SCANNING ELECTRON MICROSCOPIC EVALUATION OF ENAMEL AND DENTIN AFTER LASER VS CONVENTIONAL CLASS V CAVITY PREPARATION IN PRIMARY MOLARS: IN VITRO STUDY

Abstract

Aim or Purpose: Scanning electron Microscopic evaluation of enamel and dentin after laser (Er, Cr: YSGG) versus conventional class V cavity preparation and after restoration of prepared primary molars with injectable Giomer.Materials-Methods: Forty primary mandibular second molars were collected. Molars were divided into four equal groups, group (I) class V prepared with the high-speed Diamond bur, group (II) class V prepared with the high-speed Diamond bur and restored with injectable Giomer after adhesive application, group (III) class V prepared with non-contact (Er, Cr: YSGG) laser and group (IV) class V prepared with non-contact (Er, Cr: YSGG) laser and restored with injectable Giomer without adhesive application. Molars were sectioned perpendicular to the long axis of the tooth using a low speed diamond disc under water coolant. Evaluation of enamel and dentin after cavity preparation, and at enamel and dentin / restoration interfaces were observed with Scanning Electron Microscope.Results: In group (I) well-defined smooth cavity floor and walls were almost covered with a debris-like smear layer. In group (II) After acid etching, the smear layer was completely removed and enamel rods or dentinal tubules were clearly visible. In group (III) Irradiated enamel had a characteristic appearance resembling (Lava flow) with open enamel prisms. Protruding dentinal tubules were observed. No visible cracks or carbonization were detected. In group (IV) Laser produced micro-retentive morphological pattern without the production of smearlayer.Conclusions: It can be concluded that (Er, Cr: YSGG) laser can be an alternative technique for conservative caries removal and provided better bonding of the restoration to primary teeth.