Use of Contact Testing in the Characterization and Design of All-Ceramic Crownlike Layer Structures: A Review
Brian R. Lawn, Y N. Deng, Victoria Thompson
Ceramic-based crowns, particularly molar crowns, can fail prematurely from accumulation of fracture and other damage in continual occlusal contact. Damage modes depend on cemamic types (especially microstructures), flaw states, loading conditions, and geometric factors. These damage modes can be simulated and characterized in the laboratory with the use of Hertzian contact testing on monolayer, bilayer, and trilayer structures to represent important aspects of crown response in oral function. This article reviews the current dental materials knowledge base of clinically relevant contact-induced damage I ceramic-based layer structures in the context of all-ceramic crown lifetimes. It is proposed that simple contact testing protocols that make use of sphere indenters on model flat, ceramic-based layer structures - ceramic/polymer bilayers (simulating monolithic ceramic crowns on dentin) can provide useful relations for predicting critical occlusal loads to induce lifetime-threatening fracture. It is demonstrated that radial racking from the lower core layer surface is the dominant failure mode for ceramic layer thicknesses much below 1 mm. Such an approach may be used to establish a scientific, materials-based foundation for desinging next-generation crown layer structures.
, Deng, Y.
and Thompson, V.
Use of Contact Testing in the Characterization and Design of All-Ceramic Crownlike Layer Structures: A Review, Journal of Prosthetic Dentistry
(Accessed September 29, 2023)