Artificial caries inhibited by experimental fluoride-releasing composite and bonding agent

Objective: To evaluate the caries-inhibiting ability of an experimental fluoride-releasing composite and bonding agent. Methods: Experimental fluoride-releasing composites High-F (HF) and Low-F (LF) and experimental high-fluoride-releasing bonding agent Exp Bond (EB) were fabricated as previously reported (abstract 0113, IADR 2007). Commercial bonding agents, Clearfil SE Bond (SE) and Clearfil Protect Bond (PB), and a commercial non-fluoride releasing Clearfil Photo Core composite (NF) (Kuraray, Japan) were used for comparison. Class V cavities prepared from the extracted human molar teeth (n=5) were restored with six groups of composites and adhesives (shown results). The restored teeth were stored in an artificial caries solution (pH=4.3) for four weeks. The specimens were removed from the artificial caries solution, rinsed and imbedded in epoxy resin. The thin section specimens were prepared on Struers Accutom-50 section machine, polished to <0.2 mm thick, and photographed using a digital camera (SPOT) under a Nikon i50 polarizing light microscope. The depths of wall lesion from the enamel surface at two distances (10 µm and 25 µm) from the enamel-adhesive interface were measured. The data were analyzed using One-way ANOVA and post hoc test. Results: Depth of enamel wall-lesion at at 10 µm (mean±SD):

SE-NF 592±163(A), PB-LF 533±165(A), EB-NF 419±199(B), SE-HF 381±139(B), PB-HF 360±161(B), EB-HF 179±133(C). Depth of enamel wall-lesion at 25 µm (mean±SD): SE-NF 600±167(a), PB-LF 544±167(a), EB-NF 436±187(b), SE-HF 392±141(b), PB-HF 408±172(b), EB-HF 237±128(c). The groups with the same letter have no significant difference.

EB-HF group generated significantly smaller (p<0.05) wall lesion than all other groups. Wall lesions from PB-HF, SE-HF and EB-NF groups were similar to each other (p>0.05) but significantly smaller (p<0.05) than PB-LF and SE-NF.

Conclusion: Restoration using the combination of high-fluoride-releasing adhesive and high-fluoride-releasing composite exhibits significantly higher caries-inhibition effect than using them separately with non-fluoride/low-fluoride-releasing materials. Supported by NIH-COBRE grant #1P20RR020160-02