Increased Periodontal Attachment Loss in Patients With Systemic Sclerosis.

BACKGROUND: Patients with inflammatory rheumatic diseases and periodontitis share common pathogenetic characteristics, such as proinflammatory traits causative for tissue degradation and loss of function. The aim of the present case control study is to investigate the association between systemic sclerosis (SSc) and periodontitis. METHODS: The association between SSc and periodontitis was examined in 58 SSc patients and 52 control patients, matched for age and sex. The periodontal examination included periodontal attachment loss (AL), probing depth, bleeding on probing, plaque index (PI), and gingival index (GI). Potential risk factors of periodontitis were assessed through patients' questionnaires. RESULTS: In unadjusted analyses, patients with SSc had a significant 0.61 mm higher AL (95% confidence interval [CI] 0.24 to 0.97; P = 0.002) when compared with controls. In a stepwise logistic regression, including SSc status, age, sex, education, smoking, alcohol consumption, and body mass index, only SSc status, age, and sex remained significantly associated with periodontitis. Adjusted for age and sex, patients with SSc had a 0.52 mm higher AL compared with controls (95% CI 0.16 to 0.88; P = 0.005). The strength of the association of SSc with AL remained statistically significant after additional adjustment for PI (0.44 mm; 95% CI 0.02 to 0.86; P = 0.04) or GI (0.61 mm; 95% CI 0.24 to 0.97; P = 0.001). CONCLUSIONS: This study demonstrates higher AL in patients with SSc, which remained significant after adjustment. The study indicates a possible relationship between SSc and periodontitis.

Cross-Sectional Association Between Number of Teeth and High-Sensitivity C-Reactive Protein Among Middle-Aged Germans.

BACKGROUND: The association between number of teeth and low-grade systemic inflammation deserves consideration within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam since the association between number of teeth and myocardial infarction has been established. METHODS: Two subsamples (n = 2,439 and 728) were randomly selected from EPIC-Potsdam. Participants provided information on number of natural teeth, anthropometry, lifestyle factors, and illness-related factors. High-sensitivity C-reactive protein (hsCRP) was measured from serum. Adjusted means of hsCRP across five categories of numbers of teeth in each subsample and in the combined sample were determined, and linear trends were checked. Non-linear associations were investigated with restricted cubic spline (RCS) regression. RESULTS: In the first subsample, the full multivariable-adjusted model showed that participants with 28 to 32, 24 to 27, 18 to 23, 1 to 17, and 0 teeth had mean hsCRP values of 1.32, 1.39, 1.54, 1.38, and 1.48 mg/L, respectively; in the second subsample, mean hsCRP values were 1.64, 1.67, 1.73, 1.47, and 1.87 mg/L; combined hsCRP values were 1.49, 1.53, 1.64, 1.44, and 1.65 mg/L. No linear trend was observed in these models, and RCS regression showed no non-linear association. CONCLUSION: This study shows that number of teeth has a weak association with hsCRP, if any, thereby excluding this marker of low-grade systemic inflammation as a possible explanation for the association between number of teeth and myocardial infarction.

Association between Number of Teeth and Chronic Systemic Diseases: A Cohort Study Followed for 13 Years.

BACKGROUND: There is growing evidence of an association between oral health, specifically dental status, and chronic systemic diseases. However, varying measures of dental status across different populations and low study sample has made comparison of studies and conclusion of findings unclear. Our aim is to examine whether the number of teeth as a measure of dental status is associated with incident chronic diseases in a cohort setting. METHODS: We conducted a cohort study among 24,313 middle-aged Germans followed up for 13 years. Data on number of teeth as a measure of dental status were obtained through self-reports. Outcomes were clinically-verified incident non-fatal myocardial infarction, stroke, type 2 diabetes mellitus, and cancer. Hazard ratio (HR) and 95% confidence intervals (CI) were obtained from Cox regression models. RESULTS: Increasing number of teeth is inversely related to risk of myocardial infarction (HR: 0.97; 95% CI: 0.96, 0.99). The full multivariate model of teeth groups showed a strong linear trend for myocardial infarction, a less strong trend for stroke, and no relation with type 2 diabetes mellitus and cancer in a competing risk model. Participants with 18-23 teeth and those without teeth were at 76% (95%CI: 1.04, 3) and 2.93 times (95%CI: 1.61, 5.18) higher risk of myocardial infarction compared to those with nearly all teeth (28-32 teeth). CONCLUSIONS: Number of teeth is specifically associated with myocardial infarction and not with other chronic disease indicating that dental status further strengthens the link between oral health and cardiovascular diseases.

