 100 604727 22 1 18 3 1 1 19 . 2.6 100 604727 22 1 18 3 1 1 19 . 2.8 100 604727 22 1 18 3 1 1 19 . 3 100 604727 22 1 18 3 1 2 19 . 1 . 604727 22 1 18 3 1 2 19 . 1.2 . 604727 22 1 18 3 1 2 19 . 1.4 . 604727 22 1 18 3 1 2 19 . 1.6 . 604727 22 1 18 3 1 2 19 . 1.8 . 604727 22 1 18 3 1 2 19 . 2 . 604727 22 1 18 3 1 2 19 . 2.2 . 604727 22 1 18 3 1 2 19 . 2.4 . 604727 22 1 18 3 1 2 19 . 2.6 . 604727 22 1 18 3 1 2 19 . 2.8 . 604727 22 1 18 3 1 2 19 . 3 . 604727 22 1 18 3 1 3 19 . 1 . 604727 22 1 18 3 1 3 19 . 1.2 . 604727 22 1 18 3 1 3 19 . 1.4 . 604727 22 1 18 3 1 3 19 . 1.6 . 604727 22 1 18 3 1 3 19 . 1.8 . 604727 22 1 18 3 1 3 19 . 2 . 604727 22 1 18 3 1 3 19 . 2.2 . 604727 22 1 18 3 1 3 19 . 2.4 . 604727 22 1 18 3 1 3 19 . 2.6 . 604727 22 1 18 3 1 3 19 . 2.8 . 604727 22 1 18 3 1 3 19 . 3 . 628266 33 0 30 2 1 0 33 . 1 . 628266 33 0 30 2 1 0 33 . 1.2 98.5 628266 33 0 30 2 1 0 33 . 1.4 99.9 628266 33 0 30 2 1 0 33 . 1.6 100 628266 33 0 30 2 1 0 33 . 1.8 100 628266 33 0 30 2 1 0 33 . 2 100 628266 33 0 30 2 1 0 33 . 2.2 100 628266 33 0 30 2 1 0 33 . 2.4 100 628266 33 0 30 2 1 0 33 . 2.6 100 181 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 628266 33 0 30 2 1 0 33 . 2.8 100 628266 33 0 30 2 1 0 33 . 3 100 628266 33 0 30 2 1 1 33 . 1 . 628266 33 0 30 2 1 1 33 . 1.2 100 628266 33 0 30 2 1 1 33 . 1.4 100 628266 33 0 30 2 1 1 33 . 1.6 100 628266 33 0 30 2 1 1 33 . 1.8 100 628266 33 0 30 2 1 1 33 . 2 100 628266 33 0 30 2 1 1 33 . 2.2 100 628266 33 0 30 2 1 1 33 . 2.4 100 628266 33 0 30 2 1 1 33 . 2.6 100 628266 33 0 30 2 1 1 33 . 2.8 100 628266 33 0 30 2 1 1 33 . 3 100 628266 33 0 30 2 1 2 33 . 1 . 628266 33 0 30 2 1 2 33 . 1.2 100 628266 33 0 30 2 1 2 33 . 1.4 100 628266 33 0 30 2 1 2 33 . 1.6 100 628266 33 0 30 2 1 2 33 . 1.8 100 628266 33 0 30 2 1 2 33 . 2 100 628266 33 0 30 2 1 2 33 . 2.2 100 628266 33 0 30 2 1 2 33 . 2.4 99.9 628266 33 0 30 2 1 2 33 . 2.6 99.9 628266 33 0 30 2 1 2 33 . 2.8 100 628266 33 0 30 2 1 2 33 . 3 100 628266 33 0 30 2 1 3 33 . 1 91.7 628266 33 0 30 2 1 3 33 . 1.2 . 628266 33 0 30 2 1 3 33 . 1.4 . 628266 33 0 30 2 1 3 33 . 1.6 . 628266 33 0 30 2 1 3 33 . 1.8 . 628266 33 0 30 2 1 3 33 . 2 . 628266 33 0 30 2 1 3 33 . 2.2 . 628266 33 0 30 2 1 3 33 . 2.4 . 628266 33 0 30 2 1 3 33 . 2.6 . 628266 33 0 30 2 1 3 33 . 2.8 . 628266 33 0 30 2 1 3 33 . 3 . 988133 27 1 18 . 1 0 30 . 1 . 988133 27 1 18 . 1 0 30 . 1.2 . 988133 27 1 18 . 1 0 30 . 1.4 . 988133 27 1 18 . 1 0 30 . 1.6 . 988133 27 1 18 . 1 0 30 . 1.8 . 988133 27 1 18 . 1 0 30 . 2 . 988133 27 1 18 . 1 0 30 . 2.2 . 988133 27 1 18 . 1 0 30 . 2.4 . 988133 27 1 18 . 1 0 30 . 2.6 . 988133 27 1 18 . 1 0 30 . 2.8 . 988133 27 1 18 . 1 0 30 . 3 . 988133 27 1 18 . 1 1 30 . 1 . 182 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 988133 27 1 18 . 1 1 30 . 1.2 . 988133 27 1 18 . 1 1 30 . 1.4 . 988133 27 1 18 . 1 1 30 . 1.6 . 988133 27 1 18 . 1 1 30 . 1.8 . 988133 27 1 18 . 1 1 30 . 2 . 988133 27 1 18 . 1 1 30 . 2.2 . 988133 27 1 18 . 1 1 30 . 2.4 . 988133 27 1 18 . 1 1 30 . 2.6 . 988133 27 1 18 . 1 1 30 . 2.8 . 988133 27 1 18 . 1 1 30 . 3 . 988133 27 1 18 . 1 2 30 . 1 . 988133 27 1 18 . 1 2 30 . 1.2 . 988133 27 1 18 . 1 2 30 . 1.4 . 988133 27 1 18 . 1 2 30 . 1.6 . 988133 27 1 18 . 1 2 30 . 1.8 . 988133 27 1 18 . 1 2 30 . 2 . 988133 27 1 18 . 1 2 30 . 2.2 . 988133 27 1 18 . 1 2 30 . 2.4 . 988133 27 1 18 . 1 2 30 . 2.6 . 988133 27 1 18 . 1 2 30 . 2.8 . 988133 27 1 18 . 1 2 30 . 3 . 988133 27 1 18 . 1 3 30 . 1 100 988133 27 1 18 . 1 3 30 . 1.2 100 988133 27 1 18 . 1 3 30 . 1.4 100 988133 27 1 18 . 1 3 30 . 1.6 100 988133 27 1 18 . 1 3 30 . 1.8 100 988133 27 1 18 . 1 3 30 . 2 100 988133 27 1 18 . 1 3 30 . 2.2 100 988133 27 1 18 . 1 3 30 . 2.4 100 988133 27 1 18 . 1 3 30 . 2.6 100 988133 27 1 18 . 1 3 30 . 2.8 100 988133 27 1 18 . 1 3 30 . 3 100 280758 19 0 30 . 1 0 20 . 1 100 280758 19 0 30 . 1 0 20 . 1.2 100 280758 19 0 30 . 1 0 20 . 1.4 100 280758 19 0 30 . 1 0 20 . 1.6 100 280758 19 0 30 . 1 0 20 . 1.8 100 280758 19 0 30 . 1 0 20 . 2 100 280758 19 0 30 . 1 0 20 . 2.2 100 280758 19 0 30 . 1 0 20 . 2.4 100 280758 19 0 30 . 1 0 20 . 2.6 100 280758 19 0 30 . 1 0 20 . 2.8 100 280758 19 0 30 . 1 0 20 . 3 100 280758 19 0 30 . 1 1 20 . 1 100 280758 19 0 30 . 1 1 20 . 1.2 100 280758 19 0 30 . 1 1 20 . 1.4 100 280758 19 0 30 . 1 1 20 . 1.6 100 183 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 280758 19 0 30 . 1 1 20 . 1.8 100 280758 19 0 30 . 1 1 20 . 2 100 280758 19 0 30 . 1 1 20 . 2.2 100 280758 19 0 30 . 1 1 20 . 2.4 100 280758 19 0 30 . 1 1 20 . 2.6 100 280758 19 0 30 . 1 1 20 . 2.8 100 280758 19 0 30 . 1 1 20 . 3 100 280758 19 0 30 . 1 2 20 . 1 . 280758 19 0 30 . 1 2 20 . 1.2 . 280758 19 0 30 . 1 2 20 . 1.4 100 280758 19 0 30 . 1 2 20 . 1.6 100 280758 19 0 30 . 1 2 20 . 1.8 100 280758 19 0 30 . 1 2 20 . 2 . 280758 19 0 30 . 1 2 20 . 2.2 99.8 280758 19 0 30 . 1 2 20 . 2.4 100 280758 19 0 30 . 1 2 20 . 2.6 100 280758 19 0 30 . 1 2 20 . 2.8 99 280758 19 0 30 . 1 2 20 . 3 97.6 280758 19 0 30 . 1 3 20 . 1 . 280758 19 0 30 . 1 3 20 . 1.2 . 280758 19 0 30 . 1 3 20 . 1.4 . 280758 19 0 30 . 1 3 20 . 1.6 . 280758 19 0 30 . 1 3 20 . 1.8 . 280758 19 0 30 . 1 3 20 . 2 . 280758 19 0 30 . 1 3 20 . 2.2 . 280758 19 0 30 . 1 3 20 . 2.4 . 280758 19 0 30 . 1 3 20 . 2.6 . 280758 19 0 30 . 1 3 20 . 2.8 . 280758 19 0 30 . 1 3 20 . 3 . 296524 22 1 31 . 1 0 23 . 1 100 296524 22 1 31 . 1 0 23 . 1.2 94.8 296524 22 1 31 . 1 0 23 . 1.4 99.2 296524 22 1 31 . 1 0 23 . 1.6 100 296524 22 1 31 . 1 0 23 . 1.8 100 296524 22 1 31 . 1 0 23 . 2 99.4 296524 22 1 31 . 1 0 23 . 2.2 100 296524 22 1 31 . 1 0 23 . 2.4 99.9 296524 22 1 31 . 1 0 23 . 2.6 100 296524 22 1 31 . 1 0 23 . 2.8 100 296524 22 1 31 . 1 0 23 . 3 100 296524 22 1 31 . 1 1 23 . 1 99.9 296524 22 1 31 . 1 1 23 . 1.2 100 296524 22 1 31 . 