Theinvestigationon Antibacterial Effects Of Nd:YAG Laser On The Porphyromonas Gingivalis And Fusobacterium Nucleatum

Periodontitis is an inflammatory disease in periodontal tissues caused by dental plaque biofilms.Plaque control plays an important part in periodontal treatment.Some researchers had found that laser associated therapy have the antibacterial effects.Nd:YAG laser is one of this kind of laser that is easily absorbed by pigment tissue and exerts antibacterial effects.Objective:To investigate the antibacterial effectsof Nd: YAG laser against Porphyromonas gingivalis(P.gingivalis)and Fusobacterium nucleatum(F.nucleatum)in vitro.Methods:The Nd: YAG lasr machine was set at 6w and no air or water for cooling.The laser effects on the biofilm formation ability of planktonic P.gingivalis and F.nucleatumwere ovserved by Crystal violet test;Confocal laser scanning microscopy(CLSM)was used to detect the effects of Nd: YAG laser on the viability of mature biofilms;Scanning electron microscopy(SEM)was performed to investigate the effects of Nd: YAG laser on the morphology of mature bioflms.Results:The crystal violet test showed that the biofilm formation ability of P.gingivalis was limited under35 sec radiation.And after15 sec radiation the biofilm formation ability of F.nucleatum went down.The viability of P.gingivalis and F.nucleatum in mature biofilm went down under45 sce and 25 sec iradiation through the confocal laser scanning microscopy investigation.The deformation of mature biofilm and the deconstructi of becterium became distincted with the iradiation time raised.The major destructional form was evaporation.Conclusion:Nd:YAG laser shows the inhibition of biofilm formationability on planktonic P.gingivali and F.nucleatum.The vitality of P.gingivali and F.nucleatumin mature biofilm is depressed after laser radiation.Laser can destroy the of construction of the mature biofilm and bacteria.It promptes that the Nd:YAG lasar can be the assistant periodontitis therapy.