Date of Completion


Embargo Period



Kamran Safavi, D.M.D., M.Ed., Blythe Kaufman, D.M.D., M.D.S.

Field of Study

Dental Science


Master of Dental Science

Open Access

Open Access


Introduction: Gutta-percha is not compressible and tooth fracture can be initiated when force is applied to the gutta-percha. The aim of this study was to apply a hoop stress to roots which have been obturated with either gutta-percha and no sealer, gutta-percha and AH Plus sealer, gutta-percha and EndoSequence Bioceramic Sealer, gutta-percha and Tetranite®, or Tetranite® and no gutta-percha until fracture occurred and then compared the failure stresses. Methods: Teeth were divided into five groups based on the sealer type used, no sealer used or only sealer used. The teeth were then sectioned into 2mm thickness discs and load was applied using a piston until fracture took place. The stress generated by the gutta-percha on the tooth wall was then calculated using a hoop stress formula. One – way ANOVA with a 95% multiple range test was used to compare hoop stresses at failure for all groups (SPSS, TBM). Linear regression was used to examine failure load versus dentin wall thickness (SigmaPlot 13.0, Systa Software). Results: With respect to the amount of stress exerted by the gutta-percha on the internal tooth wall with or without sealer types showed there were significant differences between the Tetranite®/no gutta-percha group and all the groups (p < 0.05). Conclusions: Application of a hoop stress provides the field of endodontics a method to test whether sealers enhance dentin strength. The Tetranite®/no gutta-percha group enhanced dentin strength in this study.

Major Advisor

J. R. Kelly, D.D.S., Ph.D.