title: Laboratory simulation of Y-TZP all-ceramic crown clinical failures.
abstract: Clinically, zirconia-supported all-ceramic restorations are failing by veneer-chipping without exposing the zirconia interface. We hypothesized that mouth motion step-stress-accelerated fatigue testing of standardized dental crowns would permit this previously unrecognized failure mode to be investigated. Using CAD software, we imported the average dimensions of a mandibular first molar crown and modeled tooth preparation. The CAD-based tooth preparation was rapid-prototyped as a die for fabrication of zirconia core porcelain-veneered crowns. Crowns were bonded to aged composite reproductions of the preparation and aged 14 days in water. Crowns were single-cycle-loaded to failure or mouth-motion step-stress- fatigue-tested. Finite element analysis indicated high stress levels below the load and at margins, in agreement with only single-cycle fracture origins. As hypothesized, the mouth motion sliding contact fatigue resulted in veneer chipping, reproducing clinical findings allowing for investigations into the underlying causes of such failures.
authors.affiliation: Department of Biomaterials and Biomimetics, New York University College of Dentistry, 345 24th St. 804s, New York, NY 10010, USA. pgcoelho@nyu.edu
authors.forename: P G
authors.initials: PG
authors.lastname: Coelho
authors.forename: E A
authors.initials: EA
authors.lastname: Bonfante
authors.forename: N R F
authors.initials: NR
authors.lastname: Silva
authors.forename: E D
authors.initials: ED
authors.lastname: Rekow
authors.forename: V P
authors.initials: VP
authors.lastname: Thompson
mesh_terms: D003198:Computer Simulation; D003442:Crowns; D003776:Dental Porcelain; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D008334:Mandible; D008963:Molar
chemical_list: D003776:Dental Porcelain