A Modified Er,Cr:YSGG Laser Protocol Associated with Fluoride Gel for Controlling Dentin Erosion

Effective strategies to control the development of dental erosion are still needed. This study evaluated the effect of associating a modified Er,Cr:YSGG laser protocol with topical fluoride application on dentin erosion. Sound and eroded dentin specimens (n = 10/substrate) were allocated into groups: control (no treatment); APF gel (1.23% F-, for 1 min, one application, removed with cotton roll); Er,Cr:YSGG laser P1 [0.25W, 20Hz, ≅ 6.5 J/cm2, 2 mm away from the surface, two irradiation of 10 s each, with sweeping movements, under 25% air, without water, with a sapphire tip measuring 750 μm in diameter and with of 6 mm (S75)]; Er,Cr:YSGG laser P2 (same settings with P1 except 1 mm away from the surface and ≅ 8.3 J/cm2); APF gel before Er,Cr:YSGG laser P1; APF gel before Er,Cr:YSGG laser P2. Specimens underwent a 5-day erosion-remineralization cycling. Erosion depth (surface loss — SL) was determined. Environmental scanning electron microscopy images (n = 2) were obtained. Data were statistically analyzed (α = 0.05). Sound substrate: APF gel presented lowest SL, differing significantly from control and other groups. Laser P1 and P2 had highest SL. Eroded substrate: laser P1 showed highest SL, differing significantly from all other groups. For the control, APF gel, and laser P1, the eroded substrates had significantly higher SL than the sound. For laser P2, SL from sound specimens was higher than the eroded. Melted areas were observed in the laser-treated groups. Modified Er,Cr:YSGG laser parameter was unable to control progression of dentin erosion, not even when it was combined with fluoride.