Does incomplete caries removal reduce strength of restored teeth?

J Dent Res. 2010 Nov;89(11):1270-5. doi: 10.1177/0022034510377790. Epub 2010 Sep 21.


Little information is available about whether the presence of residual caries beneath an occlusal restoration affects fracture strength of the tooth. This in vitro study tested the hypothesis that restored teeth after incomplete excavation have lower fracture strengths than restored teeth after complete excavation. Fourteen pairs of molars were randomly assigned to an experimental (incomplete excavation) or to a control group (complete excavation) and loaded vertically (after cyclic loading). Failure load and fracture mode were recorded. Restored teeth in the incomplete excavation group resulted in reduced fracture strength (p < 0.001) of the tooth-restoration complex (1276 N ± 626 N) compared with the control group (2768 N ± 710 N). Teeth in the complete excavation group all fractured vertically, while in the experimental group, cracks in the restoration were observed, characterized as 'ice-cracks'. The fracture strength of teeth restored over incomplete caries excavation was significantly reduced, possibly resulting in long-term clinical failure.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Etching, Dental
  • Biomechanical Phenomena
  • Bisphenol A-Glycidyl Methacrylate / chemistry
  • Composite Resins / chemistry
  • Dental Caries / pathology*
  • Dental Cavity Preparation / methods
  • Dental Polishing / instrumentation
  • Dental Restoration Failure
  • Dental Restoration, Permanent / methods*
  • Dental Stress Analysis / instrumentation
  • Dentin / pathology
  • Dentin-Bonding Agents / chemistry
  • Humans
  • Methacrylates / chemistry
  • Microradiography
  • Phosphoric Acids / chemistry
  • Resin Cements / chemistry
  • Stress, Mechanical
  • Tooth / pathology*
  • Tooth Fractures / physiopathology
  • Tooth Root / physiopathology


  • Clearfil AP-X
  • Composite Resins
  • Dentin-Bonding Agents
  • Methacrylates
  • Phosphoric Acids
  • Photobond
  • Resin Cements
  • Bisphenol A-Glycidyl Methacrylate
  • phosphoric acid