Ti:sapphire femtosecond laser ablation of dental enamel, dentine, and cementum
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Lingfei Ji & Lin Li & Hugh Devlin & Zhu Liu & Jiao Jiao & David Whitehead
- چاپ و سال / کشور: 2011
Description
This paper reports an investigation into the characteristics of femtosecond laser (800-nm central wavelength) in the ablation of human dental enamel, dentine, and cementum at various laser fluences from 0.2 to 3.68 J/cm2 with single and multiple pulses. The femtosecond laser interaction with cementum is reported for the first time. Ablation thresholds were determined to be 0.58, 0.44, and 0.51 J/cm2 for enamel, dentine, and cementum, respectively. Under the average laser fluences of 1.13 to 3.68 J/cm2, clean ablated surfaces without debris and microcracks were obtained. Laser fluence was found to influence the ablated diameter and depth, whereas under a certain fluence, pulse number only affects the depth, without affecting the diameter. The ablation mechanism is found to be based on multi-photon absorption, not previously known for femtosecond laser ablation of dental materials. The low thermal loads of 0.708, 1.44, and 0.404 J/cm3 required for ablating enamel, dentine, and cementum, determined for the first time, are beneficial for minimizing the heat-affected zones and micro-damage. The Raman spectroscopic analysis of phosphate shows that the chemical components of the tooth remain intact before and after the fs-laser ablation. It also shows that different dental tissues respond differently to the laser irradiation.
Lasers Med Sci DOI 10.1007/s10103-011-0932-z Received: 20 August 2010 / Accepted: 26 April 2011
