Effect of tooth preparation on sealant success--an in vitro study

This study compared the depth of penetration and marginal leakage of filled and unfilled sealants, with and without tooth preparation. One hundred and twenty extracted human third molar teeth that were free of restorations, fluorosis, caries, and sealants were used. After adequate storage and surface debridement, the teeth were randomly divided into four groups of 30 teeth each. In two groups, the occlusal surfaces were left intact, while in the other two groups, the occlusal surfaces were prepared using a diamond bur. Teeth in two groups were sealed with a filled sealant, and an unfilled sealant was used to seal teeth in the other two groups. The sealed teeth were then prepared for marginal leakage, immersed in 5% methylene blue (at 37 degrees C) for 24 hours. Subsequently, buccolingual sections were made and each section was examined for sealant penetration and marginal leakage, using a stereomicroscope. The depth of dye penetration and marginal leakage was evaluated according to a method described by Ovrebo and Raadal. The unfilled sealant placed after tooth preparation showed better enamel fissure penetration and less marginal leakage than the filled sealant.