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 beta-tricalcium phosphate (beta-TCP) nanoparticles functionalized with fluoride or with fluoride plus stannous on enamel and dentin. Methods: beta-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+SnCl2, 800 ppm Sn2+); F+beta-TCP (F+40 ppm beta-TCP); F+Sn+beta- TCP (F+Sn+40 ppm beta-TCP); F+Sn+100 beta-TCP (F+Sn+100 ppm beta-TCP). Specimens underwent erosion-remineralization cycling (5 min immersion into 1 % citric acid solution and 60 min exposure to artificial saliva, 4x/day, 5 days). Immersion in the test solutions was performed for 2 min, 2x/day. Surface loss (SL, in mu m) was determined by optical profilometry at the end of cycling. Data were analyzed using one way-ANOVA and Tukey's tests (alpha=0.05). Results: XRD confirmed the beta-TCP phase. TEM micrographs showed differences between the bare nanoparticle and the beta-TCP functionalized with F and Sn. All enamel groups presented lower SL than the control, with F + Sn, F+Sn+beta-TCP, and F+Sn+100 beta-TCP showing the lowest values. For dentin, all the groups had lower SL than the control. F+beta-TCP presented the lowest SL, significantly differing from all the other groups. Conclusion: beta-TCP nanoparticles functionalized with fluoride showed improved anti-erosive effect compared to the fluoride solution on dentin. There was no significant effect of the beta-TCP nanoparticles functionalized with fluoride plus stannous in both substrates. Clinical Relevance: beta-TCP nanoparticles are a promising agent to be added to oral health products to improve the protective effect of fluoride against dentin erosion.