Beveled Cavity Preparations in Primary Molars: 18-month Follow up

Objectives: This split-mouth, double-blind, randomized controlled study evaluated the clinical performance of composite restorations in class I and II beveled margin cavity preparations in primary molars over 18-month. Methods: 112 cavity preparations (98 Class I and 14 Class II) were performed in the carious primary molars of 32 children aged 4 to 10 years. Two cavity designs were used: conventional conservative preparation (G1) and conventional preparation with cavosurface bevel (G2). All teeth were restored using TPH SpectrumTM/Dentsply and the adhesive system Prime & BondTM/Dentsply. The restorations were evaluated by two calibrated investigators (weighted Kappa above 0.86) at baseline, 6, 12 and 18 months using slight modified USPH criteria for: marginal adaptation, anatomical form, cavosurface margin discoloration, axial contour, proximal contact and secondary caries. The visible plaque index and fiber optic transilumination were also evaluated. The data were statistically analyzed using Wilcoxon and Friedman Tests (p<0.05) and the correlation for secondary caries, visible plaque index and fiber optic transilumination was also conducted at 99% of confidence level. Results: At 18 months, 89 restorations were evaluated. The clinical success rate was 78.7% and 76.6% for Class I bevel and non beveled cavities respectively and for Class II it was 88.9% for conventional preparation and 55.6% for beveled cavities preparations. Ten restorations were censored for drop out reasons, 6 were censored by natural exfoliation and 6 were excluded by secondary caries. For all evaluation criteria there was difference between the initial and final periods of the study (p<0.05) for both cavity designs. However, there were no statistically significant difference in G1 and G2 for any criteria evaluated (p>0.05) at each recall period. The visible plaque, secondary caries and fiber optic transilumination could be correlated. Conclusion: Bevel cavity design preparations did not improve the success of composite restorations in primary molars over 18 months.