The Debonding of Teeth from Removable Dentures Accounts for 22% to 30% of Denture Repairs

Multilithic Denture Teeth Promising Choice in Fabrication of Removable Dentures

A Comparison of Acrylic and Multilithic Teeth Bond Strengths to Acrylic Denture Base Material. Mosharraf R, Abed-Haghighi M:

J Contemp Dent Pract 2009; 10 (September): 1-6

There is not a significant difference in the bonding strength to acrylic-base dentures between the acrylic brands of teeth and the newer type of multilithic acrylic resin-composite denture teeth.

Background: The debonding of teeth from removable dentures accounts for 22% to 30% of denture repairs. Acrylic resin teeth bond to denture bases, but have poor wear resistance. On the other hand, all composite resin denture teeth were shown clinically to achieve poor bonding to denture bases and greater wear resistance. This paper compares 3 groups of denture teeth--2 acrylic resin and 1 multilithic. The latter consists of an acrylic gingival ridge lap and a composite outer layer. The tests conducted sought to ascertain whether this type of "hybrid" would be successful in reducing the number of fractures at the tooth-denture base interface. Objective: To compare bond strengths of a composite-acrylic denture tooth with an all-acrylic resin tooth. Data were analyzed to see if combining the properties of composites with acrylic would result in a more fracture- and abrasion-resistant tooth with superior retentive properties. Methods: 3 types of denture teeth were used: 1 multilithic (Yaghoot) and 2 conventional acrylic teeth (Super Brilian and Major). All ridge laps were lightly ground, and the teeth were bonded to the denture base by heat polymerization. After curing and deflasking, a universal testing machine applied forces to the teeth until fracture occurred. A shear compressive force at an angle of 130° was applied to lingual surfaces of the teeth, simulating the average contact angle of Class I occlusion. Fracture sites were analyzed, and mean bond strengths recorded. Results: Although the highest bond strength and lowest number of adhesive fractures was found in the Yaghoot (multilithic) tooth group, the difference among the 3 groups was not significant. More than 65% of fractures occurred at the tooth-denture base resin junction. The grinding of the ridge lap in all specimens resulted in all bonding surfaces being in acrylic. Conclusions: The multilithic acrylic resin-composite tooth and the 2 types of acrylic resin teeth exhibited similar bond strengths to the denture resin base, as well as having the same location of the fracture sites. Reviewer's Comments: Presently, the fracture of denture teeth is a common occurrence. In this study, all had an acrylic ridge lap, which accounts for the similarity in the data of the fractures. The effect of the composite surface layer on the multilithic tooth did not appear to make any difference in this area. The author attributes this tooth's slightly higher bond strength and lower adhesive fracture rate to "better ridge lap area properties in this tooth." More information about that ridge lap difference would have been helpful to enable the practitioner to utilize those properties and increase the bond strength of the teeth to the denture base. (Reviewer-Edward N. Friedman, DDS).

Keywords: Acrylic Resins, Composite Dental Resins, Denture Bases, Bonding

Print Tag: Refer to original journal article SBA Technique Mimics Native Bone, Promotes Regeneration

Sandwich Bone Augmentation for Predictable Horizontal Bone Augmentation. Lee A, Brown D, Wang HL:

Implant Dent 2009; 18 (August): 282-290

The sandwich bone augmentation technique, a type of guided bone regeneration procedure, can improve implant prognosis by achieving bone fill around dental implants.

Background: Numerous techniques have been proposed to promote guided bone regeneration (GBR) using different types of bone grafting materials and membranes. This study discusses a protocol called sandwich bone augmentation (SBA), which stresses the creation of an environment similar to that of native bone in order to promote regeneration. Objective: To demonstrate the success of the sandwich bone augmentation technique resulting in stable implants due to successful bone fill around the implants. The regeneration of this native bone is best demonstrated by promoting successful bone fill simply by reproducing an environment favorable to native bone regeneration while inserting a variety of grafting materials. Participants/Methods: SBA was chosen in order to achieve both vertical and horizontal bone augmentation. After initial incisions and a full-thickness flap, a Tapered Screw Vent implant was placed using a surgical guide. A buccal fenestration was present. Autogenous cancellous bone was applied as the first layer of the bone graft over the implant surface. Cortical bone graft was then placed as the second external layer. This layer serves to create and maintain the space needed for regeneration. The barrier membrane is then placed to cover the bone grafts and exclude soft tissue. The increase in the number of bone forming cells is critical to attaining bone fill. Radiographs at the time of second-stage surgery in 5 to 6 months demonstrated adequate bone level and no pathology. The restoration of the implant with a ceramic crown was then commenced. Results/Conclusions: This guided bone regeneration technique has proven to be predictable and successful using several types of bone graft materials. The data show that they were as successful as other implants that did not need additional bone regeneration procedures. The most frequently reported complication of the GBR is that of membrane exposure. This complication would compromise the amount of bone regenerated, allowing contamination into the area around the implant. The SBA technique helps prevent this occurrence, since the use of bone grafts may prevent membrane collapse. Reviewer's Comments: This study presents a good review of this technique of guided bone regeneration. Dr Lee stresses the basic principles of healing that apply to any type of surgical situation, and goes one step further with her use of the SBA technique. Along with a flexible approach that employs the use of different materials, this article provides the practitioner with another method to achieve and improve the amount of bone fill, ultimately enhancing the long-term prognosis of the implants. (Reviewer-Edward N. Friedman, DDS).

Keywords: Implants, Guided Bone Regeneration, Membrane, Sandwich

Print Tag: Refer to original journal article Reduce Microleakage With Silorane-Based Materials

Comparing Microleakage and the Layering Methods of Silorane-Based Resin Composite in Wide Class II MOD Cavities. Bagis YH, Baltacioglu IH, Kahyaogullari S:

Oper Dent 2009; 34 (September-October): 578-585

Microleakage can be reduced by using silorane-based materials, using either the vertical or oblique layering technique, rather than methacrylate-based composites.