1 1 23 . 1.4 100 296524 22 1 31 . 1 1 23 . 1.6 100 296524 22 1 31 . 1 1 23 . 1.8 100 296524 22 1 31 . 1 1 23 . 2 100 296524 22 1 31 . 1 1 23 . 2.2 100 184 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 296524 22 1 31 . 1 1 23 . 2.4 100 296524 22 1 31 . 1 1 23 . 2.6 100 296524 22 1 31 . 1 1 23 . 2.8 100 296524 22 1 31 . 1 1 23 . 3 100 296524 22 1 31 . 1 2 23 . 1 96.7 296524 22 1 31 . 1 2 23 . 1.2 . 296524 22 1 31 . 1 2 23 . 1.4 . 296524 22 1 31 . 1 2 23 . 1.6 . 296524 22 1 31 . 1 2 23 . 1.8 . 296524 22 1 31 . 1 2 23 . 2 . 296524 22 1 31 . 1 2 23 . 2.2 100 296524 22 1 31 . 1 2 23 . 2.4 100 296524 22 1 31 . 1 2 23 . 2.6 100 296524 22 1 31 . 1 2 23 . 2.8 100 296524 22 1 31 . 1 2 23 . 3 100 296524 22 1 31 . 1 3 23 . 1 . 296524 22 1 31 . 1 3 23 . 1.2 . 296524 22 1 31 . 1 3 23 . 1.4 . 296524 22 1 31 . 1 3 23 . 1.6 . 296524 22 1 31 . 1 3 23 . 1.8 . 296524 22 1 31 . 1 3 23 . 2 . 296524 22 1 31 . 1 3 23 . 2.2 . 296524 22 1 31 . 1 3 23 . 2.4 . 296524 22 1 31 . 1 3 23 . 2.6 . 296524 22 1 31 . 1 3 23 . 2.8 . 296524 22 1 31 . 1 3 23 . 3 . 340003 34 0 19 . 1 0 34 . 1 99.9 340003 34 0 19 . 1 0 34 . 1.2 99.9 340003 34 0 19 . 1 0 34 . 1.4 100 340003 34 0 19 . 1 0 34 . 1.6 99.8 340003 34 0 19 . 1 0 34 . 1.8 99.7 340003 34 0 19 . 1 0 34 . 2 100 340003 34 0 19 . 1 0 34 . 2.2 100 340003 34 0 19 . 1 0 34 . 2.4 99.6 340003 34 0 19 . 1 0 34 . 2.6 99.9 340003 34 0 19 . 1 0 34 . 2.8 100 340003 34 0 19 . 1 0 34 . 3 100 340003 34 0 19 . 1 1 34 . 1 99.2 340003 34 0 19 . 1 1 34 . 1.2 99.6 340003 34 0 19 . 1 1 34 . 1.4 100 340003 34 0 19 . 1 1 34 . 1.6 99.5 340003 34 0 19 . 1 1 34 . 1.8 100 340003 34 0 19 . 1 1 34 . 2 100 340003 34 0 19 . 1 1 34 . 2.2 98.9 340003 34 0 19 . 1 1 34 . 2.4 100 340003 34 0 19 . 1 1 34 . 2.6 100 340003 34 0 19 . 1 1 34 . 2.8 100 185 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 340003 34 0 19 . 1 1 34 . 3 100 340003 34 0 19 . 1 2 34 . 1 . 340003 34 0 19 . 1 2 34 . 1.2 . 340003 34 0 19 . 1 2 34 . 1.4 88.8 340003 34 0 19 . 1 2 34 . 1.6 96.5 340003 34 0 19 . 1 2 34 . 1.8 86.8 340003 34 0 19 . 1 2 34 . 2 86.5 340003 34 0 19 . 1 2 34 . 2.2 93.9 340003 34 0 19 . 1 2 34 . 2.4 99.3 340003 34 0 19 . 1 2 34 . 2.6 98.7 340003 34 0 19 . 1 2 34 . 2.8 98.5 340003 34 0 19 . 1 2 34 . 3 99.8 340003 34 0 19 . 1 3 34 . 1 . 340003 34 0 19 . 1 3 34 . 1.2 . 340003 34 0 19 . 1 3 34 . 1.4 . 340003 34 0 19 . 1 3 34 . 1.6 . 340003 34 0 19 . 1 3 34 . 1.8 . 340003 34 0 19 . 1 3 34 . 2 . 340003 34 0 19 . 1 3 34 . 2.2 . 340003 34 0 19 . 1 3 34 . 2.4 . 340003 34 0 19 . 1 3 34 . 2.6 . 340003 34 0 19 . 1 3 34 . 2.8 . 340003 34 0 19 . 1 3 34 . 3 . 142985 44 0 30 . 1 0 34 . 1 97.6 142985 44 0 30 . 1 0 34 . 1.2 99.2 142985 44 0 30 . 1 0 34 . 1.4 98.7 142985 44 0 30 . 1 0 34 . 1.6 90.3 142985 44 0 30 . 1 0 34 . 1.8 99.5 142985 44 0 30 . 1 0 34 . 2 100 142985 44 0 30 . 1 0 34 . 2.2 99.8 142985 44 0 30 . 1 0 34 . 2.4 100 142985 44 0 30 . 1 0 34 . 2.6 100 142985 44 0 30 . 1 0 34 . 2.8 100 142985 44 0 30 . 1 0 34 . 3 99.9 142985 44 0 30 . 1 1 34 . 1 98.2 142985 44 0 30 . 1 1 34 . 1.2 99.9 142985 44 0 30 . 1 1 34 . 1.4 99.2 142985 44 0 30 . 1 1 34 . 1.6 100 142985 44 0 30 . 1 1 34 . 1.8 100 142985 44 0 30 . 1 1 34 . 2 100 142985 44 0 30 . 1 1 34 . 2.2 99.8 142985 44 0 30 . 1 1 34 . 2.4 100 142985 44 0 30 . 1 1 34 . 2.6 100 142985 44 0 30 . 1 1 34 . 2.8 100 142985 44 0 30 . 1 1 34 . 3 100 142985 44 0 30 . 1 2 34 . 1 92.9 142985 44 0 30 . 1 2 34 . 1.2 80.9 186 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 142985 44 0 30 . 1 2 34 . 1.4 56.1 142985 44 0 30 . 1 2 34 . 1.6 82.9 142985 44 0 30 . 1 2 34 . 1.8 84.7 142985 44 0 30 . 1 2 34 . 2 87.3 142985 44 0 30 . 1 2 34 . 2.2 62.7 142985 44 0 30 . 1 2 34 . 2.4 96 142985 44 0 30 . 1 2 34 . 2.6 94.1 142985 44 0 30 . 1 2 34 . 2.8 91.9 142985 44 0 30 . 1 2 34 . 3 94.8 142985 44 0 30 . 1 3 34 . 1 . 142985 44 0 30 . 1 3 34 . 1.2 . 142985 44 0 30 . 1 3 34 . 1.4 . 142985 44 0 30 . 1 3 34 . 1.6 . 142985 44 0 30 . 1 3 34 . 1.8 . 142985 44 0 30 . 1 3 34 . 2 . 142985 44 0 30 . 1 3 34 . 2.2 . 142985 44 0 30 . 1 3 34 . 2.4 . 142985 44 0 30 . 1 3 34 . 2.6 . 142985 44 0 30 . 1 3 34 . 2.8 . 142985 44 0 30 . 1 3 34 . 3 . 212641 26 0 30 . 1 0 26 . 1 . 212641 26 0 30 . 1 0 26 . 1.2 . 212641 26 0 30 . 1 0 26 . 1.4 . 212641 26 0 30 . 1 0 26 . 1.6 . 212641 26 0 30 . 1 0 26 . 1.8 . 212641 26 0 30 . 1 0 26 . 2 99.7 212641 26 0 30 . 1 0 26 . 2.2 100 212641 26 0 30 . 1 0 26 . 2.4 100 212641 26 0 30 . 1 0 26 . 2.6 100 212641 26 0 30 . 1 0 26 . 2.8 100 212641 26 0 30 . 1 0 26 . 3 99.9 212641 26 0 30 . 1 1 26 . 1 . 212641 26 0 30 . 1 1 26 . 1.2 . 212641 26 0 30 . 1 1 26 . 1.4 . 212641 26 0 30 . 1 1 26 . 1.6 . 212641 26 0 30 . 1 1 26 . 1.8 . 212641 26 0 30 . 1 1 26 . 2 100 212641 26 0 30 . 1 1 26 . 2.2 100 212641 26 0 30 . 1 1 26 . 2.4 100 212641 26 0 30 . 1 1 26 . 2.6 100 212641 26 0 30 . 1 1 26 . 2.8 100 212641 26 0 30 . 1 1 26 . 3 98 212641 26 0 30 . 1 2 26 . 1 . 212641 26 0 30 . 1 2 26 . 1.2 . 212641 26 0 30 . 1 2 26 . 1.4 . 212641 26 0 30 . 1 2 26 . 1.6 . 212641 26 0 30 . 1 2 26 . 1.8 . 187 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 212641 26 0 30 . 1 2 26 . 2 95.8 212641 26 0 30 . 1 2 26 . 2.2 99.9 212641 26 0 30 . 1 2 26 . 2.4 100 212641 26 0 30 . 1 2 26 . 2.6 100 212641 26 0 30 . 1 2 26 . 2.8 99.8 212641 26 0 30 . 1 2 26 . 3 98.5 212641 26 0 30 . 1 3 26 . 1 100 212641 26 0 30 . 1 3 26 . 1.2 100 212641 26 0 30 . 1 3 26 . 1.4 99.9 212641 26 0 30 . 1 3 26 . 1.6 99.7 212641 26 0 30 . 1 3 26 . 1.8 99.9 212641 26 0 30 . 1 3 26 . 2 . 212641 26 0 30 . 1 3 26 . 2.2 . 212641 26 0 30 . 1 3 26 . 2.4 . 212641 26 0 30 . 1 3 26 . 2.6 . 212641 26 0 30 . 1 3 26 . 2.8 . 212641 26 0 30 . 1 3 26 . 3 . 402105 29 1 18 . 1 0 25 . 1 100 402105 29 1 18 . 1 0 25 . 1.2 99.9 402105 29 1 18 . 1 0 25 . 1.4 100 402105 29 1 18 . 1 0 25 . 