Ingmar Staufenbiel

Validation of reported genetic risk factors for periodontitis in a large-scale replication study.

AIM Many studies investigated the role of genetic variants in periodontitis, but few were established as risk factors. We aimed to validate the associations of recent candidate genes in aggressive periodontitis (AgP). MATERIAL AND METHODS We analysed 23 genes in 600 German AgP patients and 1441 controls on the Illumina custom genotyping array Immunochip. We tested a suggestive association in a Dutch and German/Austrian AgP case-control sample, and a German chronic periodontitis (CP) case-control sample using Sequenom iPlex assays. We additionally tested the common known risk variant rs1333048 of the gene ANRIL for its association in a Turkish and Italian population. RESULTS None of the analysed genes gave statistical evidence for association. Upon covariate adjustment for smoking and gender, in the pooled German-Austrian AgP sample, IL10 SNP rs6667202 was associated with p = 0.016, OR = 0.77 (95% CI = 0.6-0.95), and in the Dutch AgP sample, adjacent IL10 SNP rs61815643 was associated with p = 0.0009, OR = 2.31 (95% CI = 1.4-3.8). At rs61815643, binding of the transcription factor PPARG was predicted. ANRIL rs1333048 was associated in the Turkish sample (pallelic = 0.026, OR = 1.67 [95% CI = 1.11-2.60]). CONCLUSIONS Previous candidate genes carry no susceptibility factors for AgP. Association of IL-10 rs61815643 with AgP is suggested. ANRIL is associated with periodontitis across different populations.

Probiotics affect the clinical inflammatory parameters of experimental gingivitis in humans

Objectives:To determine the effects of a probiotic milk drink consumed over a period of 28 days, regarding the expression of clinical inflammatory parameters of the oral gingiva during various phases of plaque-induced gingivitis.Methods:Twenty-eight adults with healthy gingiva took part in a prospective and clinical-controlled study. The test group was advised to consume a probiotic milk drink (Yacult) daily during a period of 4 weeks; the control group did not receive any probiotic food or drink. After 2 weeks of consumption of the probiotic drink, participants were advised not to brush their teeth for 14 days. Subsequently, at baseline as well as on days 1, 3, 5, 7 and 14, the following clinical parameters were assessed: plaque index (PI), gingival index (GI), gingival crevicular fluid (GCF) volume and bleeding on probing (BOP).Results:At baseline, the PI was significantly higher in the test group compared with controls (0.44±0.50 vs 0.09±0.24 PI; P=0.0001). The termination of oral hygiene increased clinical inflammatory parameters in both groups. At day 14, the parameters PI, GI, GCF volume and BOP were significantly higher compared with baseline values (P=0.0001). At day 14, BOP levels (18.75±12.32 vs 36.88±12.54%) and GCF volume (18.78±16.7 vs 35.72±16.1 Periotron units) were significantly lower in the test group compared with the control group (P=0.005).Conclusion:The results of our study indicate that a daily consumption of a probiotic milk drink reduces the effects of plaque-induced gingival inflammation associated with a higher plaque score due to the high-carbohydrate content of the probiotic milk beverage.

Composition of Microbial Oral Biofilms during Maturation in Young Healthy Adults

In the present study we aimed to analyze the bacterial community structure of oral biofilms at different maturation stages in young healthy adults. Oral biofilms established on membrane filters were collected from 32 human subjects after 5 different maturation intervals (1, 3, 5, 9 and 14 days) and the respective phylogenetic diversity was analyzed by 16S rDNA amplicon sequencing. Our analyses revealed highly diverse entire colonization profiles, spread into 8 phyla/candidate divisions and in 15 different bacterial classes. A large inter-individual difference in the subjects’ microbiota was observed, comprising 35% of the total variance, but lacking conspicuous general temporal trends in both alpha and beta diversity. We further obtained strong evidence that subjects can be categorized into three clusters based on three differently occurring and mutually exclusive species clusters.

