Leukocyte receptor expression in chronic periodontitis

BACKGROUND AND OBJECTIVE

Microbial recognition in the periodontium through specific leukocyte receptors gives rise to the response which in susceptible individuals can lead to periodontal diseases. The aim of this study was to explore the expression of leukocyte receptors in the gingival tissues of chronic periodontitis patients and to analyse differences between diseased and control sites (sites with probing pocket depth <4 mm).

MATERIAL AND METHODS

Thirty-seven chronic periodontitis patients were included in the study. Gingival biopsies were harvested from diseased and control sites and processed by flow cytometry for the determination of the expression of 16 leukocyte receptors (CD4, CD8, CD11b, CD14, CD16, CD19, CD25, CD28, CD49d, CD49e, CD62, CD71, CD80, CCR7, Ly6G and HLA-DR).

RESULTS

Expression of all studied receptors was higher in test compared with control sites (p < 0.005). Sampled sites with less bleeding on probing exhibited higher expression of CD16 and CD14 receptors (p = 0.020 and 0.011, respectively).

CONCLUSIONS

This study points towards considerable differences in the expression of leukocyte receptors between diseased and control sites in the same periodontal patients.

Nanoadhesion of Staphylococcus aureus onto Titanium Implant Surfaces

Adhesion of bacteria to dental implant surfaces is the critical initial step in the process of biofilm colonization; however, the specific nanoadhesive interactions occurring during the first contact between bacterial cells and biomaterial substrates remain poorly understood. In this report, we utilize single-cell force spectroscopy to characterize the dynamics of the initial interaction between living Staphylococcus aureus cells and machined titanium surfaces at the nanoscale. Values for maximum adhesion force were found to increase from 0-s (-0.27 ± 0.30 nN) to 60-s (-9.15 ± 0.78 nN) surface delays, with similar results observed for total adhesion work (7.39 ± 2.38 and 988.06 ± 117.08 aJ, respectively). Single unbinding events observed at higher surface delays were modeled according to the wormlike chain model, obtaining molecular contour-length predictions of 314.06 ± 9.27 nm. Average single-bond rupture forces of -0.95 ± 0.04 nN were observed at increased contact times. Short- and long-range force components of bacterial adhesion were obtained by Poisson analysis of single unbinding event peaks, yielding values of -0.75 ± 0.04 and -0.58 ± 0.15 nN, respectively. Addition of 2-mg/mL chlorhexidine to the buffer solution resulted in the inhibition of specific adhesive events but an increased overall adhesion force and work. These results suggest that initial attachment of S. aureus to smooth titanium is mostly mediated by short-range attractive forces observed at higher surface delays.

Periodontal progression based on radiographic records: An observational study in chronic and aggressive periodontitis

OBJECTIVES

The current classification assumes that aggressive periodontitis (AgP) has a faster rate of progression than chronic periodontitis (CP). However, this has not been clearly proven and difficulties exist in establishing progression. This study aimed to assess the feasibility of retrospectively utilising previous records for clinical diagnosis of periodontal diseases and to assess if two different patterns of disease progression exist between AgP and CP.

MATERIALS AND METHODS

Previous radiographic records of a cohort of 235 patients clinically diagnosed with AgP or CP were requested from the referring general dental practitioners (GDPs). Comparable radiographic records were analysed in order to assess progression patterns and associate these with clinical diagnosis, by multilevel analysis.

RESULTS

43 patients out of the initial 235 had comparable radiographs retrieved from the GDPs. 858 sites were followed for an average 6.6 years. Radiographically, AgP showed a faster linear pattern of progression than CP (0.31mm/year vs. 0.20mm/year, p<0.001).

CONCLUSION

This study provides evidence for a faster disease progression in untreated AgP compared to CP as assessed by radiographic bone levels. Furthermore, it shows that retrievability of previous radiographs from GDPs is unpredictable and GDPs should be encouraged to send them along with their referral.

CLINICAL SIGNIFICANCE

The importance of differentially diagnosing AgP and CP might be useful in establishing a clinically relevant definition for periodontal disease progression and may have an impact on the clinical management of aggressive periodontitis, since our findings show that there is continuous destruction in patients with aggressive periodontitis if left untreated.

