title: Influence of cement thickness and mechanical cycling on the push-out bond strength between posts and root dentin.
abstract: The aim of this study was to assess the influence of mechanical cycling and cement thickness on the bond strength between fiber posts and root dentin. Forty bovine teeth were sectioned (16 mm) and randomly assigned to four groups (n = 10). Specimens in Groups 1 and 2 were cemented using a thinner cement layer, while specimens in Groups 3 and 4 were cemented using a thicker cement layer. Groups 2 and 4 were submitted to mechanical cycling. Four slices per specimen were produced and submitted to push-out testing. Bond strength values were not affected by mechanical cycling (P = 0.2893), although the thickness of the cement layer did affect bond strengths (P = 0.0059, thinner > thicker). Tukey's test showed that Group 1 (19.27 MPa) had a higher mean bond strength value than Group 3 (12.4 MPa) and Group 4 (13.6 MPa), while Group 2 (15.0 MPa) was statistically similar to all groups. These results indicate that a thicker cement layer negatively affected the push-out bond strength between a fiber post and root dentin, regardless of whether the specimens were subjected to mechanical cycling.
authors: Oral Science, School of Dentistry, Federal University of Santa Maria, Rio Grande do Sul, RG, Brazil.
authors: Ricardo Abreu
authors: RA
authors: da Rosa
authors: Cesar Dalmolin
authors: CD
authors: Bergoli
authors: Osvaldo Bazzan
authors: OB
authors: Kaizer
authors: Luiz Felipe
authors: LF
authors: Valandro
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000268:Adhesiveness; D000818:Animals; D002417:Cattle; D001840:Dental Bonding; D003786:Dental Pulp Cavity / Q000648:ultrastructure*; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D011176:Post and Core Technique / Q000295:instrumentation*; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry; D018915:Root Canal Preparation / Q000379:methods; D012821:Silanes / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D017220:Dentin-Bonding Agents; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; D012821:Silanes; D014867:Water; C070079:Prosil 28