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Purpose: New luting agents, described as resin-modified glass-ionomer cements and
compomers, have been developed during the last decade to improve the retention of
cemented restorations. The aims of this study were to (1) compare the push-out strength of
these new luting materials against both conventional cements and bonding luting agents,
and (2) evaluate the influence of dentin surface treatment on both glass-ionomer cement
and 4-META adhesive resin push-out strength. Materials and Methods: Conical
standardized cavities were drilled in the center of coronal dentin disks. Ninety sandblasted
Ni-Cr inlays, divided into nine batches, were luted into the cavities according to the
surface treatment and the nature of the following luting agents: zinc phosphate cement,
zinc polycarboxylate cement, type I glass-ionomer +/- polyacrylic acid, resin-modified
glass-ionomer, polyacid-modified composite resin, filled bis-GMA phosphate ester resin,
and 4-META adhesive resin +/- application of activated monomer. Each specimen was
placed in a holding device, and a steel rod was used to apply a force on the inlay until
rupture occurred. The push-out strength was calculated, and the failure mode was
controlled. Results: There were significant differences between some of the groups. The
highest push-out strength was achieved by the 4-META adhesive resin after application of
activated monomer. The lowest value was attained with zinc phosphate and polycarboxylate
cements. Conclusion: Both resin-modified glass-ionomer and polyacid-modified
composite resin luting materials exhibited a push-out strength similar to resin-based
materials. Specific dentin surface treatments significantly enhanced the push-out strengths
of glass-ionomer cement and 4-META adhesive resin. Int J Prosthodont 2002;15:365–370.
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