Penny J. Hodge

Molecular identification of bacteria on the tongue dorsum of subjects with and without halitosis

AIM Compare the microbial profiles on the tongue dorsum in patients with halitosis and control subjects in a UK population using culture-independent techniques. MATERIALS AND METHODS Halitosis patients were screened according to our recently developed recruitment protocol. Scrapings from the tongue dorsum were obtained for 12 control subjects and 20 halitosis patients. Bacteria were identified by PCR amplification, cloning and sequencing of 16S rRNA genes. RESULTS The predominant species found in the control samples were Lysobacter-type species, Streptococcus salivarius, Veillonella dispar, unidentified oral bacterium, Actinomyces odontolyticus, Atopobium parvulum and Veillonella atypica. In the halitosis samples, Lysobacter-type species, S. salivarius, Prevotella melaninogenica, unidentified oral bacterium, Prevotella veroralis and Prevotella pallens were the most commonly found species. For the control samples, 13-16 (4.7-5.8%) of 276 clones represented uncultured species, whereas in the halitosis samples, this proportion increased to 6.5-9.6% (36-53 of 553 clones). In the control samples, 22 (8.0%) of 276 clones represented potentially novel phylotypes, and in the halitosis samples, this figure was 39 (7.1%) of 553 clones. CONCLUSIONS The microflora associated with the tongue dorsum is complex in both the control and halitosis groups, but several key species predominate in both groups.

Markers of bone destruction and formation and periodontitis in type 1 diabetes mellitus

AIM To determine plasma concentrations of bone metabolism markers in type 1 diabetes mellitus patients and non-diabetic and to evaluate the influence of periodontitis on biomarkers of bone formation in these patient groups. METHODS Plasma concentrations of receptor activator of nuclear factor-kappaB ligand (RANKL), osteoprotegerin (OPG), C-terminal telopeptide of type 1 collagen and osteocalcin were measured in type 1 diabetes mellitus patients (n=63) and non-diabetics (n=38) who were also subdivided on the basis of their periodontal status. RESULTS Diabetics had significantly lower osteocalcin concentrations, lower RANKL to OPG ratios and higher OPG concentrations (as shown by other researchers) than non-diabetics. The ratio of RANKL to OPG was altered by the periodontal status. Osteocalcin had a negative correlation and OPG a positive correlation with the percentage of glycated haemoglobin in the blood. CONCLUSION Because, osteocalcin, a biomarker of bone formation, is lower in patients with periodontitis and in patients with type 1 diabetes mellitus with and without periodontitis than in non-diabetics without periodontitis, this might indicate that diabetics are less able to replace bone lost during active bursts of periodontitis and explain the greater severity of disease seen in studies of patients with diabetes.

Clinical associations between IL-17 family cytokines and periodontitis and potential differential roles for IL-17A and IL-17E in periodontal immunity

ObjectiveIL-17A is implicated in periodontitis pathogenesis. The roles of IL-17B–IL-17F and IL-17A/F are unknown. This study aimed to determine clinical associations between IL-17 family cytokines and periodontitis and to investigate the biological roles of IL-17A and IL-17E using in vitro model systems.Materials and methodsSamples from 97 patients with periodontitis and 77 healthy volunteers were used in the study. Serum, saliva and gingival crevicular fluid (GCF) levels of IL-17 family cytokines were measured by ELISA. Oral keratinocytes were stimulated with a P. gingivalis biofilm, or IL-17A, in the presence and absence of IL-17E and the expression of IL-8 and CXCL5 were investigated by ELISA and real-time-PCR. NF-κB phosphorylation in similar experiments was also measured using a cell-based ELISA.ResultsSerum, saliva and GCF IL-17A levels were higher in periodontitis patients and correlated positively with clinical parameters of attachment loss, pocket depth and bleeding on probing. Serum IL-17E levels were lower in periodontitis patients and the serum IL-17A:IL-17E ratio correlated positively with clinical parameters. In vitro, IL-17E inhibited Porphyromonas gingivalis and IL-17A induced expression of chemokines by reducing phosphorylation of the NF-κB p65 subunit.ConclusionsSerum IL-17A:IL-17E may be a marker of disease severity. IL-17E may have opposing roles to IL-17A in periodontitis pathogenesis. IL-17E can negatively regulate IL-17A and periodontal pathogen induced expression of chemokines by oral keratinocytes.

