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

• Published in: Lasers in medical science 2019-02, Vol.34 (1), p.99-105
• Main Authors: Shinkai, Koichi, Takada, Mayo, Kawashima, Satoki, Suzuki, Masaya, Suzuki, Shiro
• Format: Article
• Language: English
• Subjects: Ablation Techniques; Air; Chromium; Chromium - chemistry; Cutting parameters; Dental enamel; Dental Enamel - radiation effects; Dental Enamel - ultrastructure; Dentin; Dentin - radiation effects; Dentistry; Desorption; Dimpling; Enamel; Erbium; Erbium - chemistry; Explosions; Gallium; Humans; Irradiation; Laser beam cutting; Lasers; Lasers, Solid-State; Medicine; Medicine & Public Health; Optical Devices; Optics; Original Article; Photonics; Quantum Optics; Scandium; Statistical analysis; Surface roughness; Teeth; Tooth - radiation effects; Variance analysis; Water - chemistry; Water depth; Yttrium
• ISSN: 0268-8921; 1435-604X
• DOI: 10.1007/s10103-018-2607-5

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