The influence of implant-abutment corrosion products on bone metabolism

We have conducted a series of in vitro studies to measure corrosion products release under simulated accelerated corrosion conditions and test their effect on various cell lines.

Dr Lambis Petridis (Lead), Professor Jonathan Knowles,
Dr Ghada Alrabeah, Ms Matilde Duarte Silva, Mr Weerapong Anusornsit

The topic of peri implant bone loss around dental implants is of a major importance as it is a key parameter in implant success. We hypothesised that the release of corrosion products from the implant-abutment complex may contribute to the disruption of bone metabolism around dental implants. The improved peri-implant bone response demonstrated by various implant-abutment connection geometries, such as platform switching, may be the result of a reduced amount of metal ions released to the surrounding tissues.

Activities and Results

We have conducted a series of in vitro studies to measure corrosion products release under simulated accelerated corrosion conditions and test their effect on various cell lines (primary human osteoblasts and gingival epithelial cells).

The results have demonstrated, for the first time, how tribo-corrosion occurs at the implant-abutment interface, leading to the release of both metal ions and particles. These levels of metal ions resulted in an increase in the expression and secretion of cytokines and chemokines related to bone resorption from human osteoblastic cells. They also partially affected the function of human gingival epithelial cells.

Therefore, the current findings of this project, together with the ongoing work of the same research group, are initial steps towards proving the proposed theory of the possible role of corrosion products in the mediation of crestal bone loss around dental implants. If this theory is proved it will have a significant impact in the field of implant dentistry as a whole as well as the dental implant industry as it will lead to the re-thinking of materials as well as possibly exploring some patient-related factors when planning dental implants.

Impact and next steps

UCL Eastman is one of the few centres in the world looking into this theory. Our work has already attracted attention with papers published in top IF ranking Dental Journals. Dr Petridis was an invited speaker on the topic during the Southern Implants World Forum 2018 and at the ITI UK and Ireland Meeting the same year. Dr Alrabeah presented an Oral presentation during the recent Academy of Osseointegration meeting in Los Angeles. Dr Alrabeah and Mr Anusornsit will make oral presentations during the upcoming IADR meeting in London (July 2018) and Mrs Duarte Silva has a poster accepted for the same meeting.

More work is currently being done on this subject and more PhDs have joined the research team. The team is also expanding the collaborations within EDI, UCL and beyond.