[Research on the effect of root canal seal achieved by irradiation of Er, Cr:YSGG laser].

Purpose: To evaluate the effect of root canal seal achieved by routine root canal preparation and irradiation of Er, Cr:YSGG laser in root canal therapy.

Methods: One hundred and five freshly single-rooted extracted human teeth were selected for the study, which were randomly divided into seven groups of fifteen each. The anatomic crowns were removed at the cementoenamel junction and the remaining roots were prepared endodontically with conventional methods. Then they were treated with Er, Cr:YSGG laser in different parameters and patterns. The effect of root canal seal achieved by Er, Cr:YSGG laser was evaluated with microleakage measurements. Newman-Keuls test and one-way analysis of variance were used to determine the statistical differences between various groups. A value of P<0.05 was considered to be significant.

Results: The amount of dye penetration from an apical stop with irradiation of Er, Cr:YSGG laser was significantly lower (P<0.05) except 3W laser without water flow, and in 1W Er, Cr:YSGG laser without water flow, the amount of apical dye penetration was significantly decreased (P<0.01).

Conclusions: The utilizing of Er, Cr:YSGG laser in small parameters prior to root canal filling could promote the effect of apical seal. Based on our results, it appeared that the seal effect of 1W Er, Cr:YSGG laser without water flow was superior to the effects of others.