Study On The Morphology And Temperature Changes Of Root Canal Wall Treated By Semiconductor Laser Root Canal

Purpose: Explore the effect of semiconductor laser irradiation on root canal under different power,while the observe temperature changes with different power of laser irradiation on root canal of the root surface.Methods: 30 adult freshly extracted teeth with fully developed single apical root canal were randomly divided into five groups.Each group has 6 samples.Group A is the mechanical root canal preparation group(blank group).Group B is blank group under power 1 w laser irradiation for 10 s.Group C is blank group under power 1 w laser irradiation for 20 s.Group D is blank group under power 2 w laser irradiation for 10 s.Group E s blank group under power 2 w laser irradiation for 20 s.After mechanical preparation,each group was rinsed by 3 ml 5.25%sodium hypochlorite(Na Cl O)solution and 17% ethylenediamine tetraacetic acid(EDTA)solution.Then,root canals were taken under the ultrasonic preparation.SEM pictures of5 groups were obtained.Infrared images of group B,C,D,E were taken to track temperature changes before and after laser irradiation on root canal surfaces.Results:Compared with the blank group,semiconductor laser irradiation can effectively remove the smear layer of dentin,dentinal tubules.Group C is beat in results.Comparing with group B,C,group D,E have visible cracks on root surface.During laser exposure,temperature changes of group B,C,D were lower than threshold of 10 °C,which will bring damage to teeth root and surrounding tissues.However,the temperature change of group E is above this threshold.Conclusions: Routine root canal preparation combined with semiconductor laser irradiation under 1 w and 20 s can get a good root canal wall without damaging the root morphology and surrounding tissues.