Primary prevention of periodontitis: managing gingivitis

Periodontitis is a ubiquitous and irreversible inflammatory condition and represents a significant public health burden. Severe periodontitis affects over 11% of adults, is a major cause of tooth loss impacting negatively upon speech, nutrition, quality of life and self-esteem, and has systemic inflammatory consequences. Periodontitis is preventable and treatment leads to reduced rates of tooth loss and improved quality of life. However, successful treatment necessitates behaviour change in patients to address lifestyle risk factors (e.g. smoking) and, most importantly, to attain and sustain high standards of daily plaque removal, lifelong. While mechanical plaque removal remains the bedrock of successful periodontal disease management, in high-risk patients it appears that the critical threshold for plaque accumulation to trigger periodontitis is low, and such patients may benefit from adjunctive agents for primary prevention of periodontitis.

AIM

The aims of this working group were to systematically review the evidence for primary prevention of periodontitis by preventing gingivitis via four approaches: 1) the efficacy of mechanical self-administered plaque control regimes; 2) the efficacy of self-administered inter-dental mechanical plaque control; 3) the efficacy of adjunctive chemical plaque control; and 4) anti-inflammatory (sole or adjunctive) approaches.

METHODS

Two meta-reviews (mechanical plaque removal) and two traditional systematic reviews (chemical plaque control/anti-inflammatory agents) formed the basis of this consensus.

RESULTS

Data support the belief that professionally administered plaque control significantly improves gingival inflammation and lowers plaque scores, with some evidence that reinforcement of oral hygiene provides further benefit. Re-chargeable power toothbrushes provide small but statistically significant additional reductions in gingival inflammation and plaque levels. Flossing cannot be recommended other than for sites of gingival and periodontal health, where inter-dental brushes (IDBs) will not pass through the interproximal area without trauma. Otherwise, IDBs are the device of choice for interproximal plaque removal. Use of local or systemic anti-inflammatory agents in the management of gingivitis has no robust evidence base. We support the almost universal recommendations that all people should brush their teeth twice a day for at least 2 min. with fluoridated dentifrice. Expert opinion is that for periodontitis patients 2 min. is likely to be insufficient, especially when considering the need for additional use of inter-dental cleaning devices. In patients with gingivitis once daily inter-dental cleaning is recommended and the adjunctive use of chemical plaque control agents offers advantages in this group.

Systemic effects of periodontitis treatment in patients with type 2 diabetes: a 12 month, single-centre, investigator-masked, randomised trial

BACKGROUND

Chronic inflammation is believed to be a major mechanism underlying the pathophysiology of type 2 diabetes. Periodontitis is a cause of systemic inflammation. We aimed to assess the effects of periodontal treatment on glycaemic control in people with type 2 diabetes.

METHODS

In this 12 month, single-centre, parallel-group, investigator-masked, randomised trial, we recruited patients with type 2 diabetes, moderate-to-severe periodontitis, and at least 15 teeth from four local hospitals and 15 medical or dental practices in the UK. We randomly assigned patients (1:1) using a computer-generated table to receive intensive periodontal treatment (IPT; whole mouth subgingival scaling, surgical periodontal therapy [if the participants showed good oral hygiene practice; otherwise dental cleaning again], and supportive periodontal therapy every 3 months until completion of the study) or control periodontal treatment (CPT; supra-gingival scaling and polishing at the same timepoints as in the IPT group). Treatment allocation included a process of minimisation in terms of diabetes onset, smoking status, sex, and periodontitis severity. Allocation to treatment was concealed in an opaque envelope and revealed to the clinician on the day of first treatment. With the exception of dental staff who performed the treatment and clinical examinations, all study investigators were masked to group allocation. The primary outcome was between-group difference in HbA_1c at 12 months in the intention-to-treat population. This study is registered with the ISRCTN registry, number ISRCTN83229304.