1.6 100 402105 29 1 18 . 1 0 25 . 1.8 100 402105 29 1 18 . 1 0 25 . 2 100 402105 29 1 18 . 1 0 25 . 2.2 100 402105 29 1 18 . 1 0 25 . 2.4 100 402105 29 1 18 . 1 0 25 . 2.6 100 402105 29 1 18 . 1 0 25 . 2.8 100 402105 29 1 18 . 1 0 25 . 3 100 402105 29 1 18 . 1 1 25 . 1 91.3 402105 29 1 18 . 1 1 25 . 1.2 99.9 402105 29 1 18 . 1 1 25 . 1.4 100 402105 29 1 18 . 1 1 25 . 1.6 100 402105 29 1 18 . 1 1 25 . 1.8 100 402105 29 1 18 . 1 1 25 . 2 100 402105 29 1 18 . 1 1 25 . 2.2 100 402105 29 1 18 . 1 1 25 . 2.4 100 402105 29 1 18 . 1 1 25 . 2.6 100 402105 29 1 18 . 1 1 25 . 2.8 100 402105 29 1 18 . 1 1 25 . 3 100 402105 29 1 18 . 1 2 25 . 1 . 402105 29 1 18 . 1 2 25 . 1.2 . 402105 29 1 18 . 1 2 25 . 1.4 19.3 402105 29 1 18 . 1 2 25 . 1.6 2.6 402105 29 1 18 . 1 2 25 . 1.8 . 402105 29 1 18 . 1 2 25 . 2 2.8 402105 29 1 18 . 1 2 25 . 2.2 . 402105 29 1 18 . 1 2 25 . 2.4 51.6 188 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 402105 29 1 18 . 1 2 25 . 2.6 24.7 402105 29 1 18 . 1 2 25 . 2.8 71.6 402105 29 1 18 . 1 2 25 . 3 90.2 402105 29 1 18 . 1 3 25 . 1 . 402105 29 1 18 . 1 3 25 . 1.2 . 402105 29 1 18 . 1 3 25 . 1.4 . 402105 29 1 18 . 1 3 25 . 1.6 . 402105 29 1 18 . 1 3 25 . 1.8 . 402105 29 1 18 . 1 3 25 . 2 . 402105 29 1 18 . 1 3 25 . 2.2 . 402105 29 1 18 . 1 3 25 . 2.4 . 402105 29 1 18 . 1 3 25 . 2.6 . 402105 29 1 18 . 1 3 25 . 2.8 . 402105 29 1 18 . 1 3 25 . 3 . 520679 21 1 18 . 1 0 21 . 1 100 520679 21 1 18 . 1 0 21 . 1.2 99.8 520679 21 1 18 . 1 0 21 . 1.4 99.9 520679 21 1 18 . 1 0 21 . 1.6 99.9 520679 21 1 18 . 1 0 21 . 1.8 100 520679 21 1 18 . 1 0 21 . 2 100 520679 21 1 18 . 1 0 21 . 2.2 100 520679 21 1 18 . 1 0 21 . 2.4 100 520679 21 1 18 . 1 0 21 . 2.6 100 520679 21 1 18 . 1 0 21 . 2.8 99.9 520679 21 1 18 . 1 0 21 . 3 100 520679 21 1 18 . 1 1 21 . 1 99.9 520679 21 1 18 . 1 1 21 . 1.2 99.8 520679 21 1 18 . 1 1 21 . 1.4 99.9 520679 21 1 18 . 1 1 21 . 1.6 99.9 520679 21 1 18 . 1 1 21 . 1.8 100 520679 21 1 18 . 1 1 21 . 2 99.9 520679 21 1 18 . 1 1 21 . 2.2 100 520679 21 1 18 . 1 1 21 . 2.4 100 520679 21 1 18 . 1 1 21 . 2.6 99.9 520679 21 1 18 . 1 1 21 . 2.8 100 520679 21 1 18 . 1 1 21 . 3 99.9 520679 21 1 18 . 1 2 21 . 1 . 520679 21 1 18 . 1 2 21 . 1.2 . 520679 21 1 18 . 1 2 21 . 1.4 . 520679 21 1 18 . 1 2 21 . 1.6 . 520679 21 1 18 . 1 2 21 . 1.8 100 520679 21 1 18 . 1 2 21 . 2 100 520679 21 1 18 . 1 2 21 . 2.2 . 520679 21 1 18 . 1 2 21 . 2.4 . 520679 21 1 18 . 1 2 21 . 2.6 99.9 520679 21 1 18 . 1 2 21 . 2.8 99.9 520679 21 1 18 . 1 2 21 . 3 100 189 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 520679 21 1 18 . 1 3 21 . 1 . 520679 21 1 18 . 1 3 21 . 1.2 . 520679 21 1 18 . 1 3 21 . 1.4 . 520679 21 1 18 . 1 3 21 . 1.6 . 520679 21 1 18 . 1 3 21 . 1.8 . 520679 21 1 18 . 1 3 21 . 2 . 520679 21 1 18 . 1 3 21 . 2.2 . 520679 21 1 18 . 1 3 21 . 2.4 . 520679 21 1 18 . 1 3 21 . 2.6 . 520679 21 1 18 . 1 3 21 . 2.8 . 520679 21 1 18 . 1 3 21 . 3 . 841324 25 1 19 . 1 0 41 . 1 99.6 841324 25 1 19 . 1 0 41 . 1.2 98.7 841324 25 1 19 . 1 0 41 . 1.4 99.6 841324 25 1 19 . 1 0 41 . 1.6 99.8 841324 25 1 19 . 1 0 41 . 1.8 100 841324 25 1 19 . 1 0 41 . 2 100 841324 25 1 19 . 1 0 41 . 2.2 100 841324 25 1 19 . 1 0 41 . 2.4 99.9 841324 25 1 19 . 1 0 41 . 2.6 100 841324 25 1 19 . 1 0 41 . 2.8 100 841324 25 1 19 . 1 0 41 . 3 100 841324 25 1 19 . 1 1 41 . 1 99.9 841324 25 1 19 . 1 1 41 . 1.2 100 841324 25 1 19 . 1 1 41 . 1.4 100 841324 25 1 19 . 1 1 41 . 1.6 99.2 841324 25 1 19 . 1 1 41 . 1.8 100 841324 25 1 19 . 1 1 41 . 2 100 841324 25 1 19 . 1 1 41 . 2.2 100 841324 25 1 19 . 1 1 41 . 2.4 100 841324 25 1 19 . 1 1 41 . 2.6 100 841324 25 1 19 . 1 1 41 . 2.8 100 841324 25 1 19 . 1 1 41 . 3 100 841324 25 1 19 . 1 2 41 . 1 . 841324 25 1 19 . 1 2 41 . 1.2 99.6 841324 25 1 19 . 1 2 41 . 1.4 99.9 841324 25 1 19 . 1 2 41 . 1.6 73.1 841324 25 1 19 . 1 2 41 . 1.8 . 841324 25 1 19 . 1 2 41 . 2 92.6 841324 25 1 19 . 1 2 41 . 2.2 . 841324 25 1 19 . 1 2 41 . 2.4 . 841324 25 1 19 . 1 2 41 . 2.6 . 841324 25 1 19 . 1 2 41 . 2.8 . 841324 25 1 19 . 1 2 41 . 3 . 841324 25 1 19 . 1 3 41 . 1 . 841324 25 1 19 . 1 3 41 . 1.2 . 841324 25 1 19 . 1 3 41 . 1.4 . 190 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 841324 25 1 19 . 1 3 41 . 1.6 . 841324 25 1 19 . 1 3 41 . 1.8 . 841324 25 1 19 . 1 3 41 . 2 . 841324 25 1 19 . 1 3 41 . 2.2 . 841324 25 1 19 . 1 3 41 . 2.4 . 841324 25 1 19 . 1 3 41 . 2.6 . 841324 25 1 19 . 1 3 41 . 2.8 . 841324 25 1 19 . 1 3 41 . 3 . 859590 44 0 31 . 1 0 24 . 1 100 859590 44 0 31 . 1 0 24 . 1.2 100 859590 44 0 31 . 1 0 24 . 1.4 99.9 859590 44 0 31 . 1 0 24 . 1.6 99.9 859590 44 0 31 . 1 0 24 . 1.8 100 859590 44 0 31 . 1 0 24 . 2 100 859590 44 0 31 . 1 0 24 . 2.2 99.8 859590 44 0 31 . 1 0 24 . 2.4 99.8 859590 44 0 31 . 1 0 24 . 2.6 99.9 859590 44 0 31 . 1 0 24 . 2.8 100 859590 44 0 31 . 1 0 24 . 3 99.1 859590 44 0 31 . 1 1 24 . 1 100 859590 44 0 31 . 1 1 24 . 1.2 100 859590 44 0 31 . 1 1 24 . 1.4 99.9 859590 44 0 31 . 1 1 24 . 1.6 99.9 859590 44 0 31 . 1 1 24 . 1.8 100 859590 44 0 31 . 1 1 24 . 2 100 859590 44 0 31 . 1 1 24 . 2.2 99.8 859590 44 0 31 . 1 1 24 . 2.4 100 859590 44 0 31 . 1 1 24 . 2.6 99.9 859590 44 0 31 . 1 1 24 . 2.8 100 859590 44 0 31 . 1 1 24 . 3 98 859590 44 0 31 . 1 2 24 . 1 99.8 859590 44 0 31 . 1 2 24 . 1.2 99.1 859590 44 0 31 . 1 2 24 . 1.4 99 859590 44 0 31 . 1 2 24 . 1.6 80 859590 44 0 31 . 1 2 24 . 1.8 96 859590 44 0 31 . 1 2 24 . 2 79 859590 44 0 31 . 1 2 24 . 2.2 99.7 859590 44 0 31 . 1 2 24 . 2.4 99.8 859590 44 0 31 . 1 2 24 . 2.6 94.9 859590 44 0 31 . 1 2 24 . 2.8 95.7 859590 44 0 31 . 1 2 24 . 3 . 859590 44 0 31 . 1 3 24 . 1 . 859590 44 0 31 . 1 3 24 . 1.2 . 859590 44 0 31 . 1 3 24 . 1.4 . 859590 44 0 31 . 1 3 24 . 1.6 . 859590 44 0 31 . 1 3 24 . 1.8 . 859590 44 0 31 . 1 3 24 . 2 . 191 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 859590 44 0 31 . 