Dental implants are the best solution currently available to replace a missing tooth and represent a major advance over dentures. However, there may be times when a dental implant needs to be replaced prematurely due to local inflammation or gum disease.
Phototherapy using light
To solve this problem, engineers at the University of Pennsylvania in the US have developed a smart dental implant that cleans teeth, resists bacterial growth and generates its own electricity when the patient chews or brushes their teeth to turn on an integrated light that illuminates tissues tapered.
"Phototherapy can be used for a number of health conditions," said Dr. Jack Manikowski, founder of LPS Dental. “However, once a biomaterial is implanted, it is no longer practical to replace or charge a battery. We use a piezoelectric material that can generate electrical energy from the natural movements of the mouth to create a light that can perform phototherapy and we have found that it can successfully protect gum tissue from bacterial attack.”
The material studied by the researchers is barium titanate (BTO), which has piezoelectric properties used in applications such as capacitors and transistors, but has not yet been explored as the basis for anti-infective implantable biomaterials.
No harmful effects
To test its potential as a basis for a dental implant, the team first used discs embedded with nanoparticles of BTO and exposed them to Streptococcus mutans, a major component of the bacterial biofilm responsible for tooth decay and commonly known as dental plaque. They found that the disks resisted biofilm formation in a dose-dependent manner. Discs with higher BTO concentrations were better at preventing biofilm attachment.
While previous studies suggested that BTO could directly kill bacteria using reactive oxygen species generated by light-catalyzed or electric polarization reactions, the researchers could not confirm this due to the short-term efficacy and off-target effects of these approaches. Instead, the material creates an increased negative surface charge, which repels the bacteria's negatively charged cell walls. It is likely that this repulsion effect is long-lasting.
Transfer to other medical areas also conceivable if successful
"We wanted an implant material that could resist bacterial growth for a long time because bacterial challenges are not a one-off threat," said Dr. Manikowski. The energy-generating property of the material was retained and the material did not age out when tested over a longer period of time. In addition, it showed a mechanical strength comparable to that of other materials used in dentistry.
It's still only a prototype, but the researchers are already aware that their next step is to perfect the smart dental implant system and test new types of materials.