FINDINGS

Between Oct 1, 2008, and Oct 31, 2012, we randomly assigned 264 patients to IPT (n=133) or CPT (n=131), all of whom were included in the intention-to-treat population. At baseline, mean HbA_1c was 8·1% (SD 1·7) in both groups. After 12 months, unadjusted mean HbA_1c was 8·3% (SE 0·2) in the CPT group and 7·8% (0·2) in the IPT group; with adjustment for baseline HbA_1c, age, sex, ethnicity, smoking status, duration of diabetes, and BMI, HbA_1c was 0·6% (95% CI 0·3-0·9; p<0·0001) lower in the IPT group than in the CPT group. At least one adverse event was reported in 30 (23%) of 133 patients in the IPT group and 23 (18%) of 131 patients in the CPT group. Serious adverse events were reported in 11 (8%) patients in the IPT group, including one (1%) death, and 11 (8%) patients in the CPT group, including three (2%) deaths.

INTERPRETATION

Compared with CPT, IPT reduced HbA_1c in patients with type 2 diabetes and moderate-to-severe periodontitis after 12 months. These results suggest that routine oral health assessment and treatment of periodontitis could be important for effective management of type 2 diabetes.

FUNDING

Diabetes UK and UK National Institute for Health Research.

Association between overweight/obesity and periodontitis in adults. A systematic review

Overweight and obesity have been suggested to be associated with periodontitis as published in studies and narrative summaries. This project presents results of a systematic review investigating the association between overweight or obesity (as defined by the World Health Organization) and periodontitis. Search strategy included electronic and hand searching to December 2009. Ovid MEDLINE, EMBASE, LILACS, and SIGLE were searched. RCTs, cohort, case-control and cross-sectional study designs that included measures of periodontitis and body composition were eligible. Duplicate, independent screening and data abstraction were performed. Meta-analyses were performed when appropriate. A total of 526 titles and abstracts were screened, resulting in 61 full text articles and abstracts assessed for eligibility with 33 being included. Nineteen studies provided sufficient information for inclusion in meta-analyses. Meta-analyses indicated statistically significant associations between periodontitis and body mass index (BMI) category obese OR 1.81(1.42, 2.30), overweight OR 1.27(1.06, 1.51) and obese and overweight combined OR 2.13(1.40, 3.26). In conclusion, these results support an association between BMI overweight and obesity and periodontitis although the magnitude is unclear. Additional prospective studies to further quantify, or understand the mechanisms, of this association are merited. There is insufficient evidence to provide guidelines to clinicians on the clinical management of periodontitis in overweight and obese individuals.

Oxidative stress, systemic inflammation, and severe periodontitis

Periodontal infections have been associated with a state of chronic inflammation. To ascertain whether severe periodontitis and its treatment are associated with oxidative stress, we recruited 145 cases (periodontitis) and 56 controls in a case-control study. A further pilot intervention study of 14 cases (periodontal therapy) was performed. Blood samples were taken at baseline (case-control) and 1, 3, 5, 7, and 30 days after treatment (intervention). Diacron-reactive oxygen metabolites (D-ROM), anti-oxidant potential, C-reactive protein (CRP), interleukin-6, and lipid profiles were determined with high-sensitivity assays in serum. Patients with severe periodontitis exhibited higher D-ROM levels (P < 0.001) and lower total anti-oxidant capacity (P < 0.001) compared with healthy control individuals. These findings were independent of age, gender, smoking habits, ethnicity, and standard lipids differences. D-ROM levels were positively correlated with CRP (R = 0.4, P < 0.001) and clinical periodontal parameters (R = 0.20, P < 0.05). Acute increases of D-ROM (P < 0.01) were observed following periodontal therapy. Analysis of these data suggests a positive association between severe periodontitis and oxidative stress.

