Growth, viability, adhesion potential, and fibronectin expression in fibroblasts cultured on zirconia or feldspatic ceramics in vitro

Abstract

Zirconia, a biomaterial widely used in dentistry, has recently attracted much attention for its mechanical strength and toughness. Previously, its lack of mutagenic and carcinogenic power was reported. We describe here other essential aspects to be taken into account to define in vitro the biocompatibility of a material: the growth rate, viability, and adhesion capacity of normal stabilized cells growing on it. To this aim, immortalized RAT-1 fibroblasts, growing either on zirconia and on feldspatic (FE) ceramics were compared. In particular, the level of expression and the intra-and extra-cellular organization of fibronectin, a glycoprotein involved in cellular adhesion and migration during tissue repair, was analyzed. Fibroblasts cultured on zirconia showed a higher growth rate, and underwent necrosis at lower levels than cells on FE ceramic, whereas either materials did not stimulate apoptosis. Adhesion capacity of fibroblasts was evaluated measuring adherent cell nucleic acids with the fluorimetric CyQuant 1 assay, and it was found significantly higher in cells cultured on zirconia than on FE ceramic. This finding may be explained by the higher and more precocious expression of the adhesion protein fibronectin observed by indirect immunofluorescence in fibroblasts on zirconia. Overall, the results suggest that zirconia, exerting low cytotoxicity and strongly inducing adhesion capacity, increases cellular growth rate of fibroblasts. All these features suggest that zirconia could represent a more suitable biomaterial than FE ceramic for prosthesis in dentistry.2007 Wiley Periodicals, Inc. J Biomed Mater Res 86A: [959][960][961][962][963][964][965][966][967][968] 2008

Proliferation and adhesion capability of human gingival fibroblasts onto zirconia, lithium disilicate and feldspathic veneering ceramic in vitro

“…Moreover, a higher growth rate of fibroblasts cultured on both ground and polished zirconia and lithium disilicate discs, compared to that of cells growing on feldspathic ceramic, was revealed. This finding is probably related to the high biocompatibility shown by these materials and to their ability to induce in vitro fibroblast adhesion, as previously reported for zirconia 24) . In particular, after 72 h of culture, a higher proliferation rate was observed in Group B and a lower, although not statistically significant, proliferation rate was evidenced in Group C; this suggests that both of these surfaces stimulate HGFs proliferation and that lithium disilicate materials, not being completely biologically inert, may have some cytotoxic effects on HGFs.…”

In VitroComparison of the Effects of Dental Filling Materials on Mouse Fibroblasts

“…Similar to previously conducted studies (40,41), the MTT assay was used to determine the effect of each restorative material on the cell viability or proliferation over a threeday time period. The results of the MTT assays are shown in Table 3.…”

Biological and Structural Characterization of Y-TZP for Implant Abutments

“…In a previous study, Zr0 2 abutments showed higher amounts of collagen deposition as well as larger fractions of fibroblasts and leukocytes adhered to the surface than the connective tissue interface of the Ti abutments, suggesting that the soft tissue healing to zirconia's abutments is better than alloy abutments [10]. When comparing the zirconia to the feldspatic porcelain, the adhesion capacity and the cellular growth rate of the fibroblasts were strongly increased [7].…”

“…Fibroblasts are the most numerous resident cells in periodontium. However, they are needed for any implant or abutment materials that are not toxic and to be inert to them [7,8]. The formation of the epithelial attachment is influenced by the material composition of the transgingival implant components [8][9][10].…”