Repair or replacement of defective direct resin-based composite restorations: contemporary teaching in U.S. and Canadian dental schools.

BACKGROUND: Opportunities exist to promote minimally invasive dentistry by repairing rather than replacing defective and failing direct resin-based composite restorations. The authors conducted a study to investigate the current teaching of such techniques in U.S. and Canadian dental schools. METHODS: In late 2010, the authors, with the assistance of the Consortium of Operative Dentistry Educators, invited 67 U.S. and Canadian dental schools to participate in an Internet-based survey. RESULTS: The response rate was 72 percent. Eighty-eight percent of the dental schools taught repair of defective direct resin-based composite restorations. Of these schools, 79 percent reported providing both didactic and clinical teaching. CONCLUSIONS: Although teaching repair of defective resin-based composite restorations was included in the didactic curricula of most schools, students in some schools did not gain experience in minimally invasive management of defective resin-based composite restorations by means of performing repair procedures. The American Dental Association's Code on Dental Procedures and Nomenclature does not have a procedure code for resin-based composite restoration repairs, which may limit patients' access to this dental treatment. CLINICAL IMPLICATIONS: Teaching dental students minimally invasive dentistry procedures, including restoration repair, extends the longevity of dental restorations and reduces detrimental effects on teeth induced by invasive procedures, thereby serving the interests of patients.

Minimally invasive management of dental caries: contemporary teaching of posterior resin-based composite placement in U.S. and Canadian dental schools.

BACKGROUND: Resin-based composites are an increasingly popular material for restoring posterior teeth, permitting minimally invasive cavity preparations and esthetic restorations. The authors investigated current teaching of the placement of posterior resin-based composites in U.S. and Canadian dental schools. METHODS: In late 2009 and early 2010, the authors, with the assistance of the Consortium of Operative Dentistry Educators (CODE), invited 67 dental schools to participate in an Internet-based survey. RESULTS: The response rate was 73 percent. Although all schools taught the placement of resin-based composites in occlusal and most occlusoproximal cavities, eight schools (16 percent) did not teach placement of three-surface occlusoproximal resin-based composite restorations in permanent molars. Resin-based composites accounted for 49 percent of direct posterior restorations placed by dental students in 2009 and 2010, a 30 percent increase from 2005. CONCLUSIONS: Teaching placement of posterior resin-based composites continues to increase in dental schools in the United States and Canada, with predoctoral students gaining, on average, an equal amount of experience placing posterior resin-based composites and amalgams in terms of numbers of restorations. CLINICAL IMPLICATIONS: Evidence-based, up-to-date teaching programs, including those in operative dentistry, are needed to best prepare students for careers in dentistry.

Dental erosion and acid reflux disease: an overview.

Dental erosion can be difficult to detect, especially in the early stages when lesions are subtle and can be easily overlooked. Patients often are not aware of erosion until the dentition has sustained severe damage that requires extensive and expensive dental rehabilitation. The pH of stomach acid is much lower than the critical pH of enamel dissolution; therefore, reflux of stomach contents into the oral cavity over an extended period of time can cause severe loss of tooth structure. Dental treatment for reflux-induced erosion should focus not only on appropriate restoration but also on all available preventive measures, such as neutralization of acid and remineralization or strengthening of enamel against acid attack. Dentists must maintain a high degree of suspicion for reflux-induced erosion whenever a patient displays symptoms of acid reflux disease or a pattern of erosion that suggests an intrinsic source of acid exposure.

Duration and timing of sensitivity related to bleaching.

