Binnaz Leblebicioglu

Social stress enhances IL-1β and TNF-α production by Porphyromonas gingivalis lipopolysaccharide-stimulated CD11b+ cells

Psychological stress is associated with an increased expression of markers of peripheral inflammation, and there is a growing literature describing a link between periodontal pathogens and systemic inflammation. The hypothesis of the present work is that exposing mice to the social stressor, called social disruption (SDR), would enhance the inflammatory response to lipopolysaccharide (LPS) derived from the oral pathogen, Porphyromonas gingivalis. Mice were exposed to SDR for 2h per day on 6 consecutive days. On the morning following the last cycle of SDR, mice were tested for anxiety-like behavior in the open field test and novel object test. The mice were sacrificed the following day and their spleens harvested. Spleen cells were stimulated with LPS derived from P. gingivalis in the absence or presence of increasing doses of corticosterone. Social disruption resulted in anxiety-like behavior, and the production of IL-1beta and TNF-alpha was significantly higher in spleen cells from mice exposed to SDR in comparison to levels from non-stressed control mice. In addition, the viability of spleen cells from mice exposed to SDR was significantly greater than the viability of cells from non-stressed control mice, even in the presence of high doses of corticosterone. The use of cultures enriched for CD11b+ cells indicated that the stressor was affecting the activity of splenic myeloid cells. This study demonstrates that social stress enhances the inflammatory response to an oral pathogen and could provide a critical clue in the reported associations between stress, inflammation, and oral pathogens.

Effectiveness of Er,Cr:YSGG laser on dentine hypersensitivity: a controlled clinical trial

AIM Attempts have been made to treat dentine hypersensitivity (DH) with lasers. However, there is limited knowledge on the effects of erbium, chromium-doped:yttrium, scandium, gallium and garnet (Er,Cr:YSGG) laser on DH. The aim of this study was to evaluate the efficacy of Er,Cr:YSGG laser on reduction in DH. METHODS Forty-two patients (146 teeth) were included. Teeth were assigned to an experimental group and irradiated with the Er,Cr:YSGG laser. In the control group same clinical instrument was used without laser emission. DH was assessed for both groups utilizing the visual analog scale. Plaque index (PI) scores were recorded immediately following treatment, at 1 week, 1 and 3 months. RESULTS The results showed that Er,Cr:YSGG laser irradiation had a significantly higher desensitizing effect compared with the placebo immediately after treatment (p<0.05). Intra-group comparisons revealed no statistically significant differences within the placebo group (p>0.05). For the test group, the differences between baseline and all time points following treatment were statistically significant (p<0.05). No significant differences were observed in PI between the test and control groups at any follow-up examination (p>0.05). CONCLUSION Within the limits of this study, it appears that Er,Cr:YSGG laser is effective in the treatment of DH compared with the placebo treatment.

Factors affecting the accuracy of buccal alveolar bone height measurements from cone-beam computed tomography images

INTRODUCTION The reasons for inaccuracies in alveolar bone measurement from cone-beam computed tomography (CBCT) images might be multifactorial. In this study, we investigated the impact of software, the presence or absence of soft tissues, the voxel size of the scan, and the regions in the jaws on buccal alveolar bone height measurements in pigs at an age equivalent to human adolescents. METHODS Marker holes, apical to the maxillary and mandibular molar roots, and mesiodistal molar occlusal reference grooves were created in 6 fresh pig heads (12 for each jaw), followed by CBCT scans at 0.4-mm and 0.2-mm voxel sizes under soft-tissue presence and soft-tissue absence conditions. Subsequently, buccolingual sections bisecting the marker holes were cut, from which the physical alveolar bone height and thickness were measured. One blinded rater, using Dolphin (version 11.5 Premium; Dolphin Imaging, Chatsworth, Calif) and OsiriX (version 3.9; www.osirix-viewer.com) software, independently collected alveolar bone height measurements from the CBCT images. Differences between the CBCT and the physical measurements were calculated. The mean differences and the limit of agreement (LOA, ±1.96 SD) for every jaw, voxel-size, soft-tissue, and software condition were depicted. Each measurement was then assessed for clinical inaccuracy by using 2 levels of criteria (absolute differences between CBCT and physical measurements ≥1 mm, or absolute differences between CBCT and physical measurements ≥0.5 mm), and the interactions between soft-tissue and voxel-size factors for every jaw and software condition were assessed by chi-square tests. RESULTS Overall, the mean differences between the CBCT and the physical measurements for every jaw, voxel-size, soft-tissue, and software condition were near 0. With all other conditions kept equal, the accuracy of the maxillary CBCT measurements was inferior (larger limit of agreement ranges and higher frequencies of clinical inaccuracy) to the mandibular measurements. The physical thickness of the maxillary alveolar crestal bone was less than 1 mm and significantly thinner than the mandibular counterparts. For every jaw and software condition, the accuracy of measurements from the 0.2-mm soft-tissue presence CBCT images was consistently superior (smaller limit of agreement ranges and lower frequencies of clinical inaccuracy) to those from the 0.4-mm soft-tissue presence, the 0.4-mm soft-tissue absence, and the 0.2-mm soft-tissue absence images; all showed similar accuracies. Qualitatively, the soft-tissue absence images demonstrated much brighter enamel and alveolar bone surface contours than did the soft-tissue presence images. CONCLUSIONS At an adolescent age, the buccal alveolar bone height measured from the maxillary molar region based on 0.4-mm voxel-size CBCT images can have relatively large and frequently inaccurate measurements, possibly due to its thinness. By using 0.2-mm voxel-size scans, measurement accuracy might be improved, but only when the overlying facial and gingival tissues are kept intact.

