ODONTOLOGY, 2025 (SCI-Expanded)
The objective of the present study was to evaluate the efficacy of experimental varnishes containing theaflavin (TF-2a/2b) against erosive demineralization and matrix metalloproteinase enzymes (MMPs) and investigate the bonding properties of TFs to MMPs. Enamel and dentin samples, measuring 3 x 5 x 2 mm, were extracted and immersed in citric acid solution for 60 s to induce artificial erosive lesions. The samples were then randomly allocated into six experimental groups and one control (fluoride) group (n = 6). Experimental groups were treated with different varnish formulations of resin-, polymer-, or resin + polymer-based varnishes containing either TF-2a or TF-2b. Following immersion in artificial saliva, all samples were subjected to a 5-min pH cycle for 5 days. Mineral density (MD) values were assessed using MicroCT, and expression levels of MMPs were evaluated by Western Blot. In silico analyses of both TFs were conducted against MMP-2 and MMP-9. Mineral density values of all groups increased significantly following the pH cycle [TF-2b resin + polymer-based (p = 0.023); all other groups (p = 0.026)]. Varnishes based on TF-2b demonstrated numerically superior results in MD scores, but resin-polymer-based TF-2a showed better MMP expressions than other groups. The binding energies of both tested TFs with MMP-2 and MMP-9 were determined to be similar. Profile analysis of both TFs are also indicated to be effective against the activity of MMPs. Therefore, resin-based TF-2a and TF-2b experimental varnishes may serve as viable natural alternatives to fluorides in managing dental erosion.