Effect of laser pretreated enamel and dentin of primary teeth on microleakage of different restorative materials

Surface texture of the prepared dental tissue is one of the most important factors affecting the clinical performance of dental restorations. This surface area is greatly affected by the surface treatment modality used and the restorative material applied. Therefore, the purpose of this in vitro investigation was to study the effect of laser pretreatment of enamel and dentin in Class V cavities of human primary molars on microleakage of three restorative materials; a compomer, a composite resin and a Galloy. Forty-eight extracted human primary molar teeth divided into 6 groups [3 control & 3 experimental] were used in this study. A standardized Class V cavity involving enamel and dentin was made in the buccal surface of each tooth and the experimental groups were exposed to Nd: YAG laser for 90 seconds. Teeth in all groups were then restored with the tested materials according to the instructions of the manufacturers. The teeth were prepared for microleakage testing and then immersed in 5% methylene blue for 4 hours. Each tooth was subsequently sectioned and examined for dye penetration along the occlusal and gingival walls. Tukey's multiple range test showed that combined microleakage scores of unlased Pertac II, was statistically significantly higher than lased Hytac, lased Pertac II, unlased Galloy and lased Galloy. Wilcoxon matched pairs signed rank test showed statistically significant difference for unlased Pertac II group [p = 0.0176] when occlusal Vs gingival scores were compared. In conclusion, microleakage of unlased Galloy restorations were statistically significantly better than unlased Hytac and Pertac II groups. In addition, microleakage scores of lased Pertac II group was statistically significantly lower than unlased group. No statistically significant differences were found between lased and unlased Hytac and Galloy restorative materials.