A novel chlorhexidine-hexametaphosphate coating for titanium with antibiofilm efficacy and stem cell cytocompatibility

Abstract

Dental implants are an increasingly popular way to replace missing teeth. Whilst implant survival rates are high, a small number fail soon after placement, with various factors, including bacterial contamination, capable of disrupting osseointegration. This work describes the development of chlorhexidine-hexametaphosphate coatings for titanium that hydrolyse to release the antiseptic agent chlorhexidine. The aim was to develop a coating for titanium that released sufficient chlorhexidine to prevent biofilm formation, whilst simultaneously maintaining cytocompatibility with cells involved in osseointegration. The coatings were characterised with respect to physical properties, after which antibiofilm efficacy was investigated using a multispecies biofilm model, and cytocompatibility determined using human mesenchymal stem cells. The coatings exhibited similar physicochemical properties to some implant surfaces in clinical use, and significantly reduced formation of multispecies biofilm biomass up to 72 h. One coating had superior cytocompatibility, with mesenchymal stem cells able to perform normal functions and commence osteoblastic differentiation, although at a slower rate than those grown on uncoated titanium. With further refinement, these coatings may have application in the prevention of bacterial contamination of dental implants at the time of surgery. This could aid a reduction in rates of early implant failure.

Overview of strategies to improve the antibacterial property of dental implants

“…Garner et al developed a CHX-hexametaphosphate coating for Ti surfaces and investigated its antimicrobial properties using a multispecies biofilm model, and determined its cytocompatibility with human mesenchymal stem cells (MSCs). The coating showed a significant reduction in multispecies biofilm formation within 72 h and had excellent cytocompatibility, allowing MSCs to perform their functions and differentiate into osteoblasts normally ( Garner et al, 2021 ). Matos et al prepared multifunctional CHX-doped thin films on pure Ti using the glow discharge plasma approach, where the release of CHX peaked at day 8 and maintained a slow release for 22 days.…”