Contactslijtage in gerestaureerde monden

Slijtage van kroon- en brugwerk ontstaat door antagonistische contacten van harde weefsels onderling, van hard gebitsweefsel met restauratiemateriaal en van restauratiematerialen onderling. Uit een proefopstelling met kunstmatig verouderde kronen komt naar voren dat zirconiumkronen het minste invloed hebben op het glazuur van hun antagonisten.

Aging of dental zirconia roughens its surface through low temperature degradation. We hypothesized that age-related roughening of zirconia crowns may cause detrimental wear to enamel of an opposing tooth. To test our hypothesis, we subjected artificially aged zirconia and reference specimens to simulated mastication in a wear device and measured the wear of an opposing enamel cusp. Additionally, the roughness of the pretest surfaces was measured. The zirconia specimens, artificially aged by autoclave, showed no significant increase in roughness compared to the nonaged specimens. Furthermore, no significant difference in material or opposing enamel wear between the aged and nonaged zirconia was seen. All zirconia specimens showed less material and opposing enamel wear than the enamel to enamel control or veneering porcelain specimens. Scanning electron micrographs showed relatively smooth surfaces of aged and nonaged zirconia following wear testing. The micrographs of the veneering ceramic showed sharp fractured edges and fragments of wear debris. Zirconia may be considered a wear-friendly material for restorations opposing enamel, even after simulated aging.

Bron

Burgess J, Janyavula S, Lawson N, Lucas T, Cakir D. Enamel wear opposing polished and aged zirconia. Oper Dent 2013 Jul 12. doi: 10.2341/12-345-L [Epub ahead of print].