Method: Eighty-one ground flat, polished bovine enamel slabs (4x4x2mm) were selected based upon their Knoop micro hardness values. The specimens were isolated with nail varnish/wax, leaving an exposed area on their outer surface (8mm2), which was exposed to preventive treatments and erosive challenge. The specimens were divided into nine groups according to the following treatments (n=9): C – control (no treatment); F: 1.23% acidulated fluoride gel; FV: fluoride varnish; CO: CO2 laser (0.8W, 96mJ,15s, repeat pulse, irradiation distance: 2.5mm, without cooling); COF: CO2 + F; COFV: CO2 + FV; Nd: Nd:YAG laser (1W/10Hz, 100mJ, extra long pulse, 15s, contact mode, without cooling); NdF: Nd:YAG + F; NdFV: Nd:YAG + FV. The erosive challenge was performed through exposure of specimens to HCl (pH=2, 20s, 6x/d) for 5 days in order to induce erosion-like lesions, simulating the intrinsic erosive process. Wear depth was assessed using confocal laser microscopy (OLS 4000). Data were analysed by One-Way Analysis of Variance (α=0.05).
Result: CO (2.62μm ± 0.58) and F (3.07μm ± 0.85) showed the better results. FV (4.05μm ± 0.97) and Nd (4.06 μm ± 1.51) showed the higher wear with significant difference from CO without association, F and C (p <0.05). Lasers/fluoride associations were similar to C.
Conclusion: The use of CO2 laser in the treatment of erosive process showed to be promising on the intrinsic erosion inhibition.
Acknowledgment: Arotec S/A Indústria e Comércio.