Bond degradation behavior of self-adhesive cement and conventional resin cements bonded to silanized ceramic

Self-adhesive resin cement with the characteristics of glass ionomer cement is more susceptible to water than conventional resin cements. It is unknown if there is a higher risk of bond degradation at the interface with silanized ceramic in an oral environment.

The purpose of this study was to evaluate the bond degradation behavior of self-adhesive cement under simulated oral conditions, by comparing it with the behavior of 3 conventional resin cements.

Three conventional resin cements, Linkamx HV (LMHV), Clearfil Esthetic Cement (CEC), and SuperBond (SB), were bonded to silanized ceramic (ProCAD) with the manufacturer's recommended silane coupler (GC Ceramic Primer (GCCP), Clearfil Ceramic Primer (CCP), and Porcelain Liner M (PLM), respectively), while a self-adhesive cement (G-CEM) was bonded with each of the 3 silane couplers. Maximum water sorption and solubility of the resin cements were measured according to the ISO 4049 standard during 6 weeks of water storage. The microshear bond strength of each silane/cement group (n=10 per thermal cycling subgroup) was tested after 0, 10,000, and 30,000 thermal cycles (TC), and bond failure types were counted. One- and two-way ANOVAs and the Tukey multiple comparisons test (α=.05) were used to evaluate the bond strength data.

G-CEM had significantly higher water sorption (P<.001) and solubility than conventional resin cements. Statistical analysis showed that the bond strength of all silane/cement groups was reduced significantly by thermal cycling (P=.01 for CCP/G-CEM, P=.003 for GCCP/LMHV, P<.001 for other groups). The bond strength of G-CEM with the 3 silane couplers was significantly degraded from TC 0 to 10,000 (P<.001 for GCCP/G-CEM and PLM/G-CEM, P=.01 for CCP/G-CEM); however, the bond strength appeared to stabilize with no significant degradation from TC 10,000 to 30,000. This behavior was different from that of conventional resin cements, which demonstrated bond degradation throughout TC 0-30,000. After TC 30,000, the bond strength of G-CEM did not differ significantly from that of the 3 conventional resin cements.

The bond degradation behavior of G-CEM under thermal cycling conditions differs from that of conventional resin cements.