"Smart materials" invented at the National Institute of Standards and Technology (NIST) soon may be available that stimulate repair of defective teeth. Laboratory studies show that these composites, made of amorphous (loosely structured) calcium phosphate embedded in polymers, can promote re-growth of natural tooth structures efficiently. In the presence of saliva-like solutions, the material releases calcium and phosphate ions, forming a crystalline calcium phosphate similar to the mineral found naturally in teeth and bone. Developed through a long-standing partnership between NIST and the American Dental Association (ADA), these bioactive, biocompatible materials are described in a forthcoming paper in the NIST Journal of Research.
Plans are being made for clinical trials, and several companies have expressed interest in licensing the patented material once a production-ready form is available. Initial applications include adhesive cements that minimize the decay that often occurs under orthodontic braces. The material also can be used as an anti-cavity liner underneath conventional fillings and possibly in root canal therapy.
NIST and ADA scientists continue to enhance the material's physicochemical and mechanical properties and remineralizing behavior, thereby extending its dental and even orthopedic applications. For example, the researchers found that adding silica and zirconia to the material during processing stabilizes the amorphous calcium phosphate against premature internal formation of crystals, thereby achieving sustained release of calcium and phosphate over a longer period of time.
The work is funded through a grant from the National Institute of Dental and Craniofacial Research.