Sliding contact fatigue damage in layered ceramic structures

J. W. Kim, J. H. Kim, V. P. Thompson, Y. Zhang

Research output: Contribution to journalArticle

Abstract

Porcelain-veneered restorations often chip and fracture from repeated occlusal loading, making fatigue studies relevant. Most fatigue studies are limited to uni-axial loading without sliding motion. We hypothesized that bi-axial loading (contact-load-slide-liftoff, simulating a masticatory cycle), as compared with uni-axial loading, accelerates the fatigue of layered ceramics. Monolithic glass plates were epoxy-joined to polycarbonate substrates as a transparent model for an all-ceramic crown on dentin. Uni-and bi-axial cyclic contact was applied through a hard sphere in water, by means of a mouth-motion simulator apparatus. The uni-axial (contact-load-hold-liftoff) and traditional R-ratio fatigue (indenter never leaves the specimen surface) produced similar lifespans, while bi-axial fatigue was more severe. The accelerated crack growth rate in bi-axial fatigue is attributed to enhanced tensile stresses at the trailing edges of a moving indenter. Fracture mechanics descriptions for damage evolution in brittle materials loaded repeatedly with a sliding sphere are provided. Clinical relevance is addressed.

Original languageEnglish (US)
Pages (from-to)1046-1050
Number of pages5
JournalJournal of dental research
Volume86
Issue number11
DOIs
StatePublished - Nov 1 2007

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Keywords

  • Ceramics
  • Fatigue
  • Layered structures
  • Load-slide contact
  • Partial cone cracks

ASJC Scopus subject areas

  • Dentistry(all)

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