Effect of two microshear test devices on bond strength and fracture pattern in primary teeth.
This in vitro study evaluated the influence of two devices for application of shear load in microshear tests on bond strength and fracture pattern of primary enamel and dentin. Eighty primary molars were selected and flat enamel (40 teeth sectioned mesio-distally) and dentin (40 teeth sectioned transversally) surfaces were obtained. Both surfaces were polished to standardize the smear layer. Two-step etch-and-rinse adhesive systems (Adper Single Bond and XP Bond) were used. Polyethylene tubes was placed over the bonded surfaces and filled with composite resin. The microshear testing was performed after storage in water (24 h/37 °C) using two devices for application of microshear loads: a notched rod (Bisco Shear Bond Tester) or a knife edge (Kratos Industrial Equipment). Failure modes were evaluated using a stereomicroscope. Bond strength data were subjected to ANOVA and chi-square test to compare the failure mode distributions (α=0.05). No significant differences were observed between the groups for dentin and enamel bond strength or fracture patterns (p>0.05). The predominant failure mode was adhesive/mixed. In conclusion, the devices for application of shear loads did not influence the bond strength values, regardless of adhesive system and substrate.
Department of Stomatology, UFSM - Federal University of Santa Maria, Santa MariaRS, Brazil.
Tamara Kerber
TK
Tedesco
Department of Biomaterials and Oral Biology, USP - University of São Paulo, São PauloSP, Brazil.
Eugenio Jose
EJ
Garcia
Department of Restorative Dentistry, UFSM - Federal University of Santa Maria, Santa MariaRS, Brazil.
Fabio Zovico Maxnuck
FZ
Soares
Department of Stomatology, UFSM - Federal University of Santa Maria, Santa MariaRS, Brazil.
Rachel de Oliveira
Rde O
Rocha
Department of Biomaterials and Oral Biology, USP - University of São Paulo, São PauloSP, Brazil.
Rosa Helena Miranda
RH
Grande
D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D003799:Dental Stress Analysis / Q000295:instrumentation*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D008963:Molar; D033081:Shear Strength; D014094:Tooth, Deciduous
C554641:Adper single bond 2; D003738:Dental Cements; D017220:Dentin-Bonding Agents; C532387:XP-Bond