Functional layer-by-layer coatings for implant abutment surfaces: investigating the effect of controlled release of antibacterial agents on cytokine signaling and production of inflammatory mediators induced by Porphyromonas gingivalis LPS

Abstract

Peri-implantitis, a polymicrobial infection around dental implants that leads to the inflammation of peri-implant tissue followed by a progressive damage of alveolar bone, is related not only to the quantitative presence of microorganisms, but also to the virulence of the pathogens adhered onto the surfaces. In this context, Porphyromonas gingivalis (P. gingivalis) played as one of the predominant etiologic agents in peri-implantitis since expresses a variety spectrum of virulence factors. Once P. gingivalis and its products bind to toll-like receptor (TLR) on gingival epithelial cells and human fibroblasts, an inflammatory responses is stimulated resulting in further destruction of connective tissue and bone. Therefore, strategies to reduce pathogenic bacteria adhesion on dental implant components or inhibit the virulence factors from these microorganisms have been investigated in order to achieve desired properties by coatings development. Among the constituted parts from a dental implant, abutment has gained a steadily more important role in conserving implant health due to its intimate contact with the marginal mucosa. However, to our knowledge, the scientific literature still is restricted in terms of modifications to abutment surfaces maybe due to characteristics required for treatment success, such as low roughness, antimicrobial properties and absence of cytotoxicity. Hence, we aim to develop a new coating to titanium implant abutment surfaces, increasing the functionality of layer-by-layer (LbL) films by means of antimicrobial peptide delivery to inhibit P. gingivalis growth and prevent peri-implant disease. Our first goal will be to evaluate the effect of the modified titanium surface on pathogenic bacteria attachment. Then, we will investigate the capacity of those bacteria adhered to activate an inflammatory response. For that, we will analyze if the coating will change gene expression profiles involved in the protein production/secretion responsible for bone resorption. (AU)