Effect Of Multiple Factors On The Microleakage Test Of Constic Self-adhering Flowable Resin

Objectives:The aim of the study reported here was to provide a theoretical basis on the microleakage of Constic resin and 3MTM FiltekTM Supreme Ultra,DentsplyTM Spectrum TPH3 filling cervical cavity under occlusal cyclic loading,and the resins after filling different positions of the teeth surface.Methods:1 The first test: The microleakage test of different resins filling cervical cavity under occlusal cyclic loading.A total of 40 intact human premolars,extracted for orthodontic reasons were utilized in this research.Teeth were divided randomly into four groups(n=10).Cavity was prepared on the buccal surface of each tooth with half of the cavity above the cementoenamel junction(2mm)and the other half below it(2mm).All cavity preparations have the uniform dimensions mesiodistal width of 2 mm,and the depth of 2 mm.Group A Constic were filled directly.Group B Constic were filled after all-etching bonding system and Constic.Group C were filled after all-etching bonding system and 3MTM FiltekTM Supreme Ultra.Group D were filled after all-etching bonding system and DentsplyTM Spectrum TPH3.Each tooth was inserted into self-curing resin mold,with the long axis perpendicular to the acrylic resin base,and then were placed on the testing machine to perform occlusal cyclic loading.After storage of the specimen in normal saline for 24 hours,the specimen were performed by thermal cycling machine.Sticky wax was used to seal the root apex of each tooth,after this,teeth were immersed in 50% silver nitrate solution for 24 hours in light-sealed container.Then each was immersed for 10 hours in photo-developing solution while being exposed to fluorescent light to allow the silver ions to transform into metallic silver.Longitudinal sectioning ofteeth buccolingually was performed through the restoration center to be subjected to electron microscopy analysis.Evaluation criteria:0= No silver ion infiltration between interface of filling body and tooth tissue;Grade 1,Silver ion infiltration is less than or equal to the half of depth;Grade 2,Silver ion infiltration is higher than the half of depth;Grade 3,Silver ion infiltration arrive at the bottom of the cavity and even more than the bottom of the cavity.Statistical analysis:Microleakage values were statistically analyzed by Kruskal-Wallis H test and LSD at 5% confidence level.2 The second test:The microleakage test of the resins after filling different positions of the teeth surface.A total of 120 intact,non-carious human molars,extracted for impacted reasons,were utilized in this research.Teeth were divided randomly into three groups(n=40).Cavity preparation was performed on the occlusal surface of each tooth(All cavity preparations to have uniform dimensions of 4 mm Buccolingual width and 2 mm mesiodistal width,the depth was set at 1.5mm).(1)Teeth were performed on the enamel.(2)Teeth were performed on the dentin.(3)Teeth were performed on the EDJ(enamel-dentinal junction).Each group was further subdivided into four equal subgroups(n=10):(group A)Constic,(group B)Constic+adhesive,(group C)3MTM FiltekTM Supreme Ultra,(group D)DentsplyTM Spectrum TPH3.Group A were filled directly,Group B,Group C,Group D were filled after all-etching bonding system and resin.Similar to the first study after thermal cycling test,SEM was used to observe the microleakage of each sample.SPSS was used for statistical analysis:Microleakage values were statistically analyzed by Kruskal-Wallis H test and LSD at 5% confidence level.Results:1 The first test: The microleakage value of four groups have significant difference detected by Kruskal-Wallis H test(P<0.05).While the LSD test found that the microleakage value of Group A,Group C,and Group D have no significant difference(P>0.05),but significantly higher than Group B(P<0.05).2 The second test: The Kruskal-Wallis H test shown that the microleakage value of different positions of teeth surface filled with Group A,Group B and Group C have statistically difference(P<0.05),and no significant difference in filled with Group D(P>0.05).The microleakage value of group 1 and group 3 after filling different resins have statistical difference(P<0.05),and Group 2 have no statistical difference(P>0.05).Multiple-comparisons of the microleakage value used LSD test indicate that the microleakage value of the same resin after filling different positions of the teeth surface: group 1 and group 2,group 3 have statistically difference(P<0.05),group 2 and group 3 have no statistical difference(P>0.05).The microleakage value of the different resins filling in the same position: Group B and group A group C group D,group C and group D have statistical difference in enamel(P<0.05),group A and group C group D have no statistical difference(P>0.05);Group B and group A group D have statistical difference(P<0.05),group C and group B group D,group A and group D have no statistical difference(P>0.05).Conclusions:The microleakage condition of Constic was similar to Filtek TM Supreme Ultra and Spectrum TPH3.The self-adhesive flowable resin performs conveniently.The Constic combines with adhesive could have better clinical effect.