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Retreatment of Resorcinol-Formalin Past Root Fillings : Studies on Dissolving Properties of Various Solutions

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Retreatment of Resorcinol-Formalin Past Root Fillings : Studies on Dissolving Properties of Various Solutions University of Connecticut OpenCommons@UConn SoDM Masters Theses School of Dental Medicine June 2006 Retreatment of Resorcinol-Formalin Past Root Fillings : Studies on Dissolving Properties of Various Solutions. Stanislav Aleksandrovich Moline Follow this and additional works at: https://opencommons.uconn.edu/sodm_masters Recommended Citation Moline, Stanislav Aleksandrovich, "Retreatment of Resorcinol-Formalin Past Root Fillings : Studies on Dissolving Properties of Various Solutions." (2006). SoDM Masters Theses. 1. https://opencommons.uconn.edu/sodm_masters/1 Retreatment of Resorcinol-Formalin Paste Root Fillings: Studies on Dissolving Properties of Various Solutions Stanislav Aleksandrovich Moline D.M.D., Tufts University, 2002 A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Dental Science At the University of Connecticut 2006 APPROVAL PAGE Master of Dental Science Thesis Retreatment of Resorcinol-Formalin Paste Root Fillings" Studies on Dissolving Properties of Various Solutions Presented by Stanislav Aleksandrovich Moline, D.M.D. Major Advisor Reza B. Kazemi D.M.D. Associate Advisor Kamran Safavi D.M.D., M.Ed. Associate Advisor Liisa Kuhn Ph.D. University of Connecticut 2006 DEDICATION To My Wife Tatyana Moline iii TABLE OF CONTENTS Page Title Page Approval Page ii Dedication iii Table of Contents iv Acknowledgement List of Tables vi List of Graphs viii List of SEM Images ix Introduction Purpose Null Hypothesis Materials and Methods Results 19 Discussion 45 Conclusion 53 References 55 iv Acknowledgement I would like to specially thank you Dr. Reza B. Kazemi for being not just an adviser, but also a true mentor. He was very supportive and patience in guiding me through this project. I warn to also thank Dr. Safavi, Dr. Kuhn, Dr. Zhu, and Dr. Jiang for their advice in this research. I appreciate help of Dr. Walsh and Mr. Tsimikas with statistics. I thank my fellow residents for their help and support. I thank you very much my wife Tatyana for her patience, encouragement, and love. List of Tables Page Table 1 Weight of samples and their distribution between solutions at the start of pilot study la 6 Table 2 Results of pilot study l a 7 Table 3 Weight of samples and their distribution between solutions at the start of pilot study lb 8 Table 4 Results of pilot study 1 b 9 Table 5 Results of combined pilot studies la and 1 b 10 Table 6 Weight of samples and their distribution between solutions at the start of pilot study 2 11 Table 7 Results of pilot study 2 12 Table 8 Weight of resorcin-formalin paste samples and their distribution between solutions at the start of main study part 1 15 Table 9 Weight of dentin samples and their distribution between solutions at the start of main study part 2 17 Table 10 Results of main study part 1 at 20 minutes 19 Table 11 Results of main study part 1 at 3 hours 20 Table 12 Results of main study part 1 at 6 hours 21 Table 13 Results of main study part 1 at 12 hours 22 Table 14 Results of main study part 1 at 24 hours 23 Table 15 Results of main study part 1 at 7 days 24 vi Page Table 16 Resorcinol-formalin paste samples means weights in mg 29 Table 17- Resorcinol-formalin paste samples means weights in percent 31 Table 18 Results of main study part 2 at 20 minutes 35 Table 19 Results of main study part 2 at 3 hours 35 Table 20- Results of main study part 2 at 6 hours 35 Table 21 Results of main study part 2 at 12 hours 35 Table 22 Results of main study part 2 at 24 hours 35 Table 23 Results of main study part 2 at 7 days 35 Table 24 Dentin samples means weights in mg 37 Table 25- Dentin samples means weights in percent 38 vii List of Graphs Page Graph 1. Weights change of resorcinol-formalin paste samples 30 Graph 2. Weights change of resorcinol-formalin paste samples in percent 32 Graph 3. Weights change of dentin samples 37 Graph 4. Weights change of dentin samples in percent 38 viii List of SEM Images Page Image 1. SEM Analysis of 'Control' group at start 40 Image 2. SEM Analysis of 'Control' group at 7 days 40 Image 3. SEM Analysis of 'Control at 37 C' group at start 41 Image 4. SEM Analysis of 'Control at 37 C' group at 7 days 41 Image 5. SEM Analysis of'5.25% NaOCl' group at start 42 Image 6. SEM Analysis of '5.25% NaOCl' group at 7 days 42 Image 7. SEM Analysis of '2.625% NaOCl' group at start 43 Image 8. SEM Analysis of '2.625% NaOCl' group at 7 days 43 Image 9. SEM Analysis of '37% phosphoric acid' group at start 44 Image 10. SEM Analysis of '37% phosphoric acid' group at 7 days 44 ix INTRODUCTION Resorcinol-formalin root filling material has been used in many countries of Europe and Asia, particularly in former USSR, Poland, Czech