Study On Microleakage Of Pit And Fissure Sealant With Different Toothsurface Procedures

Objective:Aiming to find a reasonable,simple,better methods for pit and fissure on clinic.Methods:Forty deep groove, non-caries extracted human premolars were randomly divided into five groups.A group:CST+acid etching; B group:laser; C group:laser+acid etching; D group:round bur+acid etching; E group:diamond bur+acid etching.pit and fissure sealant, thermocycling five hundred times.6 teeth in each group were stained with methylene blue, and then were sectioned for the evaluation of microleakage by stereomicroscope. The remaining 2 teeth in each group were used for the observation of marginal adaptability of fissure sealants with tooth interface by SEM.Results:Evaluation of microleakage by stereomicroscope:There was significant difference between these groups by using Kruskal-Wallis H test to evaluation the score of five groups, P< 0.05;The microleakage of A group were the most serious, D group was the least;There was significant difference between B and D group, D and E group, C and D group, C and E group (P<0.05);There was no significant difference between B and C group, (P>0.05),the microleakage of them was almost the same.Under the SEM: Marginal seal was the worst obviously observed by SEM, pit and fissure sealant cannot access the deep groove; There was narrow crack on the marginal in B group; There was almost no crack on the marginal in C group; The marginal seal of D and E group was the best without crack,D group was better among them.Conclusion:The marginal seal and microleakage of A group were both the most serious; The laser group was obviously better then CST group,but round bur group was the best;The laser can instead CST to be the toothsurface procedure before pit and fissure on clinical without acid etching.