A Potassium Based Fluorine Containing Bioactive Glass for Use as a Desensitizing Toothpaste

Abstract

Potassium releasing bioactive glasses (BAGs) may offer improved relief for dentine hypersensitivity compared to conventional sodium containing BAGs by releasing K+ ions for nerve desensitization and occluding dentinal tubules to prevent fluid flow within dentinal tubules. Potassium oxide was substituted for sodium oxide on a molar basis in a fluoride containing BAG used in toothpastes for treating dentine hypersensitivity. The BAG powders were then immersed in an artificial saliva at pH 7 and tris buffer and the pH rise and ion release behavior were characterized by ICP-OES and ISE. The potassium and sodium containing BAGs were characterized by XRD, DSC, FTIR and NMR. Both BAGs presented amorphous diffraction patterns and the glass transition temperature of the potassium glass was higher than that of the sodium glass. The 31P MAS-NMR spectra indicated a peak at 2.7 ppm corresponding to apatite and a small peak at −103 ppm indicated crystallization to fluorapatite. Both BAGs dissolved and formed apatite at similar rates, although the dissolution of the potassium glass was slightly slower and it released less fluoride as a result of partial nanocrystallization to fluorapatite upon quenching. The potassium release from the potassium ions could potentially result in nerve deactivation when used in toothpastes.

The unexplored role of alkali and alkaline earth elements (ALAEs) on the structure, processing, and biological effects of bioactive glasses

“…Potassium-containing BGs have shown increased performance in dental applications due to the desensitization properties of K + . 165 For example, Na 2 O was fully replaced with K 2 O, on a weight basis, in the BioMinF composition (36)(37)(38)(39)(40) SiO 2 -(28-30)CaO-(22-24)Na 2 O-(4-6)P 2 O 5 -(1.5-3)CaF 2 to determine the improvement on dissolution rates, apatite forming ability, and the eventual suitability for dentin hypersensitivity treatment. Static dissolution studies showed nearly equivalent performance of both parent BioMinF and K-substituted BioMinF with similar dissolution rate, pH change, and precipitation of fluorapatite.…”

“…Several further studies have been published showing that potassium-based compositions provide therapeutic effects through blocking nerves in dentin tubules while also aiding in dental restoration. 165,348 4.1.4 Rubidium 4.1.4.1 Biological activity. Rubidium has no known natural biological role.…”