Pulsed laser ablation of dental calculus in the near ultraviolet
| Autor: | Joshua E. Schoenly, W. Seka, Peter Rechmann |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Microscope
Materials science Ultraviolet Rays medicine.medical_treatment education Biomedical Engineering Fluence Models Biological law.invention Biomaterials Optics law Microscopy Calculus medicine Humans Dental Calculus Absorption (electromagnetic radiation) Laser ablation Photobleaching business.industry Ablation Laser Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials stomatognathic diseases Wavelength Laser Therapy business Tooth |
| Zdroj: | Journal of biomedical optics. 19(2) |
| ISSN: | 1560-2281 |
| Popis: | Pulsed lasers emitting wavelengths near 400 nm can selectively ablate dental calculus without dam- aging underlying and surrounding sound dental hard tissue. Our results indicate that calculus ablation at this wavelength relies on the absorption of porphyrins endogenous to oral bacteria commonly found in calculus. Sub- and supragingival calculus on extracted human teeth, irradiated with 400-nm, 60-ns laser pulses at ≤8 J∕cm 2 , exhibits a photobleached surface layer. Blue-light microscopy indicates this layer highly scatters 400-nm pho- tons, whereas fluorescence spectroscopy indicates that bacterial porphyrins are permanently photobleached. A modified blow-off model for ablation is proposed that is based upon these observations and also reproduces our calculus ablation rates measured from laser profilometry. Tissue scattering and a stratified layering of absorbers within the calculus medium explain the gradual decrease in ablation rate from successive pulses. Depending on the calculus thickness, ablation stalling may occur at |
| Databáze: | OpenAIRE |
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