Republic, France, China, India (1), and probably other Asian countries. The main components of the paste are resorcinol and formaldehyde mixed with sodium hydroxide for hardening (1,2). The resin mixtures and placement techniques vary depending on the initial pulp vitality, canal anatomy, desired number of visits, etc. (1,2) In general, using different methods and techniques of root canal treatment success is reported at 91% success (combined teeth with vital or non-vital pulp) (4), 62.1%-96.1% success (stratified by presence of lesion and bacteriae) (5), and 84%-98% (depending on initial conditions such as number of roots, vitality, presence of radiolucency, etc.) (6). The success rate has been recorded based on the following various factors" presence of periapical lesion, pulp vitality, oral flora contamination, calcification, resorption, perforations, transportations, broken instruments, obturation material, etc. (2-6, 88, 91- 98). Studies have shown mixed results of the treatment prognosis of cases obturated with the resorcinol-formalin root canal paste (1-3). Wu et al. (1) report 82.05% success rate. However, in their study they refer to success as reduction of a lesion up to the complete resolution, but the results are not stratified based on the precondition of the teeth, including vitality or presence and size of periapical lesions. The findings of Gound et al. (3) reveal that on pre-retreatment evaluation; 22 teeth (24%) obturated with resorcinol- formalin presemed with clinical symptoms and 29 teeth (31%) had periapical radiolucency. Of total, 5% of the canals were completely filled and more then 50% had 'less then half of the canal(s) obturated'. Retreatment of root-canal systems filled with resorcinol-formalin paste is also shown to be complicated (2-3). Gound et al. (3) find that only 59% of retreatment cases were optimal. However, their finding is not based on long-term observation. In addition, the presence of certain hardeners such as sodium hydroxide can make retreatment more complicated (2). Formaldehyde toxicity is reported. Spfingberg L (12) reports that formaldehyde containing pastes 'in contact with vital tissue produced extensive damage in the form of necrosis'. Huang et al. (13) show cytotoxicity and 'persistent induction of c-jun and c-fos protooncogenes by formaldehyde-releasing root-canal sealers'. Negm et al. (14,15) assess a root canal filling material, which contains formaldehyde derivatives. When 'forced beyond the apex, in the majority of patients caused persistent pain and swelling. The periapical tissues were unable to absorb the excess material and had to be removed surgically'. Negm at al. (14) point that 'this reaction increased with time and persisted throughout the period of the study with no signs of absorption of the material.' The reaction to formaldehyde is in contrast to silver amalgam, which causes inflammation until it sets (14). However, when formaldehyde is released temporarily as a by-product of setting reaction, the damage is also transient (16,17). Due to need for retreatment of majority of root canals obturated with resorcin-formalin, and complexities to dissolve and remove the hardened resorcin-formalin, several solvents to dissolve resorcinol-formalin paste have been studied. Vranas et al. (8) examine four solutions: 0.9% sodium chloride, 5.25% sodium hypochlorite, chloroform, and Endosolv R (R). The study shows that 'both sodium chloride and sodium hypochlorite exhibit a significant softening effect within 2 min; however, the paste used for the root canal obturation had no sodium hydroxide that is normally added for hardening of the paste (2). Gambrel et al. (7) study six endodontic solutions on resorcinol paste containing sodium hydroxide" 0.9% sodium chloride, 5.25% sodium hypochlorite, chloroform, Endosolv R (R), and two more solutions of: 3% hydrogen peroxide and 70% isopropyl alcohol. They find that 'Endosolv R (R), had significantly greater penetration within the mass of material than 5.25% sodium hypochlorite and chloroform. However, this finding was not significantly better than the control'. In both studies, solutions are applied up to 20 minutes, which may not be enough. Septodont, manufacturer of Endosolv R (R), recommends a two-visit approach in addition to a single-visit one (9). PURPOSE With an estimated 2.6 million people from the above listed countries immigrated to the United States in the past 24+ years (10, 11), it is a major challenge in endodontic re- treatments of patients with failed root canal treated teeth obturated with the resorcin- formalin paste. The purpose of this study is to assess dissolving properties of various solutions applied for a prolonged period in order to retreat failed cases obturated with the resorcinol-formalin root filling paste. NULL HYPOTHESIS A solvent for hardener-containing resorcinol-formalin paste in clinical time frame is not identified.
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