抄録
In this study, microvascular changes of periodontal and peri-implant tissue after experimental induction of inflammation were investigated, using a vascular resin cast method, to gain insight into the cause-and-effect relationship between inflammation and microcirculation.
A titanium-screw implant was inserted into oneside of mandibular bone of beagle dogs, while the other side of the premolars served. In the experimental group, 90 days after implantation, dental floss was placed around the cervical area of an implant fixture and the premolars, to enhance the accumulation of plaque, for another 90 days, but the control group received no placement of dental floss. Plaque control, including brushing, rinsing, and cleaning, was prohibited during this period. To make a vascular resin cast model, synthetic resin was injected into the inferior alveolar arteries. Soft tissues of specimens were digested by a proteinase solution. All of the specimens were examined by scanning electron microscopy.
The vasculature beneath the sulcular epithelium (SE) formed vascular loops, while that of the junctional epithelium (JE) was arranged in a fishnet pattern.
In the case of periodontitis, the arrangement of the SE and JE both changed into glomerulus vascular loops. Vessels in peri-implant soft tissue (PIT) formed a dense network. Under that, a ring-shaped vascular network of connective tissue surrounded the implant neck. In the peri-implantitis, granulated blood vessels of PIT grew toward the apex, and the surrounding alveolar bone was resorbed.
These findings indicate that periodontal and peri-implant vasculature changed easily by experimental inflammation, and that it is more difficult to maintain the vascular structure of PIT than natural periodontal tissue. Protection of microcirculation from inflammation in PIT would ensure that peri-implantitis would be amenable to treatment.
