effect of different powers of er,cr:ysgg laser treatment on surface morphology of microhybride composite resin: scanning electron microscope (sem) evaluation

introduction: the aim of this study was to evaluate and compare microhybride composite treated by bur and different power of erbium, chromium doped yttrium scandium gallium garnet (er,cr:ysgg) laser by scanning electron microscope (sem). methods: 21 microhybride composite blocks (diafil tm, diadent, korea) with 2 × 4 × 4 mm dimensions were made. the bonding surface of these blocks were polished, the samples were put into 6 groups for laser irradiation as follows: group 1 (power: 1w, energy: 50 mj); group 2(power: 2 w, energy: 100mj); group 3 (power: 3w, energy: 150mj); group 4 (power: 4w, energy: 200mj); group 5 (power: 5w, energy: 250mj) and group 6(power:6 w, energy :300mj). one group prepared by bur- treated. all samples were prepared by repetition rate of 20 hz. then, the samples were prepared for sem examination. result: some irregularities were seen in er,cr:ysgg laser samples in comparison to bur group that produced favorable surface for adhesion of repair composite. conclusion: among different lasers, er;cr:ysgg laser can be chosen as a suitable technique for surface treatment of unsatisfactory composites. key words: sem evalution; laser; composite resin