Diode Laser Therapy on Enamel Resistance to Erosion in Vitro

Objectives: This in vitro study aimed to evaluate the effect of a low intensity diode laser (λ= 808 nm) on the inhibition of enamel erosion by assessing superficial hardness loss.
Methods:
Bovine slabs of enamel were flattened, polished and randomly assigned to two groups (n = 6), according to treatments (diode laser therapy and laser therapy). All slabs were subjected to a previous 24h acquired pellicle formation; laser, and fluoride treatments were performed according to the individual groups. Subsequently, the slabs were exposed to erosive challenge (citric acid 1% for 5 min twice, with a 6-hour interval). Microhardness on the surface layer of slabs were measured both before and after the erosive challenge. Data were analyzed by ANOVA followed by Turkey’s test to compare the difference between groups. The significance level was set at 0.05.
Results: After the citric acid attack, the change of microhardness in groups treated with laser was significantly less than that of control group. Laser group reduced enamel erosion compared to the control group. Compared to other types of laser, for instance Nd:YAG, diode laser has less thermal alteration and reduce the risk of damage for dental pulp.
Conclusions: Under the conditions of this study, 808nm diode laser with or without fluoride could effectively reduce enamel surface loss under acid exposures.