Objective: We determined the real effect of Erbium:YAG laser ablation on human teeth in vivo.
Summary background data: We advocated the idea that overheating of teeth, specially pulp damage can be avoided if correct laser parameters are used.
Methods: We evaluated human premolars scheduled for extraction during orthodontic treatment. Before tooth extraction, an oval cavity preparation was made with a pulsed Er:YAG laser. After extraction, the teeth were decalcified for 6 weeks. Routine staining with haematoxylin and eosin was performed on longitudinal section. One hundred seventy-two sections were prepared and examined in a light microscope.
Results: Under Er:YAG laser application, reduction of the dentin layer was observed. Dentinal tubules had a radial course up to the surface. No cracks or structural injury were observed. Inflammatory reaction in the pulp was not found. The vascularity of the pulp was normal. The odontoblasts were of the usual spindle-like or star-like cell shape. The cementum and epithelial attachment were healthy. No changes of structure or indications of inflammation were observed.
Conclusions: The results of this in vivo experiment on human teeth confirm safety of Er:YAG laser ablation of enamel and dentin under the conditions described.