Dentinal surface-cutting efficiency using a high-speed diamond bur,ultrasound and laser

We compare an ultrasound bur with a conventional one and an Er:YAG laser for cavity preparations. Human molars were embedded in resin and sliced for this study. The surface abrasion was performed by a high-speed instrument and ultrasound. The cavity preparation was initially performed with a high-speed diamond bur. After this, a 2.94-μm laser with 400 mJ/pulse at 4 Hz, and a pulse width from 250–500 μs was applied to the tooth surface for 30 s in a sweeping motion. The samples were analyzed by SEM. The abrasion surface with a conventional bur showed structure removal with different grooves, a smear-layer presence, and occluded dentinal tubules. The abraded surface with the CVD bur suggested a removal process in layers. The laser-irradiated surface showed a rough aspect with opened tubules and the absence of a smear layer. The results of this study suggest that a high-speed diamond bur, ultrasound, and laser were able to perform cavity preparation. However, the CVD bur presented a higher surface quality.