FEL Showed Dental Tissue Specificity of Laser Ablation
Objectives: Laser ablation is widely applied to dental clinics. Mechanism of laser ablation, however, has not been clarified, and lined up many candidates. Free electron laser (FEL) is featured by variable wavelength. The aim of this study was clarify the optimum wavelength for dental hard tissue ablation.
Methods: FEL was generated at LEBRA, Nihon University, at the wavelength range from 2.0 micron to 6.0 micron. Polished tooth sections were irradiated by LEBRA-FEL at the varied conditions. Pits formed on the surface of teeth were analyzed by a laser displacement meter (LT-8010, KEYENCE, Osaka).
Results: Optimum wavelength for the dental hard tissues ablation was at about 3.0 micron, but there was slight but significant difference in the optimum ablation wavelength for dental enamel and dentin, and also for enamel-dentin junction region. The formed pit shape varied not only in depth but also in width. Thermal damage was not observed around and in the pits.
Conclusion: Varied wavelength using FEL revealed that the variation in optimum wavelength for dental hard tissues. Mechanism of pit formation on the dental hard tissue surface may be due to plasma ablation rather than mechanical or heat ablation. Micro-water combustion theory should be re-discussed because of the variation in optimum wavelength. This study was supported in part by a Grant-in-Aids for Scientific Research, MEXT, Japan (17591927).
Division: Japanese Division Meeting
Meeting:2008 Japanese Division Meeting (Nagoya City, Japan) Location: Nagoya City, Japan
Year: 2008 Final Presentation ID: Abstract Category|Abstract Category(s):Scientific Groups
Authors
Sakae, Toshiro
( Nihon University School of Dentistry at Matsudo, Matsudo, N/A, Japan
)
Hayakawa, Ken
( Nihon University, Chiba, N/A, Japan
)
Sato, Isamu
( Nihon University, Chiyoda-ku, N/A, Japan
)
Sato, Yukie
( Nihon University, Matsudo Chiba, N/A, Japan
)
Okada, Hiroyuki
( Nihon University, Matsudo Chiba, N/A, Japan
)
Yamamoto, Hirotsugu
( Nihon University school of Dentistry at Matsudo, Matsudo, N/A, Japan
)
Kuwada, Takao
( Nihon University, Chiyoda-ku, N/A, Japan
)
Sakai, Takeshi
( Nihon University, Chiyoda-ku, N/A, Japan
)
Nogami, Kyoko
( Nihon University, Chiba, N/A, Japan
)
Hayakawa, Yasushi
( Nihon University, Chiba, N/A, Japan
)
Tanaka, Toshinari
( Nihon University, Chiba, N/A, Japan
)