Enamel surface roughness analysis after laser ablation and acid-etching

Laser-roughened enamel surfaces have been shown to provide for greater acid-resistance and enhanced restorative material/enamel bond strength. Extracted tooth enamel was irradiated with several lasers: CO2/Nd:YAG (CW), CO2 (RSP), Nd:YAG (CW), Nd:YAG (Q-switched), Argon (CW), and Ar:F excimer. Additional teeth were acid-etched. Energy densities were standardized at 25.47 J/cm2 for all mediums. Surface profile analyses were conducted with a profilometer to determine the amount of enamel surface roughness. The acid-etched samples exhibited both a greater amount of surface roughness and a qualitatively different type of enamel surface morphology than the laser-treated specimens. Independent use of the CO2 and Nd:YAG beams exhibited a moderate amount of roughness, while the coaxial CO2/Nd:YAG beam displayed surface roughness approaching that of the acid-etch samples. Different laser mediums produce enamel surface morphologies that are characteristic of a variety of inherent lasing parameters.