Transmission of Er,Cr:YSGG laser through different dental ceramics

The aim of this study is to evaluate the transmission of Er,Cr:YSGG laser energy through different dental ceramic with various thicknesses.

Flat ceramic plates with three different thicknesses (0.5 mm, 1 mm and 1.5 mm) were prepared by sectioning the CAD-CAM blocks made of feldspathic ceramic, lithium disilicate ceramic and monolithic zirconia ceramic. Samples were placed on a custom-made acrylic sample holder which is fitted on the sensor membrane chamber of a laser power-meter. Er,Cr:YSGG laser irradiation (50 mJ, 20 Hz, 1W, 60 μs, H-Mode) was performed over the ceramic using a laser device. The amount of transmitted energy through the ceramic samples was recorded. Ten measurements were made for each sample and the collected data were statistically analyzed (p = 0,05).

The highest transmission ratio was determined for feldspathic ceramic with 0.5 mm thickness (76,8%) and the lowest was determined for lithium disilicate-reinforced ceramic with 1.5 mm thickness (26,2%). The differences among different ceramics and different thicknesses were significant (p < 0.05).

Ceramic type and thickness have a significant effect on the transmission ratio of Er,Cr:YSGG laser through the ceramic and these factors should be taken into consideration to adjust the laser irradiation parameters when making laser debonding of adhesively cemented all-ceramic restorations.