Addition of ammonium-based methacrylates to an experimental dental adhesive for bonding metal brackets: Carious lesion development and bond strength after cariogenic challenge

Am J Orthod Dentofacial Orthop. 2017 May;151(5):949-956. doi: 10.1016/j.ajodo.2016.10.028.


Introduction: In this study, we evaluated the caries inhibition and shear bond strength achieved with the addition of the antibacterial monomer [2-(Methacryloyloxy)ethyl] trimethylammonium chloride (MADQUAT) to an adhesive used to bond orthodontic brackets.

Methods: Experimental adhesives were formulated with addition of 0% (control), 5%, or 10% MADQUAT followed by measurement of the degree of conversion. These adhesives were used to lute brackets to the enamel of premolars (n = 30). Biofilm from a microcosm model was cultivated in half of the specimens under cariogenic challenge for 5 days. The brackets were subjected to a shear bond strength test followed by measurement of the internal hardness of the enamel around the brackets to calculate the integrated mineral loss.

Results: The addition of MADQUAT slightly increased the degree of conversion. Adhesive containing 10% MADQUAT significantly reduced the integrated mineral loss around the bracket but also resulted in the lowest values of bond strength. No effects on bond strength and integrated mineral loss were observed with the addition of 5% MADQUAT to the adhesive. The cariogenic challenge did not affect the bond strength and the failure mode.

Conclusions: MADQUAT was effective to reduce the integrated mineral loss only when added to the adhesive at a concentration of 10% despite the reduction of bond strength.

MeSH terms

  • Anti-Bacterial Agents / therapeutic use
  • Biofilms / growth & development
  • Dental Bonding / adverse effects
  • Dental Bonding / methods*
  • Dental Caries / prevention & control*
  • Dental Cements / therapeutic use*
  • Dental Stress Analysis
  • Humans
  • In Vitro Techniques
  • Methacrylates / therapeutic use*
  • Orthodontic Brackets* / adverse effects


  • 2-(trimethylammonio)ethyl methacrylate
  • Anti-Bacterial Agents
  • Dental Cements
  • Methacrylates