An in Vitro Study on The Effects of Er, Cr: Ysgg Laser on The Enamel and Dentin Morphology and Microleakage

Objectives: The evaluation of the enamel and dentin cavity surface morphologies by Scanning Electron Microscopy (SEM) in Class II occlusogingival slot cavities which were prepared and etched by Er, Cr: YSGG (Erbium, Chromium: Yttrium, Scandium, Gallium, Garnet) laser and assessing their effects on the microleakage at composite resin restorations, and also comparing them with those of traditional methods. Material and Methods: Fifty-five non-carious, sound extracted human molar teeth were divided into five groups: bur preparation + acid etching (Group I), bur preparation + laser etching (Group II), laser preparation + laser etching (Group III), laser preparation (Group IV), laser preparation + acid etching (Group V). The resin-tooth interface was evaluated based on microleakage. SEM examinations of laser irradiated samples (Groups II, III, IV, V) revealed a lack of smear layer, irregular and crater-like surface in enamel. Also, these examinations revealed opened dentinal tubules orifice, step-like flattered surface, and lack of smear layer in dentin. Results: Statistically significant differences were found among the occlusal (p=0.003) and gingival regions microleakage (p=0.001) in groups. In Group V at the gingival, microleakage was significantly greater than the other groups (p