title: Nanomechanical properties of endodontically treated teeth.
abstract: BACKGROUND
  Although it is apparent that teeth become more susceptible to fracture after root canal treatment, the contributing factors for this are not completely established. The purpose of this study was to determine whether there are changes in nanomechanical properties of dentin in root canal-treated teeth compared with non-root canal-treated control teeth.
  
  
  METHODS
  Atomic force microscopy-based nanoindentation testing was performed on root canal-treated teeth and age- and type-matched control teeth. Radicular intertubular dentin was indented in 6 locations, and triplicate measurements were averaged. Paired t tests were used to compare root canal-treated teeth with control teeth.
  
  
  RESULTS
  The moduli of elasticity were 17.8 ± 2.9 GPa and 18.9 ± 2.9 GPa for root canal-treated teeth and controls, respectively; the hardness values for the 2 groups were 0.84 ± 0.25 GPa and 0.84 ± 0.18 GPa, respectively. Neither the modulus of elasticity nor the hardness differed between groups (P > .05).
  
  
  CONCLUSIONS
  It appears that root canal treatment does not result in nanomechanical changes to radicular intertubular dentin.
authors: Division of Endodontics, University of California San Francisco, San Francisco, California, USA.
authors: Robert A
authors: RA
authors: Cheron
authors: Sally J
authors: SJ
authors: Marshall
authors: Harold E
authors: HE
authors: Goodis
authors: Ove A
authors: OA
authors: Peters
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D003786:Dental Pulp Cavity; D003799:Dental Stress Analysis; D003804:Dentin; D055119:Elastic Modulus; D006244:Hardness; D006801:Humans; D018625:Microscopy, Atomic Force; D008875:Middle Aged; D049329:Nanostructures; D018709:Statistics, Nonparametric; D019553:Tooth, Nonvital