Monomer conversion, biaxial flexural strength, apatite forming ability of experimental dual-cured and self-adhesive dental composites containing calcium phosphate and nisin

Dent Mater J. 2021 Mar 31;40(2):399-406. doi: 10.4012/dmj.2020-056. Epub 2020 Nov 7.

Abstract

The aim was to develop dual-cured, self-adhesive composites containing monocalcium phosphate monohydrate (MCPM, 8 or 4 wt%) and nisin (6 or 3 wt%) with added adhesive monomer. The effect of additives on monomer conversion (MC), biaxial flexural strength (BFS), dentin shear bond strength (SBS), and surface apatite formation were examined. All experimental composites showed light-activated MC (70-75%) higher than the commercial self-adhesive composite (Vertise Flow; VF, 65%). The additives reduced BFS of the composites from 217 to 133 MPa. SBS of the experimental composites (2-6 MPa) was lower than that of VF (12 MPa). Rising MCPM level enabled apatite-like crystals precipitated on the surface of composites after immersion in simulated body fluid for 4 weeks. The additives showed negligible effect on MC and SBS. Rising level of additives reduced strength of the composites but the values were still higher than that required by the standard.

Keywords: Biaxial flexural strength; Hydroxyapatite; Monocalcium phosphate monohydrate; Monomer conversion; Nisin.

MeSH terms

  • Apatites
  • Calcium Phosphates
  • Composite Resins
  • Dental Bonding*
  • Dental Cements
  • Dentin
  • Flexural Strength
  • Materials Testing
  • Nisin*
  • Resin Cements
  • Shear Strength

Substances

  • Apatites
  • Calcium Phosphates
  • Composite Resins
  • Dental Cements
  • Resin Cements
  • Nisin