Porphyromonas gingivalis Suppresses Differentiation and Increases Apoptosis of Osteoblasts From New Zealand Obese Mice.

BACKGROUND: Metabolic syndrome (MetS), a complex cluster of risk factors for chronic diseases such as cardiovascular disease, is observed to be increasingly associated with periodontal disease. However, the fundamental contribution of periodontal bacteria to periodontal bone loss in patients with MetS remains unclear. The aim of the present study is to analyze the effect of Porphyromonas gingivalis on differentiation of primary osteoblasts from New Zealand obese (NZO) mice, a model for MetS, compared with C57 Black 6 JAX (C57BL/6J) mice osteoblasts. METHODS: Primary calvarial osteoblasts, isolated from 3-day-old NZO and control C57BL/6J mice, were stimulated with P. gingivalis. Proliferation was quantified by 5-bromo-2'-deoxyuridine incorporation. Cell cycle and early and late apoptosis were measured by flow cytometry. Gene expression was determined by real-time polymerase chain reaction (RT-PCR). RESULTS: Twelve hours after P. gingivalis stimulation, NZO osteoblasts showed significantly decreased proliferation (P ≤0.01) with increased G2 cell cycle phase compared with normal osteoblasts. Flow cytometry analysis demonstrated significant (P ≤0.01) increase of early apoptotic cells (annexin V positive) and late apoptosis (caspase 3 activity) in NZO cells compared with control cells at 3 and 6 hours after stimulation. No significant lactate dehydrogenase release was found after P. gingivalis stimulation. RT-PCR data showed significantly suppressed expression (P ≤0.01) of collagen 1, osteocalcin, and Runt-related transcription factor 2 in NZO cells compared with normal osteoblasts. CONCLUSIONS: The present data demonstrate that P. gingivalis downregulates proliferation and promotes apoptosis in primary NZO osteoblasts, unlike C57BL/6J osteoblasts. Also, suppressed osteoblastic marker expression in NZO cells may contribute to pathogenesis of periodontitis, suggesting a similar process in patients with MetS.

Effect of untreated and treated temporomandibular joint arthritis on mandibular volume development in growing rabbits.

OBJECTIVES: The goal of this work was to investigate the volume development of the mandible in growing rabbits with bilaterally induced temporomandibular joint (TMJ) arthritis that was either left untreated or treated with the tumor necrosis factor-alpha (TNF-α) antagonist etanercept. METHODS: A total of 18 New Zealand White rabbits aged 8 weeks were randomized to three groups of 6 animals each. Two of these groups were used as arthritis groups by sensitizing the 12 animals to ovalbumin (OA) at 10 weeks, followed by intraarticular OA injections to induce bilateral TMJ arthritis and repeating these injections every 3 weeks to maintain the inflammation. One of the two arthritis groups was treated by weekly subcutaneous etanercept injections, whereas the other group was left untreated. The remaining 6 animals served as controls. Maxillofacial CT scans were obtained at 3-week intervals (from week 10 of the rabbits' lives to the end of the experiment at 22 weeks) to volumetrically track the development of the mandibles after segmentation. RESULTS: The mandibles did not grow at a continuous rate, but the rate of development was found to decrease in all groups over the course of the study (weeks 10-22). The most extensive volume increases were noted during weeks 10-13. Severe growth deficiencies, especially of the condylar processes, were observed in the arthritis group not receiving treatment. The arthritis group treated with etanercept showed better rates of growth without, however, reaching the normal range of the control group. CONCLUSION: Antigen-induced TMJ arthritis was found to involve severe problems of growth similar to those in juvenile idiopathic arthritis. Etanercept can improve the volume development but does not reestablish an entirely normal rate of growth.

Pocket depth and bleeding on probing and their associations with dental, lifestyle, socioeconomic and blood variables: a cross-sectional, multicenter feasibility study of the German National Cohort.

BACKGROUND: To investigate the periodontal disease status in a multi-center cross-sectional study in Germany. Associations of dental, socio-economic, blood and biomedical variables with periodontal outcome parameters were evaluated. METHODS: From 4 different centers N = 311 persons were included, drawn randomly from the registration offices. Maximal pocket depth (PD) was used as primary indicator for periodontitis. It was classified as: no/mild ≤3 mm, moderate 4-5 mm, severe ≥6 mm. Associations between socioeconomic (household income, education), lifestyle, and biomedical factors and PD or bleeding on probing (BOP) per site ("Yes"/"No") was analyzed with logistic regression analysis. RESULTS: Mean age of subjects was 46.4 (range 20-77) years. A significantly higher risk of deeper pockets for smokers (OR = 2.4, current vs. never smoker) or persons with higher BMI (OR = 1.6, BMI increase by 5) was found. Severity of periodontitis was significantly associated with caries lesions (p = 0.01), bridges (p < .0001), crowns (p < .0001), leukocytes (p = 0.04), HbA1c (p < .0001) and MCV (p = 0.04). PD was positively correlated with BOP. No significant associations with BOP were found in regression analysis. CONCLUSIONS: Earlier findings for BMI and smoking with severity of PD were confirmed. Dental variables might be influenced by potential confounding factors e.g. dental hygiene. For blood parameters interactions with unknown systemic diseases may exist.