Single-bacterium nanomechanics in biomedicine: unravelling the dynamics of bacterial cells

The use of the atomic force microscope (AFM) in microbiology has progressed significantly throughout the years since its first application as a high-resolution imaging instrument. Modern AFM setups are capable of characterizing the nanomechanical behaviour of bacterial cells at both the cellular and molecular levels, where elastic properties and adhesion forces of single bacterium cells can be examined under different experimental conditions. Considering that bacterial and biofilm-mediated infections continue to challenge the biomedical field, it is important to understand the biophysical events leading towards bacterial adhesion and colonization on both biological and non-biological substrates. The purpose of this review is to present the latest findings concerning the field of single-bacterium nanomechanics, and discuss future trends and applications of nanoindentation and single-cell force spectroscopy techniques in biomedicine.

Panoramic measures for oral bone mass in detecting osteoporosis: a systematic review and meta-analysis

Different quantitative and qualitative indices calculated on oral panoramic radiographs have been proposed as useful tools to screen for reduced skeletal bone mineral density (BMD). Our aim was to systematically review the literature on linear and qualitative panoramic measures and to assess the accuracy of these indices by performing a meta-analysis of their sensitivity and specificity. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement was followed. Fifty studies were included in the qualitative appraisal and 19 were considered for meta-analysis. The methodological quality of the retrieved studies, assessed with the QUADAS-2 tool, was on average low. Three indices were reported by most of the studies: mandibular cortical width, panoramic mandibular index, and the Klemetti index. Mandibular cortical width presented with a better accuracy in excluding osteopenia/osteoporosis (specificity), since patients with a cortical width more than 4 mm had a normal BMD in 90% of the cases. Almost all studies used a cutoff of 0.3 for the panoramic mandibular index, resulting in an estimated sensitivity and specificity in detecting reduced BMD, respectively, of 0.723 (SE 0.160; 95% confidence interval [CI], 0.352-0.926) and 0.733 (SE 0.066; 95% CI, 0.587-0.841). The presence of any kind of mandibular cortical erosion gave an estimated sensitivity and specificity in detecting reduced BMD, respectively, of 0.789 (SE 0.031; 95% CI, 0.721-0.843) and 0.562 (SE 0.047; 95% CI, 0.47-0.651) and a sensitivity and specificity in detecting osteoporosis, respectively, of 0.806 (SE 0.105; 95% CI, 0.528-0.9200) and 0.643 (SE 0.109; 95% CI, 0.417-0.820). The mandibular cortical width, panoramic mandibular index, and Klemetti index are overall useful tools that potentially could be used by dentists to screen for low BMD. Their limitations are mainly related to the experience/agreement between different operators and the different image quality and magnification of the panoramic radiographs.

Oral health and elite sport performance

While the research base is limited, studies have consistently reported poor oral health in elite athletes since the first report from the 1968 Olympic Games. The finding is consistent both across selected samples attending dental clinics at major competitions and more representative sampling of teams and has led to calls from the International Olympic Committee for more accurate data on oral health. Poor oral health is an important issue directly as it can cause pain, negative effects on appearance and psychosocial effects on confidence and quality of life and may have long-term consequences for treatment burden. Self-reported evidence also suggests an impact on training and performance of athletes. There are many potential challenges to the oral health of athletes including nutritional, oral dehydration, exercise-induced immune suppression, lack of awareness, negative health behaviours and lack of prioritisation. However, in theory, oral diseases are preventable by simple interventions with good evidence of efficacy. The consensus statement aims to raise awareness of the issues of oral health in elite sport and recommends strategies for prevention and health promotion in addition to future research strategies.

Association between short leukocyte telomere length, endotoxemia, and severe periodontitis in people with diabetes: a cross-sectional survey

OBJECTIVE Shortened leukocyte telomere length (LTL) and diagnosis of periodontitis are associated with an increased risk of complications and mortality in diabetes. This study investigated the association between LTL, endotoxemia, and severity of periodontitis in a large cohort of people with diabetes. RESEARCH DESIGN AND METHODS Six hundred thirty individuals (371 with type 2 and 259 with type 1 diabetes) were recruited from the University College Hospital in London, U.K. During a baseline visit, blood was collected for standard biochemical tests and DNA extraction, while a dental examination was performed to determine diagnosis and extent of periodontitis. LTL was measured by real-time PCR, and endotoxemia was assessed by the limulus amoebocyte lysate method. RESULTS Two hundred fifty-five individuals were diagnosed with gingivitis, 327 with periodontitis (114 with moderate and 213 with severe disease), and 48 with edentulous. Diagnosis of periodontitis was associated with shorter LTL (P = 0.04). A negative association between LTL and endotoxemia was found in the severe periodontitis and type 2 diabetes groups (P = 0.01 for both). Shorter LTL was associated with increased extent of periodontitis (P = 0.01) and increased insulin resistance (homeostatic model assessment). Multiple adjustments for biochemical, anthropometric, and medication-use variables did not affect the results. CONCLUSIONS LTL is associated with endotoxemia and diagnosis of periodontitis in people with diabetes. LTL shortening might represent a novel biological pathway accounting for previous epidemiological data that documented higher prevalence of diabetes and its complications in people with periodontitis and vice versa.

