Study On The Sealing Effect Of Two Different Laser Irradiation Times On Dentinal Tubules

Objective: To study the effect of Er: YAG and Nd: YAG laser irradiation time on the sealing effect of dentinal tubules.Methods: A dentin sensitive model of 14 isolated teeth was made and divided into group A(Er: YAG irradiation group)and group B(Nd: YAG laser irradiation group),and each model was divided into four areas,respectively.Aa(blank control),Ab(Er: YAG laser irradiation 2 times),Ac(Er: YAG laser irradiation 4 times),Ad(Er: YAG laser irradiation 6 times),Ba(blank control),Bb(Nd: YAG laser irradiation 2 times),Bc(Nd: YAG laser irradiation 4 times),Bd(Nd: YAG laser irradiation 6 times).The sealing effect of the dentinal tubules of each group was observed by scanning electron microscopy(SEM).Results: The results of SEM observation showed that the percentage of exposed area of dentinal tubules decreased gradually with the increase of irradiation time of Er: YAG laser,and it was statistically different from the control group(P<0.05).However,when it reached 6 times,it was exposed.The rate increased,but it was statistically different from the control group(P<0.05).When irradiated with Nd: YAG laser,the exposed area of dentinal tubules gradually decreased with the prolongation of irradiation time,2 times and 4 times.There was no significant difference in the percentage of exposure to dentinal tubules in the control group.When the number of irradiations reached 6 times,the number of dentinal tubules in the image on the surface of the SEM scan model decreased significantly,and the exposed area decreased significantly.The percentage of exposed area of dentinal tubules was reduced.There was a statistical difference compared to the blank control group.Conclusion: 1.When using Er: YAG laser for dentinal tubule sealing,it is necessary to control the time of laser irradiation.After the laser irradiation number is increased from 4 times to 6 times,the exposed area of dentinal tubules is increased.2.When Nd: YAG is used to seal the dentinal tubules,the area to be desensitized should be at least uniformly illuminated at least 6 times to ensure its sealing effect on the dentinal tubules.