Use of a DPSS Er:YAG laser for the selective removal of composite from tooth surfaces.

ABSTRACT

New diode-pumped solid state (DPSS) ErYAG lasers have become available operating at high pulse repetition rates. These lasers are ideally suited for integration with laser scanning systems for the selective removal of dental decay and composite restorative materials from tooth surfaces. The purpose of this study was to determine if a DPSS ErYAG laser system is suitable for the selective removal of composite from tooth surfaces. Relative ablation rates of composite and enamel were determined and composite was removed from tooth surfaces using a DPSS ErYAG laser. Composite was removed very rapidly with ablation rates approaching 50-µm per pulse. A fluence of ~50 J/cm2 appeared optimal for the removal of composite and damage to the enamel was limited to less than 100-µm after the removal of composite as thick as 700-800-µm; however, dentin is removed at similar rates to composite. The DPSS ErYAG laser appears to be better suited for the removal of composite than conventional flash-lamp pumped ErYAG lasers since composite is ablated at higher rates than dental enamel and the high pulse repetition rates enable greater selectivity while maintaining high removal rates.