Objectives: the hypothesis of this study was that different abutment substrates would not affect epithelial cell attachment and differentiation.
Methods: 15 discs for each of 5 different materials (4 types of titanium and 1 type of zirconium) were flooded with a media containing human adenoid epithelial cells (hTERT). Cells were allowed to attach on the discs for 2 hours. The media was then collected, and remaining suspended cells counted, to determine number of attached cells. Surfaces were then flooded with fresh media, collected 24 hours later. Levels of 6 different pro-inflammatory cytokines contained in the media were measured for each disc, using a Luminex 100 IS system. Then, part of the discs was used for SEM observation of cell morphology. Another part of the discs was used for immuno-fluorescent microscopy, to observe the organization of the actin cytoskeleton, using phalloidin conjugated to a fluorophore to label the actin. The remaining discs were used to analyse alpha6-beta4 Integrin expression, using gel electrophoresis after isolation of mRNA and reverse PCR.
Results: Number of attached cells was not statistically different for the 5 types of material. For the 5 materials, levels of cytokines IL-6, 8, 12 and TNF-alpha were similar and IL-1 and 10 were not produced in amounts large enough to be detected. Again, alpha6-beta4 Integrin expression was similar for the different surfaces. Actin Cytoskeleton organization was alike for the titanium surfaces, but cells seemed to be less spread on zirconium. SEM showed comparable cell morphology for the titanium surfaces, whereas no cell could be observed on zirconium.
Conclusions: quantitatively, cell attachment and expression of alpha6-beta4 Integrin, IL-6, 8, 12 and TNF-alpha does not seem to be affected by the different surfaces. Nevertheless, attachment might be of lesser quality for zirconium.