The effect of systemic anti-tumor necrosis factor-alpha treatment on Porphyromonas gingivalis infection in type 2 diabetic mice.

OBJECTIVE: Diabetes mellitus and periodontal disease are two common chronic diseases that have long been thought to be biologically linked. Overexpression of tumor necrosis factor alpha (TNF-alpha) is thought to contribute to this bidirectional inter-relationship. This study examined the effect of anti-TNF-alpha antibody treatment on Porphyromonas gingivalis infection in diabetic mice. METHODS: In C57BL/6 (normal) and KKAy (diabetic) mice, the area adjacent to the periosteum at a point on the skull midway between the ears was inoculated with P. gingivalis. At 24h after the inoculation, the mice in the test group were treated with rat anti-murine TNF-alpha intravenously, while the control group received non-immunized rat IgG. TNF-alpha, IL-6, and fasting blood glucose levels in the mice were measured on day 3. RESULTS: Anti-TNF-alpha antibody treatment improved the host response to P. gingivalis and was associated with reduced serum TNF-alpha, IL-6, and fasting blood glucose levels in the KKAy mice. Anti-TNF-alpha antibody treatment also decreased the lesion size at the P. gingivalis inoculation. CONCLUSIONS: Our results suggest that TNF-alpha plays a role in the two-way relationship between P. gingivalis infection and diabetes mellitus. Anti-TNF-alpha antibody treatment may improve the host response to P. gingivalis infection and glycemic control in diabetes mellitus.

Removal of infected nonresorbable hydroxyapatite graft material in recurrent periodontitis: a report of two cases.

Long-term studies have indicated that alloplastic bone grafts composed of nonresorbable hydroxyapatite (NHA) are clinically stable and safe. However, our previous report suggested that NHA grafts may be an etiological factor for recurrent periodontitis in the absence of supportive periodontal treatment (SPT). We removed infected NHA from the root surface by flap surgery in two cases of recurrent periodontitis. After removal of the infected NHA, the inflammation subsided in these cases and they were clinically stable for several years.

Effects of marrow penetration on bone augmentation within a titanium cap in rabbit calvarium.

BACKGROUND: Some studies have advocated marrow penetration in guided bone augmentation (GBA), whereas others have shown that bone can be generated without marrow penetration. This study examined the effect of marrow penetration and the optimal rate of penetration. METHODS: In 10 rabbits, the calvarium was exposed, and circular grooves were prepared bilaterally. Within the circular groove, the external cortical surface of the skull was perforated mechanically using a number 4 round bur (experimental site), whereas the bone surface on the other groove (control site) was left intact. The rate of penetration was standardized as 28% for the experimental site and 0% for the control site. Subsequently, two standardized titanium caps with an inner diameter of 8 mm and an inner height of 4 mm were anchored in the prepared grooves. Five rabbits each were euthanized at 1 and 3 months, and the percent area of newly generated tissue and mineralized bone in the newly generated tissue under the titanium cap was determined. RESULTS: Histomorphometric analysis showed significantly increased bone neogenesis in the experimental site at 3 months. The percent area of mineralized bone in the newly generated tissue was consistently higher in the experimental site at 3 months. CONCLUSION: In the rabbit calvarium using a titanium cap GBA model, bone augmentation was significantly greater with marrow penetration than without penetration.