On the fracture behavior of molar teeth with MOD cavity preparation

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Mesial-occlusal-distal (MOD) cavity preparations are commonly used to restore damaged teeth. While numerous in vitro cavity designs have been devised and tested, no analytical frameworks for assessing their resistance to fracture seem to exist. This concern is addressed here by resorting to a 2D slice specimen cut from restored molar teeth with rectangular-base MOD cavity. The evolution of damage due to axial cylindrical indentation is followed in situ. The failure begins with a rapid debonding along the tooth/filler interface and continues with unstable cracking from the cavity corner. The debonding load qd is fairly fixed while the failure load qf is insensitive to the presence of filler, increasing with cavity wall thickness h and reducing with cavity depth D. The growth of the corner crack is studied using a 2D fracture analysis in conjunction with the FEM technique. The ratio h = h/D emerges as a viable system parameter. A simple expression for qf given in terms of h and dentin toughness KC is developed that predicts well the test data. In vitro studies on full-fledged molar teeth with MOD cavity preparation show that the fracture resistance of filled cavities often exceeds by a large margin that of unfilled ones. Indications are that this may reflect load sharing with the filler. Thus, the fracture resistance of the unfilled cavity provides a lower bound to a compromised MOD filling after long-term aging in the mouth. This bound is well predicted by the slice model. Finally, it is recommended that MOD cavities be prepared, if applicable, such that h > D regardless of the tooth size.

Original languageEnglish
Article number105747
JournalJournal of the Mechanical Behavior of Biomedical Materials
Volume140
DOIs
StatePublished - Apr 2023

Keywords

  • Dentin toughness
  • Fracture resistance
  • Interface cracks
  • MOD preparation
  • Slice specimens

Fingerprint

Dive into the research topics of 'On the fracture behavior of molar teeth with MOD cavity preparation'. Together they form a unique fingerprint.

Cite this