Application of Er:YAG laser to treat root caries lesion

The effect of the Er:YAG laser on caries removal was studied. Extracted human teeth with cervical root caries were used. Each root caries lesion was divided into two areas axially. A divided half was treated with the Er:YAG laser, and the other was removed with round steel burs mounted on an electric engine or was nontreated as a control. Laser irradiation was performed at 160 mJ/pulse (56.5 J/cm2/pulse) and 10 pps under water spray using a fiber delivery system with a contact probe. The time required for caries removal was measured with each treatment. SEM observation and hardness measurement of cavity floor dentin, and observation of the decalcified serial sections of the specimens were compared. The results indicated that the removal of carious dentin using Er:YAG laser could be performed to the same degree as the electric engine treatment. In addition, the Er:YAG laser treatment diminished unpleasant sound and vibration. However, it was noticed that careful laser irradiation was necessary for the removal of infected dentin layer without overreduction of intact dentin layer. The time required for the laser treatment was longer than that for the electric engine treatment under the conditions of the present experiment.