Calprotectin levels in gingival crevicular fluid predict disease activity in patients treated for generalized aggressive periodontitis.

BACKGROUND AND OBJECTIVE: Clinical parameters such as probing depth and bleeding on probing are commonly used for monitoring after periodontal treatment. However, these parameters have poor prognostic utility. The biomarker calprotectin is used to monitor conditions such as inflammatory bowel disease because of its ability to predict disease activity. Levels of calprotectin in gingival crevicular fluid correlate with periodontal disease severity and treatment outcome. The validity of calprotectin as predictor for future periodontal disease activity has not yet been investigated. MATERIAL AND METHODS: Thirty-six subjects with generalized aggressive periodontitis were treated with scaling and root planing (SRP), and with adjunctive antimicrobial medications. Probing depth, clinical attachment level and bleeding on probing were assessed at baseline, and 3 and 6mo after SRP. A gingival crevicular fluid sample was collected from the initially deepest site in each patient 3mo after SRP and analysed for calprotectin levels. Activity was defined as a probing depth increase of >0.5mm between 3 and 6mo at the sample site. The ability of individual parameters to predict activity was analysed by construction of receiver operating characteristic curves. RESULTS: Nine active sites were identified. Clinical attachment level, probing depth, bleeding on probing and gingival crevicular fluid volume showed no predictive utility [area under the curve (AUC) <0.6, p>0.05]. However, calprotectin concentration (AUC=0.793, p=0.01) and the total amount/sample of calprotectin (AUC=0.776, p=0.02) significantly predicted activity. Patients with calprotectin levels above calculated cut-off values had significantly more active sites than patients with negative results. CONCLUSION: Calprotectin levels were predictors of disease activity at both site and subject levels. The calculated cut-off values provide a dichotomous basis for prospective evaluation of calprotectin as a diagnostic marker for monitoring periodontal treatment.

Induced apoptosis of chondrocytes by Porphyromonas gingivalis as a possible pathway for cartilage loss in rheumatoid arthritis.

The role of bacterial infections in the pathogenesis of rheumatoid arthritis (RA) has gained increasing interest. Patients with RA often exhibit periodontal disease, which is associated with pathogens like Porphyromonas gingivalis. The present study examines the direct effects of P. gingivalis on apoptosis of human chondrocytes (a feature of inflammatory joint diseases) as one can assume an interrelation of pathogenesis of RA and P. gingivalis infections. Primary chondrocytes were infected with P. gingivalis. Early apoptotic and dead cell analysis was performed using Annexin-V, 7AAD, and propidium iodide and examined by flow cytometry and fluorescence microscopy. Caspase activation and DNA fragmentation were determined by western blot analysis and TUNEL reaction. Flow cytometry and fluorescence microscopy demonstrated an increase of Annexin-V-positive early apoptotic chondrocytes after infection. Western blot showed upregulation of activated caspase-3 expression, and TUNEL reaction revealed considerable DNA fragmentation following infection. The data show that P. gingivalis promotes early and later stages of apoptosis of primary human chondrocytes, which might contribute to the joint damage seen in the pathogenesis of RA.

Periodontal disease in patients with ankylosing spondylitis.

OBJECTIVE: Ankylosing spondylitis (AS) and periodontal disease (PD) are characterised by dysregulation of the host inflammatory response, resulting in soft and hard connective tissue destruction. AS has been related to other inflammatory diseases, however, there is a paucity of data on whether AS is associated with inflammatory PD. METHODS: The association between AS and PD was examined in 48 patients with AS and 48 healthy controls, matched for age and gender. AS was diagnosed according to the modified New York criteria. Periodontal examination included probing pocket depth (PPD), clinical attachment loss (CAL), plaque index (PI) and bleeding on probing (BOP). Potential risk factors of PD such as smoking, low education, alcohol consumption, body mass index (BMI), as well as chronic diseases associated with PD and AS were assessed through questionnaires. RESULTS: In stepwise logistic regression, including AS status, age, gender, education, smoking, alcohol consumption and BMI, only AS status, age and education remained significant predictors of PD. Patients with AS had significant 6.81-fold increased odds (95% CI 1.96 to 23.67) of PD (defined as mean attachment loss >3 mm) compared to controls. The strength of the association was attenuated but remained statistically significant after further adjustment for plaque accumulation (odds ratio (OR) 5.48, 95% CI 1.37 to 22.00). CONCLUSIONS: The present study shows that patients with AS have a significantly higher risk of PD, strongly suggesting the need for close collaboration between rheumatologists, periodontists and dental hygienists when treating patients with AS.

