title: Effect of simulated resin-bonded fixed partial denture clinical conditions on resin cement mechanical properties.
abstract: The purpose of this study was to determine changes in flexural properties of resin cement under simulated resin-bonded fixed partial denture (RBFPD) clinical conditions using aqueous ageing and cyclic loading. Panavia F flexural modulus and strength were measured by static loading to failure after 48-h and 60-day aqueous ageing at 37 degrees C with and without simulated cyclic occlusal loading. Panavia F sorption and solubility were also measured. Scanning electron microscopy (SEM) was used to characterize the morphology of the fractured surfaces. A two-factor anova (P </= 0.05) indicated that cyclic loading produced a significant increase in the flexural modulus with no significant effect on the flexural strength. Conversely, aqueous ageing time produced a significant decrease in flexural strength with no effect on the flexural modulus. The SEM fracture analysis indicated that resin matrix fracture occurred in static-aqueous specimens; while in the aqueous-cycled specimens, resin matrix fracture occurred in addition to an increasing proportion of filler/resin interface fracture. Collectively, these outcomes suggest that initial degradation under simulated resin cement clinical function may be related to breakdown of the filler/resin interface bond, which could contribute to in vivo RBFPD resin cement cohesive failure.
authors.affiliation: Department of Restorative Dentistry (Prosthodontics & Biomaterials), University of Missouri-Kansas City, School of Dentistry, Kansas City, MO 64108, USA. walkermp@umkc.edu
authors.forename: M P
authors.initials: MP
authors.lastname: Walker
authors.forename: P
authors.initials: P
authors.lastname: Spencer
authors.forename: J D
authors.initials: JD
authors.lastname: Eick
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D016379:Denture, Partial, Fixed, Resin-Bonded; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements; D012995:Solubility; D014867:Water
chemical_list: D003188:Composite Resins; C438843:Panavia-Fluoro; D019279:Resin Cements; D014867:Water