Experimental Gingivitis Induces Systemic Inflammatory Markers in Young Healthy Individuals: A Single-Subject Interventional Study

Objectives We here investigated whether experimental gingivitis enhances systemic markers of inflammation which are also known as surrogate markers of atherosclerotic plaque development. Background Gingivitis is a low-level oral infection induced by bacterial deposits with a high prevalence within Western populations. A potential link between the more severe oral disease periodontitis and cardiovascular disease has already been shown. Methods 37 non-smoking young volunteers with no inflammatory disease or any cardiovascular risk factors participated in this single-subject interventional study with an intra-individual control. Intentionally experimental oral inflammation was induced by the interruption of oral hygiene for 21 days, followed by a 21-days resolving phase after reinitiation of oral hygiene. Primary outcome measures at baseline, day 21 and 42 were concentrations of hsCRP, IL-6, and MCP-1, as well as adhesion capacity and oxLDL uptake of isolated blood monocytes. Results The partial cessation of oral hygiene procedures was followed by the significant increase of gingival bleeding (34.0%, P<0.0001). This local inflammation was associated with a systemic increase in hsCRP (0.24 mg/L, P = 0.038), IL-6 (12.52 ng/L, P = 0.0002) and MCP-1 (9.10 ng/l, P = 0.124) in peripheral blood samples between baseline and day 21, which decreased at day 42. Monocytes showed an enhanced adherence to endothelial cells and increased foam cell formation after oxLDL uptake (P<0.050) at day 21 of gingivitis. Conclusions Bacterial-induced gingival low-level inflammation induced a systemic increase in inflammatory markers. Dental hygiene almost completely reversed this experimental inflammatory process, suggesting that appropriate dental prophylaxis may also limit systemic markers of inflammation in subjects with natural gingivitis. International Clinical Trials Register Platform of the World Health Organization, registry number: DRKS00003366, URL: http://apps.who.int/trialsearch/Default.aspx

Level of information about the relationship between diabetes mellitus and periodontitis - results from a nationwide diabetes information program

BackgroundA comprehensive knowledge about the mutual influence between diabetes and periodontitis is decisive for the successful treatment of both diseases. The present investigation aimed at assessing the diabetic and periodontal conditions and, in particular, the degree of knowledge about the relationship between diabetes and periodontitis.MethodsDuring a diabetes information program, 111 nondiabetics (ND), 101 type 1 diabetics (T1D), and 236 type 2 diabetics (T2D) were subject to a medical and dental examination and completed a self-administered questionnaire. Medical examination included measurements of glycated hemoglobin (HbA1c), blood glucose (BG), and body mass index (BMI). Full-mouth examination consisted of the assessment of the decayed, missing, filled teeth index (DMFT) and the periodontal screening index (PSI). Chi-square test, ANOVA, t test of independent samples, univariate and multivariate logistic regression models with variable selection strategies were used for statistical analyses. Due to the exploratory character of the investigation a value of P ≤0.05 was considered to be statistically substantial.ResultsT2D had a significantly higher PSI when compared to T1D and ND (t test: P <0.001; P = 0.005). Approximately 90% of T2D suffered from periodontitis. In addition, diabetics with periodontitis showed a significantly higher BMI when compared to diabetics without periodontitis (multivariate logistic regression: P = 0.002). Almost 60% of all investigated subjects were not informed about the mutual influence between diabetes and periodontitis. T2D had almost as little information about the increased risk for periodontitis as ND.ConclusionsThe data of the present investigation suggest that there is a strong association between type 2 diabetes and chronic periodontitis. The lack of awareness of the mutual influence between diabetes and periodontitis, especially in T2D, demonstrates that this topic is still neglected in dental and diabetic treatment.

