Infrared Spectroscopy of Laser Irradiated Dental Hard Tissues Using the Advanced Light Source

摘要

FTIR Spectroscopy used in the specular reflectance mode is well suited for resolving thermally induced changes in dental hard tissue as a result of laser irradiation. High spatial resolution (10 mu m) is achievable with a high brightness synchrotron radiation source such as the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. IR spectra of modified enamel were acquired after laser ablation using several laser wavelengths from the UV to the mid-IR. Specific areas of laser ablation craters were probed non-destructively with 10-mu m spatial resolution. The chemical composition of the crater walls deviates markedly from that of hydroxyapatite after Er:YAG and CO_2 laser irradiation without added water. New mineral phases were resolved that have not been previously observed using conventional IR Spectroscopy.