IADR Abstract Archives
Antibacterial Stability of Experimental Methacrylate-Based Dental Resins
Objectives: There have been no significant advancement in restorative dental materials presenting long-lasting antimicrobial properties to assist in dental caries management. Two photosensitizers (PS), Riboflavin (B2) and zinc oxide nanoparticles (ZnO) have been proven effective against photoelimination of cariogenic bacteria when in direct contact only. In this study, we proposed for the first time to load methacrylate-based resin-blends (RB) with the two PS agents independently, and evaluate their antimicrobial responses against cariogenic bacteria, S. mutans, under dark and blue light conditions, in fresh and aged materials.
Methods: An experimental resin blend was initially produced (0%PS). Subsequently, concentrations of 0.1, 1 and 1.5wt% B2; or 5, 10 or 20 wt% ZnO were added. Disk specimens (6mm-diameter x 1-mm thickness) were fabricated using light-curing-unit (Valo, Ultradent) at 830mW/cm2 for 120s in total. Specimens were randomly divided for either immediate or aged (37°C water) tests. A S.mutans inoculum (0.5mL, 1 x 106 CFU/mL, brain-heart-infusion broth, 1% glucose) was added to RB sterile disks and incubated (6 hr, 37°C, 5%CO2). Then, samples were treated for dark or blue LED light conditions (60s, 342 mW/cm2). Then, S.mutans were collected, serially diluted in PBS, plated (blood agar) and incubated (2d, 37°C, 5%CO2) before single colony (CFU) counting (three test runs, n=9). Data were subjected to a univariate 3-factor general linear model with post-hoc Tukey (α=0.05).
Results: While there was no detected dependence CFUs on selected PSs, concentrations and 60s light treatment, the systems were able to sustain antibacterial properties after ageing.
Conclusions: A PS-loaded methacrylate-based material for a sustained aPDT is a feasible. Future investigation will seek to tune light parameters and PS concentrations.
Methods: An experimental resin blend was initially produced (0%PS). Subsequently, concentrations of 0.1, 1 and 1.5wt% B2; or 5, 10 or 20 wt% ZnO were added. Disk specimens (6mm-diameter x 1-mm thickness) were fabricated using light-curing-unit (Valo, Ultradent) at 830mW/cm2 for 120s in total. Specimens were randomly divided for either immediate or aged (37°C water) tests. A S.mutans inoculum (0.5mL, 1 x 106 CFU/mL, brain-heart-infusion broth, 1% glucose) was added to RB sterile disks and incubated (6 hr, 37°C, 5%CO2). Then, samples were treated for dark or blue LED light conditions (60s, 342 mW/cm2). Then, S.mutans were collected, serially diluted in PBS, plated (blood agar) and incubated (2d, 37°C, 5%CO2) before single colony (CFU) counting (three test runs, n=9). Data were subjected to a univariate 3-factor general linear model with post-hoc Tukey (α=0.05).
Results: While there was no detected dependence CFUs on selected PSs, concentrations and 60s light treatment, the systems were able to sustain antibacterial properties after ageing.
Conclusions: A PS-loaded methacrylate-based material for a sustained aPDT is a feasible. Future investigation will seek to tune light parameters and PS concentrations.
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