Characterization of the Mechanical Properties, Water Sorption, and Solubility of Antibacterial Copolymers of Quaternary Ammonium Urethane-Dimethacrylates and Triethylene Glycol Dimethacrylate

Abstract

The use of dental composites based on dimethacrylates that have quaternary ammonium groups is a promising solution in the field of antibacterial restorative materials. This study aimed to investigate the mechanical properties and behaviors in aqueous environments of a series of six copolymers (QA:TEG) comprising 60 wt.% quaternary ammonium urethane-dimethacrylate (QAUDMA) and 40 wt.% triethylene glycol dimethacrylate (TEGDMA); these copolymers are analogous to a common dental copolymer (BG:TEG), which comprises 60 wt.% bisphenol A glycerolate dimethacrylate (Bis-GMA) and 40 wt.% TEGDMA. Hardness (HB), flexural strength (FS), flexural modulus (E), water sorption (WS), and water solubility (SL) were assessed for this purpose. The pilot study of these copolymers showed that they have high antibacterial activity and good physicochemical properties. This paper revealed that QA:TEGs cannot replace BG:TEG due to their insufficient mechanical properties and poor behavior in water. However, the results can help to explain how QAUDMA-based materials work, and how their composition should be manipulated to produce the best performance. It was found that the longer the N-alkyl chain, the lower the HB, WS, and SL. The FS and E increased with the lengthening of the N-alkyl chain from eight to ten carbon atoms. Its further extension, to eighteen carbon atoms, caused a decrease in those parameters.

Physicochemical Properties of Novel Copolymers of Quaternary Ammonium UDMA Analogues, Bis-GMA, and TEGDMA

“…First, the physicochemical, mechanical, and antibacterial properties of QAUDMA-m copolymers with 40 wt.% TEGDMA (QAm:TEGs) were characterized [ 24 , 25 ]. The uncured QAm:TEGs had appropriate transparency ( RI from 1.4895 to 1.5001) and molecular mobility ( Tg m from −33.82 to −25.84 °C).…”

“…The QA:TEG copolymers were characterized by low volumetric contraction ( S e from 6.4 to 6.9%), high polymerization efficiency ( DC from 84.0 to 88.7%), high stiffness (polymer glass transition temperature ( Tg p ) from 60.33 to 66.32 °C), suitable surface properties (water contact angle ( WCA ) from 82.1 to 98.7°), and high antibacterial activity against S. aureus (number of adhered bacteria from 0 (no adhered bacteria) to 4.84 log(CFU/mL), inhibition zone from 6 to 19 mm), and E. coli (number of adhered bacteria from 0 (no adhered bacteria) to 3.34 log(CFU/mL), inhibition zone from 6 to 10 mm) [ 24 ]. However, they showed excessively high water sorption ( WS from 116.08 to 148.31 µg/mm 3 ) and solubility ( SL from 12.67 to 52.39 µg/mm 3 ) [ 25 ]. These properties excluded them from potential use as matrices for dental composites.…”

Cytotoxicity and Microbiological Properties of Copolymers Comprising Quaternary Ammonium Urethane-Dimethacrylates with Bisphenol A Glycerolate Dimethacrylate and Triethylene Glycol Dimethacrylate

“…Copolymers of 60 wt.% QAUDMA-m with 40 wt.% TEGDMA (QAm:TEGs) were first investigated by analogy to the 60 wt.% Bis-GMA with 40 wt.% TEGDMA copolymer (BG:TEG), representing standard DCRM matrix [ 32 , 33 ]. QAm:TEGs revealed significantly higher antibacterial activity against S. aureus and E. coli than BG:TEG, which depended on the number of carbon atoms in the N-alkyl substituent ( Cm ).…”

Bis-quaternary ammonium betulin-based dimethacrylate: synthesis, characterization, and application in dental restorative resins

“…[11][12][13] The number of methacrylate groups and quaternary ammonium functionalities affects the performance of materials. [14][15][16][17] Monomethacrylate QAMs demonstrated remarkable antibacterial effects, but these monomers could only undergo linear polymerization, which ultimately adversely affected physicochemical properties of materials once beyond their maximum addition (B5 wt%). 18,19 In contrast, di-methacrylate QAMs led to higher addition (10-60 wt%) in resins, but the antibacterial activity depended on the monomer concentration.…”