Faculty Bibliography

Today's dental patients are demanding a youthful, attractive smile. The esthetic rehabilitation of patients with functionally compromised dentitions frequently involves a multidisciplinary approach. The realization of esthetic objectives in multidisciplinary cases represents a considerable clinical challenge. To a great extent, proper case selection and careful multidisciplinary treatment planning can govern the predictability of procedures. A team approach that includes the clinicians, the laboratory technician, and the patient is essential to achieve the desired results. This clinical report demonstrates a successful multidisciplinary approach to recreating an esthetic smile of a patient whose anterior maxillary dentition had been functionally and esthetically compromised by prosthetic and periodontal problems.

PURPOSE: The purpose of this study was to compare the color changes achieved with two commonly used bleaching systems on the basis of a spectrophotometric analysis. MATERIALS AND METHODS: Two commercially available 10% carbamide peroxide bleaching systems were used by a total of 48 individuals. Subjects who had intact natural maxillary anterior teeth void of any restorations or decay that had not been subjected to any prior bleaching were included. Opalescence 10% PF (Ultradent Products Inc., South Jordan, UT, USA) was used by 23 patients for 14 days, whereas Nite White Excel (Discus Dental, Culver City, CA, USA) was applied by 25 patients for the same duration. Tooth colors for the middle one-third region of maxillary central incisors and canines were measured with a spectrophotometer prior to bleaching and after 14 days of bleaching. Color difference deltaE and color coordinates L* (lightness), a* (redness), and b* (yellowness) of CIELAB color system (developed by the Commission Internationale de l'Eclairage) were calculated. RESULTS: Mean deltaE values for Opalescence ranged from 5.03 to 8.92 and from 5.84 to 9.61 for Nite White. The most significant factor of the color change was b* followed by L* and a*. L* values were higher after bleaching, whereas values for both a* and b* decreased. There were no significant differences between the two systems examined (p < .05).

Establishing a colorimetric guideline to predict the effectiveness of tooth bleaching could produce a more reliable dental treatment. The purpose of this study was to evaluate the effectiveness of tooth bleaching and to test the predictability of tooth color changes. A 10% carbamide peroxide bleaching system was used in studies at Harvard University and at Iwate Medical University in Japan. L* a*, and b* values (CIELAB) for pre- and postbleaching were obtained and color differences (DeltaE) were calculated. The b* and L* values of the original tooth color indicated a relatively strong to moderate correlation with AE values, whereas a* showed a weak correlation. The multiple-regression equation obtained from the color data of Harvard subjects performed better than the predictive model. The predicted AE correlated strongly with the observed DeltaE (r = 0.78). The validation of this equation on data collected from Iwate confirmed the strong correlation (r = 0.74). (C) 2004 Wiley Periodicals, Inc.

STATEMENT OF PROBLEM: The utility of evidence-based clinical prosthetic dental decision making is, in part, predicated on the availability of high-quality clinical trials and the use of current best evidence. With literature or outcomes continually evolving, it is difficult to know how much information is available, how fast it changes, or where it is located. PURPOSE: This study identified and quantified the availability of high-quality prosthetic dental clinical trials, determined the dynamics of literature increase, and identified the location of relevant literature published within a specific decade. MATERIAL AND METHODS: A search strategy based on the Medical Subject Headings (MeSH) vocabulary for prosthetic dentistry was developed to examine MEDLINE with use of the Ovid Web Gateway search engine between the years 1990-1999. Specific and sensitive methodologic search filters identified 4 categories of information: etiology, diagnosis, therapy, and prognosis. The identified studies were limited to human subjects and to articles written in English. The results were subdivided by year to identify trends and location of the literature. This evaluation did not include the following: (1) other databases or languages or (2) an evaluation of the validity or clinical applicability of the literature. The first factor would increase the estimated number of relevant articles, whereas the second factor would decrease it. RESULTS: Between 1990 and 1999, MEDLINE identified 10,258 articles published in English on human prosthodontic issues. When subdivided by clinical category, the number of articles per year (mean +/- SD) for specific and sensitive searches, respectively, was as follows: etiology, 10 +/- 6 and 95 +/- 27; diagnosis, 11 +/- 5 and 77 +/- 21; therapy, 6 +/- 2 and 153 +/- 52; and prognosis, 13 +/- 6 and 91 +/- 27. For sensitive searches, this amounted to approximately 416 articles per year. The time-course analysis indicated that the number of articles in each category increased by approximately 7% per year. The articles were published in more than 60 different journals: approximately 50% of the articles were published in 14 journals, whereas the remaining articles were published in 46 journals. CONCLUSION: There appears to be substantial clinical prosthetic dental literature upon which to base clinical decisions. With the sensitive search strategy used as an estimate, to stay current, one would need to read and absorb approximately 8 articles per week, 52 weeks per year, across 60 different journals. Increases in the volume of literature each year make access even more difficult. These trends suggest the need for computer-based clinical knowledge systems

