| Popis: |
The aim of this study was to examine the use of Nd:YAG laser in removing the gutta percha filling from the root canal: a) without solvent, b) with eucalyptol and c) with dimethylformamide (MDF) as solvent regarding the temperature on the root surface and time required for the procedure. The root canals of thirty single rooted human teeth were instrumented and filled with Diaket (ESPE, Germany) sealer and gutta-percha points by cold lateral condensation. The teeth were randomly divided into three groups: group I - teeth were lased in the presence of eucalyptol, group II - teeth were lased in the presence of a MDF as a solvent, and group III - retreatment was performed by laser without a solvent. Each tooth was irradiated with Nd:YAG laser (Twinglight Dental Laser, Fotona, Slovenia), (20 Hz and 1,5 W). During the lasing the temperature on the root surface was recorded. After stabilizing the temperature of the external surface, laser irradiation was performed until the temperature rose 5°C. The temperature continue to rise for the 30 seconds approximately. The time of cooling and time required for the total retreatment was recorded. The procedure was assumed completed when the tip of the fiber had reached the apex and there was not any evidence of gutta-percha on the paper points. Each tooth received 3 laser exposures. The average temperature rose in the group I - 8.3ą0.7°C, in group II - 9.2ą0,7°C, and in group III - 9.2ą0.6°C. Average period of time to complete treatment was the shortest in the group III (6.4ą0.6 min), then in the eukalyptol group (6.6ą1.6 min) and DMF group (6.8ą1.8 min). Removal of gutta-percha root canal filling by Nd:YAG laser alone and in combination with solvents could be useful in clinical work because of the shorting of time required for the removing of the inapropriate root canal filling. |
