According to the American Academy of Implant Dentistry, two in three Americans have one or more missing teeth. To deal with this issue, American dentists perform more than five million dental implants a year. About 1% to 15% of the patients receiving implants experience dental implant failure that results in the destruction of soft tissue and bone around the implant. Our study documented the release of titanium into the surrounding plaques of patients with and without dental implant failure, which means that titanium is not as inert as we once thought it was. We showed that the electrical conductivity of titanium implants was responsible for the corrosion process. Using a bioreactor that simulated an implant in a patient’s mouth, we were able to control the electrical current spontaneously generated by the biofilm by turning it on or off. When the current was turned on, the dental implant released titanium into solution. However, when the current was turned off, much less titanium was released. From these experiments, we hypothesized the existence of a ‘vicious cycle’ in which bacteria in corrosive biofilms use the titanium for their growth, which is presumably linked to the generation of organic and inorganic acids from bacterial metabolism.
The take-home message from our study is two-fold: designing dental implants that do not conduct electricity could probably prevent biocorrosion and hence, dental implant failure; and, it might be possible to address implant failures by reversing the current flow of the implant, which is essentially manipulating the bacterial biofilms.
The article describing this research was published in the journal PlosOne on October 13, 2015. The research article is entitled: “Interruption of Electrical Conductivity of Titanium Dental Implants Suggests a Path Towards Elimination Of Corrosion”.