Scanning electron microscopic study of the apical dentine surfaces lased with Nd: YAG laser following apicectomy and retrofill

The purpose of this investigation was to study the effects of a Nd:YAG laser on the5 cut surface of teeth using scanning electron microscopy (SEM). Eighteen single‐rooted teeth were cleaned, shaped, and obturated with gutta‐percha and root canal sealer. The apical 3 mm of each tooth were resected with a diamond fissure bur, and the teeth were randomly divided into two groups of nine teeth each. The resected surface of each root in one group was lased twice. The duration of lasing and the number of pulses were recorded for each tooth. The teeth were air dried, mounted on stubs, sputter‐coated with gold‐palladium and examined under SEM. Application of the Nd:YAG laser caused melting of apical dentine surfaces. The melted material resembled the appearance of glazed interconnected droplets. Resolidification and recrystal‐ization of the melted areas appeared to be incomplete and discontinuous. Some areas between the glazed regions appeared similar to those of non‐lased apical dentine resected root surfaces.