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- Title
Ti:sapphire femtosecond laser ablation of dental enamel, dentine, and cementum.
- Authors
Ji, Lingfei; Li, Lin; Devlin, Hugh; Liu, Zhu; Jiao, Jiao; Whitehead, David
- Abstract
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/cm 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/cm for enamel, dentine, and cementum, respectively. Under the average laser fluences of 1.13 to 3.68 J/cm, 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/cm 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.
- Subjects
FEMTOSECOND lasers; MEDICAL lasers; DENTAL enamel; DENTIN; CEMENTUM; LASER endoscopy; RAMAN spectroscopy
- Publication
Lasers in Medical Science, 2012, Vol 27, Issue 1, p197
- ISSN
0268-8921
- Publication type
Article
- DOI
10.1007/s10103-011-0932-z