Method: Nanocubes with biocompatible polymeric shell and active ingredient core capable of anti-bacteria growth and tooth repair was synthesized using a two-solution phases precipitation under ultrasonication followed by deposition of polymeric coating. The physical properties of the derived nanocubes were characterized by Cryo-TEM, SEM-EDS, DLS and FTIR. Fluoride releasing kinetics, selective inhibition of cariogenic versus probiotic microorganisms as well as tooth re-mineralization capability were analyzed on human tooth preparations.
Result: The nanocube presented an average size of 150nm with a negative surface charge. Exposure of enamel slab to the particle containing aqueous solution for 2 minutes generate a homogenous surface coating. Fluoride releasing assay showed a sustained low dose release under neutral pH while in acidic environment (pH<5), a burst release was observed. Plaque forming assay showed a selective depletion of S. Mutants and preservation of probiotics such as S. Sanguis and S. salivaris. Remineralization was observed on an artificially created white spot lesion on human teeth.
Conclusion: A core shell nanocubes composed of a biocompatible pH responsive polymeric coating and a fluoride containing nanocrystal core was synthesized. The nanocube presented capability of active tooth surface adhesion and self-assembly as well as local oral flora balance modulation toward probiotics. Repair of demineralized enamel in human teeth was also evident. Such platform suggested a broad-spectrum of further new clinical disease preventive, restorative and general oral care strategic development.