Effect of primer solvent and curing mode on dentin shear bond strength and interface morphology.
There is a need to study the main and interactive bonding effects of differences in solvent and curing mode used for adhesive monomers in dentin bonding systems.


OBJECTIVE
Two solvents (acetone and ethanol) and curing methods (light cure, dual cure) were evaluated on their effects on bond strength and interfacial morphology.


METHODS
The adhesives studied were based on two monomers, pyromellitate of glyceryl dimethacrylate (PMGDM) and 2-hydroxy ethyl methacrylate (HEMA). Four groups of eight teeth each were cut to expose planar dentin sections and treated with (a) light-cure system with acetone as solvent (LCA group); (b) light-cure system with ethanol as solvent (LCE group); (c) dual-cure system with acetone as solvent (DCA group); and (d) dual-cure system with ethanol as solvent (DCE group). The treated sections were tested for shear bond strength to composite discs and interfacial morphology.


RESULTS
The mean (standard deviation) of shear bond strength values (MPa) for the different groups were: LCA: 11.8 (2.3); LCE: 12.7 (2.7); DCA: 24.9 (9.3); and DCE: 21.6 (9.6). All bonded sections were characterized by a similar hybrid layer, resin tags, and overall interfacial morphology.


CONCLUSIONS
There was a significant difference in shear bond strength as a function of cure mode, but not of solvent. The mean bond strength was higher for dual-cure systems studied. Oxygen inhibition effects may account for the difference between light-cure and dual-cure types.
Velazquez
Elisa
E
Department of Oral Biology, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103, USA.
Vaidyanathan
Jayalakshmi
J
Vaidyanathan
Tritala K
TK
Houpt
Milton
M
Shey
Zia
Z
Von Hagen
Stanley
S
D000096:Acetone / Q000737:chemistry; D000269:Adhesives / Q000737:chemistry; D000704:Analysis of Variance; D001565:Benzoates / Q000737:chemistry; D001840:Dental Bonding; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D006801:Humans; D008027:Light; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties
D000269:Adhesives; D001565:Benzoates; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; D012997:Solvents; D000096:Acetone; C080129:pyromellitic dianhydride glycerol dimethacrylate adduct; D000431:Ethanol; C005044:hydroxyethyl methacrylate