Background: One of the disadvantages of composite restorations has been the presence of microleakage due to the lack of complete marginal sealing. The volumetric shrinkage resulting from polymerization contraction can lead to hypersensitivity and recurrent decay. This study reviews 2 factors related to this microleakage--the type of layering technique and the different monomer-based composites used. Objective: To evaluate layering techniques with each of 2 different monomer systems to ascertain which combination of factors will better achieve a completed restoration with minimal or no marginal microleakage. Design/Methods: An in vitro study was used, and 32 third molars were prepared with wide MOD cavity preparations. The 32 teeth were divided into 4 groups of 8. Half of the specimens were etched, bonded, and restored with a methacrylate-based nanohybrid composite, and the other half with a silorane-based microhybrid composite. Each of these 2 groups was further subdivided according to the layering technique--16 were restored with the vertical, and 16 with the oblique. After completing the restorations, the specimens were immersed in a fuchsin dye solution for 24 hours. Then they were sectioned and examined under a stereo microscope at 10x magnification to quantify the amount of marginal microleakage. Results: The specimens restored with the silorane-based composite showed no microleakage. This result was present both in those teeth restored with the vertical as well as the oblique layering technique. However, the specimens restored with the methacrylate-based composite did show significant microleakage. There also was a difference with the layering technique used. There was less microleakage at the enamel margins on those teeth that were filled with the vertical layering technique than with the oblique. Conclusions: These in vitro results provide validity to what would result in the oral cavity. The minimizing of contraction stress and polymerization shrinkage is significant in preventing open margins and leakage. Methacrylate-based restorative materials have higher polymerization shrinkage stresses than do silorane- based resin systems. The increased contraction forces in the cavity result in a deficient marginal seal. This study concludes that microleakage can be reduced by using silorane-based materials rather than methacrylate-based composites. Reviewer's Comments: This is a relevant study that explains why postoperative sensitivity after composite placement is such a widely observed phenomena. Two variables involved when restoring teeth with composites were studied, the packing technique and the choice of material. Only after knowing the cause of postoperative sensitivity can we then proceed to its elimination, and more importantly, its prevention. This article does give valuable insight into some causes of postoperative discomfort and diminished longevity of composite restorations. (Reviewer-Edward N. Friedman, DDS).

Keywords: Microleakage, Silorane-Based Resin Composite

Print Tag: Refer to original journal article Pain Is Not Always What/Where it Seems to Be

Referred Pain, Allodynia, and Hyperalgesia. Murray GM:

J Am Dent Assoc 2009; 140 (September): 1122-1124

Some simple tests can help practitioners identify the actual source of pain so that they can give more effective and accurate treatment.

Background: Chronic pain, allodynia, hyperalgesia, and referred or heterotopic pain have been responsible for the failure of many treatments. Objective: To provide an informational review on pain sites and pain sources. Design: Informational review. Discussion: In our efforts to try to relieve pain, it's easy to be distracted by patient statements and history to the point of performing inappropriate treatments. When the patient presents with a dull pain complaint that cannot be replicated or provoked by local, site-specific stimulation, a heterotopic pain diagnosis must be considered. A suggested mechanism for deep muscle pain and referred pain involves the opening or activation of formerly silent, inactive, or latent synapses. Nociceptive afferent impulses enter the brain branch and terminate at multiple second-order synapses. Some of these allow for the action potential to continue to higher brain centers to be correctly perceived as pain. Yet, some of these synapses are not effective and the signal is not transferred. When these ineffective synapses are bombarded with prolonged intense stimuli, they can begin to connect and transmit the action potential to be realized by higher brain centers as a pain from a different origin. This has to do with central sensitization and neuroplasticity. This is the mechanism by which a muscle pain from the temporalis can be the nociception that is perceived in other higher centers of the brain as frontal headache or pulpal tooth pain. It is often exceedingly difficult for patients to accept the fact that the referred pain site is not the location of the noxious stimulation. This fact has often led to the performance of unnecessary dental procedures. A good rule of thumb is that, if the pain cannot be provoked by stimulation of the felt pain site, that area should not be treated until a very definitive diagnosis is made. Use of diagnostic local anesthesia is indicated to rule out heterotopic pain experiences. If the pain continues after the perceived pain area has been anesthetized, no treatment is indicated in that area. Another cause for poor localization and spread of pain is convergence. This is where multiple neurons from distant peripheral sites converge on one second-order neuron synapse and the higher brain centers cannot differentiate the stimulus site. Allodynia is a pain sensation from non-noxious stimuli because of the presence of inflammatory chemicals from the immune system. Hyperalgesia is the perception of a more intense pain over a larger area than is warranted by the noxious stimulus. Conclusions: The site of the felt pain is not necessarily the pain source. Reviewer's Comments: This article again exhorts us as practitioners to diagnose before we treat. There are a number of less than well understood conditions that can lead us to consider inappropriate treatment decisions. (Reviewer-Charles R. Hoopingarner, DDS).

Keywords: Chronic Pain, Allodynia, Hyperalgesia, Central Sensitization

Print Tag: Refer to original journal article PDT Can Reduce Frequency of Recurrent Herpes Labialis

Photodynamic Therapy for the Treatment of Recurrent Herpes Labialis: Preliminary Results. Sperandio FF, Marotti J, et al:

Gen Dent 2009; 57 (July/August): 415-419

The symptoms, longevity, and recurrence rates of recurrent herpes labialis can be improved with low-level laser therapy and photodynamic therapy.

Background: Recurrent herpes labialis (RHL) is a herpes simplex virus (HSV-1) that is a painful, infectious, debilitating condition affecting as much as 40% of the population. HSV exists in a latent state in the trigeminal ganglion where it is non-detectable. This is due to a downregulation of the replication process. Upon triggering by events such as illness, stress, UV light, or trauma, the virus is reactivated and travels proximally along the axon to the peripheral lesion site. There is a prodromal state highlighted by burning tingling, soreness, etc, that precedes the appearance of vesicles that erupt and then crust over in 72 to 96 hours. Episodes can be protracted and appear many times over the course of a year. Common treatments include the use of acyclovir (ACV) or valacyclovir, which can provide symptomatic relief. ACV does not alter the frequency and must be administered before vesication. Low-level laser therapy (LLLT) and photodynamic therapy (PDT) have been shown to reduce the frequency of recurrence and to be effective after vesication is present. Objective: To evaluate PDT for the treatment of RHL. Design: Case study. Methods: After obtaining informed consent, 2 patients presenting for treatment at the University of São Paulo were chosen for the study. Both had vesicular lesions. Methylene blue (MB) was chosen as the PDT mediator because of its less toxic and wide use in medicine and dentistry. The vesicles were punctured with a sterile needle and intermittently dried with gauze until the oozing terminated. MB dye at 0.01% m/V was applied to the dried lesions and after 5 minutes the area was irradiated. The light source was a 660-nm diode laser. This was applied at 2.8 J continuously for 28 seconds over a spot size of 0.028 cm2. Three points of application on each lesion resulted in a total energy of 8.4 J. At 24 hours, the patients were treated again with LLLT with 1.68 J of energy from a 14 second x 3-point irradiation with 40 mW power. Additional identical doses were delivered at 2, 3, and 7 days to accelerate healing. The patients were followed monthly for 6 months with no recurrence of signs or symptoms. Discussion: PDT is the application of a particular wavelength of light energy to excite photosensitizer (PS) molecules to their singlet state which can inactivate the HSV. The virus loses its ability to form plaques in the presence of light energy, molecular oxygen and PS. While the mechanism is not clearly understood it is thought that it involves the production of a tightly bound virus-dye complex. Conclusions: PDT with MB and LLLT is valuable for treating RHL while reducing the frequency of recurrence. Reviewer's Comments: While this study demonstrates the value of this particular technique there was no comparison to results obtained with higher energy laser irradiation with or without PDT. (Reviewer-Charles R. Hoopingarner, DDS).

