Title: 0342 - Antibacterial, Ester-Free Monomers: Polymerization Kinetics, Mechanical Properties and Anti-Biofilm Activity


Ana Paula Fugolin (Presenter)
Oregon Health & Science University

Vincent Hyunh, Oregon Health & Science University
Wilbes Mbiya, Oregon Health & Science University
Jack Ferracane, Oregon Health & Science University
Carmem Pfeifer, Oregon Health & Science University


Objectives: Quaternary ammonium (QA) methacrylate monomers have been extensively investigated and demonstrate excellent antibacterial properties. However, the presence of ester bonds makes them prone to degradation in the oral cavity. In this study, ester-free QA monomers based on meth-acrylamides were synthesized and screened for polymerization kinetics, mechanical properties and antibacterial effects.

Methods: Tertiary quaternary ammonium acrylamides (QAAM) and methacrylamides (QAMAM) with alkyl side chain lengths of 9 and 14 carbons (C9 and C14) were synthesized and incorporated at 10 wt% into experimental composites based on BisGMA:TEGDMA (1:1), camphorquinone/ethyl-4-dimethylaminobenzoate (0.2/0.8 wt%) and 70 wt% barium glass fillers. Analogous methacrylate versions (QAM) were used as controls. Degree of conversion (DC) and rate of polymerization (RP) during photoactivation (800 mW/cm2) were followed in real-time with near-IR. Flexural Strength (FS) and Modulus (E) were measured on 2x2x25 mm bars in 3-point bending after 24h dry storage and 7-day storage in water at 37°C. Antimicrobial and antifouling properties were evaluated by bioluminescence (Luciferase Assay) and biofilm removal by water spray impingement test, respectively. Data were analyzed with one-way ANOVA/Tukey's test (α=0.05).

Results: DC was similar for all groups tested. Both QAMAMs and C14QAAM presented significantly lower RP (Table 1). Under dry conditions, FS and E were similar for all groups. After water storage, all materials presented FS/E similar to the control, except for C14QAAM (for FS) and C14QAMAM (for E), which were lower. All C14 versions were strongly antibacterial, decreasing the titer counts of biofilm by more than two orders of magnitude in comparison to the control, which made it impossible to subject them to the impingement test. C9 monomers did not present significant antibacterial nor antifouling properties.

Conclusions: C14-QA monomers based on methacrylates and meth-acrylamides present strong antibacterial properties, and in general, similar conversion/mechanical properties compared to the control.


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This abstract is based on research that was funded entirely or partially by an outside source:
NIH-NIDCR (K02-DE025280; U01-DE023756)

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE