Surface Roughness of Er, Cr: YSGG Laser Etched Enamel Compared to Acid Etching: An In Vitro Study

Objectives: Erbium-based lasers have been used in dentistry with different parameters for enamel conditioning with controversial results on the optimum parameter. This study aims to compare the surface roughness of enamel after conditioning by erbium, chromium-doped: Yttrium scandium-gallium-garnet (Er, Cr: YSGG) laser or 37% phosphoric acid and after remineralization, using a scanning electron microscope (SEM). Materials and Methods: Forty-five extracted premolars for orthodontic purposes were divided into three groups according to the conditioning technique. Group 1 conditioning by Er, Cr: YSGG laser 4.5 watts/30 Hz, Group 2 conditioning by Er, Cr: YSGG laser 4.5 watts/ 20 Hz, and Group 3 conditioning by 37% phosphoric acid. Surface roughness was measured using SEM after conditioning and after remineralization using Recaldent GC MI Paste Plus. Statistical analysis was done by one-way analysis of variance ANOVA test used to compare between groups, followed by Tukey’s post hoc test. Results: Enamel surface conditioned by Er, Cr: YSGG 4.5 watts/20 Hz laser had significantly less surface roughness than 37% phosphoric acid conditioned. After remineralization both the laser groups produced significantly lower surface roughness compared to acid conditioning. Conclusion: Er, Cr: YSGG laser conditioning of enamel surfaces (with 4.5 watts and 20 Hz/ 30 Hz frequency) produced less surface roughness which could be used as a promising alternative for acid conditioning. Clinical Relevance: laser conditioning of enamel using Er, Cr: YSGG with 4.5 watts could be a promising alternative for acid conditioning since it produces less surface roughness, less plaque accumulation on the surface, and less bacterial adhesion.