PURPOSE: (1) To determine the microtensile bond strength (µTBS) of self-adhesive (SA) composite cements to unetched/etched enamel and dentin, and (2) to characterize the cements' interaction with tooth tissue. METHODS: 51 composite blocks were bonded to smear layer-covered enamel and dentin (three teeth per group). Four SA composite cements (Clearfil SA, G-CEM, RelyX Unicem, SmartCem2), and three multi-step composite cements, two used following an etch-and-rinse (E&R) approach (RelyX ARC, Variolink II 'E&R') and one used following a self-etch (SE) approach (Variolink II ' SE') were investigated. The cement-tooth specimens were perpendicularly sectioned into micro-specimens (1.0 × 1.0 mm) in order to measure the µTBS. The data were statistically analyzed by ANOVA followed by Tukey HSD (P< 0.05). 24 additional specimens (four teeth per group) were prepared for interfacial characterization using SEM. RESULTS: The tested SA cements bonded equally well to enamel and dentin. Etching of enamel improved their bonding effectiveness, which however remained inferior to that of both E&R cements. SEM revealed a very similar interfacial ultrastructure at smear layer-covered enamel and dentin for the SA cements, exhibiting very superficial interaction at enamel and absence of a clearly detectable hybrid layer and resin tags in the dentin tubules. When the SA composite cements were applied to dentin free of a smear layer, regular and long resin tags were formed. CLINICAL SIGNIFICANCE: No significant differences in bonding effectiveness were recorded for the self-adhesive composite cements when bonded to unetched/etched enamel and to dentin. Multi-step etch-and-rinse composite cements showed a better bonding effectiveness to enamel, although this could be approximated by the self-adhesive composite cements when enamel was acid-etched beforehand. On dentin, however, the bond strength of the etch-and-rinse composite cement RelyX ARC was superior.
PURPOSE: (1) To determine the microtensile bond strength (µTBS) of self-adhesive (SA) composite cements to unetched/etched enamel and dentin, and (2) to characterize the cements' interaction with tooth tissue. METHODS: 51 composite blocks were bonded to smear layer-covered enamel and dentin (three teeth per group). Four SA composite cements (Clearfil SA, G-CEM, RelyX Unicem, SmartCem2), and three multi-step composite cements, two used following an etch-and-rinse (E&R) approach (RelyX ARC, Variolink II 'E&R') and one used following a self-etch (SE) approach (Variolink II ' SE') were investigated. The cement-tooth specimens were perpendicularly sectioned into micro-specimens (1.0 × 1.0 mm) in order to measure the µTBS. The data were statistically analyzed by ANOVA followed by Tukey HSD (P< 0.05). 24 additional specimens (four teeth per group) were prepared for interfacial characterization using SEM. RESULTS: The tested SA cements bonded equally well to enamel and dentin. Etching of enamel improved their bonding effectiveness, which however remained inferior to that of both E&R cements. SEM revealed a very similar interfacial ultrastructure at smear layer-covered enamel and dentin for the SA cements, exhibiting very superficial interaction at enamel and absence of a clearly detectable hybrid layer and resin tags in the dentin tubules. When the SA composite cements were applied to dentin free of a smear layer, regular and long resin tags were formed. CLINICAL SIGNIFICANCE: No significant differences in bonding effectiveness were recorded for the self-adhesive composite cements when bonded to unetched/etched enamel and to dentin. Multi-step etch-and-rinse composite cements showed a better bonding effectiveness to enamel, although this could be approximated by the self-adhesive composite cements when enamel was acid-etched beforehand. On dentin, however, the bond strength of the etch-and-rinse composite cement RelyX ARC was superior.
Authors: P V Seredin; O A Uspenskaya; D L Goloshchapov; I Yu Ippolitov; Jitraporn Pimm Vongsvivut; Yu A Ippolitov Journal: Sovrem Tekhnologii Med Date: 2020
Authors: Konstantin Johannes Scholz; Aleksandra Bittner; Fabian Cieplik; Karl-Anton Hiller; Gottfried Schmalz; Wolfgang Buchalla; Marianne Federlin Journal: Materials (Basel) Date: 2021-01-20 Impact factor: 3.623