title: Edge-bevel fracture resistance of three direct-filling materials.
abstract: Edge strength is defined in this study as the resistance to fracture of the beveled extension normally located at the cavosurface margin of a dental restoration. The edge strength of direct-filling alloy restorations plays an important role in maintaining the integrity of margins at tooth-alloy interfaces during functional loading. The purpose of this study was to determine the relative strength of an experimental consolidated silver material in comparison to other direct filling materials. The method used was designed as a simulation for relative edge-strength clinical properties. Stainless steel dies were formed from disks 5 mm thick, each with a centered hole tapered (1/48) toward the bottom side of the disk. A 41 degrees bevel, 0.5 mm wide as viewed from above, was placed on the top-side of the disk. Dispersalloy (D) or Unison (U) amalgam, Z-100 composite (C), hand-consolidated silver powder (HAg), or pneumatically consolidated silver powder (PAg) was used to fill the die opening. Excess was polished from both sides of the disk with 600-grit abrasive paper. The sample was loaded from the beveled side with a 3 mm-in-diameter flat-ended plunger at a rate of 1.0 mm/minute until failure. Failure load and total energy to failure were recorded and compared. Tukey's multiple comparison test (p < 0.05) ranked the materials (U) > (HAg) > (D) > (PAg) > (C) for fracture strength and (HAg) > (D) > (U) > (PAg) > (C) for fracture energy.
authors.affiliation: American Dental Association Health Foundation, Paffenbarger Research Center, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Hoard
authors.forename: F C
authors.initials: FC
authors.lastname: Eichmiller
authors.forename: E E
authors.initials: EE
authors.lastname: Parry
authors.forename: A A
authors.initials: AA
authors.lastname: Giuseppetti
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry*; D003737:Dental Cavity Preparation; D003775:Dental Polishing; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D012822:Silicon Dioxide; D012834:Silver / Q000737:chemistry*; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D015040:Zirconium
chemical_list: D003188:Composite Resins; D003722:Dental Alloys; C083568:Z100 composite resin; C033470:Dispersalloy; D012834:Silver; D012822:Silicon Dioxide; D003723:Dental Amalgam; D015040:Zirconium