Effect of plasma-irradiated silk fibroin in bone regeneration.

We have recently identified plasma-irradiated silk fibroin (P-AF) as a key regulator of bone matrix properties and composition. Bone matrix properties were tested in 48 femur critical size defects (3.25 mm in diameter) with the expression of osteoblast specific genes at 1 and 2 weeks after surgery.

Silk fibroin-based scaffolds for bone regeneration.

Porous scaffolds were prepared using regenerated Bombyx mori silk fibroin dissolved in water or hexafluoroisopropanol (HFIP). The effects of these two preparations on the formation and growth of new bone on implantation into the rabbit femoral epicondyle was examined. The aqueous-based fibroin (A-F) scaffold exhibited significantly greater osteoconductivity as judged by bone volume, bone mineral content, and bone mineral density at the implant site than the HFIP-based fibroin (HFIP-F) scaffold.

Regeneration of the femoral epicondyle on calcium-binding silk scaffolds developed using transgenic silk fibroin produced by transgenic silkworm.

Genetically modified silk fibroin containing a poly-glutamic acid site, [(AGSGAG)4E8AS]4, for mineralization was produced as fibers by transgenic silkworms through systematic transformation of the silkworms. The Ca binding activity and mineralization of the transgenic silk fibroin were examined in vitro, showing that this transgenic silk fibroin had relatively high Ca binding activity compared with native silk fibroin. Porous silk scaffolds were prepared with the transgenic and native silk fibroins.

Scanning electron microscopy of root resorption of feline teeth.

Scanning electron microscopy was carried out on 10 feline extracted permanent teeth from 3 cases with root resorption. Various-sized resorption lacunae were well defined, showing an etched pattern and configuration as shown in human deciduous teeth. In cats, regardless of the shape and depth of lacunae, the resorption lacunae showed opening dentinal tubules in the wall with or without cement matrix apperring only in the deep and round lacunae of human cases.

Potential application of high-resolution microfocus X-ray techniques for observation of bone structure and bone-implant interface.

Purpose: The aim of the present study was to evaluate the potential application of 2 types of microfocus x-ray units to study the bone structure around dental implants and at the bone-implant interface.

Materials And Methods: IMZ titanium implants were placed in the maxilla and mandible of a beagle dog. After implantation periods of 1, 2, and 3 months, the bone-implant interface was evaluated with microfocus x-ray computed tomography (CT) and microfocus x-ray fluoroscopy.