A comparative study of microleakage through enamel and cementum after laser Er:YAG instrumentation in class V cavity obturations, using scanning electron microscopy.

Objective: The purpose of this study was to use scanning electron microscopy (SEM) in order to compare the surfaces of cavities prepared using laser with those prepared conventionally, and to measure the degree of leakage through both enamel and cementum.
Materials and Methods: We prepared 135 class V cavities and divided them randomly into three groups: laser-treated (group A), laser-treated, and acid-etched (group B) and rotary instrumented (group C).
Results: On analyzing the tooth enamel, the amount of leakage was found to be similar in groups A and B, whilst the samples in the group C were more prone to leakage. On analyzing the cementum, the group C samples appeared to display surfaces that were more conducive to the adhesion of the materials used in obturation (although this difference was not strictly significant), and this might have provoked the relatively low levels of leakage.
Conclusion: The use of acid etching in conjunction with both conventional and laser cavity preparation improves the adhesion of the materials used in obturation to enamel surfaces.