Azithromycin Decreases Crevicular Fluid Volume and Mediator Content

Azithromycin enhances the response to root planing and produces anti-inflammatory effects in treating chronic lung disease. This led us to hypothesize that azithromycin inhibits inflammatory mediator production in gingiva, leading to decreased gingival crevicular fluid (GCF) volume. To test this hypothesis, ten periodontally healthy volunteers received azithromycin every 24 hours for 48 hours. GCF samples were collected from 12 maxillary interproximal sites prior to azithromycin (baseline) and 2, 4, 7, and 14 days later. Samples were assayed for IL-1β, IL-8, TNF-α, VEGF, IL-6, and IL-10. With azithromycin treatment, GCF volume decreased significantly on days 2 through 7 (P < 0.05), but increased toward baseline levels on day 14. This was accompanied by a transient decrease in the content of IL-1β, IL-8, TNF-α, and VEGF (P < 0.05). IL-6 and IL-10 were not detected. Since plaque was absent throughout the study, the findings suggest that azithromycin produces anti-inflammatory effects in gingiva.

Clinical evaluation of marginal bone loss and stability in two types of submerged dental implants.

PURPOSE The aim of this prospective clinical trial was to compare the three-dimensional marginal bone level, implant stability, and peri-implant health of two types of submerged dental implants that were restored with matching or platform-switched abutments. MATERIALS AND METHODS Twenty-five subjects were recruited (test group: 43 implants with internal conical connection and back-tapered collar carrying a platform-switched abutment; control group: 50 implants carrying a matched-platform abutment). Implant uncovering and conventional loading were performed after 3 months of healing, and the total observation time was 15 months. Marginal bone levels, resonance frequency analysis, insertion torque, and peri-implant health indices were recorded and analyzed statistically. RESULTS The cumulative implant survival rate was 100%. At the second-stage surgery, bone levels were similar between groups. One year after loading, mean crestal bone loss was 0.35 ± 0.13 mm for test implants and 0.83 ± 0.16 mm for control implants, a significant difference. Primary stability was significantly higher in the test group than in the control group, but this difference disappeared after 3 months of healing prior to loading. Between-group differences for peri-implant health indices were negligible. CONCLUSIONS Both implant systems had the same survival rates. Implants with a built-in platform switch and conical connection with back-tapered collar design achieved higher primary stability at insertion and less bone resorption after 15 months.

Mechanosignaling in Bone Health, Trauma and Inflammation

SIGNIFICANCE Mechanosignaling is vital for maintaining the structural integrity of bone under physiologic conditions. These signals activate and suppress multiple signaling cascades regulating bone formation and resorption. Understanding these pathways is of prime importance to exploit their therapeutic potential in disorders associated with bone loss due to disuse, trauma, or disruption of homeostatic mechanisms. RECENT ADVANCES In the case of cells of the bone, an impressive amount of data has been generated that provides evidence of a complex mechanism by which mechanical signals can maintain or disrupt cellular homeostasis by driving transcriptional regulation of growth factors, matrix proteins and inflammatory mediators in health and inflammation. Mechanical signals act on cells in a magnitude dependent manner to induce bone deposition or resorption. During health, physiological levels of these signals are essential for maintaining bone strength and architecture, whereas during inflammation, similar signals can curb inflammation by suppressing the nuclear factor kappa B (NF-κB) signaling cascade, while upregulating matrix synthesis via mothers against decapentaplegic homolog and/or Wnt signaling cascades. Contrarily, excessive mechanical forces can induce inflammation via activation of the NF-κB signaling cascade. CRITICAL ISSUES Given the osteogenic potential of mechanical signals, it is imperative to exploit their therapeutic efficacy for the treatment of bone disorders. Here we review select signaling pathways and mediators stimulated by mechanical signals to modulate the strength and integrity of the bone. FUTURE DIRECTIONS Understanding the mechanisms of mechanotransduction and its effects on bone lay the groundwork for development of nonpharmacologic mechanostimulatory approaches for osteodegenerative diseases and optimal bone health.

Poor Sleep Quality and Associated Inflammation Predict Preterm Birth: Heightened Risk among African Americans.