Genetic dysbiosis: the role of microbial insults in chronic inflammatory diseases

Thousands of bacterial phylotypes colonise the human body and the host response to this bacterial challenge greatly influences our state of health or disease. The concept of infectogenomics highlights the importance of host genetic factors in determining the composition of human microbial biofilms and the response to this microbial challenge. We hereby introduce the term ‘genetic dysbiosis’ to highlight the role of human genetic variants affecting microbial recognition and host response in creating an environment conducive to changes in the normal microbiota. Such changes can, in turn, predispose to, and influence, diseases such as: cancer, inflammatory bowel disease, rheumatoid arthritis, psoriasis, bacterial vaginosis and periodontitis. This review presents the state of the evidence on host genetic factors affecting dysbiosis and microbial misrecognition (i.e. an aberrant response to the normal microbiota) and highlights the need for further research in this area.

Association between COX-2 rs 6681231 genotype and interleukin-6 in periodontal connective tissue. A pilot study

OBJECTIVES

The aim of this pilot study was to investigate associations between IL-6 and COX-2 expression in gingival biopsies and both clinical diagnosis and genotypes in the IL-6 and COX-2 genes.

DESIGN

A case-control study included 41 gingival biopsies obtained from Caucasian patients grouped according to clinical diagnosis of gingival health (n = 10), gingivitis (n = 15) or chronic periodontitis (n = 16). Immunohistochemistry analyses were performed to determine COX-2 expression in lamina propria, IL-6 expression in lamina propria and gingival epithelium and level of inflammatory cell infiltrate. Individual DNA was extracted and genotyped by real-time PCR for IL6 SNPs rs 2069827 and rs 2069825 and for COX-2 rs 6681231.

RESULTS

The percentage of cellular COX-2 expression was associated with the extent of periodontal disease (Arbes index p = 0.026) and inflammatory infiltrate (p<0.0001). No association was observed between IL6 haplotypes and cells positive to IL-6 or COX-2 in gingival tissues. The COX-2 rs 6681231 was associated with cells positive to IL-6 in the connective tissue (p = 0.032).

CONCLUSIONS

COX-2 expression in gingival tissues may be a marker of periodontal disease severity. COX-2 rs 6681231 may be associated with IL-6 local production in gingival tissues.

Oral health and impact on performance of athletes participating in the London 2012 Olympic Games: a cross-sectional study

BACKGROUND

Oral health is important both for well-being and successful elite sporting performance. Reports from Olympic Games have found significant treatment needs; however, few studies have examined oral health directly. The aim of this study was to evaluate oral health, the determinants of oral health and the effect of oral health on well-being, training and performance of athletes participating in the London 2012 Games.

METHODS

Cross-sectional study at the dental clinic within the Polyclinic in the athletes' village. Following informed consent, a standardised history, clinical examination and brief questionnaire were conducted.

RESULTS

302 athletes from 25 sports were recruited with data available for 278. The majority of athletes were from Africa, the Americas and Europe. Overall, the results demonstrated high levels of poor oral health including dental caries (55% athletes), dental erosion (45% athletes) and periodontal disease (gingivitis 76% athletes, periodontitis 15% athletes). More than 40% of athletes were 'bothered' by their oral health with 28% reporting an impact on quality of life and 18% on training and performance. Nearly half of the participants had not undergone a dental examination or hygiene care in the previous year.

CONCLUSIONS

The oral health of athletes attending the dental clinic of the London 2012 Games was poor with a resulting substantial negative impact on well-being, training and performance. As oral health is an important element of overall health and well-being, health promotion and disease prevention interventions are urgently required to optimise athletic performance.

