Faculty Bibliography

Evidence-based dentistry is the use by dentists of best research evidence, clinical judgment and patient values to guide practice. This article focuses on methods dentists can use to collect the best relevant evidence. Using the examples of systemic fluoridation and fluoridated dentifrices, the authors illustrate a five-step process of: 1) asking answerable questions; 2) conducting a systematic search; 3) critically appraising the literature; 4) applying results to practice; and 5) evaluating outcomes.

DATA SOURCES: Sources of studies were the Cochrane Controlled Trials Register, Medline and Embase. Personal files and the reference lists of all articles were checked for further studies. STUDY SELECTION: Trials were selected if they met the following criteria: there had been random allocation of participants; participants were adults with plaque and gingivitis; there was unsupervised use of dentifrices for at least 6 months; and primary outcomes were plaque and gingivitis after 6 months. DATA EXTRACTION AND SYNTHESIS: Data were extracted by two reviewers independently. For each plaque and gingivitis index, the mean differences for each study were pooled as weighted mean differences (WMD) with the appropriate 95% confidence intervals (CI) using the random effects model. RESULTS: Sixteen trials provided data for the meta-analysis. The triclosan/copolymer dentifrice significantly improved plaque control compared with a fluoride dentifrice, with a WMD of -0.48 (95% CI, -0.64 to -0.32) for the Quigley-Hein index and WMD of-0.15 (95% CI,-0.20 to -0.09) for the plaque severity index. When compared with a fluoride dentifrice, the triclosan/copolymer dentifrice significantly reduced gingivitis with WMD of -0.26 (95% CI, -0.34 to -0.18) and -0.12 (95% CI, -0.17 to -0.08) for the Loe and Silness index and for gingivitis. CONCLUSIONS: This systematic review indicates that a dentifrice that contains triclosan/copolymer provides a more effective level of plaque control and periodontal health than a conventional fluoride dentifrice.

Periodontal disease is a bacterial infection that results in inflammatory destruction of tissues that support the teeth, including connective tissue and bone. In this study, we report that transgenic mice that overexpress the 17-kDa form of IL-1alpha in the basal layer of oral mucosal epithelium develop a syndrome that possesses all of the cardinal features of periodontal disease, including epithelial proliferation and apical migration, loss of attachment, and destruction of cementum and alveolar bone. In this model, bacterial colonization and infection were not required, since levels of periodontal bacteria were equivalent in transgenic and wild-type mice, and continuous treatment with antibiotics from birth did not ameliorate the disease. Our findings therefore indicate that elevated levels of IL-1alpha in the oral micro-environment can mediate all of the clinical features of periodontal disease.

BACKGROUND: In a report released in January 2003, The Cochrane Collaboration Oral Health Group provided a systematic review of the effectiveness of powered versus manual toothbrushes, which generated much interest in the popular press. METHODS: The Cochrane researchers developed and implemented search strategies for the Cochrane Oral Health Group's Trial Register, the Cochrane Central Register of Controlled Trials, MEDLINE and the Cumulative Index to Nursing and Allied Health Literature. They contacted manufacturers for additional information. Trials were selected if they met the following criteria: compared power versus manual toothbrushes, had a randomized design, drew participants from a general population without disabilities, provided data regarding plaque and gingivitis, and were at least 28 days in length. Reviewers evaluated only studies published in 2001 or earlier. Six reviewers from the Cochrane study independently extracted information in duplicate. Indexes for plaque and gingivitis were expressed as standardized values for data distillation. Data distillation was accomplished using a meta-analysis, with a mean difference between powered and manual toothbrushes serving as the measure of effectiveness. RESULTS: The searches identified 354 trials, only 29 of which met the inclusion criteria. These trials involved about 2,500 subjects and provided data for meta-analysis. The results indicated that only the rotating oscillating toothbrush consistently provided a statistically significant, although modest, clinical benefit over manual toothbrushes in reducing plaque and gingivitis. CONCLUSIONS AND CLINICAL IMPLICATIONS: Some powered toothbrushes with a rotation-oscillation action achieve a significant, but modest, reduction in plaque and gingivitis compared with manual toothbrushes.

PURPOSE: The aim of this study was to answer the question: For patients requiring apicoectomy (apicectomy/root-end resection) and retrograde (root-end) obturation (filling), which retrograde obturation (root-end filling) material(s) is/are the most effective, as determined by reduction in periapical radiolucency and elimination of signs and symptoms? MATERIALS AND METHODS: A MEDLINE and a Cochrane search (two specified searches) were conducted to identify randomised (RCT) and nonrandomised controlled clinical trials (CCT), cohort studies (CS) and case-control studies (CCS), published between 1966 and 2002, October week 4, conducted on humans, and published in English, German and French language, relating to retrograde obturation materials following apicoectomy. RESULTS: The MEDLINE and the Cochrane search identified 324 and 21 published articles, respectively. The Cochrane search identified three additional articles to the MEDLINE-search articles. Fourteen studies met the inclusion criteria: two were RCTs, six were CCTs, none was a CS and six were retrospective CCSs. Nine of the 14 studies compared a new retrograde (root-end)-filling material to amalgam, 4 of the 14 studies compared orthograde root canal fillings to retrograde (root-end) amalgam and the fourteenth study compared variations of a resin composite (Retroplast) when used in combination with the bonding agent Gluma (Bayer AG, Gluma 1 and 2). The two RCTs indicated that glass ionomer cement appeared to be equivalent to amalgam. The six CCTs indicated that orthograde filling with gutta-percha and sealer was more effective than amalgam retrograde (root-end)-filling (one trial). Similarly, retrograde (root-end)-filling with (i) composite and Gluma (Bayer AG, Leverkusen, Germany) as bonding agent (one trial), (ii) reinforced zinc oxide eugenol cement (EBA cement) (Stailine, Staident, Middlesex, England; one trial) and (iii) gold leaf (one trial) appeared to be better than amalgam retrograde (root-end)-filling. Finally, gutta-percha retrograde (root-end)-filling appears to be less effective than amalgam (one trial) and Retroplast with ytterbium trifluoride is better than Retroplast with silver, when they are both used with Gluma as bonding agent (one trial). CONCLUSIONS: For the highest level of evidence (RCT) retrograde (root-end)-filling with glass ionomer cement is almost as effective as amalgam. However, there was a significant caveat as there were only two RCTs. At the next highest level of evidence (CCT), and given the additional caveat that there was only one controlled trial for each material, retrograde (root-end) EBA cement, composite with Gluma and gold leaf, as well as orthograde gutta-percha, may be more effective than retrograde (root-end) amalgam filling. In conclusion, these results suggest that additional validating CCTs and RCTs are needed.