1 3 24 . 2.2 . 859590 44 0 31 . 1 3 24 . 2.4 . 859590 44 0 31 . 1 3 24 . 2.6 . 859590 44 0 31 . 1 3 24 . 2.8 . 859590 44 0 31 . 1 3 24 . 3 . 509637 26 0 32 . 1 0 28 . 1 . 509637 26 0 32 . 1 0 28 . 1.2 . 509637 26 0 32 . 1 0 28 . 1.4 . 509637 26 0 32 . 1 0 28 . 1.6 . 509637 26 0 32 . 1 0 28 . 1.8 . 509637 26 0 32 . 1 0 28 . 2 . 509637 26 0 32 . 1 0 28 . 2.2 . 509637 26 0 32 . 1 0 28 . 2.4 . 509637 26 0 32 . 1 0 28 . 2.6 . 509637 26 0 32 . 1 0 28 . 2.8 . 509637 26 0 32 . 1 0 28 . 3 54.1 509637 26 0 32 . 1 1 28 . 1 . 509637 26 0 32 . 1 1 28 . 1.2 . 509637 26 0 32 . 1 1 28 . 1.4 . 509637 26 0 32 . 1 1 28 . 1.6 . 509637 26 0 32 . 1 1 28 . 1.8 . 509637 26 0 32 . 1 1 28 . 2 . 509637 26 0 32 . 1 1 28 . 2.2 . 509637 26 0 32 . 1 1 28 . 2.4 . 509637 26 0 32 . 1 1 28 . 2.6 . 509637 26 0 32 . 1 1 28 . 2.8 . 509637 26 0 32 . 1 1 28 . 3 99 509637 26 0 32 . 1 2 28 . 1 . 509637 26 0 32 . 1 2 28 . 1.2 . 509637 26 0 32 . 1 2 28 . 1.4 . 509637 26 0 32 . 1 2 28 . 1.6 . 509637 26 0 32 . 1 2 28 . 1.8 . 509637 26 0 32 . 1 2 28 . 2 . 509637 26 0 32 . 1 2 28 . 2.2 . 509637 26 0 32 . 1 2 28 . 2.4 . 509637 26 0 32 . 1 2 28 . 2.6 . 509637 26 0 32 . 1 2 28 . 2.8 . 509637 26 0 32 . 1 2 28 . 3 . 509637 26 0 32 . 1 3 28 . 1 40.1 509637 26 0 32 . 1 3 28 . 1.2 25.6 509637 26 0 32 3 1 3 28 . 1.4 27.5 509637 26 0 32 3 1 3 28 . 1.6 39.7 509637 26 0 32 3 1 3 28 . 1.8 59.4 509637 26 0 32 3 1 3 28 . 2 63 509637 26 0 32 3 1 3 28 . 2.2 45.4 509637 26 0 32 3 1 3 28 . 2.4 53.8 509637 26 0 32 3 1 3 28 . 2.6 59.6 192 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 509637 26 0 32 3 1 3 28 . 2.8 94.4 509637 26 0 32 . 1 3 28 . 3 . 935672 48 1 31 . 1 0 19 . 1 99.9 935672 48 1 31 . 1 0 19 . 1.2 97.8 935672 48 1 31 . 1 0 19 . 1.4 99.3 935672 48 1 31 . 1 0 19 . 1.6 100 935672 48 1 31 . 1 0 19 . 1.8 100 935672 48 1 31 . 1 0 19 . 2 100 935672 48 1 31 . 1 0 19 . 2.2 98.3 935672 48 1 31 . 1 0 19 . 2.4 100 935672 48 1 31 . 1 0 19 . 2.6 100 935672 48 1 31 . 1 0 19 . 2.8 100 935672 48 1 31 . 1 0 19 . 3 100 935672 48 1 31 . 1 1 19 . 1 . 935672 48 1 31 . 1 1 19 . 1.2 . 935672 48 1 31 . 1 1 19 . 1.4 . 935672 48 1 31 . 1 1 19 . 1.6 . 935672 48 1 31 . 1 1 19 . 1.8 . 935672 48 1 31 . 1 1 19 . 2 . 935672 48 1 31 . 1 1 19 . 2.2 . 935672 48 1 31 . 1 1 19 . 2.4 . 935672 48 1 31 . 1 1 19 . 2.6 . 935672 48 1 31 . 1 1 19 . 2.8 . 935672 48 1 31 . 1 1 19 . 3 . 935672 48 1 31 . 1 2 19 . 1 . 935672 48 1 31 . 1 2 19 . 1.2 . 935672 48 1 31 . 1 2 19 . 1.4 . 935672 48 1 31 . 1 2 19 . 1.6 . 935672 48 1 31 . 1 2 19 . 1.8 . 935672 48 1 31 . 1 2 19 . 2 . 935672 48 1 31 . 1 2 19 . 2.2 . 935672 48 1 31 . 1 2 19 . 2.4 . 935672 48 1 31 . 1 2 19 . 2.6 100 935672 48 1 31 . 1 2 19 . 2.8 98.8 935672 48 1 31 . 1 2 19 . 3 98.2 935672 48 1 31 . 1 3 19 . 1 . 935672 48 1 31 . 1 3 19 . 1.2 . 935672 48 1 31 . 1 3 19 . 1.4 . 935672 48 1 31 . 1 3 19 . 1.6 . 935672 48 1 31 . 1 3 19 . 1.8 . 935672 48 1 31 . 1 3 19 . 2 . 935672 48 1 31 . 1 3 19 . 2.2 . 935672 48 1 31 . 1 3 19 . 2.4 . 935672 48 1 31 . 1 3 19 . 2.6 . 935672 48 1 31 . 1 3 19 . 2.8 . 935672 48 1 31 . 1 3 19 . 3 . 458056 . . . 2 0 0 . . 1 . 193 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 458056 . . . 2 0 0 . . 1.2 . 458056 . . . 2 0 0 . . 1.4 . 458056 . . . 2 0 0 . . 1.6 0 458056 . . . 2 0 0 . . 1.8 6.4 458056 . . . 2 0 0 . . 2 7.7 458056 . . . 2 0 0 . . 2.2 17.3 458056 . . . 2 0 0 . . 2.4 19.2 458056 . . . 2 0 0 . . 2.6 19.2 458056 . . . 2 0 0 . . 2.8 16.8 458056 . . . 2 0 0 . . 3 18.7 458056 . . . 2 0 1 . . 1 . 458056 . . . 2 0 1 . . 1.2 . 458056 . . . 2 0 1 . . 1.4 . 458056 . . . 2 0 1 . . 1.6 4.4 458056 . . . 2 0 1 . . 1.8 0 458056 . . . 2 0 1 . . 2 8.6 458056 . . . 2 0 1 . . 2.2 0 458056 . . . 2 0 1 . . 2.4 8.2 458056 . . . 2 0 1 . . 2.6 0 458056 . . . 2 0 1 . . 2.8 0 458056 . . . 2 0 1 . . 3 7.2 458056 . . . 2 0 2 . . 1 . 458056 . . . 2 0 2 . . 1.2 . 458056 . . . 2 0 2 . . 1.4 . 458056 . . . 2 0 2 . . 1.6 . 458056 . . . 2 0 2 . . 1.8 . 458056 . . . 2 0 2 . . 2 . 458056 . . . 2 0 2 . . 2.2 . 458056 . . . 2 0 2 . . 2.4 . 458056 . . . 2 0 2 . . 2.6 . 458056 . . . 2 0 2 . . 2.8 . 458056 . . . 2 0 2 . . 3 . 458056 . . . 2 0 3 . . 1 16.9 458056 . . . 2 0 3 . . 1.2 11.3 458056 . . . 2 0 3 . . 1.4 13 458056 . . . 2 0 3 . . 1.6 . 458056 . . . 2 0 3 . . 1.8 . 458056 . . . 2 0 3 . . 2 . 458056 . . . 2 0 3 . . 2.2 . 458056 . . . 2 0 3 . . 2.4 . 458056 . . . 2 0 3 . . 2.6 . 458056 . . . 2 0 3 . . 2.8 . 458056 . . . 2 0 3 . . 3 . 127827 . . . 1 0 0 . . 1 . 127827 . . . 1 0 0 . . 1.2 . 127827 . . . 1 0 0 . . 1.4 . 127827 . . . 1 0 0 . . 1.6 . 194 SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 127827 . . . 1 0 0 . . 1.8 . 127827 . . . 1 0 0 . . 2 . 127827 . . . 1 0 0 . . 2.2 . 127827 . . . 1 0 0 . . 2.4 . 127827 . . . 1 0 0 . . 2.6 . 127827 . . . 1 0 0 . . 2.8 . 127827 . . . 1 0 0 . . 3 . 127827 . . . 1 0 1 . . 1 . 127827 . . . 1 0 1 . . 1.2 . 127827 . . . 1 0 1 . . 1.4 . 127827 . . . 1 0 1 . . 1.6 . 127827 . . . 1 0 1 . . 1.8 . 127827 . . . 1 0 1 . . 2 . 127827 . . . 1 0 1 . . 2.2 . 127827 . . . 1 0 1 . . 2.4 . 127827 . . . 1 0 1 . . 2.6 . 127827 . . . 1 0 1 . . 2.8 . 127827 . . . 1 0 1 . . 3 . 127827 . . . 1 0 2 . . 1 . 127827 . . . 1 0 2 . . 1.2 . 127827 . . . 1 0 2 . . 1.4 . 127827 . . . 1 0 2 . . 1.6 . 127827 . . . 1 0 2 . . 1.8 . 127827 . . . 1 0 2 . . 2 . 127827 . . . 1 0 2 . . 2.2 . 127827 . . . 1 0 2 . . 2.4 . 127827 . . . 1 0 2 . . 2.6 . 127827 . . . 1 0 2 . . 2.8 . 127827 . . . 1 0 2 . . 3 . 127827 . . . 1 0 3 . . 1 20.5 127827 . . . 1 0 3 . . 1.2 30 127827 . . . 1 0 3 . . 1.4 0.68 127827 . . . 1 0 3 . . 1.6 0 127827 . . . 1 0 3 . . 1.8 0 127827 . . . 1 0 3 . . 2 0 127827 . . . 1 0 3 . . 2.2 0 127827 . . . 1 0 3 . . 2.4 0 127827 . . . 1 0 3 . . 2.6 0 127827 . . . 1 0 3 . . 2.8 0 127827 . . . 1 0 3 . . 3 0

