EFFECT OF SEMICONDUCTOR LASER ROOT CANAL DISINFECTION ON MORPHOLOGY AND SURFACE TEMPERATURE OF ROOT CANAL WALL
Objective To investigate the effect of semiconductor laser intracanal irradiation at a power of 1 W or 3 W on the morphology of root canal wall,as well as the effect of laser irradiation at different powers and with different durations on the surface temperature of root canal wall.Methods A total of 30 freshly extracted adult teeth with fully developed root apex were randomly divided into five groups,with 6 teeth in each group.Blank control group was treated with mechanical root canal preparation.Experimental group 1 was treated with mechanical root canal preparation and laser irradiation at a power of 1 W for 10 s.Experimental group 2 was treated with mechanical root canal preparation and laser irradiation at a power of 1 W for 20 s.Experimental group 3 was treated with mechanical root canal preparation and laser irradiation at a power of 3 W for 10 s.Experimental group 4 was treated with mechanical root canal preparation and laser irradiation at a power of 3 W for 20 s.Each group was treated with laser irradiation for 5 seconds each time,which was repeated according to related requirements at an interval of 5 s.A scanning electron microscope was used to observe the morphological changes of root canal wall surface in all groups.An infrared imager was used to monitor the change in the surface temperature of root canal wall from before to after laser irradiation.Results Compared with the blank control group,the experimental groups showed removal of smear layer on dentin and closure of dentinal tubules,and experimental group 2 had the most satisfactory results.Compared with experimental groups 1 and 2,experimental groups 3 and 4 had visible cracks on root canal wall.After laser irradiation,the change in the surface temperature of root canal wall in experimental groups 1,2,and 3 was lower than the threshold of 10 ℃ which could cause injuries in the root of tooth and surrounding tissues,while in experimental group 4,the change in temperature was higher than this thre-shold.Conclusion Routine root canal preparation combined with semiconductor laser irradiation at a power of 1 W for 20 se-conds can obtain good morphology of root canal wall without damaging the root of tooth and surrounding tissues.
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NSTL
万方数据
维普
