Cluster Effects in a National Dental PBRN restorative study.

Items in clusters, such as patients of the same clinician or teeth within the same patient, tend to be more similar than items from different groups. This within-group similarity, represented by the intraclass correlation coefficient (ICC), reduces precision, yielding less statistical power and wider confidence intervals, compared with non-clustered samples of the same size. This must be considered in the design of studies including clusters. We present ICC estimates from a study of 7,826 restorations placed in previously unrestored tooth surfaces of 4,672 patients by 222 clinicians in the National Dental Practice-Based Research Network, as a resource for sample size planning in restorative studies. Our findings suggest that magnitudes of ICCs in practice-based research can be substantial. These can have large effects on precision and the power to detect treatment effects. Generally, we found relatively large ICCs for characteristics that are influenced by clinician choice (e.g., 0.36 for rubber dam use). ICCs for outcomes within individual patients, such as tooth surfaces affected by a caries lesion, tended to be smaller (from 0.03 to 0.15), but were still sufficiently large to substantially affect statistical power. Clustering should be taken into account in the design of oral health studies and derivation of statistical power estimates for these studies (ClinicalTrials.gov, NCT00847470).

Differences between reported and actual restored caries lesion depths: results from The Dental PBRN.

OBJECTIVE: The objectives of this research were to (1) quantify the discordance between the caries lesion depth at which dentists restored initial lesions during a clinical study ("actual depth") and the lesion depth that they reported during a hypothetical clinical scenario ("reported depth"); (2) test the hypothesis that certain practitioner, practice, patient, and caries lesion characteristics are significantly associated with this discordance. METHODS: Practitioner-investigators who perform restorative dentistry in their practices completed an enrollment questionnaire and participated in two consecutive studies on caries diagnosis and treatment. The first study was a survey asking about caries treatment. The second study collected data on restorations placed in routine clinical practice due to caries in patients over 19 years of age on occlusal surfaces only or proximal surfaces only. We report results on 2691 restorations placed by 205 dentists in 1930 patients with complete data. RESULTS: Discordance between actual depth and reported depth occurred in only about 2% of the restorations done due to proximal caries, but about 49% of the restorations done due to occlusal caries. Practice type, restorative material used and the diagnostic methods used were significantly associated with discordance. CONCLUSION: Dentists frequently restored occlusal caries at a shallower depth as compared to their reported depth, but the discordance was very small for proximal lesions. Discordance for occlusal caries was more common when radiographs were not taken or if a resin restoration was placed.

Teaching of posterior resin-based composite restorations in Brazilian dental schools.

OBJECTIVE: The purpose of this study was to evaluate the teaching program of Class I and Class II resin-based composite (RBC) restorations in Brazilian dental schools and to observe if any differences were found from similar surveys conducted in North American, European, and Japanese dental schools. METHOD AND MATERIALS: A questionnaire containing 15 questions was distributed to 92 Brazilian dental schools, and 64 (70%) schools returned the questionnaire. The questions inquired the amount of time the curriculum dedicated to teaching of posterior RBC restorations, future expectation regarding the teaching time, limitation in extension of the occlusal width and the proximal box in Class II, contraindications for placing posterior RBC restorations, protocol for using bases and liners, brand of bonding agents and RBC used, instruments and techniques employed for finishing, cost relative to amalgam restorations, and biologic reactions related to the use of posterior RBC. The responses were calculated as percentages based on the number of schools that responded to the questionnaire. Where appropriate, the Chi-squared test and the Fisher exact test were used for statistical analysis. RESULTS: Of the dental schools that responded, 88% dedicated 10% to 50% of the teaching time in operative dentistry to posterior RBC restorations. A significant correlation (P = 0.041) was found between the percentage of time dedicated to the teaching of posterior RBC restorations and the higher cost of posterior RBC compared to amalgam restorations. Resin-based composite restorations cost 30% to 70% more than amalgam restorations in the 40% of dental schools that charged a fee. Posterior composites for large restorations in molars were used by 14% of the dental schools. Base and liner were not placed by 10% of dental schools in deep Class I or Class II RBC restorations. One school did not recommend acid etching of the dentin. CONCLUSION: No major differences were found in the teaching philosophy of posterior RBC restorations by comparing the Brazilian data to the data from similar surveys done in North America, Japan, and Europe.

A review of atraumatic restorative treatment (ART).

The purpose of this paper was to critically analyse the results obtained with the Atraumatic Restorative Treatment (ART) technique. The ART approach involves the excavation of cavitated carious lesions with hand instruments and restoration of the cavities and associated pits and fissures with a glass ionomer restorative material. The clinical trial outcomes involving ART include retention rates, cost effectiveness, operative sensitivity, and the effect of personnel with different educational backgrounds involved in this alternative operative treatment. Comparative studies involving permanent and deciduous teeth using amalgam and glass ionomer sealants have also been included in the same projects. Specially defined clinical criteria have been used to evaluate the results. ART offers an opportunity for restorative dental treatment under field conditions where no electricity is available. Three-year data have been published, but long term studies using relevant comparison alternatives are lacking. ART has so far been largely employed on populations with a low DMFT. The technique should also be applied to high risk patients with rampant caries before the maximal benefit of the treatment can be ascertained.