195

NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 165435 . . . . 1 0 . . 1 25.5 165435 . . . . 1 0 . . 1.2 27.9 165435 . . . . 1 0 . . 1.4 50.3 165435 . . . . 1 0 . . 1.6 49.4 165435 . . . . 1 0 . . 1.8 41.7 165435 . . . . 1 0 . . 2 . 165435 . . . . 1 0 . . 2.2 . 165435 . . . . 1 0 . . 2.4 . 165435 . . . . 1 0 . . 2.6 . 165435 . . . . 1 0 . . 2.8 . 165435 . . . . 1 0 . . 3 . 165435 . . . . 1 1 . . 1 98.1 165435 . . . . 1 1 . . 1.2 100 165435 . . . . 1 1 . . 1.4 95.1 165435 . . . . 1 1 . . 1.6 100 165435 . . . . 1 1 . . 1.8 92.9 165435 . . . . 1 1 . . 2 . 165435 . . . . 1 1 . . 2.2 . 165435 . . . . 1 1 . . 2.4 . 165435 . . . . 1 1 . . 2.6 . 165435 . . . . 1 1 . . 2.8 . 165435 . . . . 1 1 . . 3 . 165435 . . . . 1 2 . . 1 . 165435 . . . . 1 2 . . 1.2 65.5 165435 . . . . 1 2 . . 1.4 13.6 165435 . . . . 1 2 . . 1.6 2.9 165435 . . . . 1 2 . . 1.8 3.1 165435 . . . . 1 2 . . 2 . 165435 . . . . 1 2 . . 2.2 . 165435 . . . . 1 2 . . 2.4 . 165435 . . . . 1 2 . . 2.6 . 165435 . . . . 1 2 . . 2.8 . 165435 . . . . 1 2 . . 3 . 165435 . . . . 1 3 . . 1 . 165435 . . . . 1 3 . . 1.2 . 165435 . . . . 1 3 . . 1.4 . 165435 . . . . 1 3 . . 1.6 . 165435 . . . . 1 3 . . 1.8 . 165435 . . . . 1 3 . . 2 84.7 165435 . . . . 1 3 . . 2.2 83.3 165435 . . . . 1 3 . . 2.4 81.9 165435 . . . . 1 3 . . 2.6 93.8 165435 . . . . 1 3 . . 2.8 90.6 165435 . . . . 1 3 . . 3 97.4

