Surface morphology and ablation characteristics of two XeCl excimer lasers: a comparison of pulse-duration effect

Lasers are rapidly gaining recognition as an effective tool for dental hard tissue procedures. The prospect of using UV lasers for modifying tooth structure is severely limited by the question of delivery mode. One class of UV laser which can be delivered through optical fibers are the XeCl excimer lasers with a pulse duration of 120 ns which are also used for angioplasty procedures. In this study we compared morphological and thermal characteristics of the two XeCl excimer lasers. The study also shed some light on plasma emission and its role in ablative processes. It is shown that the two lasers exhibit relatively similar characteristics. However, while temperature effects are quite similar and ablation rates are slightly improved during longer pulse ablation, morphological structures as indicated by SEM are quite different, illustrating a different role and effect for the laser plasma.