In an effort to lower the risk of infection and improve the long-term effectiveness of dental implants, researchers with the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in cooperation with industry partners - have developed a new type of implant coating.
Each year millions of dental implants are inserted. They often need to be replaced because of issues such as tissue infections caused by bacteria because when dental implants acquire a bacterial infection it carries a high risk of jawbone degeneration. When an artificial dental root is implanted it sets off a race between infectious pathogens and the bodys cellular defenses. If the bacteria wins then they form a biological film over the titanium to protect themselves from antibiotics. When the implant gets colonized by germs the result is an inflammatory reaction which can result in bone atrophy.
The researchers hope that these infections will be prevented in the future with the new plasma implant coating which kills pathogens with the use of silver ions. This implant will also lower the risk of infection and improve long-term effectiveness of the implant.
How It Works
The researchers integrated silver nanoparticles into the thin plasma polymer coating which is 100 nanometers thick. The silver nanoparticles dissolve over several weeks and continuously release small quantities of anti-microbial silver ions which kill bacteria. By combining surface materials that feature physical and chemical properties, the DentaPlas coating helps prevent bacteria growth and allows the implant to properly attach and form a faster and more permanent bond with the jawbone. "We have given the DentaPlas coating a rough texture, which promotes cellular growth, in addition to combining it with a hydrophilic plasma polymer coating, which attracts moisture," said Dr. Ingo Grunwald, project manager at the IFAM.
"The DentaPlas system consists of three layers, with two plasma polymer layers surrounding a center layer of silver, added developed Dr. Dirk Salz. Within this structure a biocide reservoir is formed, and the outermost layer releases the ions. This is beneficial because it prevents direct contact between the tissue and the silver particles, which can be toxic when exposed."
The researchers can also tailor the silver concentration as well as the thickness and porosity of the layers so the silver ions can penetrate the outermost plasma polymer layer over a set period of time necessary to properly integrate the implant. When the silver reservoir is exhausted no more silver ions are released which avoids any long-term toxic effects.
Passing With Flying Colors
In trials using finished implants and titanium test samples, the IFAM researchers demonstrated that the DentaPlas coating is not only anti-microbial but also fully biocompatible and sterilizable. The test samples were coated using a plasma polymerization facility at the IFAM in Bremen. Researchers confirmed the mechanical stability and robustness of the DentaPlas coating in trials using the lower jawbones of pigs taken from butcher shops. Here, they subjected the DentaPlas coated implants to the rigors of being screwed into place using the instruments found in modern dental practices. The DentaPlas coating passed this stress test with flying colors.