196 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 293452 . . . . 2 0 . . 1 80.2 293452 . . . . 2 0 . . 1.2 41.5 293452 . . . . 2 0 . . 1.4 44.9 293452 . . . . 2 0 . . 1.6 66.7 293452 . . . . 2 0 . . 1.8 100 293452 . . . . 2 0 . . 2 100 293452 . . . . 2 0 . . 2.2 0 293452 . . . . 2 0 . . 2.4 100 293452 . . . . 2 0 . . 2.6 100 293452 . . . . 2 0 . . 2.8 97.6 293452 . . . . 2 0 . . 3 100 293452 . . . . 2 1 . . 1 70.1 293452 . . . . 2 1 . . 1.2 80 293452 . . . . 2 1 . . 1.4 82.4 293452 . . . . 2 1 . . 1.6 74.4 293452 . . . . 2 1 . . 1.8 93.1 293452 . . . . 2 1 . . 2 96.8 293452 . . . . 2 1 . . 2.2 99.1 293452 . . . . 2 1 . . 2.4 100 293452 . . . . 2 1 . . 2.6 100 293452 . . . . 2 1 . . 2.8 100 293452 . . . . 2 1 . . 3 100 293452 . . . . 2 2 . . 1 . 293452 . . . . 2 2 . . 1.2 . 293452 . . . . 2 2 . . 1.4 . 293452 . . . . 2 2 . . 1.6 . 293452 . . . . 2 2 . . 1.8 . 293452 . . . . 2 2 . . 2 . 293452 . . . . 2 2 . . 2.2 . 293452 . . . . 2 2 . . 2.4 . 293452 . . . . 2 2 . . 2.6 . 293452 . . . . 2 2 . . 2.8 . 293452 . . . . 2 2 . . 3 . 293452 . . . . 2 3 . . 1 . 293452 . . . . 2 3 . . 1.2 . 293452 . . . . 2 3 . . 1.4 . 293452 . . . . 2 3 . . 1.6 . 293452 . . . . 2 3 . . 1.8 . 293452 . . . . 2 3 . . 2 . 293452 . . . . 2 3 . . 2.2 . 293452 . . . . 2 3 . . 2.4 . 293452 . . . . 2 3 . . 2.6 . 293452 . . . . 2 3 . . 2.8 . 293452 . . . . 2 3 . . 3 . 386996 . . . . 2 0 . . 1 100 386996 . . . . 2 0 . . 1.2 100 197 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 386996 . . . . 2 0 . . 1.4 100 386996 . . . . 2 0 . . 1.6 100 386996 . . . . 2 0 . . 1.8 100 386996 . . . . 2 0 . . 2 100 386996 . . . . 2 0 . . 2.2 100 386996 . . . . 2 0 . . 2.4 100 386996 . . . . 2 0 . . 2.6 100 386996 . . . . 2 0 . . 2.8 100 386996 . . . . 2 0 . . 3 100 386996 . . . . 2 1 . . 1 7.2 386996 . . . . 2 1 . . 1.2 100 386996 . . . . 2 1 . . 1.4 100 386996 . . . . 2 1 . . 1.6 100 386996 . . . . 2 1 . . 1.8 100 386996 . . . . 2 1 . . 2 100 386996 . . . . 2 1 . . 2.2 100 386996 . . . . 2 1 . . 2.4 100 386996 . . . . 2 1 . . 2.6 100 386996 . . . . 2 1 . . 2.8 100 386996 . . . . 2 1 . . 3 100 386996 . . . . 2 2 . . 1 . 386996 . . . . 2 2 . . 1.2 . 386996 . . . . 2 2 . . 1.4 . 386996 . . . . 2 2 . . 1.6 . 386996 . . . . 2 2 . . 1.8 . 386996 . . . . 2 2 . . 2 . 386996 . . . . 2 2 . . 2.2 . 386996 . . . . 2 2 . . 2.4 . 386996 . . . . 2 2 . . 2.6 . 386996 . . . . 2 2 . . 2.8 . 386996 . . . . 2 2 . . 3 . 386996 . . . . 2 3 . . 1 . 386996 . . . . 2 3 . . 1.2 . 386996 . . . . 2 3 . . 1.4 . 386996 . . . . 2 3 . . 1.6 . 386996 . . . . 2 3 . . 1.8 . 386996 . . . . 2 3 . . 2 . 386996 . . . . 2 3 . . 2.2 . 386996 . . . . 2 3 . . 2.4 . 386996 . . . . 2 3 . . 2.6 . 386996 . . . . 2 3 . . 2.8 . 386996 . . . . 2 3 . . 3 . 480412 . . . . 2 0 . . 1 . 480412 . . . . 2 0 . . 1.2 . 480412 . . . . 2 0 . . 1.4 31.7 480412 . . . . 2 0 . . 1.6 61 198 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 480412 . . . . 2 0 . . 1.8 93.8 480412 . . . . 2 0 . . 2 87 480412 . . . . 2 0 . . 2.2 100 480412 . . . . 2 0 . . 2.4 100 480412 . . . . 2 0 . . 2.6 99.3 480412 . . . . 2 0 . . 2.8 97.6 480412 . . . . 2 0 . . 3 97.4 480412 . . . . 2 1 . . 1 . 480412 . . . . 2 1 . . 1.2 . 480412 . . . . 2 1 . . 1.4 64.6 480412 . . . . 2 1 . . 1.6 70.1 480412 . . . . 2 1 . . 1.8 98.7 480412 . . . . 2 1 . . 2 98.8 480412 . . . . 2 1 . . 2.2 99 480412 . . . . 2 1 . . 2.4 98.6 480412 . . . . 2 1 . . 2.6 100 480412 . . . . 2 1 . . 2.8 99.8 480412 . . . . 2 1 . . 3 100 480412 . . . . 2 2 . . 1 . 480412 . . . . 2 2 . . 1.2 . 480412 . . . . 2 2 . . 1.4 0 480412 . . . . 2 2 . . 1.6 0 480412 . . . . 2 2 . . 1.8 0 480412 . . . . 2 2 . . 2 74.4 480412 . . . . 2 2 . . 2.2 0 480412 . . . . 2 2 . . 2.4 0 480412 . . . . 2 2 . . 2.6 0 480412 . . . . 2 2 . . 2.8 0 480412 . . . . 2 2 . . 3 0 480412 . . . . 2 3 . . 1 49.6 480412 . . . . 2 3 . . 1.2 29.1 480412 . . . . 2 3 . . 1.4 . 480412 . . . . 2 3 . . 1.6 . 480412 . . . . 2 3 . . 1.8 . 480412 . . . . 2 3 . . 2 . 480412 . . . . 2 3 . . 2.2 . 480412 . . . . 2 3 . . 2.4 . 480412 . . . . 2 3 . . 2.6 . 480412 . . . . 2 3 . . 2.8 . 480412 . . . . 2 3 . . 3 . 958802 . . . . 2 0 . . 1 . 958802 . . . . 2 0 . . 1.2 . 958802 . . . . 2 0 . . 1.4 . 958802 . . . . 2 0 . . 1.6 . 958802 . . . . 2 0 . . 1.8 . 958802 . . . . 2 0 . . 2 . 199 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 958802 . . . . 2 0 . . 2.2 99.7 958802 . . . . 2 0 . . 2.4 100 958802 . . . . 2 0 . . 2.6 . 958802 . . . . 2 0 . . 2.8 100 958802 . . . . 2 0 . . 3 100 958802 . . . . 2 1 . . 1 . 958802 . . . . 2 1 . . 1.2 . 958802 . . . . 2 1 . . 1.4 . 958802 . . . . 2 1 . . 1.6 . 958802 . . . . 2 1 . . 1.8 . 958802 . . . . 2 1 . . 2 . 958802 . . . . 2 1 . . 2.2 100 958802 . . . . 2 1 . . 2.4 100 958802 . . . . 2 1 . . 2.6 100 958802 . . . . 2 1 . . 2.8 . 958802 . . . . 2 1 . . 3 100 958802 . . . . 2 2 . . 1 . 958802 . . . . 2 2 . . 1.2 . 958802 . . . . 2 2 . . 1.4 . 958802 . . . . 2 2 . . 1.6 . 958802 . . . . 2 2 . . 1.8 . 958802 . . . . 2 2 . . 2 . 958802 . . . . 2 2 . . 2.2 100 958802 . . . . 2 2 . . 2.4 100 958802 . . . . 2 2 . . 2.6 . 958802 . . . . 2 2 . . 2.8 100 958802 . . . . 2 2 . . 3 54.2 958802 . . . . 2 3 . . 1 83.7 958802 . . . . 2 3 . . 1.2 81.2 958802 . . . . 2 3 . . 1.4 97.7 958802 . . . . 2 3 . . 1.6 75.5 958802 . . . . 2 3 . . 1.8 100 958802 . . . . 2 3 . . 2 . 958802 . . . . 2 3 . . 2.2 . 958802 . . . . 2 3 . . 2.4 . 958802 . . . . 2 3 . . 2.6 . 958802 . . . . 2 3 . . 2.8 . 958802 . . . . 2 3 . . 3 . 214717 . . . . 1 0 . . 1 100 214717 . . . . 1 0 . . 1.2 100 214717 . . . . 1 0 . . 1.4 100 214717 . . . . 1 0 . . 1.6 100 214717 . . . . 1 0 . . 1.8 100 214717 . . . . 1 0 . . 2 100 214717 . . . . 1 0 . . 2.2 100 214717 . . . . 1 0 . . 2.4 100 200 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 214717 . . . . 1 0 . . 2.6 100 214717 . . . . 1 0 . . 2.8 . 214717 . . . . 1 0 . . 3 . 214717 . . . . 1 1 . . 1 59.5 214717 . . . . 1 1 . . 1.2 45.5 214717 . . . . 1 1 . . 