Influence of Er:YAG and ND:YAG laser irradiation and fluoride application on surface roughness and dentin surface wear after erosive challenge - An in vitro study.

ABSTRACT

Background: To evaluate the effectiveness of ErYAG and NdYAG laser on dentin hypersensitivity prevention, associated or not to acidulated phosphate fluoride (APF) after erosive challenge. Material and Methods: 104 specimens were obtained from bovine dentine and divided into groups (n=13) G1 ErYAG; G2 ErYAG followed by application of APF; G3 application of APF followed by ErYAG, simultaneously; G4 NdYAG; G5 NdYAG followed by application of APF; G6 application of APF followed by NdYAG, simultaneously; G7application of APF; G8 untreated. The parameters for ErYAG were10s, distance of 4mm, water cooling flow of 2mL/min, 2Hz, 3.92J/cm2. For the NdYAG 10s, distance of 1mm, without cooling, 10Hz, 70.7J/cm2. The erosive drink was a cola at 4°C, 3×/day for 1 minute, for 5 days. Roughness and wear analysis were done in confocal laser microscope. Data were statistically analyzed (α=0.05). Results: As regards roughness, there was no statistically difference among the groups. The groups irradiated with ErYAG had a volume loss lower. G6 showed higher values than the groups irradiated with ErYAG and lower than the other groups. The other groups irradiated with NdYAG showed similar wear results to the control. Conclusions: The ErYAG laser showed the lowest volume loss from wear analysis, suggesting the increased the acid resistance of dentin. Key wordsDentine sensitivity, Lasers, Sodium fluoride.