Keywords: Photodynamic Therapy, Low-Level Laser Therapy, Herpes Simplex

Print Tag: Refer to original journal article Simple Intervention Can Prevent Early Childhood Caries

Effect of Long-Term Consumption of Milk Supplemented With Probiotic Lactobacilli and Fluoride on Dental Caries and General Health in Preschool Children: A Cluster-Randomized Study. Stecksén-Blicks C, Sjöström I, Twetman S:

Caries Res 2009; 43 (5): 374-381

Daily ingestion of fluoridated milk containing probiotics prevents dental caries in preschool children.

Background: Childhood caries continues to be a significant public health problem, disproportionately affecting underprivileged children and necessitating a creative approach to disease prevention. Fluoridated milk has been offered as an alternative to water fluoridation because of additional health benefits. Probiotic Lactobacillus sp. added to milk may inhibit cariogenic bacteria and further reduce caries risk. Objective: To evaluate the caries-preventive effect of daily intake of fluoridated milk supplemented with probiotic Lactobacillus rhamnosus LB21 on preschool children compared to regular milk. Design/Participants: Children aged 1 to 5 years from 14 day care centers (27 units) in Sweden participated in a clustered, double-blinded placebo-controlled trial. Methods: Health data, water fluoride level, breastfeeding, allergies, food intolerances, and oral health habits were recorded. Exclusions were severe chronic diseases, milk intolerance, and water fluoride >0.5 mg/L. In total, 470 children were eligible; 248 enrolled. Fifty-eight children transferred to primary school before study completion; 4 dropped out. Children had 150 mL 1.5% fat milk at lunch, on weekdays only and no holidays or vacations. The intervention group had fluoride and probiotic bacteria in skim milk added for a final concentration in the milk of 2.5 mg/L fluoride and 107 CFU/mL L rhamnosus LB21. Parents recorded number of sick days, antibiotics, and medical visits. At baseline and at 21 months, caries was recorded and plaque sampled and cultured. Caries increment (change in dmfs) was calculated for each. Prevented fraction was the difference in mean caries increment between the intervention and control groups, as a percentage of the control group's increment. Results: 186 children completed at least 12 months of the study. There was a statistically significant difference in caries increment after 21 months between the groups (P <0.05), with a prevented fraction of 75%. The absolute risk reduction for remaining caries-free was 21% and number needed to treat was 4.8. The proportion of S mutans in the total plaque bacteria was less in the intervention group, but was not significant. No increase was seen over time in Lactobacilli counts in the treatment group. When the children who participated for the entire study were analyzed separately, they had statistically significantly fewer days with otitis media (P <0.05). Conclusions: Milk supplementation with fluoride and probiotic Lactobacillus prevented dental caries and reduced number of days with otitis media in preschool children. Reviewer's Comments: This is an exciting study because it shows how a relatively simple intervention can prevent childhood caries in a high-risk population. One limitation is that we cannot assess whether the effect is primarily due to the fluoride, the probiotic, or both. (Reviewer-Carol Anne Murdoch-Kinch, DDS, PhD).

Keywords: Probiotics, Caries Prevention, Fluoride

Print Tag: Refer to original journal article Smoking Worsens Prognosis for Women With Oral Cancer

Women and Squamous Cell Carcinomas of the Oral Cavity and Oropharynx: Is There Something New? Girod A, Mosseri V, et al:

J Oral Maxillofac Surg 2009; 67 (September): 1914-1920

In females with head and neck cancer, worse prognosis was associated with smoking, age <45 and >70 years, and oral cavity site.

Background: Women represent an increasing proportion of new cases of oral and oropharyngeal squamous cell carcinomas (SCCs) worldwide. The proportion of women with SCC with no history of tobacco and alcohol use is greater than in men. Objective: To define the demographics and survival of women with SCC of the oral cavity and oropharynx in France. Design/Methods: From 1989 to 2002, a prospective study enrolled 1362 patients with oral cavity and oropharyngeal SCC; data were extracted for 171 female patients. Oral cavity sites were tongue, floor of mouth, gingiva, and other mouth (palate, buccal mucosa, and vestibule). Oropharyngeal sites were tonsil and oropharynx. Age, tobacco and alcohol use, TNM classification, and histology were recorded. Disease outcomes included recurrence, second cancer or metastasis, overall survival, and cancer-specific survival. Results: 171 women with SCC of oral cavity and oropharynx were included. Mean age was 62 years (22 to 102); 11.1% were aged <45 years, 58.5% were aged 46 to 69 years, 30.4% were aged >70 years. In total, 51.5% did not use tobacco and 65.5% did not use alcohol. Smoking and alcohol use >100 g/day was significantly less frequent in patients aged >70 years (P =0.0014, and 0.013 respectively). Overall, 37.4% had SCC of tongue, 29.2% oropharynx, 18.7 % other mouth, 8.8% floor of mouth, and 5.9% gingiva; 70.8% of SCCs were in oral cavity and 29.2% in oropharynx. A total of 72.5 % were T1/T2, 27.5 % had T3/T4, and 71.3 % had no nodal spread. More oral cavity tumors were T1/T2 (P =0.018). Overall survival at 5 years was 58.0% and cancer-specific survival was 71.7 %. The cause of death was local spread in 29.4%, metastases in 15.3%, second cancer in 15.3%, or other cause in 40%.T1 and T2 SCCs were associated with better overall (P =0.0027) and cancer-specific survival (P =0.0069). Non-smokers had better overall 5-year survival rates (66.7%) and cancer-specific survival rates (79.45%). Prognosis was worse for oral cavity compared to oropharyngeal SCC (P =0.054). In female smokers, SCC of oral cavity and oropharynx appeared 10 years earlier than in non-smokers. Conclusions: In women with oral and oropharyngeal SCC, poorer prognosis was associated with age <45 years and >70 years, smoking, oral cavity versus oropharyngeal location, stage at diagnosis, and nodal involvement. Reviewer's Comments: Clearly, smoking and alcohol use are still a significant risk factor for women with oral cavity and oropharyngeal SCC, even in women aged <45 years. Smoking was associated with poorer prognosis. Smoking cessation is essential to prevent deaths from oral and oropharyngeal cancer in women. (Reviewer-Carol Anne Murdoch-Kinch, DDS, PhD).

Keywords: Oral & Oropharyngeal Squamous Cell Carcinoma

Print Tag: Refer to original journal article Are You Using an Antiquated Shade Guide?

Color Matching in Dentistry. II. Practical Applications of the Organization of Color. Sproull RC:

J Prosthet Dent 1973; 29 (May): 556-566

The foundational principles of color matching in dentistry introduced generations ago still apply today.

