抄録
Erbium: YAG (Er: YAG) laser has a characteristic of higher absorbability in water. The purpose of the present study was to determine whether this laser would be applicable for use on treatment of root dental caries lesion. Thirty-five 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 Er: YAG laser, and the other was removed with a round steel bur mounted on an electronic engine or was non treated control. Er: YAG laser irradiation was performed at 160mJ/pulse (56.5J/cm2) and 10 pps under water spray using a fiber delivery system with a contact probe. With both methods, the removal of the infected dentin layer was checked by using a cariesdisclosing agent (Caries DetectorTM), and the time required for caries removal was determined. Furthermore, SEM observation and hardness measurement of cavity floor dentin, and histological observation of the decalcified serial sections of the specimens were conducted.
As a result, obvious remnant lesion was not observed at the laser-treated site. SEM observation of the laser-treated site revealed interesting features which could not be observed with the conventional methods. The removal of carious dentin using the Er: YAG laser with water spray could be possible in vitro.
It seemed that the Er: YAG laser treatment diminished unpleasant sound and vibration, compared with the conventional methods. However, it is noticed that careful laser irradiation was necessary to remove infected dentin layer completely.
