Focal adhesion contact formation by fibroblasts cultured on surface‐modified dental implants: an in vitro study

Abstract

A major consideration in designing dental implants is to create a surface that provides strong attachment of the implant to bone, connective tissue and epithelium. The aim of the present study was to examine the influence of different treatments of titanium (Ti) implant surfaces on focal adhesion contact (FAC) formation in fibroblast cultures. Human gingival fibroblasts were cultured on glass sheets and polished Ti discs with different surface coatings (applied by physical vapor deposition (PVD): Ti, titanium nitride (TiN), zirconium nitride (ZrN)) or on Ti discs with different surface topographies. For characterization of all surfaces, modified estimation of surface roughness and spacing parameter was carried out using a contact stylus profilometer. Contact angle measurements were carried out to calculate surface energy. Fibroblasts were prepared for transmission electron microscopy at day 3 after seeding, and the number of FACs and the ratio FAC/cellular cross-sections was determined at a length of 300 microm in ultrathin sections. To visualize the extracellular fibronectin and vitronectin molecules and the intracellular actin and vinculin in FAC areas, immunogold labeling was performed. The results revealed a strong correlation between the number of FACs and the surface roughness. The highest number of FACs and the majority of the immunogold-labeled intra- and extracellular matrix molecules were counted on surfaces with the lowest surface roughness: glass sheets coated with either Ti, TiN or ZrN (roughness average=0.03-0.1 microm). These surfaces appear to favor cellular attachment of human gingival fibroblasts and moreover in previous studies the hard coatings have been shown to reduce bacterial adhesion.

The Impact of Different Acids Etch on Sandblasted Titanium Dental Implant Surfaces Topography

“…The increase in surface roughness could be because of the sharp edges of alumina particle on the surface, in addition to the action of the blasting process on the titanium. 7 Ra values were however lower than those found by 16 Größner-Schreibere et al, 15 and this could be because they used a larger particle size (125 µm).…”

Machine grinding as an alternative method for creating functional surfaces for controlling cell behaviour

“…This finding links to other work which shows that increases in surface roughness can have a negative impact on fibroblast cell adhesion and may potentially prevent initial adaption of the cells to surface [21]. This effect is possibly linked to the number of focal adhesion contacts being formed between the cell and the surface as Grossner-Schreiber et al had previously shown that there were an increased number of focal adhesion contacts on surfaces with a lower Ra value [14]. However, this is not seen for the unprocessed polymer, which shows a lower level of adhesion and also shows much lower surface analysis values.…”

Relative Contributions of Surface Roughness and Crystalline Structure to the Biocompatibility of Titanium Nitride and Titanium Oxide Coatings Deposited by PVD and TPS Coatings

“…An in vitro study with mouse fibroblasts had revealed that MTT activities and total protein contents were significantly increased on TiN coated polished Ti surfaces compared to the thermally oxidized and laser radiation structured surfaces [47]. In another study, glass sheets coated with Ti and TiN presented the highest number of focal adhesion contacts (FACs) of human gingival fibroblasts as a proof of good adhesion [48]. Clem et al [49] applied TiN coating onto Ti alloys by Microwave Plasma Chemical Vapor Deposition and investigated the biocompatibility of these newly formed TiN surfaces using different cell lines.…”