Comparative Study of the Restoration Quality in Cavities prepared with Er:YAG Laser in Quantum Square Pulse Mode

Nowadays, dental treatment has been enriched by the use of lasers. The introduction of the novel treatment parameter of quantum square pulse (QSP) constitutes an additional challenge to older techniques, promising minimally invasive treatments. The aim of this study is to comparatively investigate the quality of cavity preparations using erbium-doped yttrium-aluminumgarnet (Er:YAG) laser with QSP technology as opposed to the conventional bur. The Er:YAG laser (2940 nm) has been used at 120 mJ energy level in QSP and medium short pulse (125 μs) modes. Subsequently, the dentin and enamel surfaces were examined using scanning electron microscopy techniques and compared with cuttings prepared with conventional bur. The laser-treated dentin samples exhibited relatively homogenous surfaces without smear layer and with open dentinal tubules. Laser-treated enamel showed scaly surfaces but again free of smear layer. In contrast, both dentin and enamel samples treated with the conventional bur showed abundance of smear layer, groove marks, small-scale cracks, and closed dentinal tubules.