Lysyl oxidase (lox) gene deficiency affects osteoblastic phenotype.

Lysyl oxidase (LOX) catalyzes cross-linking of elastin and collagen, which is essential for the structural integrity and function of bone tissue. The present study examined the role of Lox gene deficiency for the osteoblast phenotype in primary calvarial osteoblasts from E18.5 Lox knockout (Lox ( -/- )) and wild type (wt) (C57BL/6) mice. Next to Lox gene depletion, mRNA expression of Lox isoforms, LOXL1-4, was significantly downregulated in Lox ( -/- ) bone tissue. A significant decrease of DNA synthesis of Lox ( -/- ) osteoblasts compared to wt was found. Early stages of osteoblastic apoptosis studied by annexin-V binding as well as later stages of DNA fragmentation were not affected. However, mineral nodule formation and osteoblastic differentiation were markedly decreased, as revealed by significant downregulation of osteoblastic markers, type I collagen, bone sialoprotein, and Runx2/Cbfa1.

Effects of Porphyromonas gingivalis on cell cycle progression and apoptosis of primary human chondrocytes.

BACKGROUND: It has been suggested that bacterial infections have a role in the pathogenesis of rheumatoid arthritis (RA). P gingivalis, a Gram-negative, anaerobic rod, is one of the major pathogens associated with periodontal disease. OBJECTIVE: To examine P gingivalis infection and its effects on cell cycle progression and apoptosis of human articular chondrocytes. METHODS: Primary human chondrocytes cultured in monolayers were challenged with P gingivalis. Infection and invasion of P gingivalis into chondrocytes was analysed by scanning electron microscopy, double immunofluorescence and by antibiotic protection and invasion assay. Cell cycle progression of infected chondrocytes was evaluated by flow cytometry. Also, cell apoptosis was visualised by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) of DNA strand breaks and by western blot analysis. RESULTS: Data showed that P gingivalis could adhere and infect primary human chondrocytes. After chondrocyte infection, intracellular localisation of P gingivalis was noted. Flow cytometry analyses demonstrated affected cell cycle progression, with an increase of the G(1) phase and a significant decrease of the G(2) phase after infection. In addition, increased apoptosis of P gingivalis-infected chondrocytes was visualised by TUNEL assay and by upregulation of caspase-3 protein expression. CONCLUSION: These data demonstrate that P gingivalis infects primary human chondrocytes and affects cellular responses, which might contribute to the tissue damage seen in the pathogenesis of rheumatoid arthritis.

Association among rheumatoid arthritis, oral hygiene, and periodontitis.

BACKGROUND: A limited number of studies suggest a higher prevalence of periodontal disease among individuals with rheumatoid arthritis (RA); however, results have been inconsistent. Further, it is unclear to what extent poor oral hygiene among patients with RA may account for this association. METHODS: The association between RA and periodontitis was examined in 57 subjects with RA and 52 healthy controls, matched by age and gender. Oral examination included plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment loss (CAL). Potential risk factors for periodontal disease, such as smoking, education, alcohol consumption, and body mass index (BMI), as well as chronic diseases associated with RA and periodontal disease were assessed through questionnaires. RESULTS: In a stepwise logistic regression, including RA status, age, gender, education, smoking, alcohol consumption, and BMI, only RA status and age remained significant predictors of periodontal disease. Subjects with RA had a significant 8.05-fold increased odds (95% confidence interval: 2.93 to 22.09) of periodontitis compared to controls. The strength of the association was attenuated but remained statistically significant after further adjustment for PI, GI, or both. PI alone accounted for 12.4%, GI alone accounted for 11.1%, and PI and GI combined accounted for 13.4% of the association between RA and periodontitis. CONCLUSIONS: Subjects with RA have significantly increased periodontal attachment loss compared to controls. Oral hygiene may only partially account for this association.

Clinical and inflammatory effects of galvano-ceramic and metal-ceramic crowns on periodontal tissues.