PROBLEM: Reports of sensitivity vary greatly from one study to another, probably because studies are small. Generally, only the percentage of subjects is reported. PURPOSE: This study reports sensitivity using a large database. We investigated the source, duration, and timing of sensitivity during 14 days of active bleaching. MATERIALS AND METHODS: One hundred and seventy-two people recorded sensitivity from any of the five sources on a daily basis. RESULTS: No one withdrew from the study because of sensitivity. Forty-seven percent of participants experienced sensitivity. Seventy-seven percent had sensitivity of 3 or fewer days. Temperature sensitivity tended to occur later in the 14-day bleaching cycle, and hot and cold sensitivity tended to occur together. CONCLUSIONS: There was great variability in sensitivity levels from person to person. Temperature sensitivity tended to occur later in the active phase of bleaching, whereas irritation of the tongue tended to occur earlier. CLINICAL SIGNIFICANCE: The results from a large group of people are more likely to include a wide cross-section of the population sampled. This data provides practitioners with a better estimate of what their patients are likely to experience. It is estimated that, during 2 weeks of active bleaching, 77% of people will experience 3 or fewer days of sensitivity. On average, sensitivity is short-lived, thus making it is easy to underestimate the importance of discussing sensitivity with patients considering bleaching. However, for some, the duration of sensitivity is much greater and has a very negative impact on satisfaction.

Performance of 2 packable composites at 12 months.

OBJECTIVE: The purpose of this randomized, double-blind, clinical trial was to compare the marginal seal of 2 packable resin composite materials in moderate to large lesions on molars. METHOD AND MATERIALS: Fifty participants in need of a moderate to large Class 2 or complex Class 1 molar restoration were randomly distributed into 4 groups, to receive either Alert (Jeneric/Pentron) or SureFil (Dentsply/Caulk) resin composite with or without a surface sealer. Each participant received one restoration. With the exception that study protocol limited increments to no more than 4 mm, teeth were restored according to the manufacturers' instructions, and surface sealer was applied after finishing in the designated groups. Use of Alert includes routine placement of a flowable composite liner. Clinical performance of the restorations was evaluated in 8 categories at baseline, 6 months, and 12 months. The 2 materials were compared to determine if a difference in marginal seal existed between groups. The number of restorations exhibiting marginal staining was compared using Fischer's exact test at a significance level of 5%. RESULTS: Six participants did not present for the 12-month recall. At 12 months, 19 (90.5%) Alert restorations and 15 (68.2%) SureFil restorations did not exhibit marginal staining. There was no statistically significant difference between the 2 restorative materials for marginal staining. Overall, 3 restorations were rated as failures. CONCLUSION: At 12 months, materials placed with a flowable liner were not associated with a significant reduction in marginal staining.

Safety and efficacy of a nightguard bleaching agent containing sodium fluoride and potassium nitrate.

OBJECTIVES: Transient sensitivity during bleaching is generally reported to affect 67% of patients. While most people tolerate this sensitivity, some find it impossible to continue treatment. The purpose of this study was to determine the safety and efficacy of an experimental, low-sensitivity bleaching agent. METHOD AND MATERIALS: Twenty-two participants bleached for a minimum of 6 hours per night over a 2-week period. The bleaching agent used, Experimental Product E, is a 10% carbamide peroxide gel containing potassium nitrate and sodium fluoride. Evaluations were performed at baseline and 1,2,13, and 26 weeks. Color change was measured using a value-ordered Vita classic shade guide and a colorimeter. Sensitivity of the teeth, gingiva, tongue, and/or throat was measured daily using a patient log. RESULTS: The median color change after 2 weeks was eight tabs. Approximately 36% reported sensitivity during the active whitening phase of the study. As a group, participants reported sensitivity during 13.7% of the total days spent whitening. CONCLUSION: Experimental Product E was shown to be safe. Participants experienced minor sensitivity during the active bleaching phase only. Experimental Product E was shown to be an effective bleaching agent for the subjects tested in this study.

Application of rapid prototyping to operative dentistry curriculum.

Computers are becoming an integral part of dental education and dental practice. Rapid prototyping is a technique for the production of solid objects from computer models. The variety of rapid prototyping devices and materials that can be processed is increasing all the time. In this article, the authors present a discriminative learning device and associated exercises for developing visual recognition skills and examine the potential for the application of rapid prototyping to the operative dentistry curriculum. Other rapid prototyping technologies as applied in dentistry are also discussed.

