I’ve always been fascinated with the balance of things. Like how radar guns are used to detect speeders and then radar detectors (fuzz-busters) were invented. Like how fungi fight bacteria by making penicillin, and then bacteria become resistant.
It seems that bacteria have had a secret weapon to accelerate tooth decay. Fluoride has long been used to fight tooth decay. The main action is through the binding of fluoride to the enamel of the tooth. But, researchers found long ago that high levels of fluoride will be toxic to most bacteria. Recently Yale researchers discovered that bacteria have a weapon against fluoride- the riboswitch. This process can detect the build-up of fluoride and activate the defenses of bacteria, including those that contribute to tooth decay.
We should have known that these little test tubes of evolution would come up with something! These riboswitches appear to not be a recent adaption and the mechanism seems only to be triggered for the survival of the organism. So it probably won’t affect the way dentistry uses fluoride for tooth decay, coating the tooth to prevent the attack from causing damage. Bacteria could use this pathway in the future to become resistant to the actions of current toothpastes and mouthwashes. Of course much more research is needed. Be assured that dentistry will continue to emphasize prevention as the best way to fight disease.
Jenny L. Baker, Narasimhan Sudarsan, Zasha Weinberg, Adam Roth, Randy B. Stockbridge, and Ronald R. Breaker.Widespread Genetic Switches and Toxicity Resistance Proteins for Fluoride. Science, 22 December 2011 DOI:10.1126/science.1215063