Novel fluoride and stannous -functionalized β-tricalcium phosphate nanoparticles for the management of dental erosion

Objective: To evaluate the anti-erosive effect of solutions containing β-tricalcium phosphate (β-TCP) nanoparticles functionalized with fluoride or with fluoride plus stannous on enamel and dentin. Methods: β-TCP nanoparticles were synthesized and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Sixty enamel and dentin specimens were randomly allocated into the groups (n = 10): Control (water); F (NaF, 225 ppm F⁻); F + Sn (NaF + SnCl_2, 800 ppm Sn²⁺); F+β-TCP (F+40 ppm β-TCP); F + Sn+β-TCP (F + Sn+40 ppm β-TCP); F + Sn+100β-TCP (F + Sn+100 ppm β-TCP). Specimens underwent erosion-remineralization cycling (5 min immersion into 1 % citric acid solution and 60 min exposure to artificial saliva, 4×/day, 5 days). Immersion in the test solutions was performed for 2 min, 2×/day. Surface loss (SL, in μm) was determined by optical profilometry at the end of cycling. Data were analyzed using one way-ANOVA and Tukey's tests (α = 0.05). Results: XRD confirmed the β-TCP phase. TEM micrographs showed differences between the bare nanoparticle and the β-TCP functionalized with F and Sn. All enamel groups presented lower SL than the control, with F + Sn, F + Sn+β-TCP, and F + Sn+100β-TCP showing the lowest values. For dentin, all the groups had lower SL than the control. F+β-TCP presented the lowest SL, significantly differing from all the other groups. Conclusion: β-TCP nanoparticles functionalized with fluoride showed improved anti-erosive effect compared to the fluoride solution on dentin. There was no significant effect of the β-TCP nanoparticles functionalized with fluoride plus stannous in both substrates. Clinical Relevance: β-TCP nanoparticles are a promising agent to be added to oral health products to improve the protective effect of fluoride against dentin erosion.