Selective ablation of surface enamel caries with a pulsed Nd:YAG dental laser

BACKGROUND AND OBJECTIVE: High intensity infrared light from the pulsed Nd:YAG dental laser is absorbed by carious enamel and not absorbed by healthy enamel. Consequently, this system has potential for selective removal of surface enamel caries. Safety and efficacy of the clinical procedure was evaluated in two sets of clinical trials at three dental schools. Selective ablation was evaluated with FTIR spectroscopy. STUDY DESIGN/MATERIALS AND METHODS: Carious lesions were randomized to drill or laser treatment. Pulp diagnosis, enamel surface condition, preparations, and restorations were evaluated by blinded evaluators. In Study I, surface caries were removed from 104 third molars scheduled for extraction. One-week post-treatment teeth were evaluated clinically, extracted, and the pulp was examined histologically. In Study II, 90 patients with 462 lesions on 374 teeth were randomized to laser or drill and followed for 6 months. RESULTS: Pulsed Nd:YAG laser removal of surface enamel caries was demonstrated to be both safe and effective. Caries were removed in all conditions. There were no adverse events and both clinical and histological evaluations of pulp vitality showed no abnormalities. A significantly greater number of preparations in the drill groups vs. laser groups entered dentin (drill = 11, laser = 1, P = 0.007). CONCLUSION: The more conservative laser treatment removed the caries but not the sound enamel below the lesion. The pulsed Nd:YAG dental laser was found to be both safe and effective for surface caries removal.