Preparation of dental resin composites with anti-bacterial adhesion against Streptococcus mutans using fluorinated and silicon containing dimethacrylates.

Objective: The purpose of this study was to enhance the anti-bacterial adhesion effect against Streptococcus mutans (S. mutans) of fluorinated dimethacrylate (DF MA) based dental resin composites (DRCs) by using silicone dimethacrylate (SMA-MEO).

Method: The SMA-MEO was added into mixture of DFMA and tricyclo (5.2.1.0) decanedimethanol diacrylate (SR833s) (DFMA/SR833s = 50 wt./50 wt.) with mass ratios of 10 wt% and 20 wt% to form resin matrix both with fluorinated and silicon containing dimethacrylates, and then DRCs named DS+ 10 %SMA-MEO and DS+ 20 %SMA-MEO were prepared by mixing the resin matrix with silaned BaAlSiO filler particles at a mass ratio of 30 wt./70 wt. Double bond conversion, volumetric shrinkage and shrinkage stress, flexural strength and modulus, water sorption and solubility, contact angle and surface free energy, anti-bacterial adhesion effect against Streptococcus mutans (S. mutans), and cytotoxicity of prepared DRCs were investigated according to standard or referenced methods. Fluorinated dimethacrylate (DFMA) based DRC named DS and 2,2-bis[4-(2-hydroxy-3-methacryloy-loxypropyl)-phenyl]propane (Bis-GMA) based DRC named BT were used as controls.

Results: Adding SMA-MEO into DFMA based DRC could lead to higher double bond conversion (p < 0.05), higher hydrophobicity (p < 0.05), and lower surface free energy (p < 0.05). Only DS+ 10 %SMA-MEO had better anti-bacterial adhesion effect against S. mutans than DS (p < 0.05). The SMA-MEO had no influence on volumetric shrinkage, shrinkage stress, flexural modulus, water sorption and solubility of DRC (p > 0.05), but could reduce flexural strength of dry DRC (p < 0.05). After water immersion, SMA-MEO containing DRCs had comparable flexural strength as DS (p > 0.05). Compared with BT, DS and SMA-MEO containing DRCs had better or comparable physicochemical properties, and lower amount of adherent S. mutans. All of DRCs had comparable cytotoxicity (p > 0.05).

Significance: DRCs with both DFMA and SMA-MEO could have better anti-bacterial adhesion effect against S. mutans than DRC only with DFMA due to increased hydrophobicity and decreased Surface free energy, and the optimal mass fraction of SMA-MEO in DFMA based resin matrix was 10 wt%.