Team:Warwick/HP/Gold Integrated
Integrated Human Practices
During our initial research phase, we contacted Dr. Cyril Voisard, the Head of the Medical Division at Medicoat, a Swiss company who specialize in plasma spraying and implant coatings. We asked whether calcium, particularly calcium phosphate, was critical for implant coatings, as we had come across several papers about how it can improve osteoconduction. After speaking to Dr. Voisard, we established that calcium was not needed for osseointegration and that it was structural features that decided how well bone adhered. From this, we decided that we could 3d print in any biocompatible material, and settled on cellulose.
After conducting our research, and talking to Dr. Malik in particular, we recognized that we had to design our project with three key properties in mind.
Our cellulose surface coating must:
1. Successfully adhere to titanium implant structures both in the short and long term
2. Be osseoconductive and osseoinductive
3. Have antimicrobial properties to reduce the risk of bacterial infection
We discovered that sand blasted and acid etched titanium implants integrate well with bone and allow shorter and narrower implants to be used. However, the microscopic recesses created by this rough surface can encourage bacterial infections to occur. After learning this, we aimed to create an implant surface coating which, unlike Hydroxyapatite, adheres well to the titanium implant as well as bone, thus reducing the risk of late failure. After surgery, a dental implant undergoes initial stability with mechanical loading, i.e. the implant is effectively ‘screwed’ into the bone. However, we’re aiming to improve secondary integration, which would reduce initial healing time, increase long-term stability and subsequently the improve the lifespan of the implant.
One of our biggest concerns was achieving an aseptic surface coating with long-lasting antimicrobial properties. We spoke to experts from the Warwick Antimicrobial Interdisciplinary Centre and put devised a plan for overcoming this issue:
- Creation of a continuous supply of high concentration antibiotic
- Covalent attachment of the antibiotic to the surface coating
- Antibiotic release to be triggered only in the presence of bacteria
UV light treatment of titanium implants has been reported to increase BIC from 55% to a near maximum level of 98.2% in an animal model [5]. The increased BIC resulted in a threefold increase in the strength of bone to implant integration. This subsequently was shown to significantly reduce the risk of peri-implantitis post-healing [6][7]. We therefore resolved to include UV treatment within our design. The surface coating would be produced using our 3D printer, and then the entire surface would be treated with ultraviolet light.
It is important to note that although our research has largely focussed on dental implants, there is no reason why the same principles couldn’t be applied to other types, such as titanium hip or knee implants.
After conducting our survey into public opinions, we decided that we wanted to major on outreach and public engagement activities. We organised a series of events, ranging from a lab-based day for A-level students to accessible lectures for members of the public. You can find out more here: Public Engagement
References:
[1] Simonis P, Dufour T, Tenenbaum H. Long-term implant survival and success: a 10-16-year follow-up of non-submerged dental implants. Clin Oral Implants Res. 2010;21:772–777.
[2] Vanchit John, Daniel Shin, Allison Marlow, and Yusuke Hamada, “Peri-Implant Bone Loss and Peri-Implantitis: A Report of Three Cases and Review of the Literature,” Case Reports in Dentistry, vol. 2016, Article ID 2491714, 8 pages, 2016. doi:10.1155/2016/2491714
[3] Mombelli, A. "Microbiology and antimicrobial therapy of peri-implantitis," Periodontology 2000 2002;28:177–189.
[4] https://geneticliteracyproject.org/2015/05/18/food-genetic-engineering-and-public-opinion-do-popular-concerns-matter/
[5] Aita H, Hori N, Takeuchi M, et al. The e ect of ultraviolet functional- ization of titanium on integration with bone. Biomaterials 2009;30: 1015–1025.
[6] Ogawa T. UV photofunctionalization of titanium implants. J Cranio- fac Tissue Eng 2012;2:151–158.
[7] Att W, Ogawa T. Biological aging of implant surfaces and their restoration with ultraviolet light treatment: A novel understanding of osseointegration. Int J Oral Maxillofac Implants 2012;27:753–761.
