Optimal power settings of aluminum gallium arsenide lasers in caries inhibition — An in vitro study

CONTEXT: Incipient carious lesions are characterized by subsurface dissolution due to more fluoride ions in the 50-100 microns of the tooth's outer surface. AIMS: To determine an optimal power setting for 810 nm aluminum gallium arsenide laser for caries inhibition. MATERIALS AND METHODS: Fifty-four caries-free extracted teeth were sectioned mesiodistally. The samples were divided into 18 groups for each power setting being evaluated. Each group had six samples. The laser used is 810 nm aluminum gallium arsenide laser with power setting from 0.1 watts to 5 watts. Laser fluorescence based device was used to evaluate the effect of irradiation. STATISTICAL ANALYSIS USED: Paired “t” test, one-way analysis of variance (ANOVA), Tukey's post hoc test, and the Pearson's correlation test. RESULTS: The paired t-test showed that there is minimum divergence from the control for 3.5 watts. Tukey's post hoc test also showed statistically significantly results for 3.5 watts. The Pearson's correlation test showed that there was negative correlation between the watts and irradiation. CONCLUSIONS: The power setting that gave statistically significant results was 3.5 watts.