Prosthetic crowns made by galvano-forming are considered to be highly biocompatible and aesthetic restorations. Therefore, they represent an alternative crown-system to conventional metal-ceramic crowns in replacing lost tooth structure. However, there are few data available on clinical and biochemical effects of galvano-ceramic crowns on periodontal tissues. The purpose of this controlled study was to test the impact of galvano-ceramic crowns and metal-ceramic crowns on clinical and inflammatory responses of periodontal tissues. A prospective, blinded randomized clinical trial was conducted. Galvano-ceramic crowns and metal-ceramic crowns were placed in 52 periodontally healthy patients in split-mouth design. Clinical parameters (gingival index, plaque index, probing depths and recessions) were recorded from six sites per tooth. Initial tissue alteration was accessed analysing the gingival crevicular fluid flow rate and IgG concentration in gingival crevicular fluid. After 24 months, 34 patients could be re-evaluated. All crowns were in adequate function and obvious clinical inflammation was rarely observed. After 24 months of follow-up, gingival tissues adjacent to galvano-ceramic crowns showed significantly less signs of clinical and inflammatory responses according to plaque index (P = 0.004), gingival index (P < 0.001), gingival crevicular fluid flow rate (P = 0.012) and IgG (P = 0.002). Data were also analyzed for buccal and oral sites separately. Gingival tissues adjacent to metal-ceramic crowns showed significantly increased clinical and inflammatory values for plaque index (P = 0.005), gingival index (P = 0.008), gingival crevicular fluid flow rate (P = 0.006), IgG (P = 0.007) at oral sites compared to galvano-ceramic crowns. Our data suggest a stabilizing effect of galvano-ceramic crowns on periodontal tissues over time.

Prediction of periodontal disease from multiple self-reported items in a German practice-based sample.

BACKGROUND: Ascertainment of periodontal disease using self-reported measures would be useful for large epidemiologic studies. This study evaluates whether a combination of self-reported items with established risk factors in a predictive model can assess periodontal disease accurately. METHODS: Responses of 246 subjects to a detailed questionnaire were compared to their periodontal disease history as assessed from radiographs. Multiple regression modeling was used to construct predictive models using self-reported items and established risk factors. RESULTS: Depending on the definition of gold-standard periodontal disease, two or three self-reported items were selected for the predictive models, in addition to age, gender, and smoking. Self-reported tooth mobility was associated strongly with periodontal disease independent of other risk factors and was selected in all models. For dichotomous definitions of periodontal disease, discrimination of predictive logistic regression models was good with areas under the receiver operating characteristic curve >0.80. Assessment of periodontal disease history based on extreme quantiles of model-predicted values yielded high sensitivity and specificity. CONCLUSION: The combination of several self-reported items may be useful for ascertainment of periodontal disease in epidemiologic studies.

Porphyromonas gingivalis dihydroceramides induce apoptosis in endothelial cells.

Porphyromonas gingivalis dihydroceramides are found in extracts of calculus-contaminated root surfaces, diseased gingival tissue, and atherosclerotic plaques. These ceramides have been shown to promote inflammatory secretory responses in gingival fibroblasts. Little is known about their effects on the vascular system. We tested the hypothesis that P. gingivalis lipids induce apoptosis of human endothelial cells, and investigated the effects of extracted and purified P. gingivalis lipids on human umbilical vein endothelial cells. P. gingivalis phosphoglycerol dihydroceramides induced apoptosis, but not necrosis, in endothelial cells. Early apoptotic cells showed exposure of phosphatidylserine on the cell surface, followed by the cleavage of procaspases 3, 6, and 9. The release of apoptosis-inducing factor was increased, suggesting mitochondrial involvement. Different caspase inhibitors and cAMP elevation blocked DNA fragmentation. Moreover, N-acetylcysteine significantly reduced apoptosis, suggesting a role for reactive oxygen species in this process. Analysis of these data indicates that dihydroceramides may be important virulence factors of P. gingivalis.

Obesity, inflammation, and periodontal disease.

The prevalence of obesity has increased substantially over the past decades in most industrialized countries. Obesity is a systemic disease that predisposes to a variety of co-morbidities and complications that affect overall health. Cross-sectional studies suggest that obesity is also associated with oral diseases, particularly periodontal disease, and prospective studies suggest that periodontitis may be related to cardiovascular disease. The possible causal relationship between obesity and periodontitis and potential underlying biological mechanisms remain to be established; however, the adipose tissue actively secretes a variety of cytokines and hormones that are involved in inflammatory processes, pointing toward similar pathways involved in the pathophysiology of obesity, periodontitis, and related inflammatory diseases. We provide an overview of the definition and assessment of obesity and of related chronic diseases and complications that may be important in the periodontist's office. Studies that have examined the association between obesity and periodontitis are reviewed, and adipose-tissue-derived hormones and cytokines that are involved in inflammatory processes and their relationship to periodontitis are discussed. Our aim is to raise the periodontist's awareness when treating obese individuals.