The effect of microstructured surfaces and laminin-derived peptide coatings on soft tissue interactions with titanium dental implants.

In the present study, we investigated the dental implant protection from peri-implant inflammation by improving the soft tissue adhesion on the titanium surface. Porous titanium was used to create, at the level of the transmucosal part of the implants (the "neck"), a microstructured 3-dimensional surface that would tightly seal the interface between the implant and soft tissue. Cell-specific adhesion properties were induced via an adhesion peptide derived from laminin-5 coupled to native or cross-linked PLL/PGA multilayered polyelectrolyte films (MPFs), which are used for biomedical device coatings. Porous titanium exhibited good cell-adhesion properties, but the colonisation of the material was further improved by a coating with laminin-5 functionalised MPFs and especially with (PLL/PGA)(6,5)-PGA-peptide film. Focal contact formation was observed on cross-linked architectures, reflecting cell anchorage on these surfaces. In contrast, when seeded on laminin-5-functionalised native films, epithelial cells formed only very diffuse focal contacts, but adhered via hemidesmosome formation. In vivo experiments confirmed that the porous titanium was colonised by cells of soft tissue. Altogether, the results indicate that the microstructure of the implant neck combined with a specific bioactive coating could constitute efficient routes to improve the integration of soft tissue on titanium dental implants, which could significantly protect implants from peri-implant inflammation and enhance long-term implant stabilisation.