Periodontal status of HIV-infected patients undergoing antiretroviral therapy compared to HIV-therapy naive patients: a case control study

BackgroundAlthough severe oral opportunistic infections decreased with the implementation of highly active antiretroviral therapy, periodontitis is still a commonly described problem in patients infected with human immunodeficiency virus (HIV). The objective of the present investigation was to determine possible differences in periodontal parameters between antiretroviral treated and untreated patients.MethodsThe study population comprised 80 patients infected with HIV divided into two groups. The first group was receiving antiretroviral therapy while the second group was therapy naive. The following parameters were examined: probing pocket depth, gingival recession, clinical attachment level, papilla bleeding score, periodontal screening index and the index for decayed, missed and filled teeth. A questionnaire concerning oral hygiene, dental care and smoking habits was filled out by the patients.ResultsThere were no significant differences regarding the periodontal parameters between the groups except in the clinical marker for inflammation, the papilla bleeding score, which was twice as high (P < 0.0001) in the antiretroviral untreated group (0.58 ± 0.40 versus 1.02 ± 0.59). The participants of this investigation generally showed a prevalence of periodontitis comparable to that in healthy subjects. The results of the questionnaire were comparable between the two groups.ConclusionThere is no indication for advanced periodontal damage in HIV-infected versus non-infected patients in comparable age groups. Due to their immunodeficiency, HIV-infected patients should be monitored closely to prevent irreversible periodontal damage. Periodontal monitoring and early therapy is recommended independent of an indication for highly active antiretroviral therapy.

Pyrosequencing of supra- and subgingival biofilms from inflamed peri-implant and periodontal sites

BackgroundTo investigate the microbial composition of biofilms at inflamed peri-implant and periodontal tissues in the same subject, using 16S rRNA sequencing.MethodsSupra- and submucosal, and supra- and subgingival plaque samples were collected from 7 subjects suffering from diseased peri-implant and periodontal tissues. Bacterial DNA was isolated and 16S rRNA genes were amplified, sequenced and aligned for the identification of bacterial genera.Results43734 chimera-depleted, denoised sequences were identified, corresponding to 1 phylum, 8 classes, 10 orders, 44 families and 150 genera. The most abundant families or genera found in supramucosal or supragingival plaque were Streptoccocaceae, Rothia and Porphyromonas. In submucosal plaque, the most abundant family or genera found were Rothia, Streptococcaceae and Porphyromonas on implants. The most abundant subgingival bacteria on teeth were Prevotella, Streptococcaceae, and TG5. The number of sequences found for the genera Tannerella and Aggregatibacter on implants differed significantly between supra- and submucosal locations before multiple testing. The analyses demonstrated no significant differences between microbiomes on implants and teeth in supra- or submucosal and supra- or subgingival biofilms.ConclusionDiseased peri-implant and periodontal tissues in the same subject share similiar bacterial genera and based on the analysis of taxa on a genus level biofilm compositions may not account for the potentially distinct pathologies at implants or teeth.

A genome-wide association study identifies nucleotide variants at SIGLEC5 and DEFA1A3 as risk loci for periodontitis.

Abstract Periodontitis is one of the most common inflammatory diseases, with a prevalence of 11% worldwide for the severe forms and an estimated heritability of 50%. The disease is characterized by destruction of the alveolar bone due to an aberrant host inflammatory response to a dysbiotic oral microbiome. Previous genome‐wide association studies (GWAS) have reported several suggestive susceptibility loci. Here, we conducted a GWAS using a German and Dutch case‐control sample of aggressive periodontitis (AgP, 896 cases, 7,104 controls), a rare but highly severe and early‐onset form of periodontitis, validated the associations in a German sample of severe forms of the more moderate phenotype chronic periodontitis (CP) (993 cases, 1,419 controls). Positive findings were replicated in a Turkish sample of AgP (223 cases, 564 controls). A locus at SIGLEC5 (sialic acid binding Ig‐like lectin 5) and a chromosomal region downstream of the DEFA1A3 locus (defensin alpha 1‐3) showed association with both disease phenotypes and were associated with periodontitis at a genome‐wide significance level in the pooled samples, with P = 1.09E‐08 (rs4284742,‐G; OR = 1.34, 95% CI = 1.21‐1.48) and P = 5.48E‐10 (rs2738058,‐T; OR = 1.28, 95% CI = 1.18‐1.38), respectively. SIGLEC5 is expressed in various myeloid immune cells and classified as an inhibitory receptor with the potential to mediate tyrosine phosphatases SHP‐1/‐2 dependent signaling. Alpha defensins are antimicrobial peptides with expression in neutrophils and mucosal surfaces and a role in phagocyte‐mediated host defense. This study identifies the first shared genetic risk loci of AgP and CP with genome‐wide significance and highlights the role of innate and adaptive immunity in the etiology of periodontitis.

