In-Silico Modelling and 3D-printing of Dental Implants with Photo-active and Infection-Resistant Coatings (PERIo-Dent-ItiS)

Peri-implantitis is an infection-related condition around the implant, which occurs because of inflammation arising from the acidic interstitial fluid, produced by the presence of bacteria in the biofilm. The biofilms form on the peripheral surface of implants. The acid slowly resorbs the healthy bones, enervates soft-tissue anchorage, loosens the implant, and causes pain. Loss of mechanical support also aggravates the pain and, therefore, compromises the chewing and mastication which are essential for the easier digestion of food. Although, the success rate of implants is 85-90%, however, 10-15% implants fail during lifetime because of the lack of early diagnosis. The diagnosis of failed implants is poor and only when the pain is felt, the patients are prescribed pain killers, monitored before the surgical intervention removes the implant.

Innovative Vision: With increasing 50+-years age group needing more implants, there is an urgent need for improving the implants for better osseointegration for preventing mechanical failure. Our goal is to provide infection resistance against bacteria and to design means for ascertaining early signs of biofilm formation. During secondment at Attenborough Dental (AD) in Nottingham, the secondee will use the 3D-printing and Additive Manufacturing facility for fabricating implants for promoting the formation of a strong hard-soft tissue anchorage, and vascularization which will intrinsically prevent the risk of infection from bacteria. The materials patented (PCT/GB2015/052557) at the University of Leeds will form the basis for developing new generations of infection-resistant and photo-responsive implants for the early signs of detection of infection.

Objectives: The four objectives are: O.1) to demonstrate in silico and biomechanical modelling approach for the fabrication of standard implants with infection-resistance and photo-responsive coatings, designed from calcium phosphate with CeSr-oxide (CeSrOx)/chitosan as the antibacterial and Europium-Samarium oxide (EuSMOx) as photo-responsive coating, respectively.

O.2) We will adopt the steps in O.1 and demonstrate the fabrication of porous Ti-implants for improved micro-fluidics and osseointegration with infection resistance and photo-responsive features for non-invasive diagnostics. The porosity control for microfluidic properties is essential for infection control, improved vascularization, and strong tissue anchorage.

O.3) The UoL-AD team will review in silico and biocompatible modelling for design and fabrication of route analogues using 3D-AM with the porous Ti-alloy structure. Such a new design offers one-step surgery for improved osseointegration, infection resistance (CeSrOx), and methods for monitoring healing by interrogating the photo-active EuSmOx layer.

O.4) We will focus on microstructural and physical characterizations, stress analysis, bio-compatibility (toxicity, attachment, proliferation), osteogenesis and angiogenesis, and photo-active response in cellular and simulated oral fluid condition of implant materials which will be essential for future animal studies.

Secondee: A full-time secondment will fulfil the goals of each objective. The secondment will develop the digital imaging approach for controlling the porosity and bio-mechanical stress using 3D-printing and additive manufacturing facility at AD. The manufacturing of implants with the standard Ti-alloy powder, CeSrOx and EuSmOx mixed with calcium phosphate will be demonstrated, and the properties of implants will be characterized using the state-of-the-art analytical and modelling facilities at AD and UoL. The results of fabrication and characterization will be used for ascertaining the longevity of implants in the oral environment under acidic condition. The training will also aim towards developing business-relevant skills. Important non-confidential results will be published in the peer-reviewed journal, after securing the patent position.

The proposed secondment is a collaboration between the University of Leeds and Attenborough Dental (AD) in Nottingham. AD aims to demonstrate a novel 3D-printing and additive manufacturing process for new generations of dental implants. These implants are targeted to minimize the risk of infection, which causes the peri-implantitis, which is often observed in 10-15% of patients with implants. In the case of peri-implantitis, the implants fail due to loosening. The symptom also occurs in combination with the prevalent bacterial infection around the implant surface where the acidic fluid slowly resorbs healthy bone. The bone resorption may accelerate under the chewing and mastication. Currently, there is no long-term solution for early detection of the onset of bacterial infection until the pain starts, which implies that the infection has spread and surgical intervention might be necessary, depending on the acuteness of peri-implantitis.

The number of cases of peri-implantitis is rising at 6% per annum in the 50+ years age group. A solution must be found which must be able to minimize the risk of peri-implantitis by improving the implant design.
The industrial secondment at AD aims to demonstrate a new paradigm in implant manufacturing by transferring the knowledge from UoL and by building a co-creation approach for manufacturing via research in the following areas:

a) by providing CAD implant design which will be porous instead of solid Ti-alloy. Novel design will offer a much better opportunity for implant-tissue integration;

b) by designing biomechanically robust implant which in the oral acid condition does not fail and curtails bacterial infection; and

c) by forming infection resistant film on the implant which protects against bacterial infection, and allows blood vessels to grow inside and around the porous implant for minimizing infection.
AD will benefit from knowledge exchange during the secondment by training a person for industry.