The effect of adhesive systems on the pullout strength of a fiberglass-reinforced composite post system in bovine teeth.
OBJECTIVE
To evaluate the pullout strength of a glass fiber-reinforced composite post (glass FRC) cemented with three different adhesive systems and one resin cement. The null hypothesis was that pullout strengths yielded by the adhesive systems are similar.


METHODS
Thirty bovine teeth were selected. The size of the specimens was standardized at 16 mm by sectioning off the coronal portion and part of the root. The specimens were divided into three groups, according to the adhesive system, which were applied following the manufacturers' instructions: G1, ScotchBond Multi-Purpose Plus; G2, Single Bond; G3, Tyrian SPE/One-Step Plus. The glass FRCs (Reforpost) were etched with 37% H3PO4 for 1 min and silanized (Porcelain Primer). Thereafter, they were cemented with the dual resin cement En-Force. The specimens were stored for 24 h, attached to an adapted device, and submitted to the pullout test in a universal testing machine (1 mm/min). The data were submitted to the one-way ANOVA and Tukey's test (alpha = 0.05).


RESULTS
G1 (30.2 +/- 5.8 Kgf) displayed the highest pullout strength (p < 0.001) when compared to G2 (18.6 +/- 5.8 Kgf) and G3 (14.3 +/- 5.8 Kgf), which were statistically similar. Analysis of the specimens revealed that all failures occurred between the adhesive system and the root dentin (pullout of the post cement), regardless of group.


CONCLUSIONS
The multiple-bottle, total-etch adhesive system provided higher pullout strength of the glass FRC when compared to the single-bottle, total-etch, and single-step self-etching adhesive systems. The null hypothesis was rejected (p < 0.001).
Valandro
Luiz Felipe
LF
Department of Restorative Dentistry, School of Dentistry, Federal University of Santa Maria, Santa Maria, Brazil. lfvalandro@smail.ufsm.br
Filho
Osvaldo Daniel Andreatta
OD
Valera
Márcia Carneiro
MC
de Araujo
Maria Amélia Maximo
MA
D000134:Acid Etching, Dental; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D003786:Dental Pulp Cavity / Q000648:ultrastructure; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D010756:Phosphoric Acids / Q000737:chemistry; D011176:Post and Core Technique / Q000295:instrumentation*; D019279:Resin Cements / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D013314:Stress, Mechanical
D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; C103503:EnForce-Sure Cure; D010756:Phosphoric Acids; D019279:Resin Cements; C425844:Scotchbond Multi-Purpose Plus; D012821:Silanes; C481138:Tyrian SPE; C009753:fiberglass; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate