In vitro push-out strength of seven luting agents to dentin.
OBJECTIVE
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.


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 1 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.


CONCLUSIONS
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.
Cheylan
Jean-Marie
JM
Department of Prosthodontics, Faculty of Dental Surgery, University of Paris V, 1 Rue Maurice Arnoux, F-92120 Montrogue, France.
Gonthier
Samuel
S
Degrange
Michel
M
D000134:Acid Etching, Dental; D000180:Acrylic Resins; D001896:Boron Compounds; D002858:Chromium Alloys; D020770:Compomers; D001840:Dental Bonding; D003799:Dental Stress Analysis; D003804:Dentin; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D006801:Humans; D007284:Inlays; D008422:Materials Testing; D008963:Molar; D011076:Polycarboxylate Cement; D019279:Resin Cements; D013499:Surface Properties; D015036:Zinc Phosphate Cement
D000180:Acrylic Resins; D001896:Boron Compounds; D002858:Chromium Alloys; D020770:Compomers; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D011076:Polycarboxylate Cement; D019279:Resin Cements; C009523:tri-n-butylborane; D015036:Zinc Phosphate Cement; C031172:4-META resin