1.4 51.3 214717 . . . . 1 1 . . 1.6 100 214717 . . . . 1 1 . . 1.8 100 214717 . . . . 1 1 . . 2 100 214717 . . . . 1 1 . . 2.2 100 214717 . . . . 1 1 . . 2.4 100 214717 . . . . 1 1 . . 2.6 100 214717 . . . . 1 1 . . 2.8 100 214717 . . . . 1 1 . . 3 99.2 214717 . . . . 1 2 . . 1 . 214717 . . . . 1 2 . . 1.2 . 214717 . . . . 1 2 . . 1.4 . 214717 . . . . 1 2 . . 1.6 . 214717 . . . . 1 2 . . 1.8 . 214717 . . . . 1 2 . . 2 . 214717 . . . . 1 2 . . 2.2 . 214717 . . . . 1 2 . . 2.4 . 214717 . . . . 1 2 . . 2.6 . 214717 . . . . 1 2 . . 2.8 . 214717 . . . . 1 2 . . 3 . 214717 . . . . 1 3 . . 1 . 214717 . . . . 1 3 . . 1.2 . 214717 . . . . 1 3 . . 1.4 . 214717 . . . . 1 3 . . 1.6 . 214717 . . . . 1 3 . . 1.8 . 214717 . . . . 1 3 . . 2 . 214717 . . . . 1 3 . . 2.2 . 214717 . . . . 1 3 . . 2.4 . 214717 . . . . 1 3 . . 2.6 . 214717 . . . . 1 3 . . 2.8 . 214717 . . . . 1 3 . . 3 . 488732 . . . . 2 0 . . 1 . 488732 . . . . 2 0 . . 1.2 29.4 488732 . . . . 2 0 . . 1.4 23.8 488732 . . . . 2 0 . . 1.6 12.1 488732 . . . . 2 0 . . 1.8 . 488732 . . . . 2 0 . . 2 . 488732 . . . . 2 0 . . 2.2 . 488732 . . . . 2 0 . . 2.4 . 488732 . . . . 2 0 . . 2.6 . 488732 . . . . 2 0 . . 2.8 67.5 201 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 488732 . . . . 2 0 . . 3 87 488732 . . . . 2 1 . . 1 . 488732 . . . . 2 1 . . 1.2 74.5 488732 . . . . 2 1 . . 1.4 66 488732 . . . . 2 1 . . 1.6 52.5 488732 . . . . 2 1 . . 1.8 . 488732 . . . . 2 1 . . 2 . 488732 . . . . 2 1 . . 2.2 . 488732 . . . . 2 1 . . 2.4 . 488732 . . . . 2 1 . . 2.6 . 488732 . . . . 2 1 . . 2.8 67 488732 . . . . 2 1 . . 3 89 488732 . . . . 2 2 . . 1 . 488732 . . . . 2 2 . . 1.2 100 488732 . . . . 2 2 . . 1.4 100 488732 . . . . 2 2 . . 1.6 100 488732 . . . . 2 2 . . 1.8 . 488732 . . . . 2 2 . . 2 . 488732 . . . . 2 2 . . 2.2 . 488732 . . . . 2 2 . . 2.4 . 488732 . . . . 2 2 . . 2.6 . 488732 . . . . 2 2 . . 2.8 . 488732 . . . . 2 2 . . 3 33.4 488732 . . . . 2 3 . . 1 54.1 488732 . . . . 2 3 . . 1.2 . 488732 . . . . 2 3 . . 1.4 . 488732 . . . . 2 3 . . 1.6 . 488732 . . . . 2 3 . . 1.8 33.9 488732 . . . . 2 3 . . 2 25.2 488732 . . . . 2 3 . . 2.2 40 488732 . . . . 2 3 . . 2.4 40 488732 . . . . 2 3 . . 2.6 54.8 488732 . . . . 2 3 . . 2.8 . 488732 . . . . 2 3 . . 3 . 520661 . . . . 2 0 . . 1 98.3 520661 . . . . 2 0 . . 1.2 100 520661 . . . . 2 0 . . 1.4 100 520661 . . . . 2 0 . . 1.6 100 520661 . . . . 2 0 . . 1.8 100 520661 . . . . 2 0 . . 2 100 520661 . . . . 2 0 . . 2.2 100 520661 . . . . 2 0 . . 2.4 100 520661 . . . . 2 0 . . 2.6 100 520661 . . . . 2 0 . . 2.8 100 520661 . . . . 2 0 . . 3 99.7 520661 . . . . 2 1 . . 1 65.5 202 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 520661 . . . . 2 1 . . 1.2 72.6 520661 . . . . 2 1 . . 1.4 78.6 520661 . . . . 2 1 . . 1.6 92.2 520661 . . . . 2 1 . . 1.8 81.6 520661 . . . . 2 1 . . 2 95.1 520661 . . . . 2 1 . . 2.2 100 520661 . . . . 2 1 . . 2.4 95.2 520661 . . . . 2 1 . . 2.6 100 520661 . . . . 2 1 . . 2.8 99.3 520661 . . . . 2 1 . . 3 100 520661 . . . . 2 2 . . 1 . 520661 . . . . 2 2 . . 1.2 0 520661 . . . . 2 2 . . 1.4 0 520661 . . . . 2 2 . . 1.6 56.1 520661 . . . . 2 2 . . 1.8 . 520661 . . . . 2 2 . . 2 . 520661 . . . . 2 2 . . 2.2 . 520661 . . . . 2 2 . . 2.4 . 520661 . . . . 2 2 . . 2.6 . 520661 . . . . 2 2 . . 2.8 . 520661 . . . . 2 2 . . 3 . 520661 . . . . 2 3 . . 1 . 520661 . . . . 2 3 . . 1.2 . 520661 . . . . 2 3 . . 1.4 . 520661 . . . . 2 3 . . 1.6 . 520661 . . . . 2 3 . . 1.8 . 520661 . . . . 2 3 . . 2 . 520661 . . . . 2 3 . . 2.2 . 520661 . . . . 2 3 . . 2.4 . 520661 . . . . 2 3 . . 2.6 . 520661 . . . . 2 3 . . 2.8 . 520661 . . . . 2 3 . . 3 . 862184 . . . . 2 0 . . 1 . 862184 . . . . 2 0 . . 1.2 . 862184 . . . . 2 0 . . 1.4 . 862184 . . . . 2 0 . . 1.6 . 862184 . . . . 2 0 . . 1.8 . 862184 . . . . 2 0 . . 2 . 862184 . . . . 2 0 . . 2.2 . 862184 . . . . 2 0 . . 2.4 . 862184 . . . . 2 0 . . 2.6 . 862184 . . . . 2 0 . . 2.8 61.7 862184 . . . . 2 0 . . 3 56.5 862184 . . . . 2 1 . . 1 . 862184 . . . . 2 1 . . 1.2 . 862184 . . . . 2 1 . . 1.4 . 203 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 862184 . . . . 2 1 . . 1.6 . 862184 . . . . 2 1 . . 1.8 . 862184 . . . . 2 1 . . 2 . 862184 . . . . 2 1 . . 2.2 . 862184 . . . . 2 1 . . 2.4 . 862184 . . . . 2 1 . . 2.6 . 862184 . . . . 2 1 . . 2.8 93.2 862184 . . . . 2 1 . . 3 93.4 862184 . . . . 2 2 . . 1 . 862184 . . . . 2 2 . . 1.2 . 862184 . . . . 2 2 . . 1.4 . 862184 . . . . 2 2 . . 1.6 . 862184 . . . . 2 2 . . 1.8 . 862184 . . . . 2 2 . . 2 . 862184 . . . . 2 2 . . 2.2 . 862184 . . . . 2 2 . . 2.4 . 862184 . . . . 2 2 . . 2.6 . 862184 . . . . 2 2 . . 2.8 100 862184 . . . . 2 2 . . 3 100 862184 . . . . 2 3 . . 1 90 862184 . . . . 2 3 . . 1.2 89.6 862184 . . . . 2 3 . . 1.4 91.8 862184 . . . . 2 3 . . 1.6 91.6 862184 . . . . 2 3 . . 1.8 85.5 862184 . . . . 2 3 . . 2 63.4 862184 . . . . 2 3 . . 2.2 61.7 862184 . . . . 2 3 . . 2.4 67.6 862184 . . . . 2 3 . . 2.6 74.5 862184 . . . . 2 3 . . 2.8 . 862184 . . . . 2 3 . . 3 . 882975 . . . . 2 0 . . 1 . 882975 . . . . 2 0 . . 1.2 . 882975 . . . . 2 0 . . 1.4 . 882975 . . . . 2 0 . . 1.6 . 882975 . . . . 2 0 . . 1.8 100 882975 . . . . 2 0 . . 2 81.3 882975 . . . . 2 0 . . 2.2 82.1 882975 . . . . 2 0 . . 2.4 94.9 882975 . . . . 2 0 . . 2.6 84.8 882975 . . . . 2 0 . . 2.8 96.3 882975 . . . . 2 0 . . 3 66.5 882975 . . . . 2 1 . . 1 . 882975 . . . . 2 1 . . 1.2 . 882975 . . . . 2 1 . . 1.4 . 882975 . . . . 2 1 . . 1.6 . 882975 . . . . 2 1 . . 1.8 21.9 204 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 882975 . . . . 2 1 . . 2 40 882975 . . . . 2 1 . . 2.2 77 882975 . . . . 2 1 . . 2.4 66.6 882975 . . . . 2 1 . . 2.6 84.4 882975 . . . . 2 1 . . 2.8 100 882975 . . . . 2 1 . . 3 88.9 882975 . . . . 2 2 . . 1 . 882975 . . . . 2 2 . . 1.2 . 882975 . . . . 2 2 . . 1.4 . 882975 . . . . 2 2 . . 1.6 . 882975 . . . . 2 2 . . 1.8 0 882975 . . . . 2 2 . . 2 0 882975 . . . . 2 2 . . 2.2 0 882975 . . . . 2 2 . . 