Wettability characteristics of an Al₂O₃/SiO₂-based ceramic modified with CO₂, Nd:YAG, excimer and high-power diode lasers

Abstract

Interaction of CO2, Nd:YAG, excimer and high power diode laser (HPDL) radiation with the
\nsurface of an Al2O3/SiO2 based ceramic was found to effect significant changes in the
\nwettability characteristics of the material. It was observed that interaction with CO2, Nd:YAG
\nand HPDL radiation reduced the enamel contact angle from 1180 to 310, 340 and 330
\nrespectively. In contrast, interaction with excimer laser radiation resulted an increase in the
\ncontact angle to 1210. Such changes were identified as being due to: (i) the melting and partial
\nvitrification of the Al2O3/SiO2 based ceramic surface as a result of interaction with CO2,
\nNd:YAG HPDL radiation. (ii) the surface roughness of the Al2O3/SiO2 based ceramic
\nincreasing after interaction with excimer laser radiation. (iii) the surface oxygen content of the
\nAl2O3/SiO2 based ceramic increasing after interaction with CO2, Nd:YAG and HPDL radiation.
\nThe work has shown that the wettability characteristics of the Al2O3/SiO2 based ceramic could
\nbe controlled and/or modified with laser surface treatment. In particular, whether the laser
\nradiation had the propensity to cause surface melting. However, a wavelength dependance of
\nthe change of the wetting properties could not be deduced from the findings of this work.