The Use of Er:YAG Laser for Cavity Preparation: An SEM Evaluation

Objective: The purpose of this study was to evaluate morphological changes in cavities prepared by the Er:YAG laser (2.94 μm) at different parameters of irradiation and by a diamond bur. Experimental design: Cavities were prepared on 27 human molars (n = 3): G1, 15 Hz/160 mJ enamel/6 Hz/200 mJ dentin; G2, 15 Hz/180 mJ enamel/6 Hz/200 mJ dentin; G3, 15 Hz/160 mJ enamel/6 Hz/250 mJ dentin; G4, 15 Hz/180 mJ enamel/6 Hz/250 mJ dentin; G5, 15 Hz/180 mJ enamel/10 Hz/180 mJ dentin; G6, 15 Hz/160 mJ enamel/10 Hz/180 mJ dentin; G7, 15 Hz/160 mJ enamel/10 Hz/160 mJ dentin; G8, 15 Hz/180 mJ enamel/10 Hz/160 mJ dentin; G9, diamond bur. For SEM analysis, samples were fixed (2.5% glutaraldheyde, 12 h, 4°C), dehydrated (25–100% ethanol), dried, and sputter‐coated with gold. Results: Despite the changes on energy and repetition‐rate settings, all laser‐treated samples showed no evidence of thermal damage or signs of burning and melting. Er:YAG laser ablated dental hard tissues showed exposed enamel prisms, dentin surface without smear layer, and opened dentinal tubules. Conclusion: Different Er:YAG laser parameters were effective for ablation of hard tissues, creating an irregular and microretentive morphological pattern without hard tissue damage. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.