STUDY OBJECTIVES Poor sleep promotes inflammation. In turn, inflammation is a causal mechanism in term as well as preterm parturition. In the United States, a persistent racial disparity in preterm birth exists, with African Americans showing ∼1.5 times greater risk. This study examined associations among sleep quality, serum proinflammatory cytokines, and length of gestation in a racially diverse sample of 138 pregnant women. DESIGN Observational. MEASUREMENTS Women completed the Pittsburgh Sleep Quality Index (PSQI) and other psychosocial and behavioral measures during midpregnancy. Serum levels of interleukin (IL)-6, IL-8, IL-1β, and tumor necrosis factor (TNF)-α were determined by high-sensitivity assays. Birth outcomes were determined via medical record review. RESULTS Among African American women (n = 79), shorter gestation was predicted by poorer overall sleep (rs = -0.35, P = 0.002) as well the following PSQI subscales: subjective sleep quality (rs = -0.34, P = 0.002), sleep latency (rs = -0.27, P = 0.02), and sleep efficiency (rs = -0.27, P = 0.02). African American women with poor sleep quality (PSQI > 5) had 10.2 times the odds of preterm birth compared to those with good sleep quality. In contrast, among European American women (n = 53), gestational length was not significantly predicted by sleep quality (Ps > 0.12). Bootstrapping analyses showed that, among African Americans, IL-8 significantly mediated the association between sleep quality and length of gestation (indirect effect estimate -0.029; 95% confidence interval -0.06, -0.002). CONCLUSIONS The data provide novel evidence that African American women exhibit greater inflammation in response to sleep disturbance than European American women and these effects correspond with length of gestation. Racial differences in susceptibility to sleep induced immune dysregulation may contribute to marked racial disparities in preterm birth.

Self-Rated Health among Pregnant Women: Associations with Objective Health Indicators, Psychological Functioning, and Serum Inflammatory Markers

BackgroundBiobehavioral correlates of self-rated health in pregnancy are largely unknown.PurposeThe goals of this study were to examine, in pregnant women, associations of self-rated health with (1) demographics, objective health status, health behaviors, and psychological factors, and (2) serum inflammatory markers.MethodsIn the second trimester of pregnancy, 101 women provided a blood sample, completed measures of psychosocial stress, health status, and health behaviors, and received a comprehensive periodontal examination.ResultsThe following independently predicted poorer self-rated health: (1) greater psychological stress, (2) greater objective health diagnoses, (3) higher body mass index, and (4) past smoking (versus never smoking). Poorer self-rated health was associated with higher serum interleukin-1β (p = 0.02) and marginally higher macrophage migration inhibitory factor (p = 0.06). These relationships were not fully accounted for by behavioral/psychological factors.ConclusionsThis study provides novel data regarding factors influencing subjective ratings of health and the association of self-rated health with serum inflammatory markers in pregnant women.

Salivary detection of periodontopathic bacteria and periodontal health status in dental students.

OBJECTIVE Saliva may become a potential source of contamination through vertical and horizontal transmissions as well as cross-infections. This study aims to use saliva as a screening tool to detect putative periodontal pathogens in a young population with fairly good oral hygiene. MATERIALS AND METHODS Stimulated saliva samples were obtained from 134 dental students (20.5+/-1 years, range 18-22 years). Among those, 77 subjects also completed a periodontal examination including attachment loss, modified dental, gingival and plaque indices (AL, mDI, GI and PI). The test bacteria were identified using a 16S rRNA-based PCR detection method. RESULTS One or more of the test bacteria was found in 67% of the subjects. Prevotella nigrescens was detected as single bacterium in 16% of the subjects followed by Treponema denticola (4%), Porphyromonas gingivalis (2%), Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans (1%) and Tannerella forsythia (1%). Two or more pathogens were detected in 42% of the subjects. Clinical examination revealed health with no attachment loss (AL) in 84% of the students. In no AL group, 38% of the students were pathogen free while this was 25% for students in localized AL group (p>0.05). There was a statistically significant association between the detection of salivary periodontal pathogen in general and higher PI (p=0.018) and GI (p=0.043). CONCLUSION Within the limits of this study, it is possible to detect all six periodontal pathogens in the saliva of dental students. Although a correlation can be observed between the presence of salivary periodontal pathogen and clinical signs of inflammation such as plaque accumulation and gingival bleeding, detection of specific bacteria in saliva is not related to the presence of localized AL based on the presented study population.

Principles of endocrinology

The endocrine system plays a major role in human survival. Endocrine glands secrete chemical messengers or hormones that affect every tissue of the body, including the periodontium, during the life of the individual. As the endocrine system influences a broad assortment of biological activities necessary for life, a general understanding of the principal components and functions of this system is essential. A fundamental assessment of hormone structure, mechanism of action and hormone transport, as well as influence on homeostasis is reviewed. A concise evaluation of the functions of the central endocrine glands, the functions of the major peripheral endocrine glands (other than gonadal tissues) and the known relationships of these hormones to the periodontium is examined.