Mechanical attachment of soft fibrous tissues to implants by using mesh structures

Objectives: Increase of soft tissue attachment is a major concern for improving the design of novel dental implants. This study evaluated the use of mesh structures placed on the implant surface for the anchorage of fibrous tissues. Material and methods: Specimens were prepared by covering their surfaces with a nylon mesh. The following mesh spacings were used: 30, 46, 100, 200, and 500 μm. The specimens were retrieved along with the surrounding subcutaneous tissues at 4 weeks after their implantation into the dorsal subcutaneous tissues of rats. A tensile test was performed by using a material testing machine, and the load required to tear the tissue from the mesh was measured. Histological sections stained with hematoxylin-eosin or Azan were prepared and examined by performing light microscopy. The amount of fibrous tissue contributing to the mechanical attachment of the fibers to the mesh was qualitatively evaluated by performing image analysis. Results: The attachment strength was the greatest in the 200-μm mesh-spacing group and considerably greater than that in the 30-μm mesh-spacing group. In addition, the effective width of the anchoring fibrous tissues was the greatest in the 200-μm mesh-spacing group. As compared with the other groups, the 200- and 500-μm mesh-spacing groups exhibited a considerably greater width of the anchoring fibrous tissues. Conclusions: The efficiency of mesh structures for the attachment of soft tissues to implants was demonstrated. A mesh spacing of approximately 200 μm was observed to be favorable for the anchorage of fibrous tissues.