Class I and Class V composite restorations: Influence of light-curing techniques on microleakage

Abstract

Purpose: To evaluate the effect of light-curing techniques on in vitro microleakage of class I and class V composite restorations.

Methods: Sixty human premolars were used to prepare 30 class I and 30 class V cavities, which were cleaned and treated with one step self-etching adhesive (Xeno III - Dentsply). A resin composite (TPH 3 - Dentsply) was inserted in two layers and light-cured using two protocols (n=15 each): conventional curing (500 mW/cm2, 30 s each increment) and pulse delay technique (first increment similar to the conventional technique and the last increment initially cured with 200 mW/cm2 for 3 s and after 5 min light-cured again with 500 mW/cm2 for 30 s). The specimens were polished, submitted to 800 thermal cycles, sealed, and immersed in a 2% basic fuchsin solution. The teeth were cleaned, sliced, and scored according to the dye penetration. Data were analyzed by Mann-Whitney U test.

Results: In class I cavities the pulse delay light-curing technique showed statistically significant better sealing than the conventional technique. In class V restorations no difference was detected between the two techniques in enamel and dentin.

Conclusion: Light-curing technique affected the microleakage in class I composite restorations but not in class V.