A marker of oxidative stress in saliva: association with periodontally-involved teeth of a hopeless prognosis.

The aim of this study was to determine the association between levels of a marker of oxidative stress, 8-hydroxydeoxyguanosine (8-OHdG), in saliva and the presence of teeth with a hopeless prognosis as a result of advanced periodontitis. Thirty-four periodontitis patients were divided into two groups based on the presence or absence of periodontally-involved teeth of hopeless prognosis. Salivary levels of 8-OHdG in those with were significantly higher than in subjects without periodontally-involved teeth of hopeless prognosis (4.78 +/- 0.14 ng/ml and 2.35 +/- 0.18 ng/ml, respectively). We also evaluated 8-OHdG levels in gingival crevicular fluid (GCF) of teeth with advanced periodontal destruction (mean probing depth = 7.2). In this case, 8-OHdG was detected only from those periodontally-involved teeth of hopeless prognosis, and only in some cases (8 out of 18 samples). These data suggest that periodontally-involved teeth of hopeless prognosis are a major source of salivary 8-OHdG. Measurement of salivary 8-OHdG levels may prove to be useful in identifying patients with teeth of hopeless prognosis.

New biomarker evidence of oxidative DNA damage in whole saliva from clinically healthy and periodontally diseased individuals.

BACKGROUND: There is an increasing body of evidence implicating reactive oxygen species in the pathogenesis of periodontal tissue destruction. 8-Hydroxy-deoxyguanosine (8-OHdG) is one of the most commonly used markers to evaluate oxidative damage in a number of disorders including chronic inflammatory diseases. The aim of the present study was to evaluate 8-OHdG levels in whole saliva of patients with periodontitis and to assess the changes after initial treatment. METHODS: Saliva samples were collected from 78 patients with untreated periodontitis and 17 healthy control subjects. Clinical parameters and levels of 8-OHdG were assessed first to establish a baseline and again after initial periodontal treatment from 15 patients. 8-OHdG levels were determined by enzyme-linked immunosorbent assay. RESULTS: The mean value of 8-OHdG in the saliva of periodontally diseased subjects, 4.28 +/- 0.10 ng/ml, was significantly higher (P<0.01) than that of clinically healthy subjects (1.56 +/- 0.10 ng/ml). A significant decrease in salivary 8-OHdG was observed after therapy (P<0.01). CONCLUSION: In the present study, we evaluated for the first time 8-OHdG levels in whole saliva of patients with periodontitis and assessed changes after initial periodontal treatment. Our study indicated that 8-OHdG levels in saliva appear to reflect the status of periodontal health.

Detection of Streptococcus anginosus and 8-hydroxydeoxyguanosine in saliva.

Several studies have demonstrated a close association between Streptococcus (S.) anginosus infection and head and neck cancer. Accumulation of 8-hydroxy-deoxyguanosine (8-OHdG), which may result from the continuous generation of reactive oxygen species associated with chronic inflammation, has been reported in human preneoplastic lesions and in cancerous tissues. The purpose of the present investigation was to assess the salivary levels of S. anginosus and 8-OHdG in patients with periodontitis. Salivary levels of S. anginosus were measured by real-time PCR. S. anginosus was detected in 28 out of 38 (73.7%) of subjects. The 8-OHdG level was significantly higher in patients positive for S. anginosus than in patients negative for the bacterium. A significant decrease in S. anginosus and 8-OHdG levels was observed after initial periodontal treatment. Our findings indicate that, although the levels of S. anginosus are relatively low, there is a correlation between the salivary level of S. anginosus and 8-OHdG, and that periodontal treatment can decrease the levels of these hazard factors.

Effect of a chitosan sponge impregnated with platelet-derived growth factor on bone augmentation beyond the skeletal envelope in rat calvaria.

We evaluated the ability of platelet-derived growth factor (PDGF) to promote bone augmentation beyond the skeletal envelope in rat calvaria. The calvariae of 14 rats were exposed, and two plastic caps-one with 0.03% PDGF and a chitosan sponge and one with a chitosan sponge alone-were placed. Microcomputed tomography and histologic sections were used to determine the amount of bone augmentation within the plastic caps. Bone volume was calculated using measurement software. Bone volume and amount of bone augmentation were significantly greater in the PDGF group than in the control group. In conclusion, a chitosan sponge containing 0.03% PDGF enhanced bone formation beyond the skeletal envelope in rat calvaria.

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.

Clinical application of cone beam computed tomography for ideal absorbable membrane placement in interproximal bone defects.

When a guided tissue regeneration (GTR) membrane is placed in an interproximal area, adjustment of the membrane is difficult because of the complex anatomy of the root surface and presence of bone defects, thus prolonging the surgery. This report describes the clinical application of cone beam computed tomography (CT) images to aid insertion of a barrier membrane in the treatment of interproximal bone defects. Using CT images, the membrane can be pre-cut into the optimal shape to cover the bone defect and fit the roots tightly, thus shortening the time required to adjust the GTR membrane, and providing excellent clinical outcomes.