title: Competition of fracture mechanisms in monolithic dental ceramics: flat model systems.
abstract: Monolithic (single layer) glass-ceramic restorations often fail from chipping and fracture. Using blunt indentation of a model flat porcelain-like brittle layer bonded onto a dentin-like polymer support system, a variety of fatigue fracture modes has been identified and analyzed: outer cone, inner cone, and median cracks developing in the near-contact region at the occlusal surface; radial cracks developing at the internal cementation surface along the loading axis. Our findings indicate that monolithic glass-ceramic layers are vulnerable to both occlusal surface damage and cementation internal surface fracture. Clinical issues in the longevity of ceramic restorations are discussed in relation to biting force, physical properties of ceramic crowns and luting cement, and thicknesses of ceramic and cement layers.
authors.affiliation: Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, New York 10010, USA. yz21@nyu.edu
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jae-Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Sanjit
authors.initials: S
authors.lastname: Bhowmick
authors.forename: Van P
authors.initials: VP
authors.lastname: Thompson
authors.forename: E Dianne
authors.initials: ED
authors.lastname: Rekow
mesh_terms: D003776:Dental Porcelain; D008954:Models, Biological; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D003776:Dental Porcelain