The Influence of Glycated Hemoglobin on the Cross Susceptibility Between Type 1 Diabetes Mellitus and Periodontal Disease

BACKGROUND Periodontal disease is a major complication of type 1 diabetes mellitus (T1DM). The aim of the present study is to investigate the relationship between glycated hemoglobin and circulating levels of interleukin (IL)-6, IL-8, and C-X-C motif chemokine ligand 5 (CXCL5) in non-smoking patients suffering from T1DM, with and without periodontitis. In addition, to determine the effect of advanced glycation end products (AGE) in the presence and absence of Porphyromonas gingivalis lipopolysaccharide (LPS) on IL-6, IL-8, and CXCL5 expression by THP-1 monocytes and OKF6/TERT-2 cells. METHODS There were 104 participants in the study: 19 healthy volunteers, 23 patients with periodontitis, 28 patients with T1DM, and 34 patients with T1DM and periodontitis. Levels of blood glucose/glycated hemoglobin (International Federation of Clinical Chemistry [IFCC]) were determined by high-performance liquid chromatography. Levels of IL-6, IL-8, and CXCL5 in plasma were determined by enzyme-linked immunosorbent assay (ELISA). In vitro stimulation of OKF6/TERT-2 cells and THP-1 monocytes was performed with combinations of AGE and P. gingivalis LPS. Changes in expression of IL-6, IL-8, and CXCL5 were monitored by ELISA and real-time polymerase chain reaction. RESULTS Patients with diabetes and periodontitis had higher plasma levels of IL-8 than patients with periodontitis alone. Plasma levels of IL-8 correlated significantly with IFCC units, clinical probing depth, and attachment loss. AGE and LPS, alone or in combination, stimulated IL-6, IL-8, and CXCL5 expression in both OKF6/TERT-2 cells and THP-1 monocytes. CONCLUSIONS Elevated plasma levels of IL-8 potentially contribute to the cross-susceptibility between periodontitis and T1DM. P. gingivalis LPS and AGE in combination caused significantly greater expression of IL-6, IL-8, and CXCL5 from THP-1 monocytes and OKF6/TERT-2 cells than LPS alone.

Radiographic bone loss in a Scottish non-smoking type 1 diabetes mellitus population; a bitewing radiographic study

BACKGROUND The dental complications of uncontrolled diabetes include reduced salivary flow rate, candidiasis and periodontal manifestations. A recent meta-analysis concluded that diabetes patients have a significantly higher severity, but not extent, of destructive periodontal disease than non-diabetics. The authors reported that most type-1 diabetes studies using dental radiographic data have not controlled for confounding factors such as smoking. The aim of this cross-sectional study was to compare radiographic alveolar bone loss between type 1 diabetes (T1DM) and non-diabetes (NDM) participants in a Scottish non-smoking population. METHODS Digital bitewing radiographs for 174 Scottish adults never or ex-smoker (>5 years) participants (108 T1DM, 66 NDS), recruited from outpatient clinics throughout Greater Glasgow and Clyde, were included in the analysis. A single blinded, trained, and calibrated examiner recorded the radiographic bone loss seen on bitewing radiographs using the digital screen caliper (Screen Calliper ICONICO version 4.0 (Copyright (C) 2001-6 Iconico), New York). The bone loss was measured as the distance between the cemento-enamel junction (CEJ) and the deepest radiographic alveolar bone margin interproximally of each tooth. RESULTS T1DM participants had more radiographic alveolar bone loss throughout the all teeth measured (median:1.27 mm versus 1.06 mm, P < 0.001) and more than a two-fold increase in the risk of having sites with ≥2 mm periodontal destruction (OR = 2.297, 95%CI 1.058 to 4.986, P = 0.036) compared with non-diabetes subjects. CONCLUSIONS Patients suffering from type 1 diabetes are at higher risk of periodontitis even when controlling for multiple possible confounding factors and this difference can be detected on routine dental radiographs at an early stage. These data confirm radiographically the previously reported association between T1DM and periodontal bone loss.

Smoking cessation and periodontal health – a missed opportunity?

DESIGN This was a cohort study. COHORT SELECTION: A longstanding prospective study was carried out of a birth cohort born in Dunedin (New Zealand) in 1972-1973. EXPOSURE MEASUREMENT: Periodontal examinations of the study participants were carried out when they reached the age of 26 and 32 years by calibrated examiners; smoking exposure was measured by questioning at ages 15, 18, 21, 26 and 32 years. Socioeconomic status (SES) was measured at the age of 26 years by categorising adult occupation using standard New Zealand occupation indices. Dental visiting behaviour was assessed by questioning at age 25 and 32 years. DATA ANALYSIS Chi-square tests were used to examine the statistical significance of differences observed with categorical dependent variables. Analysis of variance was used for continuous variables. Logistic regression modelling was used to examine smoking exposure and periodontitis prevalence and incidence while controlling for sex, SES, dental plaque accumulation and the use of dental services. RESULTS Complete data were available for 810 individuals of whom 48.9% had smoked at some point (31.5% were current smokers). Table 1 shows the prevalence, for a selection of smoking exposure groups of attachment loss at age 32 and the odds ratio compared with never-smokers and Table 2 the incidence of 3+ mm attachment loss. Sites with >5 mm attachment loss and were more likely to be incident cases after age 26 (OR, 5.2 and 3.2, respectively). Two thirds of new cases in individuals older than 26 years were attributable to smoking. There were no significant differences in periodontal health between never-smokers and those who had quit smoking after age 26. CONCLUSIONS Current and long-term smoking in young adults is detrimental to periodontal health, but smoking cessation may be associated with a relatively rapid improvement in the periodontium.