Antimicrobial, biocompatibility, and physicochemical properties of novel adhesive methacrylate dental monomers

Abstract

For the advancement of Class V restoratives, our goal was to evaluate the physicochemical and mechanical properties, antimicrobial functionality, and cytotoxic potential of novel antimicrobial copolymers. 5-Carboxy-N-(2-(methacryloyloxy)ethyl)-N,N-dimethylpentan-1-aminium bromide (AMadh1) and 10-carboxy-N-(2-(methacryloyloxy)ethyl)-N,N-dimethyldecan-1-aminium bromide (AMadh2) were incorporated into light-curable urethane dimethacrylate, polyethylene glycol–extended urethane dimethacrylate, ethyl 2-(hydroxymethyl) acrylate resin (UPE resin). In the AMadhs-UPE resin, the hydrophobic/hydrophilic balance, degree of vinyl conversion, flexural strength, elastic modulus, and shear bond strength were assessed. Antimicrobial properties were measured using Streptococcus mutans (planktonic and biofilm). Cytotoxicity was tested using human gingival fibroblasts and mouse connective tissue fibroblasts (ATCC® CCL-1™) exposed to two-fold serial dilutions (≤10.6 mmol/L AMadh1 or ≤8.8 mmol/L AMadh2). At 10% mass of AMadh, the attained degree of vinyl conversion values (AMadh1 = 90.1% and AMadh2 = 88.5%) were not statistically different from the UPE resin (88.1%). At both AMadh levels, the flexural strength was reduced in a dose-dependent manner. Elastic modulus and contact angle were not significantly affected by AMadh1. Variations in elastic modulus and contact angle were observed with AMadh2; however, this does not disqualify it in future design of Class V restoratives. Compared to UPE resin, AMadh1-UPE and AMadh2-UPE (10% mass) copolymers reduced S. mutans biofilm 4.2- and 1.6-fold, respectively (p ≤ 0.006). In direct contact with human gingival fibroblasts or ATCC CCL-1 cells, at biologically relevant concentrations, the AMadhs did not adversely affect cell viability or their metabolic activity. This effort addresses a significant oral health issue associated with elderly populations. Its successful completion is expected to yield dental restoratives with well-controlled biofunction.

Physicochemical, Mechanical, and Antimicrobial Properties of Novel Dental Polymers Containing Quaternary Ammonium and Trimethoxysilyl Functionalities

“…Testing of Streptococcus mutans UA-159 (ATCC ® 700610) planktonic forms was according to described methods [47,58]. Briefly, bacterial cultures with an optical density of 1.2-1.3 at 600 nm (Unico ® 1200 Spectrophotometer, United Products & Instruments, Inc., Dayton, NJ, USA) were diluted and seeded onto copolymer disks at a density of~3 × 10 7 CFU/disk.…”

“…A bioluminescent S. mutans strain JM 10 (derivative of wild type UA159 [59] was used to assess the AM properties of AM sil s . Methods of the real-time bioluminescence assay were as described [41,58].…”

Use of Protein Repellents to Enhance the Antimicrobial Functionality of Quaternary Ammonium Containing Dental Materials

“…However, the antimicrobial efficacy–structure relationships are not strictly linear. For instance, the longer chain length of novel adhesive methacrylate dental monomers had a less marked effect on reducing S. mutans biofilms [ 20 ]. Furthermore, when drawing conclusions about chain length, it is important to consider that antimicrobial functionality is also affected by molecular mass, spacer rigidity, hydrophobicity, charge density, and charge distribution [ 21 , 22 ].…”

“…Furthermore, when drawing conclusions about chain length, it is important to consider that antimicrobial functionality is also affected by molecular mass, spacer rigidity, hydrophobicity, charge density, and charge distribution [ 21 , 22 ]. Since the first Imazato and coworkers’ QAC resin manuscript, advances have been made in synthesizing QAC monomers with dual functionality, such as increased shear bond strength [ 20 , 23 , 24 ] and silane-coupling capabilities [ 25 , 26 , 27 ]. Similarly, other antimicrobial approaches have been studied in dentistry, including metallic nanoparticles with inherent bactericidal properties [ 28 ] and are not discussed in this review.…”

Microwave assisted urethane grafted nano-apatites for dental adhesives

“…8 It is reported that urethane dimethacrylate considered as a favorable resin to attain uniform distribution of calcium phosphate based fillers. 9 Silane is the most common coupling agent used to immobilize HA particles and connect organic and inorganic phases in the resin matrix. During the silanization process, several factors can affect coupling efficiency such as the nature of solvent, pH, and concentration of the coupling agent.…”