Effects Of Different Cleaning Methods On The Shear Bond Strength Of Saliva-contaminated Zirconia Ceramics

Objective:The purpose of this study was to evaluate the influence of different cleaning methods on the shear bond strength between zirconia and resin after saliva contamination,so as to provide reference for clinical bonding operation.Methods:Cut the zirconia ceramic block,and then use 200-,400-,600-grit silicon carbide sandpaper to grind,ultrasonically clean with distilled water for 10 min,blow dry,after sintering,obtain 80 ceramic blocks of 12 mm × 10 mm × 4 mm,and Randomly divided into 8 groups(n=20),Group A(control group): air abrasion,coating Z-Prime Plus primer;Group B: air abrasion,saliva contamination,water rinse,coating Z-Prime Plus primer;Group C: air abrasion,saliva contamination,air abrasion again,coating Z-Prime Plus primer;Group D: air abrasion,saliva contamination,Zir-clean cleaning,coating Z-Prime Plus primer;Group E: air abrasion,saliva contamination,1.0 wt% sodium hypochlorite cleaning,coating Z-Prime Plus primer;Group F: air abrasion,coating Z-Prime Plus,saliva contamination,water rinse,coating Z-Prime Plus primer;Group G: saliva contamination,air abrasion,coating Z-Prime Plus primer;Group H: air abrasion,coating Z-Prime Plus primer,saliva contamination,water rinse.Duo-Link Universal resin cement was used to make the resin cylinders,and the prefabricated resin cylinders were bonded to the zirconia specimens through Duo-link Universal.The bonded specimens were allowed to stand at room temperature for 10 minutes.Each group of specimens was stored in distilled water at 37 ° C for 24 hours.After storage,the shear bond strength of the bonded specimens was measured using a universal testing machine with a crosshead speed of 0.5 mm/min.Statistical analysis was performed by ANOVA and data were analyzed.Results:Results of shear bond strength: Group A(6.65±1.98)MPa> Group D(5.09±0.34)MPa> Group C(4.94±1.09)MPa> Group F(4.58±1.27)MPa> Group E(3.87±0.41)MPa> Group G(3.18±1.28)MPa> Group B(2.89±0.81)MPa> Group H(2.71±0.79)Mpa.The differences between group A and group B,group E,group G and group H were statistically significant(P < 0.05),while the differences between the other groups were not statistically significant(P > 0.05).Conclusions:Saliva contamination significantly reduces the shear bond strength between zirconia and resin.Airborne-particle abrasion and the use of cleaning agent Zir-clean can restore the shear bond strength between zirconia and resin to uncontaminated levels.Before saliva contamination,apply zirconia primer Z-Prime Plus on the zirconia bonding surface.Re-coating zirconia primer before bonding can restore the shear bond strength of zirconia to the uncontaminated level.