In vitro evaluation of dentinal hydraulic conductance and tubule sealing by a novel calcium-phosphate desensitizer

J Biomed Mater Res B Appl Biomater. 2013 Feb;101(2):303-9. doi: 10.1002/jbm.b.32840. Epub 2012 Nov 19.

Abstract

In the current trend of materials used for dentin hypersensitivity treatment, calcium-phosphate-containing desensitizers are expected to have advantages in oral environment. A newly formulated desensitizer containing tetracalcium phosphate and dicalcium phosphate anhydrous (CPD-100) was evaluated in comparison to oxalate containing desensitizer (SS) regarding permeability reduction (PR%) by measuring hydraulic conductance on the etched dentin discs in vitro. CPD-100 exhibited mean PR% of 91%, which significantly increased to 98% after immersion in artificial saliva (AS) for 4 weeks (p < 0.001), while SS showed a significant decrease from 99% to 93% (p < 0.01). SEM observation showed newly formed crystallites on CPD-100 treated dentin, which did not exist in SS treated dentin after AS immersion, suggesting that calcium oxalate inhibited formation of new calcium-phosphate minerals. Five-minute acid challenge did not significantly affect PR% of dentin treated by any of the desensitizers. The energy dispersive X-ray spectroscopy (EDS) analysis indicated that the formed layer of CPD-100 were minerals with similar Ca/P ratio to hydroxyapatite. In conclusion, the newly developed calcium-phosphate desensitizer has the potential to exhibit long-term stability in the oral environment, owing to its chemical properties that promote the crystal growth in salivary fluid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium Phosphates / chemistry*
  • Calcium Phosphates / pharmacology*
  • Crystallization
  • Dentin / drug effects
  • Dentin / pathology
  • Dentin / physiopathology
  • Dentin Desensitizing Agents / chemistry*
  • Dentin Desensitizing Agents / pharmacology*
  • Dentin Permeability / drug effects
  • Dentin Permeability / physiology
  • Dentin Sensitivity / drug therapy*
  • Dentin Sensitivity / pathology
  • Dentin Sensitivity / physiopathology
  • Humans
  • Hydrodynamics
  • In Vitro Techniques
  • Materials Testing
  • Microscopy, Electron, Scanning
  • Spectrometry, X-Ray Emission

Substances

  • Calcium Phosphates
  • Dentin Desensitizing Agents