Effect of the 308-nm excimer laser on tooth dentin

Abstract

The use of the laser for applications in electronics, industry and medicine is growing at a rapid pace. Dental applications for lasers, developed to date, have primarily been used for surgery on soft tissues. The pulsed output of the 308 nm excimer laser and the photochemical rather than photothermal action offers the ability to cut on dental structures with minimal generation of heat. In a previous study the action of the 308 nm excimer laser on dental enamel was demonstrated. This study showed that a hole of controlled diameter and depth could be produced. The study has now been extended to determine the effect of the 308 nm excimr laser on dentin. Energy densities of 50, 70 and 90 mJ/mm' were used while exposing points on the dentin surface 500, 1000, 1500, 3000 and 4000 pulses (each 100 pulses equal to 5 seconds time). Tooth samples were rigidly fixed in position while the laser beam was transmitted to the dentin surface through a uv-grade fused silica fiber optic light guide, 600 microns in core diameter. Results showed that a symmetrical hole could be produced in the dentin surface, accurately controlling diameter and depth of penetration. Further results demonstrated that the dentin smear layer was removed and the dentinal tubules could be sealed with the 308 nm excimer laser.