Influence of access cavity designs, root canal enlargement and short-term calcium hydroxide intracanal medicament on fracture susceptibility of root-filled teeth

Rada Mazen Fa'eq Haddadin

Research output: ThesisDoctoral Thesis

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[Truncated] Introduction
Tooth fracture is a common cause of tooth loss. Endodontic treatment is associated with loss of tooth structure when an access cavity is cut and the root canals are enlarged. Intracanal medicaments can change the structure and quality of dentine which also affects the tooth’s mechanical properties.

Fracture susceptibility is routinely assessed in-vitro with the Instron Universal Test Machine. The effects of access cavity preparation, root canal preparation and calcium hydroxide on the force required to fracture teeth have been assessed with this method. Unfortunately, the effect of mastication has been overlooked and the models lack clinical relevance when dentine specimens or roots without coronal tooth structure and/or restorations have been used, root canal treatment was not or was only partially performed, the load was applied from an angle or vertically via D11 spreaders in thecanals, and periodontal ligament and alveolar bone simulation were not considered. Theuse of simulated chewing prior to testing for fracture may provide more precise information about the clinical performance of root-filled teeth.

The aims were to investigate whether the force required to fracture root-filled and restored mandibular molars is affected by:
(1) simulated chewing,
(2) access cavity designs,
(3) degree of root canal enlargement, and
(4) short-term exposure to calcium hydroxide.

An in-vitro controlled trial was conducted using human mandibular molars without previous restoration. Quantitative methods were used to measure the forces required to fracture the teeth after root-filling and access cavity restoration. Generally, all samples had standardised endodontic treatment (except the variable being tested) and anamalgam restoration. Teeth were mounted in acrylic with a simulated periodontal ligament. Forces required to fracture the teeth were determined with an Instron Universal Test Machine and results were statistically analysed.
Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • The University of Western Australia
Award date27 Jun 2016
Publication statusUnpublished - 2016


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