Compositional, structural, and phase changes in in vitro laser-irradiated human tooth enamel

摘要: Tooth enamel laser irradiated under certain conditions previously has been shown to have reduced subsurface demineralization rates. Identification of these laser-induced changes bearing on understanding the dissolution rate reduction mechanism; some changes, ones that occur in high temperature regions, were studied this report. X-ray diffraction and infrared spectroscopy used identify extracted intact human teeth subjected energy density (∼10,000 J/cm2) 10.6 µm wavelength carbon dioxide irradiance. The irradiance melted apatite; solidified melt was composed minor phases α-tricalcium phosphate, α-Ca3(PO4)2, tetracalcium Ca4(PO4)2O, a major phase modified apatite. apatite modifications, as compared with original (1) reductions contents water, protein, carbonate, chloride (or rearrangement); (2) essentially no change hydroxide content; (3) possible incorporation oxide replacing ions; (4) an uptake traces cyanate. An band at 434 cm−1 appears spectra hydroxyapatite partially dehydroxylated by thermal treatment assigned translation. This utilized search for formation laser-irradiated tooth enamel.