Body mass index as a predictive factor of periodontal therapy outcomes

Body mass index (BMI) and obesity are associated with the prevalence, extent, and severity of periodontitis. This study investigated the predictive role of overweight/obesity on clinical response following non-surgical periodontal therapy in patients with severe periodontitis. Two hundred sixty adults received an intensive course of non-surgical periodontal therapy. Periodontal status at baseline and 2 months was based upon probing pocket depths (PPD), clinical attachment levels (CAL), and whole-mouth gingival bleeding (FMBS) as assessed by two calibrated examiners. Generalized estimating equations (GEE) were used to estimate the impact of BMI and overweight/obesity on periodontal treatment response while controlling for baseline status, age, smoking status (smoker or non-smoker), and full-mouth dental plaque score. BMI (continuous variable) and obesity (vs. normal weight) were associated with worse mean PPD (p < .005), percentage of PPD > 4 mm (p = .01), but not with FMBS (p > .05) or CAL (p > .05) at 2 months, independent of age, smoking status, or dental plaque levels. The magnitude of this association was similar to that of smoking, which was also linked to a worse clinical periodontal outcome (p < .01). BMI and obesity appear to be independent predictors of poor response following non-surgical periodontal therapy.

Periodontitis and redox status: a review

Periodontal diseases are common inflammatory conditions of the supporting apparatus of the teeth which lead to early tooth loss. This review discusses the evidence for a role of reactive oxygen species in inducing periodontal tissue damage and focuses on recent evidence showing increased local and systemic alterations in the redox balance of periodontitis. An appraisal of the methods for analysis of oxidative stress in periodontal disease research is provided, showing an increase in oxidative stress measures and oxidative damage fingerprints detected in studies investigating periodontitis cases compared to healthy controls. Hypotheses on the relationships between oxidative stress and inflammatory responses and on the role of redox status in periodontal medicine are discussed. Finally, the review provides an overview of possible intervention pathways for the use of antioxidants as adjuncts to mechanical biofilm removal for the treatment of periodontitis.

Changes in dental plaque following hospitalisation in a critical care unit: an observational study

Introduction

Previous research has suggested that deterioration in oral health can occur following hospitalisation. The impact of such deterioration could increase the risk of oral disease, reduce quality of life and increase the potential for healthcare-associated infections (HCAI) such as healthcare-associated pneumonia (HAP). However, the strength of the evidence is limited by, amongst other factors, the few observational studies published that assess oral health longitudinally. In view of the microbiological component of oral diseases and HCAIs, the objective of this study was to investigate the microbiological changes in dental plaque following hospitalisation in a Critical Care Unit (CCU): (1) total number of cultivable bacteria and (2) presence and changes in specific HAP pathogens.

Methods

We conducted a prospective, longitudinal observational study in the CCU of University College Hospital, London. Study participants were recruited within 24 hours of admission. Dental plaque samples were collected from up to six sites per patient. The primary outcome was microbiological change from baseline to seven days with additional analysis for participants still present at day 14.

Results

50 patients were recruited with 36 available for review at one week, with early discharge accounting for much of the loss to follow-up. The median total viable count of the plaque microbiota at baseline was 4.40 × 10⁵ cfu/ml and increased at week one to 3.44 × 10⁶ cfu/ml. The total viable microbe counts increased by a median of 2.26 × 10⁶ cfu/ml from baseline to week one (95% CI: 3.19 × 10⁶, 1.24 × 10⁷) and this was statistically significant (P < 0.01). Specific HAP bacteria were detected in 26% of participants sampled, although accounted for a relatively low proportion of the total viable bacteria.

Conclusion

Total bacterial count of dental plaque increases during hospitalisation in CCU. This finding, together with the colonisation of dental plaque by HAP bacteria strengthens the evidence for a deterioration in oral health in CCU and a risk factor for negative health and quality of life outcomes.

Socioeconomic disparities of periodontitis in Koreans based on the KNHANES IV

OBJECTIVES

The aim of this study was to identify the socioeconomic factors associated with the prevalence of periodontitis in Koreans.

METHODS

Cross-sectional data from 12 763 subjects, 15 years old and above, who underwent periodontal examinations were obtained from the Korean National Health and Nutrition Examination Survey IV (2007-209). Multivariate linear and logistic regression analyses were applied to estimate the association between socioeconomic indicators and prevalence of periodontitis.