2.4 5.4 882975 . . . . 2 2 . . 2.6 18.6 882975 . . . . 2 2 . . 2.8 14.9 882975 . . . . 2 2 . . 3 49.6 882975 . . . . 2 3 . . 1 0 882975 . . . . 2 3 . . 1.2 0 882975 . . . . 2 3 . . 1.4 8.6 882975 . . . . 2 3 . . 1.6 19.2 882975 . . . . 2 3 . . 1.8 . 882975 . . . . 2 3 . . 2 . 882975 . . . . 2 3 . . 2.2 . 882975 . . . . 2 3 . . 2.4 . 882975 . . . . 2 3 . . 2.6 . 882975 . . . . 2 3 . . 2.8 . 882975 . . . . 2 3 . . 3 . 932656 . . . . 1 0 . . 1 27.2 932656 . . . . 1 0 . . 1.2 50.1 932656 . . . . 1 0 . . 1.4 . 932656 . . . . 1 0 . . 1.6 . 932656 . . . . 1 0 . . 1.8 . 932656 . . . . 1 0 . . 2 . 932656 . . . . 1 0 . . 2.2 . 932656 . . . . 1 0 . . 2.4 . 932656 . . . . 1 0 . . 2.6 . 932656 . . . . 1 0 . . 2.8 . 932656 . . . . 1 0 . . 3 . 932656 . . . . 1 1 . . 1 40.2 932656 . . . . 1 1 . . 1.2 46.8 932656 . . . . 1 1 . . 1.4 . 932656 . . . . 1 1 . . 1.6 . 932656 . . . . 1 1 . . 1.8 . 932656 . . . . 1 1 . . 2 . 932656 . . . . 1 1 . . 2.2 . 205 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 932656 . . . . 1 1 . . 2.4 . 932656 . . . . 1 1 . . 2.6 . 932656 . . . . 1 1 . . 2.8 . 932656 . . . . 1 1 . . 3 . 932656 . . . . 1 2 . . 1 . 932656 . . . . 1 2 . . 1.2 . 932656 . . . . 1 2 . . 1.4 . 932656 . . . . 1 2 . . 1.6 . 932656 . . . . 1 2 . . 1.8 . 932656 . . . . 1 2 . . 2 . 932656 . . . . 1 2 . . 2.2 . 932656 . . . . 1 2 . . 2.4 . 932656 . . . . 1 2 . . 2.6 . 932656 . . . . 1 2 . . 2.8 . 932656 . . . . 1 2 . . 3 . 932656 . . . . 1 3 . . 1 . 932656 . . . . 1 3 . . 1.2 . 932656 . . . . 1 3 . . 1.4 40.8 932656 . . . . 1 3 . . 1.6 34.3 932656 . . . . 1 3 . . 1.8 35 932656 . . . . 1 3 . . 2 33.6 932656 . . . . 1 3 . . 2.2 50.8 932656 . . . . 1 3 . . 2.4 44.6 932656 . . . . 1 3 . . 2.6 56.4 932656 . . . . 1 3 . . 2.8 60.9 932656 . . . . 1 3 . . 3 58.1 377896 . . . . 1 0 . . 1 . 377896 . . . . 1 0 . . 1.2 . 377896 . . . . 1 0 . . 1.4 96.5 377896 . . . . 1 0 . . 1.6 89.7 377896 . . . . 1 0 . . 1.8 93.5 377896 . . . . 1 0 . . 2 93.5 377896 . . . . 1 0 . . 2.2 99.1 377896 . . . . 1 0 . . 2.4 100 377896 . . . . 1 0 . . 2.6 100 377896 . . . . 1 0 . . 2.8 100 377896 . . . . 1 0 . . 3 100 377896 . . . . 1 1 . . 1 . 377896 . . . . 1 1 . . 1.2 . 377896 . . . . 1 1 . . 1.4 94.6 377896 . . . . 1 1 . . 1.6 85.7 377896 . . . . 1 1 . . 1.8 100 377896 . . . . 1 1 . . 2 100 377896 . . . . 1 1 . . 2.2 100 377896 . . . . 1 1 . . 2.4 100 377896 . . . . 1 1 . . 2.6 100 206 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 377896 . . . . 1 1 . . 2.8 100 377896 . . . . 1 1 . . 3 100 377896 . . . . 1 2 . . 1 . 377896 . . . . 1 2 . . 1.2 . 377896 . . . . 1 2 . . 1.4 5.5 377896 . . . . 1 2 . . 1.6 27.5 377896 . . . . 1 2 . . 1.8 72.5 377896 . . . . 1 2 . . 2 . 377896 . . . . 1 2 . . 2.2 . 377896 . . . . 1 2 . . 2.4 100 377896 . . . . 1 2 . . 2.6 100 377896 . . . . 1 2 . . 2.8 . 377896 . . . . 1 2 . . 3 . 377896 . . . . 1 3 . . 1 41.1 377896 . . . . 1 3 . . 1.2 61.7 377896 . . . . 1 3 . . 1.4 . 377896 . . . . 1 3 . . 1.6 . 377896 . . . . 1 3 . . 1.8 . 377896 . . . . 1 3 . . 2 . 377896 . . . . 1 3 . . 2.2 . 377896 . . . . 1 3 . . 2.4 . 377896 . . . . 1 3 . . 2.6 . 377896 . . . . 1 3 . . 2.8 . 377896 . . . . 1 3 . . 3 . 883117 . . . . 1 0 . . 1 . 883117 . . . . 1 0 . . 1.2 . 883117 . . . . 1 0 . . 1.4 . 883117 . . . . 1 0 . . 1.6 . 883117 . . . . 1 0 . . 1.8 . 883117 . . . . 1 0 . . 2 . 883117 . . . . 1 0 . . 2.2 . 883117 . . . . 1 0 . . 2.4 . 883117 . . . . 1 0 . . 2.6 . 883117 . . . . 1 0 . . 2.8 . 883117 . . . . 1 0 . . 3 . 883117 . . . . 1 1 . . 1 . 883117 . . . . 1 1 . . 1.2 . 883117 . . . . 1 1 . . 1.4 . 883117 . . . . 1 1 . . 1.6 . 883117 . . . . 1 1 . . 1.8 . 883117 . . . . 1 1 . . 2 . 883117 . . . . 1 1 . . 2.2 . 883117 . . . . 1 1 . . 2.4 . 883117 . . . . 1 1 . . 2.6 . 883117 . . . . 1 1 . . 2.8 . 883117 . . . . 1 1 . . 3 . 207 NEW ULTRASONIC IRRIGATING TIP GRADES SUB AGE SEX TOOTH TYPE METHOD CANAL CUR NP LEVEL CLEAN in # Yrs 0=fem # 0=CONT 0=ml 0=st % # % 1=mal 1=6% 1=mb 1=cur WL 2=3% 2=ism 3=comm 883117 . . . . 1 2 . . 1 . 883117 . . . . 1 2 . . 1.2 . 883117 . . . . 1 2 . . 1.4 . 883117 . . . . 1 2 . . 1.6 . 883117 . . . . 1 2 . . 1.8 . 883117 . . . . 1 2 . . 2 . 883117 . . . . 1 2 . . 2.2 . 883117 . . . . 1 2 . . 2.4 . 883117 . . . . 1 2 . . 2.6 . 883117 . . . . 1 2 . . 2.8 . 883117 . . . . 1 2 . . 3 . 883117 . . . . 1 3 . . 1 100 883117 . . . . 1 3 . . 1.2 100 883117 . . . . 1 3 . . 1.4 100 883117 . . . . 1 3 . . 1.6 90.3 883117 . . . . 1 3 . . 1.8 83.7 883117 . . . . 1 3 . . 2 81.2 883117 . . . . 1 3 . . 2.2 81.2 883117 . . . . 1 3 . . 2.4 82.4 883117 . . . . 1 3 . . 2.6 82.4 883117 . . . . 1 3 . . 2.8 82.7 883117 . . . . 1 3 . . 3 87.7

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APPENDIX E

BIOMEDICAL SUBMISSION FORMS

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APPENDIX F

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WANTED Subjects for a Dental Ultrasonic Irrigation Study

Purpose: To determine if there is a difference between 3% and 6% NaOCl with ultrasonic irrigation in debriding the mesial canals of human mandibular molars with irreversible pulpitis (vital pulp).

Eligibility: • 18 to 65 years of age • Medically healthy • Patients must have a pulpal diagnosis of Irreversible Pulpitis (vital pulp) • Patient wishes to have their tooth extracted

Time Required: One 70 minute appointment will be required. Follow-up visits will be needed only in the case of complications relating to tooth extraction (eg. dry socket).

Compensation: $100 for completing all aspects of the study. If unable to complete the study, no compensation will be given. Patients are responsible for the cost of emergency exam and extraction.

Location: College of Dentistry 4th floor, Advanced Endodontics Clinic

Contact: Dr. Aaron Aue College of Dentistry Department of Endodontics (917) 363-0366 or 292-5399

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LIST OF REFERENCES

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