Etiologic factors of hyposalivation and consequences for oral health.

Hyposalivation is represented by a reduced salivary flow rate and can be caused by etiologic factors such as systemic diseases and intake of various medications or by radiotherapy following head and neck cancer. The aim of this review was to compile data about the qualitative and quantitative changes of salivary components during hyposalivation, and to summarize their consequences for oral health. A Medline/PubMed/Scopus search was conducted to identify and summarize articles published in English and German that reported on etiology of hyposalivation and changes in the salivary composition due to hyposalivation of different origins. The search revealed 94 articles, 71 of which were original articles. Apart from the reduction of the salivary flow rate, the quality of saliva is strongly altered because of systemic diseases, medications, and radiotherapy, including increased viscosity and pH shift to more acidic values and changes in salivary protein compositions. Furthermore, hyposalivation may be accompanied by pronounced shifts in specific microbial components, in particular toward a highly acidogenic microflora. Moreover, therapy of hyposalivation is often restricted to palliative treatment (ie, saliva substitutes or gels). To prevent tooth tissue demineralization, clinicians should consider saliva substitutes that are supersaturated with calcium and phosphates and contain fluoride.

Influence of periodontal therapy on the regulation of soluble cell adhesion molecule expression in aggressive periodontitis patients.

BACKGROUND: Inflammatory periodontal disease is associated with an increased risk of cardiovascular disease. Circulating cell adhesion molecules (CAM) (intercellular adhesion molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1], and E-selectin) have been suggested as potential candidate markers of endothelial dysfunction, which contribute to the pathogenesis of cardiovascular diseases. The regulation of CAM in subjects with severe periodontitis and the influence of periodontal intervention on systemic CAM levels are not clear. The aim of this study was to determine whether intensive periodontal therapy reduces serum levels of CAM in patients with generalized aggressive periodontitis. METHODS: Blood samples were collected at six treatment time points from 21 patients with previously untreated generalized aggressive periodontitis (mean age: 34.6 +/- 4.3 years). Patients received subgingival scaling and root planing and antibiotic therapy and were monitored over a 6-month recall period. Serum levels of soluble ICAM-1 (sICAM-1), VCAM-1 (sVCAM-1), and E-selectin (sE-selectin) were measured by enzyme-linked immunosorbent assay. RESULTS: sE-selectin plasma levels decreased significantly (P <0.01) during periodontal therapy. Mean plasma levels were 65.95 ng/ml before treatment and 44.71 ng/ml 6 months after antibiotic therapy. sICAM-1 and sVCAM-2 serum levels were unaffected by therapeutic intervention. CONCLUSIONS: Periodontal therapy reduces plasma sE-selectin levels. Whether this leads to a reduction in risk of future cardiovascular events in patients with aggressive periodontal disease warrants further studies.

Effects of an enamel matrix derivative on human osteoblasts and PDL cells grown in organoid cultures.

OBJECTIVE: The objective of this study was to investigate cellular effects of enamel matrix derivative (EMD) in human derived, primary osteoblasts and periodontal ligament (PDL) cells grown in organoid cultures. STUDY DESIGN: Cell replication was assessed by BrdU-incorporation. [(3)H]-proline incorporation was measured to determine the synthesis of proline-containing proteins, such as collagen. In addition, calcium accumulation and alkaline-phosphatase-activity were quantified. Electron microscopy for morphological analysis was performed. RESULTS: Our results showed that EMD enhances BrdU-incorporation in PDL cells and osteoblasts. Also, in osteoblast organoid cultures [3H]-proline incorporation was 3-fold increased (P < .01). Extensive matrix deposition was noted in osteoblast cultures by electron microscopy. In osteoblasts, high levels of calcium accumulation and alkaline-phosphatase-activity were found. However, EMD did not promote mineralization. CONCLUSION: Our results indicate that under organoid culture conditions EMD is able to promote the synthesis of proline-containing proteins such as collagen but not matrix mineralization of primary human osteoblastic cells.

Effects of enamel matrix derivative on proliferation and differentiation of primary osteoblasts.

