thermal changes of root surface of anterior primary teeth in pulpectomy with er: yag laser

Objectives: successful root treatment depends on elimination of microorganisms from the root canal. considering incomplete removal of bacteria from the canal by usual methods, lasers have been suggested as a new modality. despite their anti-bacterial properties, lasers can cause thermal changes. this study assessed the thermal changes of root surface in pulpectomy of primary teeth following the use of er:yag laser. materials and methods: sixty primary anterior teeth were collected and prepared by k-file up to number 50. then, they were randomly divided into two groups and were irradiated with er:yag laser. the first group was irradiated with 1 w laser and the second group with 1.5 w laser. the laser irradiation time was two 10-second cycles with a 2-second interval in both groups. thermal changes were measured by a thermometer in the apical and coronal areas per second. the results were analyzed by repeated measures anova considering the laser power as between-subject variable. results: there was a temperature increase in the coronal and apical areas in use of 1 w power. there was a temperature rise in the coronal and apical areas in use of 1.5 w power. the temperature rise in the apical third was more than that in the coronal third; also, the average temperature rise was more in use of 1.5 w power than 1 w power. conclusions: as the average temperature increase was not more than 7°c in any group, this type of laser seems to be suitable for root treatment of primary anterior teeth.