Objectives: To formulate experimental antibacterial fluoride-releasing infiltration resins and test their microtensile bonding strength (MTBS) to enamel, fluoride release and fluoride recharge capabilities. Methods: A commercial infiltration resin [Icon, DMG] was used as Control. Three experimental infiltration resins were formulated using synthesized antibacterial fluoride-releasing monomers (AFRM) and other dental monomers: A1: 10% AFRM added to Icon. A2: 10%Bis-GMA, 20%TEGDMA, 20% HEMA, 25% AFRM, 24% Ethanol, 1% photoinitiators. A10: A2 with 10% F-releasing glass filler. For MTBS test, eight extracted molars with previous white spot lesions were divided into four groups. Samples were etched, infiltrated with experimental and control resins, and light cured following the instructions. Filtek Supreme composite (3M ESPE) was built incrementally 4-5 mm on top of the cured infiltration resin. Samples were sectioned into bars specimens (1x1 mm cross sections), thermocycled 5-55oC for 1000 cycles, and tested for MTBS. Lighted-cured disk specimens (6 mm in diameter, 1 mm thickness, n=5) from each material were immersed 2 mL of deionized water. Their [F-] was measured daily using F-ISE for 14 days. Then the discs were recharged with Neutra-Foam (2% fluoride, Oral-B) for one minute, rinsed for 30 seconds, measured for F-release for 4 days, and repeated 3 times. The data was analyzed using ANOVA and Tukey test.
Results:
Table 1 | MTBS (MPa) | Fluoride Release (mg/cm2) | Fluoride Release with Recharge (mg/cm2) |
Control | 15.62±3.25a | 0.00±0.00 a | 0.00±0.00a |
A1 | 15.57±3.23a | 13.66±5.27b | 2.60±0.91b |
A2 | 23.77±5.44b | 107.67±31.52d | 22.36±16.60d |
A10 | 15.89±3.74a | 29.27±9.51 c | 6.94±3.01c |
Different letters indicate significant difference (p<0.05)
Conclusion: The infiltration resins containing AFRM have similar or higher bonding strength to enamel and higher fluoride release and recharge than the tested commercial product. (Supported by NIH/NIDCR grant R01DE019203)