Effective remineralizing effect on dentine
The natural repair mechanism of (initial) carious lesions works by calcium and phosphate ions from saliva repairing enamel defects quickly and effectively. To date, fluoride salts were the substance of choice to improve remineralisation. Fluoride ions cause the ions in the saliva to be integrated more quickly. For exposed dentine, as is the case with exposed tooth necks, the remineralisation potential of fluorides in the administered quantities is negligible. More and more studies show the potential of new biocompatible substances to repair carious lesions. Hydroxyapatite is a promising substance in this regard.
How effectively does hydroxyapatite remineralize enamel and dentine defects?
Material and methods
A total of 85 dentine samples and 70 enamel samples (from bovine teeth) were used for this in vitro study. These were divided into five equal groups and simulated artificial acid damage. A coating that is not acid-soluble was applied to each tooth as a reference. Then the teeth were cleaned twice daily for 2 minutes over a period of up to 5 weeks with the products (hydroxyapatite vs. amine fluoride) and then rinsed with deionised water. The samples were prepared for analysis so that transverse microradiography (TMR) could be performed. This method measures the mineral loss, as would happen after acid attacks. Then comparative statistics between the groups were prepared.
Better remineralisation could be observed with hydroxyapatite oral care products both for acid lesions of the dentine as well as the enamel compared to amine fluoride oral care products. The best results could be seen with pure hydroxyapatite compared to amine fluoride. All results were statistically significant.
Hydroxyapatite is able to remineralise acid lesions both in dentine and enamel and shows better effects than amine fluoride.
The publication of the study can be found here.
Source: Tschoppe, P., D. L. Zandim, P. Martus and A. M. Kielbassa (2011). “Enamel and dentine remineralization by nano-hydroxyapatite toothpastes.” J. Dent. 39: 430-437.