Classic Article Review - Background: Working with inadequate shade guides and dealing with the frustration of matching complex colors of natural teeth is a long-standing issue in dentistry. Dr Sproull is widely regarded as having introduced the foundational principles of color and their applications to modern dentistry with his classic series of articles on "Color Matching in Dentistry." He shed light on the color problem in dentistry more than 3.5 decades ago. Objective: To investigate the objective color space of natural teeth and to compare the color range and distribution of various dental shade guides in relationship to the Munsell Color Order System and natural teeth. Methods: Criteria were set for classifying a shade guide as acceptable, which include: (1) a logical color space arrangement and (2) adequate distribution of the shade tabs in color space. The color coordinates of natural teeth were measured with an electric recording spectrophotometer and interpreted according to the Munsell's Color Order System of Hue, Chroma, and Value. The same color measurements were taken for multiple shade guides and graphed according to the 3 dimensions of color. Results: Color measurement comparisons among teeth and shade guides demonstrated that none of the shade guides met the criteria for an ideal shade guide. The shade guides lacked the tabs to fill the color space of natural teeth and were not logically arranged. Color tabs did not extend the full range of Chroma and Value in the available Hues and were not equally distributed, as the color coordinates were clustered within the given color space. Conclusions: Dental shade guides should be modified to better represent the color range and distribution of natural teeth. Improvements in color training and education in dental schools, along with increased research and consultation with color experts were recommended. Reviewer's Comments: Reviewer's Comments: While some improved shade guides have recently been introduced to the dental market, inadequate shade guides of ≥50 years are still widely used today. Dr Sproull wrote, "The ever-increasing demand for esthetics by an increasing sophisticated dental clientele requires dentists to abandon antiquated and unsuitable guides and to take advantage of modern color technology." This is just as true in 2009 as it was in 1973. (Reviewer-Joe C. Ontiveros, DDS, MS).

Keywords: Color/Shade Guides

Print Tag: Refer to original journal article Differences Exist in Rotary Instrument Use

Usage Parameters of Nickel-Titanium Rotary Instruments: A Survey of Endodontists in the United States. Bird DC, Chambers D, Peters OA:

J Endod 2009; 35 (September): 1193-1197

Taking a lesson from endodontists, general dentists should be familiarized with advantages of rotary filing systems and be carefully trained in their use to keep pace with the specialty.

Background: While rotary endodontic instruments have been available for some time, there are little data on their actual usage characteristics among endodontic specialists. Objective: To survey, using a detailed questionnaire, the usage characteristics of rotary endodontic instruments among all active members of the specialty of endodontics. Design: An online questionnaire was distributed electronically using a Web-based interface. The survey instrument consisted of both check-box and free-text responses, with questions based on recent literature reviews and standard textbooks dealing with the subject of root canal preparation. Participants: All 954 active members of the American Association of Endodontists were invited to complete the survey via e-mail. Methods: Incomplete surveys were not analyzed, and complete surveys that were returned were analyzed with appropriate computer software. Data were analyzed by geographic region of the specialist, year of graduation, and type of practice (group, solo, or university). Other questions included items on percentage of treatments using rotary files, type of equipment, configuration of equipment, access cavity design, preferred working stroke, preparation sequence, irrigation, lubrication and instrument reuse, and cleaning and storage. Results: From 359 completed surveys (38% response rate), no differences were observed for year of graduation or geographic region. In total, 60% indicated that they used rotary instruments in all cases and 30% used them primarily (81% to 99% of their cases). Recent graduates (2000 to 2007) were more likely to use rotary systems in all cases. A majority of respondents used multiple rotary systems at 300 rpm as the preferred rotational speed, and 76% indicated that access cavity preparation did not differ between filing systems. Approximately equal numbers used a "pecking," "marching," and manufacturer-specified working stroke. Overall, 79% used a "crown down" preparation sequence, and most reported using sodium hypochlorite alone or in combination with EDTA (57%), while 53% used an EDTA paste. More than 50% of endodontists surveyed re-used rotary instruments (in multiple patients), and 57% treated them with ultrasonic cleaning and sterilization between treatments. Conclusions: There is a high usage rate of rotary instruments among endodontists in all regions of the U.S., but there are some differences in how they are used. Based on the survey, endodontists expect that future rotary systems will be similar to the current system, but will be improved over the next 10 years. Reviewer's Comments: We can be grateful to these authors for confirming what we may have suspected regarding the high usage rates of rotary instrumentation by endodontists, and for providing us with information on how these systems are actually utilized in practice. (Reviewer-Arthur H. Jeske, DMD, PhD).

Keywords: Nickel-Titanium, Rotary Root Canal Instruments, Survey, Usage

Print Tag: Refer to original journal article Chlorhexidine Equally Effective as Root Canal Medicament

Proportion of Healed Teeth With Apical Periodontitis Medicated With Two Percent Chlorhexidine Gluconate Liquid: A Case-Series Study. Tervit C, Paquette L, et al:

J Endod 2009; 35 (September): 1182-1185

An acceptable degree of healing equal to that achieved with the traditional irrigant sodium hypochlorite can be expected from 2% chlorhexidine.

Background: Elimination of bacteria in root canals of teeth with apical periodontitis results in predictable healing and the introduction of an antibacterial agent between the initiation and completion of root canal therapy. Objective: To compare healing outcomes of endodontic treatment using sodium hypochlorite as a historic control versus 2% chlorhexidine (CHX) as an intracanal medicament. Design: Prospective case series that used a cohort of patients with apical periodontitis, treated with conventional endodontic technique. Participants: Patients in the study had a single rooted tooth with sufficient coronal tooth structure to facilitate isolation and endodontic treatment. Methods: Following isolation, 22 teeth were endodontically treated using an apex locator and filing with ProFile 0.04 and 0.06 taper rotary files and K-type hand files to size 35 to 60 at the working length using 2.5% sodium hypochlorite as an irrigant. Canals were medicated with 2% CHX for 7 to 15 days, and then irrigated with sodium hypochlorite at the second visit and filled with Pulp Canal sealer, followed by vertical condensation of warm gutta percha. Following inactivation of irrigants, bacterial sampling was done before and after canal enlargement and after canal medication with CHX. In some subjects, additional bacterial sampling was done before root filling. Bacterial presence was determined by anaerobic culture and epifluorescence microscopy. Results: 17 of 22 subjects were re-evaluated after an average elapsed time of 34 months, for a recall rate of 81%. Sixteen of 17 treated teeth (94%) were determined to be healed by 1 clinical evaluator not involved in the actual endodontic treatment. Radiographs of the teeth were evaluated by 2 other examiners and scored using a Periapical Index. Of 16 "healed" teeth, 37.5% had no bacterial growth at the start of the second treatment visit and 43.7% had no bacterial growth before root filling. All teeth with positive bacterial growth healed, and the single tooth that did not heal had no bacterial growth at the start of the second treatment visit. Use of sodium hypochlorite as an intracanal medicament between treatment visits yielded an overall 90% healing rate in other studies, for comparison. Conclusions: 2% CHX produces results equivalent to those with calcium hydroxide. The study does not establish a definite relationship between bacterial loads and healing in the treatment of apical periodontitis. Reviewer's Comments: The authors of this study acknowledged that their sample size was too small to conclusively relate their outcomes to bacterial counts, but a lack of correlation with healing outcomes is consistent with several other studies. This does not mean that reduction of bacteria is unimportant in endodontics, but that better identification techniques are needed. (Reviewer-Arthur H. Jeske, DMD, PhD).

