A Novel Biomimetic Approach to Repair Enamel Cracks/Carious Damages and to Reseal Dentinal Tubules by Amorphous Polyphosphate

Abstract

Based on natural principles, we developed a novel toothpaste, containing morphogenetically active amorphous calcium polyphosphate (polyP) microparticles which are enriched with retinyl acetate ("a-polyP/RA-MP"). The spherical microparticles (average size, 550 ± 120 nm), prepared by co-precipitating soluble Na-polyP with calcium chloride and supplemented with retinyl acetate, were incorporated into a base toothpaste at a final concentration of 1% or 10%. The "a-polyP/RA-MP" ingredient significantly enhanced the stimulatory effect of the toothpaste on the growth of human mesenchymal stem cells (MSC). This increase was paralleled by an upregulation of the MSC marker genes for osteoblast differentiation, collagen type I and alkaline phosphatase. In addition, polyP, applied as Zn-polyP microparticles ("Zn-a-polyP-MP"), showed a distinct inhibitory effect on growth of Streptococcus mutans, in contrast to a toothpaste containing the broad-spectrum antibiotic triclosan that only marginally inhibits this cariogenic bacterium. Moreover, we demonstrate that the "a-polyP/RA-MP"-containing toothpaste efficiently repairs cracks/fissures in the enamel and dental regions and reseals dentinal tubules, already after a five-day treatment (brushing) of teeth as examined by SEM (scanning electron microscopy) and semi-quantitative EDX (energy-dispersive X-ray spectroscopy). The occlusion of the dentin cracks by the microparticles turned out to be stable and resistant against short-time high power sonication. Our results demonstrate that the novel toothpaste prepared here, containing amorphous polyP microparticles enriched with retinyl acetate, is particularly suitable for prevention/repair of (cariogenic) damages of tooth enamel/dentin and for treatment of dental hypersensitivity. While the polyP microparticles function as a sealant for dentinal damages and inducer of remineralization processes, the retinyl acetate acts as a regenerative stimulus for collagen gene expression in cells of the surrounding tissue, the periodontium.

Engaging a Battle on Two Fronts: Dual Role of Polyphosphates as Potent Inhibitors of Struvite Nucleation and Crystal Growth

“…Moreover, it is interesting to point out that previous studies have demonstrated the presence of particles in solutions comprised of PolyPs and cationic species (e.g., Mg 2+ ions). Similar types of particulates containing PolyPs and inorganic divalent cations have also been observed in nature, such as granules in mitochondria, while synthetic analogues can be prepared in alkaline solutions with excess cations − for use in applications of bone regeneration and cartilage repair, among others.…”

Impact of Various Resin Adhesive Strategies on Micro Shear Bond Strength to Sound, Caries- Affected and Remineralized Dentin Substrates: An in-Vitro Esem Analysis

“…(21,22) Repair of demineralized collagen fibrils by mineral implementation within the gaps between the collagen fibrils was tried by the application of topical remineralizing agents such as casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) known as MI paste plus TM (16,(23)(24)(25)(26) CPP-ACPF is a remineralizing agent derived from the milk and can promote high degree of remineralization in enamel as well as dentin compared to fluoride gel or fluoride tooth paste. (27) It has a great potential to modulate bioavailability of Ca and P levels by stabilization of ionic super saturation of Ca and P to enhance the remineralization process and can bind to positively and negatively charged ions. (28) ACP is the controller of the precipitation of CPP.…”

Amorphous polyphosphate nanoparticles: application of the morphogenetically active inorganic polymer for personalized tissue regeneration

“…This sealant consists of biomimetic amorphous polyP microparticles that can be applied as bioactive ingredient of a toothpaste, mouth rinse, chewing gum or other oral care product. The polyP particles do not only efficiently close enamel/dentin cracks and fissures and carious cavities, but even induce re-mineralization in the treated enamel and dentin, as demonstrated recently by electron microscopy and synchrotron-based x-ray tomography microscopy (SRXTM) (Ackermann et al 2019) and show antimicrobial activity against the cariogenic bacterium Streptococcus mutans (Müller et al 2016b(Müller et al , 2017a(Müller et al , 2017c. This toothpaste repairs enamel defects after short-term treatment and reseals open dentinal tubules, which lead to hypersensitivity of the teeth.…”