Masato Matsuo

In this study, vascular resin cast models in the periodontium of beagle dogs were prepared and three‐dimensional observation of the relationship between the gingiva and periodontal ligament (PDL) vascular network was performed. After the perfusion of Ringer's solution and fixative, synthetic resin was injected from the inferior alveolar arteries. Soft tissue was digested by proteinase solution and specimens were examined under scanning electron microscope (SEM). The gingival vascular network (GVN) in the region facing the teeth consisted of sulcular and junctional epithelium. The vascular network of the sulcular epithelium (SE) had a renal glomerulus‐like form and the junctional epithelium (JE) consisted of squamous mesh. The gingival sulcular fluid exudated from the vascular network directly beneath the JE, and leukocytes permeated from the vascular network beneath the epithelium. Thus, we considered that the GVN performs an important function in the protection against the inflammation. Periodontal ligament had a polygonal mesh vascular network that was anastomosed to the venous plexus of alveolar bone through Volkmann's canals (VC). When occlusal force was applied, the blood in the periodontal vessels flowed out through VC into the bone marrow, and when the force was removed, it flowed backward into the PDL. This blood transfer acted as an absorber against occlusal force. Our findings suggest that the blood vessels of the gingiva perform an important function in defending against inflammation, while the blood vessels of the PDL play a key role in absorbing occlusal force. Microsc. Res. Tech. 56:3–14, 2002.

Background: The purpose of this study was to clarify the osseointegration process of titanium implants through study of the vascular architecture and bone apposition. The smooth machined‐surface implant is tightly fixed to the bone by its threads. The rough titanium plasma‐sprayed (TPS) coated implants give a scaffold for new bone. Methods: Twelve beagle dogs were used, and 2 surface types of implants were inserted in the mandible. Vascular injection was given 14, 30, and 120 days after surgery. The soft tissue was digested by proteinase solution, and specimens were examined by scanning electron microscope (SEM).Results: Fourteen days after placement of machined implants, new vessels could be seen branching out from the vascular network of the bone marrow. In TPS implants, a vascular network was seen between the bone‐implant interface. At 30 days, the vessels were arranged in a groove corresponding to the machined fixture. With TPS implants, new bone was visible along the surface of the fixture, and the vascular network was buried in the bone. At 120 days after placement of machined implants, bone had formed a smooth surface. A few blood vessels were arranged along the bone surface. With TPS implants, a rough bone surface and flat vessels were observed on its surface.Conclusions: Implants become osseointegrated in different ways, depending on their structures and the characteristics of their surfaces. From the microcirculation point of view, the vessels are an important factor for the remodeling of bone. J Periodontol 1999;70:1330‐1338.