Evaluation of Primary Tooth Enamel Surface Morphology and Microhardness after Nd: YAG Laser Irradiation and APF Gel Treatment—An in vitro study

Abstract

Objective: Laser irradiation and fluoride has been used as a preventive tool to combat dental caries in permanent teeth, but little has been done for primary teeth which are more prone to caries. The purpose of this study was to evaluate microhardness alterations in the primary tooth enamel after Nd-YAG laser irradiation alone and combined with topical fluoride treatment either before or after Nd-YAG laser irradiation.Method: Ten primary molars were sectioned and assigned randomly to: control group, Nd-YAG laser irradiation,Nd-YAG lasing before APF and APF followed by Nd-YAG lasing. The groups were evaluated for microhardness. Surface morphological changes were observed using SEM. Results: Statistical comparisons were performed. The control group's SEM showed a relatively smooth enamel surface and lasing group had fine cracks and porosities. In the lasing + fluoride group a homogenous confluent surface was seen. In the fluoride + lasing group an irregular contour with marked crack propagation was noted. There was a significant increase in the microhardness of the treatment groups. Conclusion: Nd-YAG laser irradiation and combined APF treatment of the primary tooth enamel gave morphologically hardened enamel surface which can be a protective barrier against a cariogenic attack