Effect Of Carbonated Beverage Of Cola On Adhesive Strength Of ZrO₂ Restorations And Tooth

Objectives To ivestigate the effects of cola carbonated drinks on the adhesive strength of three kinds of adhesives?3M Rely X luting,3M ESPE Rely X Veneer,PULPDENT Embrace?with bonded zirconia restorations and natural teeth in order to provide the experimental basis for selecting the ideal cement for zirconia prosthesis.Methods According to the collection standard of tooth,select 45 recently-removed maxillary first premolars?Patients sign the informed consent paper?for saline preservation.By Carborundum needle,the buccal surface of each extracted tooth was prepared into a plane with an area of 3mm * 3mm,thickness of 0.8-1mm.The exposed surface is enamel layer.Polished into smoothness with sandpaper,these 45 isolated teeth were randomly divided into 9 groups without any difference on the roughness of the polished teeth according to the roughness meter.Select zirconium in the same texture,cut and polish and sinter,use Vernier caliper to accurately select 45 zirconia porcelain blocks with unified specification of 3mm × 3mm × 3mm.Randomly divide them into 9 groups.No difference on roughness of each ceramic block can be detected by the roughness meter.Then randomly pair these isolated teeth and zirconia blocks into three groups with 15 per group.Group A: Luting Group,Group B: 3M Veneer Group,Group C: PULPDENT Group.Teeth in Group A,B,C are cemented with zirconia zirconium blocks by 3M Rely X luting,3M ESPE Rely X Veneer,PULPDENT Embrace respectively.The fifteen specimens in each group were then randomly divided into three groups?n = 5?.5-minutes group: A1,B1,C1;24-hours group: A2,B2,C2;control group: A3,B3,C3.4 minutes after curing,all the specimens were immersed in normal saline.After curing for 5 minutes,A1,B1 and C1 group were removed from normal saline,and then soaked in Coca-Cola for 5 minutes every time,2 times a day with intervals of 12 hours.After curing for 24 hours,A2,B2 and C2 group were removed from normal saline,and then soaked in Coca-Cola,for 5 minutes every time,2 times a day with intervals of 12 hours.The remaining A3,B3,C3 group were kept in saline.All the samples,when not soaked in Coca-Cola,were immersed in physiological saline with 37 ? constant temperature water bath.The saline for all the samples was renewed every day and Coca-Cola abandoned after replacement.This procedure continues for three months in succession.All the specimens were tested after three months: 1 Test for shear strength: use electronic universal testing machine to test the shear strength of the samples.The data were analyzed by statistical software SPSS17.0.Set P <0.05 as the indication of statistical distinction.All the data were expressed as mean ± standard deviation.2 Bonding surface observation: After the shear test,the fracture surface occurred between the zirconium block and the cement.The fracture surface was observed by electron microscopy,and the effect of Cola on bonding interface was thus analyzed.Results 1 The test results of shear strength: 1)Intragroup comparison of cohesive strength,Group A: 5 minutes group <24 hours group <control group?P <0.05?,Group B: no difference between 5 minutes group and 24 hours group,lower than the control group;Group C: 5 minutes group <control group,no difference between 24 hours group and the control group.2)Intergroup comparison of bond strength,the results of 5-minute group,24-hour group were: group A was lower than Group B and C?P<0.05?;there was no significant difference between group B and C?P>0.05?;2 Results of scanning electron microscope observation: Through the electron microscope observation,all three different kinds of adhesives in Coca-Cola soak have different degrees of dissolution fracture.Groupof 3M Rely X Luting: dense and obvious fracture texture can be seen on the bonding surface of Group A1;The adhesion of group A2 was also obvious,but the cracks were less than A1;for group A3,although there are cracks as well,the cracks per unit area are relatively less.Group of 3M ESPE Rely X Veneer: In group B1 and group B2,there were tiny cracks,and the bonding surface of B3 group was smooth and flat..Group of PULPDENT Embrace: obvious fracture in Group C1,small cracks on the ashesive surface of Group C2,and no obvious signs of fracture in Group C3.Conclusions 1 Cola type carbonated beverage can obviously reduce the adhesive strength of 3M Rely X luting and Zr O₂.However,the influence on the bond strength of 3M Rely X Veneer and PULPDENT Embrace is relatively small.2 The influence of cola type carbonated drinks on the bond strength of Rely 3M X luting and zirconium dioxide tends to decline with the increase of curing time.3 The effect of cola carbonated beverage on the bond strength of 3M ESPE Rely X Veneer and zirconia was not closely related to the curing time.4 PULPDENT Embrace is less affected by cola carbonated drinks after 24 hours of curing.