Objectives: To formulate and characterize a novel antibacterial fluoride-releasing dentin bonding agents. Methods: A new hydrolytically stable self-etching monomer 2-(11-methacrylamido-undecanamido)ethylphosphonic acid (MAUAEP) has been synthesized. A two-bottle experimental bonding agent has been formulated. Bottle A (primer): 7.5% MAUAEP, 7.5%DEG-DA, 25%HEMA, 40%EtOH, 20%H2O. Bottle B (adhesive): three adhesives have been formulated: (1) No-filler-adhesive: 25%F-releasing antibacterial monomer, 20%BisGMA, 20%TEGDMA, 20%UEDMA, 15%HEMA. (2) NM-10: adhesive containing 10% silanized NovaMin bioactive glass nanoparticles (45 nm), (3) NM-20: adhesive containing 20% silanized NovaMin nanoparticles. Clearfil SE Bond (Kuraray) has been included for comparison. The four adhesive bonding agents were applied to disc specimens (10mm diameter, 1mm thick, n=5) of the experimental antibacterial F-releasing composite (AADR 2010 abstract 1032). These samples were immersed in 4 ml HEPES buffer. The solutions were withdrawn and replenished daily for 14 days. The fluoride release was analyzed by a fluoride-ion-selective electrode. Calcium and phosphorous released were analyzed by ICP-MS. Microtensile bond strengths (MTBS) to dentin of extracted human teeth were measured on a microtensile tester (BISCO) after the sectioned bar specimens (1.2x1.2mm cross-section, n=10-12) were stored in distilled water at 37oC for 24h. The data were analyzed using ANOVA and post hoc Tukey test.
Results: (mean ± SD)
Bonding Agent | MTBS (MPa) | Cumulative F- release in 14 days (µmole/cm2) | Cumulative Ca-release in 7 days (nmole/cm2) | Cumulative P-release in 7 days (nmole/cm2) |
No Filler | 40.24±6.23a | 3.54±0.35a | 14.47±0.96a | 4.72±0.23 a |
NM-10 | 26.94±7.14b | 2.53±0.17b | 30.09±2.47b | 19.9±0.34b |
NM-20 | 16.37±3.23c | 3.35±0.87a | 107.1±5.49c | 28.9±0.29c |
SE Bond | 32.23±10.71b | 2.11±0.21b | - | - |
Data with the same superscript latter in each column have no significant difference (p>0.05).
Conclusions: Novel antibacterial F-releasing bonding agent (No Filler) has significantly higher bond strength and fluoride release than SE Bond. Adding increasing amount of bioactive glass particles can increase Ca and P release but decrease the bond strength. Supported by NIH/NIDCR grant (1R01DE019203-01A1)