EFFECT OF DIFFERENT CLEANING AGENTS ON SHEAR BOND STRENGTH OF RESIN CEMENTS TO CONTAMINATED CERAMICS

Abstract

The objective of this study was to investigate the effect of different cleaning agents on shear bond strength of resin cements to saliva contaminated ceramics. Three hundred and sixty slabs of ceramic specimens (lithium disilicate ceramic and zirconia) were prepared. The round specimens of lithium disilicate ceramics with diameter of 15 mm and a thickness of 2 mm and the square specimens of zirconia with a width of 10 mm and a thickness of 1 mm were used in this study. The substrate surfaces were conditioned according to manufacturer’s instructions. Specimens of each ceramic were randomly divided into six groups (n=10). The first group was control group. The others were contaminated with saliva and then cleaned using five cleaning conditions. They were deionized water, 37% phosphoric acid, 5% hydrofluoric acid, Ivoclean and 30% sodium silicate solution. Resin composite block (Clearfil DC core automix) was bonded to ceramic using resin cements ( RelyX U200, Panavia F2.0, Superbond C&B ). The specimens were stored in 37 degree celsius distilled water for 24 hours. The shear bond strength tested was performed using a universal testing machine with a cross head speed of 0.5 mm/min. For RelyX U200 group, saliva contaminated lithium disilicate ceramics cleaning with Ivoclean or 30% sodium silicate solution provided statistically significant higher shear bond strengths (24.10 MPa / 24.40 MPa) respectively than the other methods (p< 0.05). Panavia F2.0 group and Superbond C&B groups, saliva contaminated lithium disilicate ceramics cleaning with Ivoclean, 30% sodium silicate solution or 5% hydrofluoric acid provided statistically significant higher shear bond strengths (11.96MPa/ 10.76MPa/ 10.08MPa and 27.41MPa/ 28.72MPa/ 27.98MPa ) respectively than the other methods (p< 0.05). RelyX U200 and Panavia F2.0 groups, saliva contaminated zirconia cleaning with Ivoclean or 30% sodium silicate solution provided statistically significant higher shear bond strengths (10.71 MPa / 9.24 MPa and 10.55 MPa / 10.06 MPa ) respectively than the other methods (p< 0.05). Superbond C&B, saliva contaminated zirconia cleaning with Ivoclean provided statistically significant higher shear bond strengths (20.12 MPa ) than the other methods (p< 0.05). The results suggest that Ivoclean and 30% sodium silicate solution were more effective in decontaminating the saliva from lithium disilicate ceramic than the other methods for all resin cements. Ivoclean was the most effective in decontaminating the saliva from zirconia than the other methods for all resin cements.