Effects of the percentage of air/water in spray on the efficiency of tooth ablation with erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation

Abstract

We aimed at examining the effects of a percentage of air/water in spray on the cutting efficiency of Er,Cr:YSGG laser for enamel and dentin. The intensity and frequency of irradiation were 3.0 W and 20 Hz for the enamel surface and 2.0 W and 20 Hz for the dentin surface, respectively. Flattened surfaces of enamel and dentin were irradiated at nine points for approximately 1 s under various percentages of air/water in spray using Er,Cr:YSGG laser. A high-speed video microscope was used to record each laser irradiation on the tooth surface. A slow video image was used to count the number of water micro-explosions yielded on the tooth surface during laser irradiation. A surface roughness tester was used to measure the depth of the dimple prepared with laser irradiation on each specimen. Each individual depth of dimple was divided by the number of water micro-explosions (pulse). This allowed for the calculation of the cutting depth per pulse. Following laser irradiation, several representative specimens were observed using an SEM. Two-way ANOVA was used as the statistical analysis. This revealed that there was no significant effect of the percentage of air/water in spray on the cutting depth for enamel surface (p > 0.05). On the contrary, a significant effect was observed in air-ratio for dentin cutting (p < 0.05). Both enamel and dentin were characterized by the presence of rough surfaces, as shown by the SEM images of the dimples. The percentage of air/water in spray was not significantly effective in laser cutting for enamel. Air-percentage was significantly effective in laser cutting for dentin.

Comparative evaluation of microleakage after root-end resection by erbium, chromium: Yttrium-scandium-gallium-garnet (Er, Cr:YSGG) laser and carbide bur with or without placement of mineral trioxide aggregate: An in vitro study

“…Therefore, in this study, the power setting of 4.5 W was used to prevent overheating and other unwanted effects on dental tissue, and also, air percentage was chosen as 50% as the previous study by Shinkai et al . [21] concluded that lower percentage of air has a better dentin-cutting efficacy than higher percentage of air, when the percentage of air was between 50% and 70%.…”

Effect Of Er, Cr: YSGG And Er: YAG Lasers During Debonding Of Orthodontic Ceramic Brackets: In Vitro Study

“…According to Zach and Cohen (1) , a 5.5°C temperature increase could cause pulp necrosis in 15% of teeth, thus the laser was applied with water-cooling in the present study to reduce the probability of intra-pulpal temperature increase while debonding the ceramic brackets. Shinkai et al (25) stated that a spray with 70% water was the most efficient. They also showed that shallow ablation of dentin was optimized with a spray with 70% air.…”

Water jet as a novel technique for enamel drilling ex vivo

“…Hopefully, in other fields, the water jet drilling technique will become increasingly mature. Colliding water jet is a case in which the water jet drilling technique can drill accurately and safely [44,45].…”