OBJECTIVE: The aim of this study was to investigate the effects of enamel matrix derivative (EMD) on proliferation, protein synthesis, and mineralization in primary mouse osteoblasts. STUDY DESIGN: Osteoblasts were obtained from mouse calvaria by enzymatic digestion and grown in monolayer together with EMD (2-100 microg/ml). Metabolic activity and cell proliferation were determined by tetrazolium salt assay (MTT) and by 5-bromo-2'-deoxyuridine (BrdU) incorporation. For differentiation studies, a 3-dimensional organoid culture system was used. Osteoblastic differentiation was estimated by alkaline phosphatase (ALP) activity and calcium content. Collagen synthesis was assessed by [(3)H]-proline incorporation. Morphologic observations were made by electron microscopy. RESULTS: EMD treatments increased metabolic cell activity and BrdU incorporation. In the organoid cultures, ALP activity and calcium accumulation were enhanced by EMD treatment, but [(3)H]-proline incorporation was not. Morphologically, an increased deposition of mineralized nodules was found. CONCLUSIONS: EMD treatment enhanced cellular activities of primary osteoblasts and might support the regeneration of periodontal bony defects.

The propeptide domain of lysyl oxidase induces phenotypic reversion of ras-transformed cells.

Lysyl oxidase is an extracellular enzyme critical for the normal biosynthesis of collagens and elastin. In addition, lysyl oxidase reverts ras-mediated transformation, and lysyl oxidase expression is down-regulated in human cancers. Since suramin inhibits growth factor signaling pathways and induces lysyl oxidase in ras-transformed NIH3T3 cells (RS485 cells), we sought to investigate the effects of suramin on the phenotype of transformed cells and the role of lysyl oxidase in mediating these effects. Suramin treatment resulted in a more normal phenotype as judged by growth rate, cell cycle parameters, and morphology. beta-aminopropionitrile, the selective inhibitor of lysyl oxidase enzyme activity, was remarkably unable to block suramin-induced reversion. By contrast, ectopic antisense lysyl oxidase demonstrated that lysyl oxidase gene expression mediated phenotypic reversion. Since lysyl oxidase is synthesized as a 50 kDa precursor and processed to a 30 kDa active enzyme and 18 kDa propeptide, the effects of these two products on the transformed phenotype of RS485 cells were then directly assessed in the absence of suramin. Here we report, for the first time, that the lysyl oxidase propeptide, and not the lysyl oxidase enzyme, inhibits ras-dependent transformation as determined by effects on cell proliferation assays, growth in soft agar, and Akt-dependent induction of NF-kappaB activity. Thus, the lysyl oxidase propeptide, which is released during extracellular proteolytic processing of pro-lysyl oxidase, functions to inhibit ras-dependent cell transformation.

Regulation of collagen deposition and lysyl oxidase by tumor necrosis factor-alpha in osteoblasts.

Tumor necrosis factor-alpha (TNF-alpha) inhibits osteoblast function in vitro by inhibiting collagen deposition. Studies generally support that TNF-alpha does not inhibit collagen biosynthesis by osteoblasts but that collagen deposition is in some way diminished. The study investigated TNF-alpha regulation of biosynthetic enzymes and proteins crucial for posttranslational extracellular collagen maturation in osteoblasts including procollagen C-proteinases, procollagen C-proteinase enhancer, and lysyl oxidase. The working hypothesis is that such regulation could inhibit collagen deposition by osteoblasts. We report that in phenotypically normal MC3T3-E1 osteoblasts, TNF-alpha decreases collagen deposition without decreasing collagen mRNA levels or procollagen protein synthesis. Analyses of the cell layers revealed that TNF-alpha diminished the levels of mature collagen cross-links, pyridinoline and deoxypyridinoline. Further analyses revealed that the mRNA expression for lysyl oxidase, the determining enzyme required for collagen cross-linking, is down-regulated by TNF-alpha in a concentration- and time-dependent manner by up to 50%. The decrease was accompanied by a significant reduction of lysyl oxidase protein levels and enzyme activity. By contrast, Northern and Western blotting studies revealed that procollagen C-proteinases bone morphogenic protein-1 and mammalians Tolloid and procollagen C-proteinase enhancer were expressed in MC3T3-E1 cells and not down-regulated. The data together demonstrate that TNF-alpha does not inhibit collagen synthesis but does inhibit the expression and activity of lysyl oxidase in osteoblasts, thereby contributing to perturbed collagen cross-linking and accumulation. These studies identify a novel mechanism in which proinflammatory cytokine modulation of an extracellular biosynthetic enzyme plays a determining role in the control of collagen accumulation by osteoblasts.