Expression of antimicrobial peptides and interleukin‐8 during early stages of inflammation: An experimental gingivitis study

BACKGROUND AND OBJECTIVES In the oral cavity, the epithelial surface is constantly exposed to a number of different microorganisms that are organized in a well-structured biofilm. The aim of this study was to monitor gingival expression of antimicrobial peptides (AMPs) and interleukin-8 (IL-8) in an early gingivitis model. MATERIAL AND METHODS Experimental gingivitis was allowed to develop in healthy volunteers (n = 17). Bleeding on probing (BOP%) and gingival crevicular fluid volume (GCF) were assessed at baseline and day 1, 3, 5, 7 and 14. Expression of AMPs (human beta-defensin-2, hBD-2; CC-chemokine ligand 20, CCL20; psoriasin, pso/S100A7) and IL-8 was analyzed by immunohistochemistry in gingival biopsies. In addition, hBD-2 and IL-8 protein expression was monitored in GCF using the ELISA technology. RESULTS Experimental gingivitis gradually developed with an increase in BOP scores and GCF volume over time. In GCF, elevated concentrations of hBD-2 and IL-8 were monitored at day 1, 5 and 7 (p ≤ 0.0002). Immunohistochemical analysis of gingival sections demonstrated increased staining for hBD-2 at day 3, whereas the CCL20, pso/S100A7, and IL-8 expression was increased at later time points (p < 0.05). CONCLUSION For the first time, this study showed the time-dependent regulation of AMPs, following clinical signs of experimentally induced gingival inflammation. Differential temporal expression for AMPs may ensure a constant antimicrobial activity against changes in the bacterial composition of the growing dental biofilm.

Periodontal conditions in vegetarians: a clinical study.

BACKGROUND/OBJECTIVES:Investigations about possible correlations between vegetarian diet and periodontal conditions are rare and characterized by small case numbers. The aim of this clinical study was to investigate the influence of a vegetarian diet on periodontal parameters with an appropriate sample size.SUBJECTS/METHODS:A total of 200 patients, 100 vegetarians and 100 non-vegetarians, were included in the study. All patients were examined including a full mouth assessment of the periodontal and dental conditions. In addition, a questionnaire was handed out to ask for patients’ oral hygiene habits and level of education. For statistical analysis the Mann–Whitney Test (χ2 for analysis of the questionnaire) was applied (level of significance: P<0.05).RESULTS:Well known periodontal risk factors like age, gender and smoking habits were equally distributed within each group (71 females, 29 males, respectively and 10 smokers in each group; mean age: 41.45 years vegetarians versus 41.72 years non-vegetarians). Vegetarians had significantly lower probing pocket depths (P=0.039), bleeding on probing (P=0.001), periodontal screening index (P=0.012), a better hygiene index (P<0.001) and less mobile teeth (P=0.013). Dental examinations revealed significantly less missing teeth (P=0.018) but also more decayed (P=0.001) and eroded (P=0.026) teeth in vegetarians. Furthermore, vegetarians had a higher level of education (P<0.001), but visited dentists significantly less frequent.CONCLUSIONS:Vegetarians revealed better periodontal conditions (less inflammation signs, less periodontal damage and a better dental home care). However, it should be considered that vegetarians are not only avoiding meat in their nutrition but are also characterized by an overall healthier life style.