Influence of Fibronectin Immobilization on the Orientation of Collagen Bundles in Soft Tissue around Zirconia Implants

抄録

In the present study, the soft tissue response toward a fibronectin–immobilized zirconia implant was evaluated by animal experiment. Quartz crystal microbalance (QCM) analyses for atelocollagen adsorption to zirconia were also performed. Cylindrically shaped yttria stabilized tetragonal zirconia polycrystals (Y-TZP) was sandblasted and acid etching–treated (SLA/Y-TZP). Fibronectin–immobilized Y-TZP (Fn/Y-TZP) was obtained using the tresyl chloride–activated method. Implants were placed in the tooth socket of the extracted maxillary teeth of rats. Soft tissue responses 3-weeks after implantation were observed. Long collagen fibers perpendicularly oriented to the Y-TZP implant surface were more abundant in Fn/Y-TZP than in SLA/Y-TZP. The lengths of vertically oriented collagen fibers on the palatal side and the total of the buccal and palatal sides of Fn/Y-TZP were significantly higher than that of SLA/Y-TZP. Fn/Y-TZP showed a significantly higher area of vertically oriented collagen fibers on the buccal side and the total sides as compared to SLA/Y-TZP. There were no significant differences among the ratios of epithelial attachments to fibrous attachments. QCM analyses indicated that the pre–adsorption of fibronectin significantly decreased the amounts of atelocollagen adsorption. In conclusion, the immobilization of fibronectin had a clear effect on the orientation of gingival fibers toward the zirconia implant surface. Atelocollagen adsorption to zirconia was influenced with by fibronectin pre–adsorption.