Dentin deformation after scratching with clinically-relevant forces

Jean Camps, Jean Pierre Salomon, Bart Van Meerbeek, Franklin Tay, David Pashley

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


Objective: In order to understand the mechanism of dentin sensitivity to tactile stimuli, the purpose of this study was to evaluate possible permanent deformation of dentin produced by scratching dentin surfaces with clinically-relevant forces. Methods: Midcoronal dentin was prepared from twenty human teeth and polished to 4000-grit and ultrasonicated. The dentin surface of each specimen was scratched under forces ranging from 30 to 100 centi-Newtons (cN). The depth of the grooves were measured with a profilometer and the overall hardness of dentin in the vicinity of the grooves was measured. Additional dentin specimens were prepared for SEM evaluation. Results: Dentin hardness was constant and no statistical difference was found among the specimens. Statistically significant differences in groove width and depth were found when increasing force was applied to the dental explorer tip. The depth of the groove ranged from 0.21 ± 0.09 μm for the 30 cN group to 1.27 ± 0.39 -m for the 100 cN group. The width of the groove ranged from 19.3 ± 4.0 μm for the 30 cN group to 43.0 μm for the 100 cN group. Conclusions: (1) The threshold force necessary to create scratches in dentin with a dental explorer was 30 cN or a compressive stress of 1003 MPa. As this exceeds the crushing strength of dentin, this force produces plastic deformation of dentin; (2) Theoretical calculations indicated that even the highest scratching forces (100 cN) could not induce sufficient fluid flow to activate pulpal mechanoreceptors, although it could induce sufficient elastic deformation to theoretically shift dentinal fluid at a rate sufficient to activate mechanoreceptors; (3) The results of this work may lend support the hydrodynamic theory in that scratching of dentin surfaces causes both elastic and plastic deformation of dentin that may displace dentinal fluid toward the pulp where it could activate mechanoreceptors.

Original languageEnglish (US)
Pages (from-to)527-534
Number of pages8
JournalArchives of Oral Biology
Issue number7
StatePublished - Jul 1 2003
Externally publishedYes


  • Dentin compressive strength
  • Dentin sensitivity
  • Dentinal fluid
  • Probe force

ASJC Scopus subject areas

  • Otorhinolaryngology
  • Dentistry(all)
  • Cell Biology


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