Keywords: Apical Periodontitis, Chlorhexidine, Sodium Hypochlorite, Healing, Long-Term Follow-Up

Print Tag: Refer to original journal article Mucograft -- Quicker, More Comfortable Alternative to Connective Tissue Graft

Clinical Evaluation of a New Collagen Matrix (Mucograft® Prototype) to Enhance the Width of Keratinized Tissue in Patients With Fixed Prosthetic Restorations: A Randomized Prospective Clinical Trial. Sanz M, Lorenzo R, et al:

J Clin Periodontol 2009; 36 (October): 868-876

This new 3-dimensional collagen matrix graft is as effective but less painful than the standard connective tissue graft for increasing the width of keratinized gingivae.

Background: The free connective tissue graft (CTG) increases the width of keratinized gingivae (KG) but is associated with significant pain. Allogenic cadaverous collagen grafts can be used but have ethical and disease transmission issues. A new 3-dimensional porcine collagen matrix (CM) material (Mucograft®) has been developed to increase the width of KG. Objective: To test the efficacy of CM and compare it to that of CTG for increasing the width of KG, esthetic results, and patient morbidity. Design/Participants: Longitudinal, parallel-designed clinical trial enrolling 20 patients. Methods: Each patient was randomly assigned to receive either CM or CTG. Inclusion criteria were as follows: age >18 years; periodontally and systemically healthy; at least 1 site, an abutment for a bridge, with minimal KG (≤1 mm); and plaque score <20%. Exclusion criteria were as follows: Smoked >10 cigarettes/day; allergy to collagen; and systemic disease that affects wound healing. Four weeks before surgery, subjects had periodontal treatment. Periodontal probing, gingival index, KG width, plaque score, and bleeding score were performed under standardized conditions before and after treatment. A split-thickness flap was elevated, then either CTG or CM was sutured in place. Ibuprofen was given with instructions to take as needed and to record use. Sutures were removed at 10 days, and photos were taken. Patient-completed pain questionnaires were completed, and periodontal measures and photos were repeated at 10 days and at 1, 3, and 6 months posttreatment. Results: At 10 days postsurgery, 3 of 10 controls had partial necrosis of CTG without loss of graft. KG increased in both groups at 30 days: CTG 3.1 ± 0.8 mm and CM 2.8 ± 1.0 mm. Between 30 and 180 days, there was contraction of graft in both groups. At 6 months, KG was greater than baseline, with CTG at 2.6 ± 0.9 mm and CM at 2.5 mm ± 0.9 mm. There was no difference between groups. Periodontal measures were not different after surgery. At 10 days, the CTG group had a mean pain score of 4.01 ± 8.5 compared to CM 2.30 ± 2.39 (P =0.0002). At 30 days, no patient in the CM group had any pain; mean pain score in the CTG group was 1.30 ± 3.19. Total ibuprofen dose at 20 days for CTG was 5140 ± 5336 mg and for CM was 720 ± 860 mg. Duration of surgery was greater for CTG than for CM (P =0.0006). Esthetic results were comparable for CM and CTG. Conclusions: The CM was as effective as CTG in increasing the width of KG but was associated with significantly less patient morbidity. Reviewer's Comments: The CM graft is a promising alternative to CTG and allogenic cadaver collagen for increasing the width of KG because of its comparable results with less pain. (Reviewer-Carol Anne Murdoch- Kinch, DDS, PhD).

Keywords: Collagen Matrix Graft

Print Tag: Refer to original journal article Periodontal Disease, Tooth Loss -- Risk Factors for COPD?

Periodontal Health, Oral Health Behaviours, and Chronic Obstructive Pulmonary Disease. Wang Z, Zhou X, et al:

J Clin Periodontol 2009; 36 (September): 750-755

After adjusting for smoking status, poor oral hygiene, periodontal disease, and infrequent dental visits appear to be associated with an increased risk for development of chronic obstructive pulmonary disease.

Background: Periodontal disease (PD) and poor oral health have been associated with chronic obstructive pulmonary disease (COPD). Smoking increases risks of both. Dental plaque may serve as a reservoir for bacteria that cause pneumonia. Objective: To examine the relationship of periodontal status, oral health behaviors, and COPD in Chinese patients. Design/Participants: Case-control study of 306 consecutive patients with COPD and 328 randomly selected subjects with normal pulmonary function aged >30 years conducted between March 2007 and November 2008. Methods: Periodontal assessment included probing, oral hygiene, plaque index, number of teeth, clinical attachment loss, bleeding index, dental caries, oral mucosal disease, and radiographic examination of the alveolar bone. Lung function was measured using spirometry and was categorized according to standardized methods. A standardized patient-completed questionnaire was used to assess oral health behaviors, including toothbrushing time and method, dental floss use, frequency of dental visits, periodontal treatment, smoking, alcohol use, and oral health knowledge. Age, gender, and body mass index (BMI) were included in a multivariate analysis to control for potential confounding, and analyses were stratified by smoking status. Results: Mean age of COPD patients was 63.94 ± 9.84 years; 68.6% were males. Mean age of control patients was 63.2 ± 8.98 years; 50% were males. Compared to controls, COPD patients had higher proportions of former and current smokers (P <0.0001). There was no difference in BMI between groups. COPD patients had fewer remaining teeth (P =0.001), a higher plaque index (P =0.001), and more site percentage of clinical attachment level >4 mm (P =0.011) than did controls. There were no significant differences in other periodontal variables. The number of remaining teeth among non-smokers (P =0.045) and plaque index among current smokers (P =0.044) were also significantly associated with COPD. When adjusted for smoking and other confounders, COPD patients had shorter toothbrushing times (P <0.0001) and oral health knowledge scores (P <0.0001 for non-smokers, P =0.019 former smokers, and P =0.044 current smokers). For non-smokers, COPD patients were more likely to use horizontal toothbrushing methods (P =0.025). Former smokers (P <0.0001) and non-smokers (P =0.027) with COPD were less likely to receive regular scaling. Conclusions: In addition to smoking, poor periodontal health, dental care, and oral health knowledge were significantly associated with an increased risk for COPD. Oral health care and education in COPD patients may help prevent progression. Reviewer's Comments: Reviewer's Comments: The observational retrospective nature of this study cannot prove a cause-and-effect relationship between periodontal disease and COPD. However, oral health care and education should be included in the management of patients with COPD to optimize their health. (Reviewer- Carol Anne Murdoch-Kinch, DDS, PhD).

