Antibacterial, cytotoxic and mechanical properties of a orthodontic cement with phosphate nano-sized and phosphorylated chitosan: An in vitro study

J Dent. 2024 Jul:146:105073. doi: 10.1016/j.jdent.2024.105073. Epub 2024 May 22.

Abstract

Objectives: Evaluate, in vitro, the effect of incorporating nano-sized sodium trimetaphosphate (TMPnano) and phosphorylated chitosan (Chi-Ph) into resin-modified glass ionomer cement (RMGIC) used for orthodontic bracket cementation, on mechanical, fluoride release, antimicrobial and cytotoxic properties.

Methods: RMGIC was combined with Chi-Ph (0.25%/0.5%) and/or TMPnano (14%). The diametral compressive/tensile strength (DCS/TS), surface hardness (SH) and degree of conversion (%DC) were determined. For fluoride (F) release, samples were immersed in des/remineralizing solutions. Antimicrobial/antibiofilm activity was evaluated by the agar diffusion test and biofilm metabolism (XTT). Cytotoxicity in fibroblasts was assessed with the resazurin method.

Results: After 24 h, the RMGIC-14%TMPnano group showed a lower TS value (p < 0.001); after 7 days the RMGIC-14%TMPnano-0.25%Chi-Ph group showed the highest value (p < 0.001). For DCS, the RMGIC group (24 h) showed the highest value (p < 0.001); after 7 days, the highest value was observed for the RMGIC-14%TMPnano-0.25%Chi-Ph (p < 0.001). RMGIC-14%TMPnano, RMGIC-14%TMPnano-0.25%Chi-Ph, RMGIC-14%TMPnano-0.5%Chi-Ph showed higher and similar release of F (p > 0.001). In the SH, the RMGIC-0.25%Chi-Ph; RMGIC-0.5%Chi-Ph; RMGIC-14%TMPnano-0.5%Chi-Ph groups showed similar results after 7 days (p > 0.001). The RMGIC-14%TMPnano-0.25%Chi-Ph group showed a better effect on microbial/antibiofilm growth, and the highest efficacy on cell viability (p < 0.001). After 72 h, only the RMGIC-14%TMPnano-0.25%Chi-Ph group showed cell viability (p < 0.001).

Conclusion: The RMGIC-14%TMPnano-0.25%Chi-Ph did not alter the physical-mechanical properties, was not toxic to fibroblasts and reduced the viability and metabolism of S. mutans.

Clinical relevance: The addition of phosphorylated chitosan and organic phosphate to RMGIC could provide an antibiofilm and remineralizing effect on the tooth enamel of orthodontic patients, who are prone to a high cariogenic challenge due to fluctuations in oral pH and progression of carious lesions.

Keywords: Chitosan; Cytotoxicity; Microbiota; Orthodontics; Phosphates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents* / pharmacology
  • Biofilms* / drug effects
  • Cell Survival / drug effects
  • Chitosan* / pharmacology
  • Compressive Strength
  • Dental Cements / chemistry
  • Dental Cements / pharmacology
  • Fibroblasts* / drug effects
  • Fluorides* / pharmacology
  • Glass Ionomer Cements* / chemistry
  • Glass Ionomer Cements* / pharmacology
  • Hardness
  • Humans
  • Materials Testing*
  • Nanoparticles
  • Orthodontic Brackets
  • Phosphates / pharmacology
  • Phosphorylation
  • Polyphosphates / pharmacology
  • Resin Cements / chemistry
  • Streptococcus mutans / drug effects
  • Surface Properties
  • Tensile Strength

Substances

  • Chitosan
  • Anti-Bacterial Agents
  • Glass Ionomer Cements
  • Fluorides
  • Resin Cements
  • Polyphosphates
  • Dental Cements
  • Phosphates