Effects of acid and laser treatments on dentin nanocrystals

The effects of laser or acid exposure on dentin have been explored for a number of years. Many researchers quite the recrystallization process, therefore there has been no scientific-oriented analysis regarding this issue. The first use of the word 'recrystallization' in laser treated dentin, was done by Dederich et al. They referred to needle-like crystals observed under Scanning Electron Microscopy (SEM) with high magnification. Further researchers continued quoting the recrystallization process in their works even though no evidence of crystals could be seen in their SEM pictures. In this work, four specimens of third human molars were prepared: one specimen was conditioned with 37 percent phosphoric acid, another was irradiated with a 10 Hz Nd:YAG laser at 1,5 W, after receiving the Er:YAG laser treatment. We maintained a control sample with no treatment. The samples were submitted to x-ray diffraction measurements and SEM, performed with the JSM-5900LV microscope of the LME/LNLS.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.