Approach for Treating Tooth Hypersensitivity

A promising new approach for treating tooth hypersensitivity, while simultaneously preventing bacteria from causing further harm, has been indentified by researchers at the New York University (NYU) College of Dentistry. In the study, a coating made from fluoride and zinc ions in a calcium-phosphate matrix proved effective in reversing damage to the tubules caused by Streptococcus mutans. The coating not only caused the exposed tubules to close again, but also prevented S mutans from causing further damage. Tooth hy­persensitivity occurs when the den­tin becomes exposed, causing tu­bules to open up. When open tubules come in contact with cold, hot, sweet, or acidic substances, painful stimuli are transmitted to the tooth nerve. Typically, hypersensitivity is caused by oral bacteria, which attach to the tooth surface and leave an acidic residue of tartar and plaque. Most toothpastes, protective strips, and other treatments for tooth hy­persensitivity utilize potassium oxa­late to close the tubules. But potassium oxalate cannot prevent a recurrence of tooth hypersensitivity be­cause it is highly susceptible to the effects of acids in tartar, plaque, citrus drinks, and other liquids. In­ves­tigators compared 2 groups of dentin samples immersed for 24 hours in a solution containing S mutans. One group was treated for 8 minutes with the calcium-phosphate/fluoride/zinc formulation, while the second group received no treatment. Bacteria multiplied on the untreated samples, but their growth and development was inhibited on the treated dentin. In addition, the treated group had significantly fewer open tubules than the untreated one. The calcium, phosphate, and fluoride ions formed a solution that occluded the open dentin tubules, and the zinc ions inhibited bacterial growth and colonization, suggesting that this formulation may represent a tooth hypersensitivity treatment that is less susceptible to the effects of acid than treatments made with potassium oxalate. Additional testing is planned to confirm the findings.