In conjunction with its problem-based learning curriculum, Harvard School of Dental Medicine (HSDM) developed a shortened preclinical restorative training curriculum. This study compared our curriculum with those in other dental schools and examined student reaction to it. Twenty-nine U.S. dental schools responded to a survey regarding the length of their preclinical course in Operative Dentistry. Nationally, preclinical courses ranged from 179 hours to 280 hours (mean +/- SEM = 193 +/- 9 hours; n = 29). In marked contrast, the new seventy-five-hour preclinical curriculum at Harvard was the lowest of any school, and significantly lower than the U.S. average (p < 0.01). In Harvard's previous curriculum, students spent 232 curriculum hours. Reactions of Harvard students to this compact preclinical curriculum were surveyed using a three-topic, three-category survey instrument. Results indicated that, prior to beginning clinical patient care, approximately 80 percent of students felt that the course was too short and 20 percent just right. Conversely, and retrospectively, after completing their dental school training, only 35 percent felt it was too short, and 65 percent felt it was just right. Retrospectively, in terms of clinical preparedness, 55 percent felt adequately prepared and 35 percent felt well prepared to treat their patients. No significant change was noted between Part II National Board scores following the change to the reduced curricula time. The average National Board Part II scores prior to initiating the new curriculum was 86.3, and afterwards, it was 86.2. Further, for the North East Regional Board, HSDM students in the past four years demonstrated a 98 percent overall success rate with 100 percent primary pass in the operative dentistry part of the examination. These results suggest that an abbreviated preclinical training is not only possible, but may make time available for training opportunities in other areas, such as aesthetic dental procedures and new biomaterials

Evidence-based clinical practice integrates the best available evidence with clinical expertise. This article presents a clinical case scenario and, using a four-step, evidence-based approach, demonstrates how to (1) ask an evidence-based question; (2) search MEDLINE for the best evidence; (3) critically appraise the evidence; and (4) apply the evidence to the patient. The procedure is demonstrated with the sample question, Does bleaching of bonded porcelain veneers increase marginal leakage? A MEDLINE search strategy was developed for synonyms of the key words that best identify the problem, the intervention, and the outcome. The synonyms were combined using the Boolean operator "or" to identify a "sensitive" (i.e., inclusive) universe of 140,000 journal articles. These categories were then combined using the Boolean operator "and" to identify the most "specific" (i.e., exclusive) four articles from among the 140,000. Finally, to find the best evidence, the articles were limited to "humans" and "randomized controlled trials." This identified one article. Critical appraisal of the limited data in this one article indicates that the methods are valid and statistically significant, but because of the methods employed, may not be clinically important. Evidence-based methods take one to the edge of the available information universe in about 15 minutes. The results can be both exhilarating and sobering. They can indicate the depth or limits of available information and suggest gaps in the knowledge-base that require further study. Most importantly, however, the results allow practitioners to communicate incisively and truthfully with patients and to make more informed clinical choices.