The effect of prophylactic polishing pastes and toothbrushing on the surface roughness of resin composite materials in vitro.

Polishing composite restorations at recall prophylaxis may affect their surface roughness. This investigation evaluated the effect of prophy paste on the surface roughness of a microfilled (Filtek A110) and a microhybrid (Filtek Z250) resin composite before and after simulated toothbrushing. Twenty, two-sided samples of both materials were fabricated in acrylic molds against a Mylar strip (baseline). Three roughness readings were recorded for each surface using a Surfanalyzer 5400 to determine the mean roughness. The samples were finished and polished with the Sof-Lex disk system and the surface roughness (Ra) was re-measured. Samples were randomly assigned and five surfaces for each material were polished with Nupro coarse, medium, fine or Clinpro prophy paste and the surface roughness measured again. All surfaces were brushed 60,000 times at 1.5Hz using a 2N brush-head force (Manly V-8 cross-brushing machine) in a 50:50 (w/w) slurry of toothpaste and water. The surface roughness was measured followed by the application of prophy paste as previously described and this final roughness recorded. Data were analyzed using repeated measures two-factor ANOVA with TUKEY HSD pairwise comparison as appropriate (alpha = 0.05). No significant difference in surface roughness was determined between the microfilled and microhybrid materials at baseline or disk treatment, yet significant differences were observed following brushing and/or prophy paste application. In conclusion, although baseline and disk treated surfaces were not significantly different in microfilled versus microhybrid composites, subsequent prophy paste application and/or simulated toothbrushing caused significant differences.

A technique to determine a desired preparation axial inclination.

The guidelines recommended in the literature for the convergence angle of a crown preparation vary from 3 to 24 degrees. There is a lack of guidelines on techniques to achieve a specific axial inclination. The purpose of this article was to present a practical technique, with a diamond rotary cutting instrument of known axial inclination, to determine the diamond rotary cutting instrument angulations required to achieve the desired axial inclination of a preparation.

The teaching and treatment of upper airway sleep disorders in North American dental schools.

STATEMENT OF PROBLEM: Many dental patients suffer from upper airway sleep disorders (UASD) that affect the quantity and quality of their sleep. These disorders vary from minor annoyances to life-threatening conditions. Even though dentists can play a role in the successful treatment of these patients with oral devices, few do. This lack of participation, in part, may be due to lack of education. PURPOSE: The purpose of this study was to determine which North American dental schools include the treatment of UASD in their curriculum. This information may prove helpful to other schools in determining whether, and to what degree, they should teach about UASD and its treatment options. MATERIAL AND METHODS: A survey instrument (questionnaire) was mailed to all of the North American dental schools (n = 64) affiliated with the American Association of Dental Schools. The questionnaire consisted of 9 multipart questions. Major categories of questions included the following: (1) Is the subject of UASD a part of the school curriculum? If so, in what department is it taught? (2) Are oral devices fabricated for patients or is the experience only at the didactic level? (3) What diagnostic procedures are required? (4) What types of oral devices are fabricated and what is the success rate/recall frequency? (5) What is the patient source? (6) If this subject area is not covered either didactically or clinically, why not? The data were analyzed by use of descriptive statistics. RESULTS: Forty-three of the 64 schools that received the survey responded. Forty-two percent of the schools that responded are teaching the treatment of UASD with oral devices. There is no apparent consensus with regard to whether to teach the subject, at what level, or to what degree. CONCLUSION: Even though many dental patients suffer from potentially life-threatening sleep disorders, many of which could be treated with oral devices, fewer than half of the reporting dental schools currently include this area as part of their curriculum. This lack of inclusion is caused primarily by a lack of familiarity with the information available and a lack of available curriculum time.