Physical properties and enamel remineralization potential of arginine-fluoride varnishes

The study objectives were to examine the physical properties and enamel remineralization potential of fluoride (F) varnishes incorporated with arginine (Arg). Four commercial F varnishes: 1) Duraphat®; 2) Flúor Protector®, 3) Fluor Protector S®, and 4) Fluorimax™ were supplemented with 2% w/v. Arg. The control/experimental varnishes underwent rheometric analysis to assess varnish density (δ), velocity (ν), and associated viscosity, both quantitatively (ν/δ) and qualitatively based on determined mass, volume, distance flow, and time under experimentation. The varnish wet/dry weights (at 2 h) were also analysed. Further, sound enamel specimens (T0) with artificial incipient caries-like lesions (T1) were treated with control/experimental varnishes and subjected to remineralization assay with artificial saliva for 6 h. Thereafter (T2), the specimens were characterized to estimate precipitated Ca and net enamel F uptake. Additionally, mineral density (MD) was assessed using micro-CT at T0, T1, and T2 to derive mineral gain (MG) and % remineralization for the treatment groups. When Arg is incorporated, the physical properties of the F-containing varnishes undergo a significant transformation, resulting in higher density, varnish weight, dry varnish weight, and viscosity compared to their respective control varnishes (p < 0.05). Incorporating Arg-in Duraphat®, Fluor Protector S®, and Fluorimax™ significantly improved both enamel Ca precipitation and F uptake compared to the respective controls (p < 0.05). Additionally, the enamel F uptake was significantly higher with all the tested varnishes when enriched with Arg (p < 0.05). The combined data for MD, MG, and % remineralization suggests that the remineralization potential of F-varnishes significantly increased when enriched with Arg (p < 0.05). Incorporating Arg in inorganic F varnishes improves their physical properties and enhances the enamel remineralization potential of the varnishes. This study highlights the possibility of incorporating Arg in distinct F-source varnishes. The synergism between active components (Arg-F) aids in enhanced remineralization and superior varnish physical properties, demonstrating a promising approach for high caries-risk patients.