RESULTS

A significant association was found between increasing age and periodontitis. Participants with higher income were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.78-0.98, and aOR = 0.7 and 95% CI = 0.60-0.80 in the middle and highest quintiles of monthly household income, respectively). In addition, participants living in rural areas were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.81-0.99), and current smokers were more likely to have periodontitis (aOR = 1.7 and 95% CI = 1.49-1.89). The analysis of comorbidities revealed that individuals with diabetes mellitus (DM) were significantly more likely to have periodontitis (aOR = 1.4 and 95% CI = 1.18-1.68).

CONCLUSIONS

In a rapidly increasing Korean population, the lower socioeconomic groups as well as individuals with DM were significantly more likely to present with periodontitis.

Tooth loss in aggressive periodontitis: a systematic review

Aggressive periodontitis (AgP) is thought to have a faster rate of progression than chronic periodontitis (CP). However, there is a lack of studies systematically investigating disease progression and tooth loss in AgP. A systematic search of the literature was conducted by two independent reviewers for longitudinal studies including patients with AgP (previously known as 'periodontosis', 'juvenile' or 'early-onset' periodontitis) indicating measures of disease progression. Ovid MEDLINE(®) and Embase databases were searched for at least 5-year longitudinal human studies in AgP patients. In total, 16 studies were included in the review, from an initial search of 1,601 titles. Heterogeneity was detected for disease definition and clinical data reporting; hence meta-analysis was feasible only for the objective measure 'tooth loss'. The average tooth loss for all AgP cases was 0.09 (95% C.I. = 0.06-0.16) per patient-year. The corresponding values by diagnosis were 0.05, 0.14, and 0.12 tooth loss per patient-year, respectively, for LAgP, GAgP, and un-specified AgP. For studies reporting tooth loss during the 'observational period' (excluding extractions at initial therapy), the average tooth loss for AgP was 0.09 per patient-year. High heterogeneity was detected for these analyses. In conclusion, most studies report good long-term stability of treated AgP cases.

Clinical review: Association between metabolic syndrome and periodontitis: a systematic review and meta-analysis

BACKGROUND

Several epidemiological studies have reported an association between metabolic syndrome (MetS) and periodontal diseases (PDs). The aim of this systematic review was to investigate the existence and magnitude of this association.

MATERIALS AND METHODS

A systematic search of the literature was conducted looking for case-control, cross-sectional, cohort studies and population surveys including patients with measures of MetS and PD. Ovid MEDLINE, EMBASE, LILACS, and Cochrane library databases were used for the search by 2 independent reviewers. A meta-analysis was conducted to investigate the association for coexistence of MetS and PD.

RESULTS

A total of 20 studies were included in the review, from an initial search of 3486 titles. Only 1 study reported longitudinal data on the onset of MetS components in association with periodontal measures. However, several studies investigated coexistence. A random effects meta-analysis showed that the presence of MetS is associated with the presence of periodontitis in a total of 36 337 subjects (odds ratio = 1.71; 95% confidence interval = 1.42 to 2.03). When only studies with "secure" diagnoses were included (n = 16 405), the magnitude of association increased (odds ratio = 2.09; 95% confidence interval = 1.28 to 3.44). Moderate heterogeneity was detected (I(2) = 53.6%; P = .004).

CONCLUSIONS

This review presents clear evidence for an association between MetS and periodontitis. The direction of the association and factors influencing it should be investigated by longitudinal and treatment studies. Periodontal diagnostic procedures should be routinely carried out in MetS patients.

The impact of hospitalization on dental plaque accumulation: an observational study

AIM

To investigate the effect of hospitalization on oral health as assessed by dental plaque.

MATERIALS AND METHODS

Observational study in a critical care unit (CCU). Participants were recruited within 24 h of admission. Dental plaque amount was assessed at baseline, 1 and 2 weeks using the Debris index-soft deposits (Greene & Vermillion 1960).

RESULTS

Fifty participants were recruited with 36 available for outcome assessment at 1 week and 10 at 2 weeks. The principal reason for losses was early discharge with no evidence of a difference between patients present only at baseline and those present at 1 week. The median value for dental plaque at baseline was 4 (95% CI: 4, 6). The median dental plaque increase from baseline to week 1 was 1.5 (95% CI: -1, 4), and this was statistically significant (p = 0.04). The median increase from week 1 to week 2 was 1.0 (95% CI -8, 6) and not statistically significant (p = 0.68).

CONCLUSIONS

Oral health as assessed by dental plaque deteriorates following hospitalization in CCU. Such change could lead to impairment of quality of life and well-being as well as to increasing the risk of important healthcare-associated infections such as nosocomial pneumonia.