Microtensile bond strength of tooth-colored materials to primary tooth dentin.
OBJECTIVE
This study measured the microtensile bond strengths of 2 tooth-colored restorative materials with and without conditioning of primary teeth dentin, and examined the micromorphology of the debonded surfaces and material-dentin interfaces.


METHODS
Cylindrical specimens of packable composite resin (PCR) and resin-modified glass ionomer cement (RMGIC) bonded to dentin of primary teeth were ground to an hourglass shape and tested for microtensile bond strength. The debonded surfaces and material-dentin interfaces were prepared and examined under a scanning electron microscope (SEM).


RESULTS
The microtensile bond strength values (mean +/- SD, in MPa) of PCR (Filtek P60 with Single Bond) and RMGIC (Fuji II LC), with or without the application of Cavity Conditioner (14.8 +/- 5.36, 12.01 +/- 4.43, 11.94 +/- 4.60, respectively), did not differ significantly (P > .05). Partial adhesive and partial cohesive failures within the restorative material predominated. The distributions of failure modes did not differ significantly between groups (P > .05). Under SEM, each material was seen to be closely adapted to dentin. Dentinal tubules were enlarged with etching, and the depth of penetration of resin tags of PCR was greater than for RMGIC. Smear plugs were incompletely removed by cavity conditioning.


CONCLUSIONS
The bond strength of the PCR, Filtek P60 with Single Bond, to dentin of primary teeth was comparable to that of the RMGIC, Fuji II LC. Conditioning of the cavity preparation with Cavity Conditioner did not improve the bond strength of Fuji II LC. The distribution of failure modes did not differ between materials.
Suwatviroj
Preenan
P
University of Melbourne, Victoria, Australia.
Messer
Louise B
LB
Palamara
Joseph E A
JE
D000134:Acid Etching, Dental; D000180:Acrylic Resins / Q000737:chemistry; D000268:Adhesiveness; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000379:methods; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry*; D012117:Resins, Synthetic / Q000737:chemistry; D016369:Smear Layer; D013499:Surface Properties; D013718:Tensile Strength; D014094:Tooth, Deciduous / Q000648:ultrastructure*
D000180:Acrylic Resins; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C438835:Filtek P60 Composite Resin; C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D019279:Resin Cements; D012117:Resins, Synthetic; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; C006903:carbopol 940