Bioactive Glasses

How Bioactive Glasses Work

Bioactive glasses are a group of surface reactive glass-ceramic biomaterials. The biocompatibility of these glasses has led them to be investigated extensively for use as implant materials in the human body to repair and replace diseased or damaged bone.

Bioactive glasses dissolve faster under acidic conditions than neutral or basic conditions.

Thus when faced with an acid challenge as a result of bacteria metabolising sugars or drinking an acidic beverage the glass dissolves quickly raising the pH and releasing calcium phosphate and optionally fluoride ions to minimise the acid dissolution of the enamel apatite crystals.

Five inorganic reaction stages are commonly thought to occur when a bioactive glass is immersed in a physiological environment:

  1. Ion exchange in which modifier cations (mostly Na+) in the glass exchange with Hydronium ions in the external solution.
  2. Hydrolysis in which Si-O-Si bridges are broken, forming Si-OH Silanol groups, and the glass network is disrupted.
  3. Condensation of Silanols in which the disrupted glass network changes its morphology to form a gel-like surface layer, depleted in Sodium and Calcium ions.
  4. Precipitation in which an amorphous calcium phosphate layer is deposited on the gel.
  5. Mineralisation in which the Calcium Phosphate layer gradually transforms into Crystalline Hydroxyapatite, that mimics the natural mineral phase.

Bioactive Glasses are used in both BioMin™ F and BioMin™ C toothpaste using different formulations.
Find out how BioMin™ differers from a Novamin® based toothpaste additive.

Novamin® is a registered trademark of GlaxoSmithKlinePLC (GSK).