Keywords: Oral, Systemic Health Associations, Chronic Obstructive Pulmonary Disease

Print Tag: Refer to original journal article Helping to Assure Good Outcomes for Anterior Implant-Supported Restorations

Maintenance of Soft-Tissue Emergence Profile Around Dental Implants in the Esthetic Zone. Petrungaro PS:

Dent Implantol Update 2009; 20 (September): 65-72

To ensure excellent soft tissue esthetics, anterior implants should be provisionalized with carefully designed temporary restorations based on periodontal sounding and optimal location of proximal contacts.

Background: While multi-stage implant delivery and coronal restorations have resulted in good implant success rates, esthetic outcomes may be compromised as a result of multiple surgeries. These multi-stage techniques do not allow for esthetic features of final crowns to be determined at the time of implant placement. Objective: To describe a surgical and restorative approach to the replacement of a missing anterior tooth with improved esthetics using a carefully designed immediate provisional restoration. Case Report: A 36-year-old, non-smoking male with need for replacement of a fractured maxillary lateral incisor, with the requirement to duplicate existing esthetics. Methods: The author outlines necessary steps to addressing this demanding clinical situation: (1) digital radiographs, (2) periodontal sounding, (3) mounted study models, (4) diagnostic wax-up, (5) fabrication of surgical guide based on wax-up that would also serve as a provisional, (6) atraumatic extraction of the tooth, (7) creation of an incisal-edge restoration (using bite registration material) to establish contact points and contours, (8) re-sounding so orient placement of the implant collar is 4 mm above the free gingival margin, (9) careful assessment of the buccal bony plate, (10) creation of a full-thickness flap to form a soft tissue pouch, using a specially designed elevator, (11) actual implant placement, with a minimal torque measurement of 30 Ncm to ensure stability, (12) augmentation of bone space with 1- to 2-mm bone chips and platelet-rich plasma, (13) placement of the abutment, and (14) bonding of the temporary restoration formed by filling the stent with composite resin, and recontouring with flowable resin as appropriate prior to temporary cementation. Results: The authors observed acceptable papillae after 1 week, and preservation of the emergence profile at the 6-week follow-up. The final zirconia restoration was completed by the referring restorative dentistry at 3 months. Conclusions: Implant-supported restorations in the esthetic zone demand accurate emergency profiles that must be developed at the time of implant placement surgery, through careful planning for facial contour and proper proximal contacts and line angles. Reviewer's Comments: The authors propose a comprehensive sequence of treatment planning and implant placement and provisionalization for optimal esthetic outcomes in the esthetic zone. However, as a single case report, it is acknowledged that the long-term success of this approach will require additional research. (Reviewer-Arthur H. Jeske, DMD, PhD).

Keywords: Dental Implants, Peri-Implantitis, Bone Graft

Print Tag: Refer to original journal article Predicting Development of Complications Remains Challenging

Incidence of Symptoms in Previously Symptom-Free Impacted Lower Third Molars Assessed in General Dental Practice. Fernandes MJ, Ogden GR, et al:

Br Dent J 2009; 207 (September): E10

When assessing the prognosis of third molars, patient age, angulation, and degree of impaction are key factors.

Background: Controversy surrounds the philosophies of retaining versus removing impacted third molars, particularly since the procedures frequently are considered to be "prophylactic." Objective: To assess the relationship of symptoms to the retention of impacted third molars assessed over a definite time period. Design: 1-year, prospective clinical study of a cohort of general practice dental patients with impacted third molars in 3 centers. Participants: Subjects were adults, aged 18 to 70 years, who were patients-of-record at 1 of 3 study centers and had at least 1 symptom-free, impacted third molar, with a panoramic radiograph that had been taken between 1995 and 2002. Methods: All subjects were evaluated by the same dentist, calibrated against an external oral surgeon. Impacted third molars were classified by angulation and as being either partially erupted or unerupted. A periodontal examination was performed, with assessment of bleeding and plaque. Subjects also completed a questionnaire regarding education, employment, oral hygiene practices, dental visits, and use of tobacco and alcohol. Subjects were completely re-evaluated 1 year later. Results: In the younger age group (defined as age <35 years), 22.5% of subjects had developed symptoms associated with impacted third molars. In the middle age group (age 35 to 50 years), 21% developed symptoms. In the older age group (age >50 years), only 5% had developed symptoms after 1 year. Age-related differences were statistically significant, but there were no statistically significant differences based on gender. Distally angulated mandibular third molars were most frequently associated with development of symptoms (24.7%), and partially erupted teeth were associated with symptoms significantly more frequently that were unerupted ones (23.0% vs 10.5%). No correlation was found between education, employment, dental hygiene, smoking, and alcohol use and development of symptoms. Conclusions: The ability to predict development of complications remains challenging, although certain factors, such as patient age, angulation of impaction, and eruption (partial vs unerupted), would seem to indicate higher likelihood of symptoms within a relatively short time period. Reviewer's Comments: While this study does not establish definite criteria for prophylactic removal of third molar teeth, it certainly indicates that development of associated problems is not simply a matter-of-chance occurrence, and distal angulation and partial eruption signal the need for close attention and follow-up. (Reviewer-Arthur H. Jeske, DMD, PhD).

Keywords: Third Molars, Impacted Third Molars

Print Tag: Refer to original journal article Are Repeated Doses of BTA Safe?

Facial Aesthetics: Is Botulinum Toxin Treatment Effective and Safe? A Systematic Review of Randomised Controlled Trials. Gadhia K, Walmsley AD:

Br Dent J 2009; 207 (September): E9

Patients who present for cosmetic improvement may want to consider botulinum toxin A as an adjunctive treatment that is relatively safe and effective.

Background: Esthetic dentistry is increasingly being provided for patients who are concurrently receiving plastic and cosmetic medical care, including use of botulinum toxin type A (Botox®, BTA). Dental management of such patients requires a working knowledge of beneficial and adverse effects of BTA. Objective: To conduct a systematic review of scientific reports on the efficacy and adverse effects of BTA in human subjects, from 1977 to January 2009. Design: Systematic review using Medline, Cochrane Library, EMBASE, and CINAHL databases for electronic searches of reports of study outcomes using BTA, as compared to placebo. Hand searches were also used. Only double-blind randomized studies with crossover or parallel group evaluations were considered for inclusion in the review. Methods: 2 reviewers assessed the quality of studies and their outcome data, with regard to the anatomic site of BTA injection, how outcomes were assessed, and type(s) and duration of beneficial and adverse effects of BTA. Results: 11 randomized, controlled clinical trials (RCTs) were deemed suitable for inclusion in the review, consisting of a total of 1203 patients who received BTA. BTA injection generally showed significant improvement in the appearance of facial wrinkles when compared to placebo, with no greater incidence of pain at the injection site, headache, and minor hematomas. However, blepharoptosis (drooping eyelids) occurred more frequently with BTA (in up to 5.4% of subjects). The beneficial effect of BTA began immediately after application and appeared to reach peak level at about 1 month following administration, and it lasted up to 6 months. No studies reported on effects of repeated injections of BTA. Conclusions: BTA has a high rate of success with a rapid onset and a relatively long duration of action (4 to 6 months). The low incidence of adverse effects of BTA injection was likely due to precise injections that avoided muscles of the eyelids. The studies could not be used to determine an appropriate injection interval for repeated doses of BTA. Reviewer's Comments: This article demonstrates all methods appropriate to a systematic review, and this type of review will continue to be increasingly important for decisions related to both dental and medical care. However, the relative paucity of studies that met criteria for inclusion in this review and the total lack of RCTs focusing on repeated administrations suggest that more studies are needed. BTA appears to be both safe and effective for most patients. (Reviewer-Arthur H. Jeske, DMD, PhD).

