Kuwada-Kusunose Takao, Kusunose Alisa, Wakami Masanobu, Takebayashi Chikako, Goto Haruhiko, Aida Masahiro, Sakai Takeshi, Nakao Keisuke, Nogami Kyoko, Inagaki Manabu, Hayakawa Ken, Suzuki Kunihiro, Sakae Toshiro
Department of Liberal Arts (Biology), Nihon University School of Dentistry at Matsudo, 2-870-1, Sakaecho-Nishi, Matsudo, Chiba, 271-8587, Japan.
Department of Crown Bridge Prosthodontics, Nihon University School of Dentistry at Matsudo, 2-870-1, Sakaecho-Nishi, Matsudo, Chiba, 271-8587, Japan.
Lasers Med Sci. 2017 Aug;32(6):1349-1355. doi: 10.1007/s10103-017-2251-5. Epub 2017 Jun 14.
In the application of lasers in dentistry, there is a delicate balance between the benefits gained from laser treatment and the heat-related damage arising from laser irradiation. Hence, it is necessary to understand the different processes associated with the irradiation of lasers on dental materials. To obtain insight for the development of a safe and general-purpose laser for dentistry, the present study examines the physical effects associated with the irradiation of a near-infrared free-electron laser (FEL) on the surface of a commonly used silver dental alloy. The irradiation experiments using a 2900-nm FEL confirmed the formation of a pit in the dental alloy. The pit was formed with one macro-pulse of FEL irradiation, therefore, suggesting the possibility of efficient material processing with an FEL. Additionally, there was only a slight increase in the silver alloy temperature (less than 0.9 °C) despite the long duration of FEL irradiation, thus inferring that fixed prostheses in the oral cavity can be processed by FEL without thermal damage to the surrounding tissue. These results indicate that dental hard tissues and dental materials in the oral cavity can be safely and efficiently processed by the irradiation of a laser, which has the high repetition rate of a femtosecond laser pulse with a wavelength around 2900 nm.
在激光在牙科领域的应用中，激光治疗所带来的益处与激光照射产生的热相关损伤之间存在着微妙的平衡。因此，有必要了解与激光照射牙科材料相关的不同过程。为了深入了解用于牙科的安全通用激光的开发，本研究考察了近红外自由电子激光（FEL）照射常用银基牙科合金表面时的物理效应。使用波长为2900纳米的自由电子激光进行的照射实验证实了牙科合金中形成了凹坑。该凹坑由自由电子激光的一个巨脉冲照射形成，因此表明自由电子激光进行高效材料加工的可能性。此外，尽管自由电子激光照射持续时间长，但银合金温度仅略有升高（低于0.9摄氏度），从而推断口腔中的固定修复体可用自由电子激光进行加工，而不会对周围组织造成热损伤。这些结果表明，波长约为2900纳米、具有飞秒激光脉冲高重复率的激光照射能够安全有效地加工口腔中的牙齿硬组织和牙科材料。
