Ana P Fugolin1, Adam Dobson1, Vincent Huynh1, Wilbes Mbiya1, Oscar Navarro1, Cristiane M Franca1, Matthew Logan1, Justin L Merritt1, Jack L Ferracane1, Carmem S Pfeifer2. 1. Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, OHSU School of Dentistry, Oregon Health & Science University, 2730 SW Moody Ave, Portland, OR 97201, USA. 2. Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, OHSU School of Dentistry, Oregon Health & Science University, 2730 SW Moody Ave, Portland, OR 97201, USA. Electronic address: pfeiferc@ohsu.edu.
Abstract
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. MATERIALS AND METHODS: Tertiary quaternary ammonium acrylamides (AM) and methacrylamides (MAM) 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 (MA) 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 2 × 2 × 25 mm bars in 3-point bending after 24 h dry storage and 7-day storage in water at 37 °C. Antimicrobial properties and biofilm adhesion (fouling) were evaluated by bioluminescence (Luciferase Assay) and biofilm removal by water spray microjet impingement test, respectively. Cytotoxicity was assessed by MTT assay on dental pulp stem cells (DPSC). Data were analyzed with one-way ANOVA/Tukey's test (α = 0.05). RESULTS: DC was similar for all groups tested (∼70%). Both MAMs and C14-AM presented significantly lower RP. Under dry conditions, FS (110-120 MPa) and E (8-9 GPa) were similar for all groups. After water storage, all materials presented FS/E similar to the control, except for C14-AM (for FS) and C14-MAM (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. C9 monomers did not present significant antibacterial nor antifouling properties. And biofilms had approximately equivalent adhesion on the C9 composites as on the control. Cytotoxicity did not show significant differences between the MA and AM versions and the control group. CONCLUSIONS: C14-QA monomers based on methacrylates and meth-acrylamides present strong antibacterial properties, and in general, similar conversion/mechanical properties compared to the methacrylate control. STATEMENT OF SIGNIFICANCE: This work demonstrates the viability of methacrylamides and acrylamides as potential components in dental restorative materials with antimicrobial properties. The use of ester-free polymerizable functionalities has the potential of improving the degradation resistance of these materials long-term. The use of (meth)acrylamides did not interfere with the antimicrobial potential of quaternary ammonium-based materials.
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. MATERIALS AND METHODS:Tertiary quaternary ammonium acrylamides (AM) and methacrylamides (MAM) 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 (MA) 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 2 × 2 × 25 mm bars in 3-point bending after 24 h dry storage and 7-day storage in water at 37 °C. Antimicrobial properties and biofilm adhesion (fouling) were evaluated by bioluminescence (Luciferase Assay) and biofilm removal by water spray microjet impingement test, respectively. Cytotoxicity was assessed by MTT assay on dental pulp stem cells (DPSC). Data were analyzed with one-way ANOVA/Tukey's test (α = 0.05). RESULTS:DC was similar for all groups tested (∼70%). Both MAMs and C14-AM presented significantly lower RP. Under dry conditions, FS (110-120 MPa) and E (8-9 GPa) were similar for all groups. After water storage, all materials presented FS/E similar to the control, except for C14-AM (for FS) and C14-MAM (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. C9 monomers did not present significant antibacterial nor antifouling properties. And biofilms had approximately equivalent adhesion on the C9 composites as on the control. Cytotoxicity did not show significant differences between the MA and AM versions and the control group. CONCLUSIONS:C14-QA monomers based on methacrylates and meth-acrylamides present strong antibacterial properties, and in general, similar conversion/mechanical properties compared to the methacrylate control. STATEMENT OF SIGNIFICANCE: This work demonstrates the viability of methacrylamides and acrylamides as potential components in dental restorative materials with antimicrobial properties. The use of ester-free polymerizable functionalities has the potential of improving the degradation resistance of these materials long-term. The use of (meth)acrylamides did not interfere with the antimicrobial potential of quaternary ammonium-based materials.
Authors: Gloria Cazzaniga; Marco Ottobelli; Andrei C Ionescu; Gaetano Paolone; Enrico Gherlone; Jack L Ferracane; Eugenio Brambilla Journal: J Dent Date: 2017-07-24 Impact factor: 4.379
Authors: Valeria V Gordan; Joseph L Riley; D Brad Rindal; Vibeke Qvist; Jeffrey L Fellows; Deborah A Dilbone; Solomon G Brotman; Gregg H Gilbert Journal: J Am Dent Assoc Date: 2015-12 Impact factor: 3.634
Authors: Han Zhou; Michael D Weir; Joseph M Antonucci; Gary E Schumacher; Xue-Dong Zhou; Hockin H K Xu Journal: Int J Oral Sci Date: 2014-04-11 Impact factor: 6.344
Authors: A P P Fugolin; Oscar Navarro; Matthew G Logan; Vincent Huynh; Cristiane M França; Jack L Ferracane; Carmem S Pfeifer Journal: Acta Biomater Date: 2020-08-24 Impact factor: 8.947
Authors: Eliseu A Münchow; Adriana F da Silva; Evandro Piva; Carlos E Cuevas-Suárez; Maria T P de Albuquerque; Rodolfo Pinal; Richard L Gregory; Lorenzo Breschi; Marco C Bottino Journal: J Mater Chem B Date: 2020-11-10 Impact factor: 6.331
Authors: Ziwen Zhang; Megan M Jones; Camila Sabatini; Stephen T Vanyo; Ming Yang; Abhishek Kumar; Yancheng Jiang; Mark T Swihart; Michelle B Visser; Chong Cheng Journal: Biomater Sci Date: 2021-01-19 Impact factor: 6.843