Keywords: Botulinum Toxin, Systematic Reviews, Facial Esthetics

Print Tag: Refer to original journal article Newer Cements Significantly Outperform Older Counterparts

Retention of Metal-Ceramic Crowns With Contemporary Dental Cements. Johnson GH, Lepe X, et al:

J Am Dent Assoc 2009; 140 (September): 1125-1136

Although a bit less convenient to use, power-liquid resin-modified glass-ionomer cements (eg, RelyX Luting) provide excellent retention of metal-ceramic crowns.

Background: Metal-ceramic crowns are widely used, but their ultimate clinical success depends greatly on the quality of their cementation. Newer glass-ionomer and resin cements may offer significant advantages over zinc phosphate. Objective: To compare zinc phosphate, resin-modified glass ionomer, conventional resin, and self-adhesive modified resin cements for retention of standardized metal-ceramic crowns. Methods: The study was done in 3 phases. In phase A, evaluating 3 common cements (conventional resin), 2 resin-modified glass-ionomers (bottle-liquid systems), and 1 self-adhesive modified resin cement. In phase B, the paste-paste systems of the same resin-modified glass ionomers were compared to an original powder- liquid system (RelyX Luting). In phase C, 3 new self-adhesive modified resin paste-paste cements were compared against an older product in this class (RelyX Unicem Clicker and zinc phosphate cement [Fleck's]). Extracted human molar teeth were milled to a standard metal-ceramic crown preparation with a high degree of occlusal convergence to simulate demanding clinical conditions, with a standard axial length of 4 mm. Following impressions of the teeth, dies were fabricated, and 2 coats of die spacer were used for 24 μm of cement space. Crowns were fabricated using a high-noble alloy. Prior to cementation, axial and occlusal surface areas of each crown were determined so that each type of cement tested had teeth with similar values for crown preparation surface area. Following crown cementation, crowns were stored and thermally cycled. After thermocycling, teeth were mounted in a standard testing machine (Instron), and a dislodgement force was applied to the apico-occlusal axis until failure occurred. Results: In phase A, the resin-modified glass ionomer RelyX Luting cement and the self-adhesive resin- modified RelyX Unicem were the most retentive at 8.0 and 7.3 mPa, respectively. In phase B, again, RelyX Luting cement resulted in the best retention (8.1 mPa), which was significantly better than that of paste-paste cements (Fuji CEM, 2.8 mPa; RelyX Luting Plus, 2.6 mPa). In phase C, Maxcem (4.9 mPa) was significantly more retentive than BisCem (4.0 mPa), RelyX Unicem Clicker (2.9 mPa), and zinc phosphate (2.3 mPa). Conclusions: All cements tested reliably retained the metal-ceramic crowns used in the study. The authors recommend that, when additional retention is desirable, a conventional resin cement with a dentin adhesive, a resin-modified glass-ionomer, or a self-adhesive modified resin cement be used. Powder-liquid systems in this study were superior to their paste-paste counterparts. Reviewer's Comments: While in vitro studies in limited numbers of extracted teeth do not completely replicate actual clinical conditions, and since metal-ceramic crowns on natural teeth are subject to more variables of force application, the standardized protocols used in this study validate differences in resistance to dislodgement. (Reviewer-Arthur H. Jeske, DMD, PhD).

Keywords: Metal-Ceramic Crowns, Dental Cements, Zinc Phosphate Cement

Print Tag: Refer to original journal article Saliva Protects Against Erosion, but Effect Varies With Age, Dental Site

The Effect of Salivary Factors on Dental Erosion in Various Age Groups and Tooth Surfaces. Piangprach T, Hengtrakool C, et al:

J Am Dent Assoc 2009; 140 (September): 1137-1143

Age and erosion involving dentin should be carefully considered when treatment planning, especially for older dental patients.

Background: 3 factors are consistently observed to be associated with tooth erosion: saliva, tooth position, and disease/restorative history of the tooth. Objective: To determine the relationship between patient age and salivary factors in dental erosion. Design: Comparative single-phase study comparing clinical findings to dental erosion in patients grouped by age. Participants: Subjects were recruited from 3 age groups (16 to 20 years, 26 to 30 years, and 46 to 50 years). Participants were both male and female, and all had ≥20 teeth and no systemic disease. Methods: A calibrated examiner classified dental erosion in subjects as no erosion, erosion enamel-only, and erosion dentin/at least 1 surface. Exams were confirmed with photographic analysis, and subjects were queried regarding habit and dietary factors associated with erosion. Unstimulated and stimulated whole saliva was collected for determination of flow rates, and salivary pH and salivary buffering capacity, total protein, and urea were assessed. Data were analyzed statistically to correlate salivary factors with age and erosion characteristics. Results: Frequency of erosion was lowest in the 16- to 20-year age group, and when erosion was present, it most likely occurred on occlusal surfaces in all age groups. In the 16- to 20-year group, salivary buffering and urea concentration were related directly to absence of erosion. Severity of erosions was related to age, and in the 26- to 30-year group, stimulated whole salivary flow rate was higher when only enamel erosion was present than when both enamel and dentin were affected. In 2 groups (youngest and oldest), presence of erosion was correlated with a preference for sour food tastes. Conclusions: The authors acknowledge that this study was underpowered, but this was overcome by statistical calculations to achieve relevance of data. They concluded that both stimulated and unstimulated saliva appear to provide some degree of protection against erosion, but this protective factor depends on other variables, including severity of erosive lesions, age of the patient, and tooth surface (occlusal vs buccal/lingual). Reviewer's Comments: Many outcomes of this study are intuitively consistent with what we observe in clinical practice, and we need to be particularly aware of erosions that involve dentin, in that saliva is more protective for enamel than dentin, and this has important implications for management of older dental patients. (Reviewer-Arthur H. Jeske, DMD, PhD).

Keywords: Dental Erosion, Saliva, Salivary Flow, Age, Tooth Surface

Print Tag: Refer to original journal article Low-Shrinkage Composite May Not Be as Important for Durability

Clinical Effectiveness of a Low-Shrinkage Resin Composite: A Five-Year Evaluation. van Dijken JWV, Lindberg A:

J Adhes Dent 2009; 11 (April): 143-148

A standard hybrid composite may perform as well as a low-shrinkage composite.

Background: Eliminating or minimizing polymerization shrinkage stress remains a goal with contemporary restorative composites. By reducing contraction stress at the adhesive-composite interface, it is believed that the restorative seal is improved and, ultimately, the longevity of the restoration. Low-shrinkage composites are increasingly being introduced for clinical use in dentistry. Objective: To evaluate the clinical durability of a low-shrinkage composite in Class II restorations compared to a standard composite. Participants/Methods: 50 subjects who received pairs of Class II composites restored with either a low- shrinkage composite (InTen-S) or a standard composite (Point 4). Teeth were prepared using etch-and-rinse adhesives, and composites were placed using an incremental layering technique. Each increment was cured using a standard curing light (Astralis 7) for 40 seconds. Filled restorations were completed with diamond bur finishing and rubber polishers. Clinical evaluations of restorations were performed annually for 5 years according to modified USPHS criteria. Results: Cumulative failure rates after 5 years were approximately 10% for the low-shrinkage composite and 14% for the standard composite, with most clinical failures occurring between 3 and 5 years due to secondary caries or fractures; however, there was no significant difference between groups. Nearly double the rate in marginal discoloration was observed with standard composite restorations as compared to the low-shrinkage composite, both within acceptable levels. Conclusions: The 5-year clinical longevity of a low-shrinkage composite was shown to perform as well as a standard composite, but it was not significantly better. The primary cause for failure was secondary caries. Reviewer's Comments: The reason for restoring resin-bonded restorations with low-shrinkage composite in order to counteract forces of polymerization stresses is still lacking long-term evidence. In this study, the low- shrinkage composite showed very slight improvements in performance, but these were not dramatic. (Reviewer-Joe C. Ontiveros, DDS, MS).

Keywords: Composite, Low-Shrinkage

Print Tag: Refer to original journal article Simplified Does Not Always Mean Better

Two-Year Clinical Evaluation of Self-Etching Adhesives in Posterior Restorations. Perdigão J, Dutra-Corrêa M, et al:

J Adhes Dent 2009; 11 (April): 149-159

This 2-year clinical study demonstrates under-performance of all-in-one adhesives.

Background: The latest generations of self-etching adhesives have all the components combined in one to simplify the dental bonding procedure. These so-called all-in-one bonding agents do not have the same long- term record we find with the standard etch-and-rinse adhesive. Clinical trials are necessary to prove the long- term efficacy of the most recent bonding agents on the dental market. Objective: To determine the efficacy and durability of posterior composite restorations using 3 all-in-one, self- etching adhesives in vivo. Participants/Methods: 38 patients were recruited requiring a bonded posterior composite restoration. Class I or II cavity preparations were treated with 1 of 3 all-in-one, self-etching adhesives (Prompt L-Pop, S3 Bond, or iBond) or a standard etch-and-rinse adhesive (One-Step Plus). Composite resin (Filtek Supreme) was applied incrementally and polymerized with a standard halogen curing light. Restorations were finished with carbide burs, polishing points, and aluminum oxide disks. Annual evaluation using modified USPHS criteria was performed for the duration of 2 years. Replicas were fabricated for marginal analysis under scanning electron microscopy. Results: Clinical evaluation at 2 years showed significant differences in color, marginal staining, and marginal adaption for all groups of self-etching adhesives. After 1 year, 96.3% of restorations showed marginal staining in the iBond group, which increased to 100.0% after 2 years. Furthermore, the iBond group showed a marginal defect rate of 90.5% after 2 years. The Prompt L-Pop, S3 Bond, and One-Step Plus groups showed a 2-year marginal defect rate of 64%, 50%, and 13%, respectively. Conclusions: Overall, evaluated posterior bonded restorations showed poor clinical performance after 2 years when using all-in-one self-etching adhesives. Restorations bonded with One-Step Plus resulted in the best performance among all adhesives. Reviewer's Comments: Simplified self-etch adhesives have shown mixed results under laboratory investigations. This study demonstrates the importance of referring to long-term clinical studies when making decisions on use of materials newly introduced to the market. Generally, research shows that simplified all-in- one self-etch adhesives do not perform, over the long term, as well as etch-and-rinse adhesives. (Reviewer- Joe C. Ontiveros, DDS, MS).

Keywords: Composite Clinical Trial, All-in-One Adhesives, Posterior Restorations

Print Tag: Refer to original journal article Do Nanofilled Composites Really Improve Polishability?

Three-Year Randomized Clinical Trial to Evaluate the Clinical Performance and Wear of a Nanocomposite Versus a Hybrid Composite. Palaniappan S, Bharadwaj D, et al:

Dent Mater 2009; 25 (November): 1302-1314

Filtek Supreme performs as well as Z100 but with improved polishability.

Background: The smaller, more evenly distributed particle size of the nanofilled composite is purported to improve polishability and to allow an increase in filler loading and for better physical properties. Objective: To evaluate the qualitative and quantitative clinical performance, including wear, of bonded restorations using a nanofilled and microhybrid composite. Participants/Methods: 16 patients were enrolled in the clinical study, and 37 molar teeth were prepared for posterior Class I or II bonded restorations; all enamel margins, including the cavosurface, were beveled. Cavity preparations were treated with a standard etch-and-rinse adhesive (Single Bond) followed by incremental placement of 1 of 2 composite materials, a standard microhybrid (Z100) or a nanohybrid (Filtek Supreme), and curing with a standard curing light. Restorations were finished with diamond burs and aluminum oxide disks (Sof-Lex). Evaluation was performed annually up to 3 years using qualitative (USPHS criteria) and quantitative (3-dimensional laser scan) methods. Replicas were fabricated for volumetric wear and marginal analysis under scanning electron microscopy. Results: There was no statistically significant difference between the 2 composite groups for all USPHS criteria with the exception of polishability, for which the nanohybrid was smoother. There was no difference in volumetric wear for the nanohybrid (0.27 mm3) compared to the microhybrid (0.36 mm3). Both groups showed significantly greater wear on the composite than on the enamel. Conclusions: Nanohybrid (Filtek) restored composites demonstrated 100% acceptable clinical performance after 3 years, similar to a standard microhybrid (Z100) but with superior polishability. Reviewer's Comments: Z100 is a material that has stood the test of time, with some referring to it as the "gold standard" of microhybrid composites. It is a significant breakthrough in technology that affords the manufacturing of composites such as Filtek Supreme with nanofiller particles that significantly improve the polishability without compromising on performance. (Reviewer-Joe C. Ontiveros, DDS, MS).

Keywords: Composite Clinical Trial, Nanofilled Composite

Print Tag: Refer to original journal article