Investigational study of the use of Er:YAG laser versus dental drill for caries removal and cavity preparation--phase I

We determined that the Er:YAG pulsed 2.94 micron radiation was successful in the removal of caries, cavity preparation, and etching prior to acid etching. The laser group was compared to a control group in which the high-speed drill was employed. Parameters measured included histological evaluation of the pulp, scanning electron microscopy of the surface morphology of the tooth, dye penetration studies, bond strength measurements, and rating of the laser's ability to remove caries and form the preparation. We collectively evaluated 60 patients with 106 teeth in both the laser and control groups over a 1-year period. Teeth were treated in vivo and then extracted immediately, at 2 days, 1 month, and up to 1-year to assess pulpal healing, surface morphology, and the quality of the preparation, restoration, and pain. The dental laser was shown to be equal or better than the drill in the tested procedures of caries removal, cavity preparation, and etching prior to acid etching. The scanning electron microscopy revealed no microfracturing, open dentinal tubules, and effective etching with the laser having a mean of 2.7 with an optimum rating of 3. The histological testing confirmed that the pulp was not compromised using the laser with scores of theta for hemorrhage, 0.47 for hyperemia, and 0.12 for inflammation on a scale of 0 to 3 where 0 is no effect. The FDA has recently cleared the Er:YAG to remove all classes of caries, form the cavity preparation, and modify the enamel and dentin prior to acid etching. In this Phase I study conducted as part of the clinical trials, there were no complications and no tooth was compromised. Patients were consistently treated without anesthesia with the same or better results than the drill as confirmed by scanning electron microscopy and histological studies.