Development of hexamethyldisiloxane films incorporated with chlorhexidine onto titanium surface: antimicrobial potential and cytotoxicity

Abstract

A stable connection between the implant titanium surface/abutment and periimplant soft tissues is an important approach for the long-term success of dental implant. Thus, such surface should minimize the bacterial colonization while allowing a good adhesion of the oral tissues. Therefore, the objective of this research project is to develop hexamethyldisiloxane films incorporated with different concentrations of chlorhexidine (CHX) (0 - control, 0.35, 0.70 and 1.40% - w/w) onto commercially pure titanium (cpTi) surface and to evaluate their antimicrobial potential and cytotoxicity. Machined surface will also be used as control. Discs surfaces will be characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM), x-ray diffraction analysis (XRD), surface roughness, Raman spectroscopy, film thickness, wettability and surface free energy. In the microbiological assay, biofilm of Streptococcus sanguinis will grow on discs surfaces during 2 hours (biofilm adhesion) and 48 hours (mature biofilm). The colony forming units will be determined and confocal laser scanning will be used to investigate the biofilm structure. High performance liquid chromatography analysis is used to quantify the amount of drug released as a function of time. Another microbiological assay will be performed after stabilization of chlorhexidine release. For the cytotoxicity assay cultures of fibroblasts will be used and the cell morphology and viability, genes and collagen expressions will be determined. Quantitative data will be statistically analyzed at a significant level of 5%. The number of samples for each assay will be determined by a pilot study.