Objective: To formulate and characterize a new experimental antibacterial fluoride-releasing dental composite. Method: A new antibacterial F-releasing methacrylate monomer containing bis(carboxymethyl)-L-lysine zirconia-fluoride chelate and a long-chain quaternary ammonium fluoride has been synthesized. Two experimental dental composites have been formulated: (1) Antibacterial F-releasing composite (wt %): F-releasing monomer 5.8, BisGMA 8.7, EBPADMA 8.7, HDDMA 5.8, (2) Control composite: BisGMA 11.6, EBPADMA 11.6, HDDMA 5.8; both composites have silanized F-releasing glass filler 70 and photo initiators 1.0. Fluoride release of both materials from cylindrical samples (4x9mm (DxH), n=5) in 2-ml de-ionized water was analyzed daily for 30 days and then weekly for 100 days using ion-selective electrode. Then the specimens were recharged by “60 Second Taste Gel” (containing 1.23 w/w% fluoride ion) for 1 min and rinsed with running de-ionized water for 30 seconds. Fluoride release after recharge was measured daily for 5 days and the recharge cycles were repeated 3 times. Comprehensive strength specimens (4x9mm (DxH), n=10) and flexure strength specimens (25x2x2mm, n=10) were prepared, immersed in de-ionized water, stored 370C for 24 hrs, and tested on the Instron 5566 testing machine with crosshead speed of 1 mm/min. The water sorption and solubility test were conducted using disk specimens (15x2mm (DxH), n=5) according to ISO standard 4049. The data were analyzed using ANOVA-Tukey test.
Results:
Materials | Cumulative F- release in 100 days (µg/cm2) | Cumulative F- release in 3 days after recharge (µg/cm2) | Flexure Strength (MPa) | Comprehensive Strength (MPa) | Water Sorption (μg/mm3) | Solubility (μg/mm3) |
Antibacterial F-releasing composite | 55.20±2.61 | 46.64±4.05 | 111.0±14.5 | 220.7±22.3 | 16.39±2.2 | 3.52±5.56 |
Control Composite | 14.82±2.22 | 24.77±2.25 | 122.4±16.8 | 230.0±29.9 | 13.55±1.22 | 1.48±0.86 |
P (α=0.05) | 0.000 | 0.000 | 0.244 | 0.442 | 0.044 | 0.388 |
Conclusion: the new antibacterial fluoride-releasing composite has significantly higher fluoride release and fluoride recharge capability than conventional fluoride-releasing composite (p<0.05) but they have similar physical and mechanical properties. Sponsored by NIH/NIDCR grant 1R01DE019203-01A1.