Slow-release drug reservoir in implant reduces risk of infection
Scientists have developed a dental implant containing a reservoir for the slow release of drugs, which can prevent and eliminate bacterial biofilms, a major cause of infection associated with dental implants.
Mouth infections are often cited as the main reason for the failure of dental implants. This has led to researching ways to protect against infection, such as by developing an antimicrobial coating for the implant.
The lead author of the study, Dr. Kaat De Cremer, from the Centre of Microbial and Plant Genetics at KU Leuven in Belgium, explained that the reservoir in the implant can be filled by removing the cover screw. She went on to explain that because the implant is “made of a porous composite material, so that the drugs gradually diffuse from the reservoir to the outside of the implant, which is in direct contact with the bone cells. As a result, the bacteria can no longer form a biofilm.”
Biofilms are incredibly hard to treat, and, when they become chronic, are extremely resistant to antibiotics.
In their study paper, the researchers note that implant developers are increasingly using materials with rough surfaces because they enlarge the contact area, improving anchorage with bone cells and integration into the bone. However, greater surface area also increases the risk of biofilm development.
The new implant is a composite of a silicon-based “diffusion barrier” integrated into a porous, load-bearing titanium structure.
The researchers subjected the implant to various laboratory tests, during which they filled the reservoir with chlorhexidine. The tests showed that the implant stopped Streptococcus mutans, a common mouth bacterium, from forming biofilms. It also eliminated biofilms that were on the implant prior to loading the reservoir.
Researchers say that the results show that the implant is effective at both preventing and eliminating biofilms, and could potentially prevent and cure infections in patients.
Further research should now be done to show that the implants are effective in patients.
The authors concluded that the study “focuses on dental implant applications, but the concept could, in principle, be translated to any percutaneous implant that can incorporate an internal reservoir, such as percutaneous fixation devices, as long as this does not compromise the mechanical strength of such load-bearing devices.”
