Objectives: To determine the immediate shear bond strength(SBS) of three resin cements to saliva-contaminated zirconia using five different cleaning methods.
Methods: Sixty sintered zirconia specimens (20mm x 20mm x 2mm) were embedded in acrylic resin . They were airblasted with 5µm Al2O3, 1-bar pressure (10s, 10mm). Ten samples were the control-group, and the rest of them were immersed in human–saliva for 10min. Specimens were divided into 5 groups(n=10), and were treated according to following procedures: 1)no treatment, 2)5s steam-cleaning, 3)30s H3PO4-application, 4)1min HF-application 5)10s water-syringe rinsing. SBS was tested 15min after bonding using Multilink Automix(MA), RelyX Unicem(RU), Maxcem Elite(ME) according to the manufacturer's directions. One-way ANOVA, and Student-Newman-Keuls tests were used for statistical analysis.
Results: ANOVA revealed statistically significant differences among the groups (P<0.001). The table shows SBS values. Groups connected by the same letters are not statistically different at 95% confidence level.
SBS(MPa)-Mean±SD | |||
Multilink-Automix | RelyX-Unicem | Maxcem-Elite | |
Control | 8.65±2.37(a) | 8.58±2.29(a) | 5.68±2.18(b,c,d) |
Saliva | 5.18±2.41(b,c,d,e) | 0.88±1.22(g) | 2.53±1.41(f,g) |
Water | 4.58±1.38(c,d,e,f) | 2.78±1.54(e,f,g) | 1.40±1.08(g) |
Steam | 6.33±1.89(b,c) | 2.19±1.56(f,g) | 4.48±1.37(c,d,e,f) |
H3PO4 | 7.27±4.45(a,b) | 2.71±1.60(e,f,g) | 3.34±1.05(d,e,f,g) |
HF | 5.87±1.09(b,c) | 2.76±1.46(e,f,g) | 2.29±1.76(f,g) |
Conclusion: All the tested cements were affected by saliva contamination of the zirconia surfaces, specially RU and ME. The overall effect of saliva contamination and cleaning methods is specific for each cement. Zirconia and MA samples were provided by Ivoclar Vivadent.