Effect of ER:YAG and diode laser irradiation on the root surface: morphological and thermal analysis.

ABSTRACT

BACKGROUND: The aim of the present study was to compare the effects of ErYAG and diode laser treatments of the root surface on intrapulpal temperature after scaling and root planing with hand instruments. METHODS: Fifteen extracted single-rooted teeth were scaled and root planed with hand instruments. The teeth were divided into 3 groups of 5 each and irradiated on their buccal and lingual surfaces group A ErYAG laser, 2.94 microm/100 mJ/10 Hz/30 seconds; group B diode laser, 810 nm/1.0 W/0.05 ms/30 seconds; group C diode laser, 810 nm/1.4 W/0.05 ms/30 seconds. The temperature was monitored by means of a type T thermocouple (copper-constantan) positioned in the pulp chamber to assess pulpal temperature during and before irradiation. Afterwards, the specimens were longitudinally sectioned, and the buccal and lingual surfaces of each root were analyzed by scanning electron microscopy. RESULTS: In the ErYAG laser group, the thermal analysis revealed an average temperature of -2.2 +/- 1.5 degrees C, while in the diode laser groups, temperatures were 1.6 +/- 0.8 degrees C at 1.0 W and 3.3 +/- 1.0 degrees C at 1.4 W. Electronic micrographs revealed that there were no significant morphological changes, such as charring, melting, or fusion, in any group, although the specimens were found to be more irregular in the ErYAG laser group. CONCLUSIONS: The application of ErYAG and diode lasers at the utilized parameters did not induce high pulpal temperatures. Root surface irregularities were more pronounced after irradiation with an ErYAG laser than with a diode laser.