Modified titanium surfaces promote accelerated osteogenic differentiation of mesenchymal stromal cells in vitro

Titanium (Ti) is the material of choice for dental and orthopaedic implants due to its highly biocompatible nature. Modification of the implant surface, either topographically (as roughness) or chemically, can promote accelerated osteogenesis in vivo and greatly increase bone-implant contact and bonding strength. In this paper, we sought to characterise the cellular and molecular responses of human bone marrow-derived mesenchymal stromal cells (hMSCs) to two modified Ti surfaces: a rough hydrophobic surface that was sand-blasted and acid-etched (SLA) and an SLA surface of the same roughness that was chemically modified to have high wettability/hydrophilicity (SLActive). A smooth polished (SMO) Ti surface was used as a control. Whilst no differences in initial cell attachment to any of the surfaces were observed, we found that hMSCs cultured on the rough surfaces underwent a decrease in cell number early in culture, yet simultaneously expressed higher levels of the osteogenic markers SPP1, RUNX2 and BSP. Furthermore, deposits of calcified matrix were observed at earlier time points on both SLA and SLActive surfaces compared to SMO and this correlated with increased expression of the osteogenic promoter WNT5A in response to the rough surfaces. Osteogenic responses to SLActive were moderately better than the hydrophobic SLA surface and gene expression studies indicate that WNT5A activation may be responsible for this increased osteogenic differentiation.

Association of the metabolic syndrome with severe periodontitis in a large U.S. population-based survey

CONTEXT

Metabolic syndrome and periodontitis both have an increasing prevalence worldwide; however, limited information is available on their association.

OBJECTIVE

The objective of the study was to assess the association between periodontitis and the metabolic syndrome in a cross-sectional survey of a nationally representative sample of the noninstitutionalized civilians in the United States.

DESIGN, SETTING, AND PARTICIPANTS

Data analysis from the Third National Health and Nutrition Examination Survey on 13,994 men and women aged 17 yr or older who received periodontal examination were studied.

MAIN OUTCOME MEASURES

Association of diagnosis and extent of periodontitis (gingival bleeding, probing pocket depths) with the metabolic syndrome and its individual component conditions (central obesity, hypertriglyceridemia, low high-density lipoprotein-cholesterol, hypertension, and insulin resistance) were measured. Adjustment for age, sex, years of education, poverty to income ratio, ethnicity, general conditions, and smoking were considered.

RESULTS

The prevalence of the metabolic syndrome was 18% [95% confidence interval (CI) 16-19], 34% (95% CI 29-38), and 37% (95% CI 28-48) among individuals with no-mild, moderate, and severe periodontitis, respectively. After adjusting for confounders, participants aged older than 45 yr suffering from severe periodontitis were 2.31 times (95% CI 1.13-4.73) more likely to have the metabolic syndrome than unaffected individuals. Diagnosis of metabolic syndrome increased by 1.12 times (95% CI 1.07-1.18) per 10% increase in gingival bleeding and 1.13 times (95% CI 1.03-1.24) per 10% increase in the proportion of periodontal pockets.

CONCLUSIONS

Severe periodontitis is associated with metabolic syndrome in middle-aged individuals. Further studies are required to test whether improvements in oral health lead to reductions in cardiometabolic traits and the risk of metabolic syndrome or vice versa.

Healing of human intrabony defects following treatment with enamel matrix proteins or guided tissue regeneration

The aim of the present study was to evaluate histologically in humans the healing of advanced intrabony defects following treatment with enamel matrix proteins (EMD) or guided tissue regeneration (GTR). Fourteen patients, each of them displaying 1 advanced intrabony defect around teeth scheduled for extraction were included in the study. The defects were treated randomly either with an enamel matrix protein derivative (Emdogain, BIORA AB, Malmö, Sweden) or with a bioabsorbable membrane (Resolut, Regenerative Material, W.L. Gore & Assoc., Flagstaff, Arizona, USA). At baseline the mean probing pocket depth (PPD) in the EMD group was 11.3 +/- 1.8 mm and the mean clinical attachment level (CAL) 12.1 +/- 2.0 mm, whereas in the GTR group the mean PPD was 11.4 +/- 2.2 mm and the mean CAL 13.3 +/- 2.3 mm. Healing was uneventful in all cases. Neither allergic reactions against EMD or the bioabsorbable membrane, nor suppuration or abscesses were observed. The clinical results revealed at 6 months in the EMD group a mean PPD of 5.6 +/- 1.3 mm and a mean CAL of 9.1 +/- 1.5 mm. In the GTR group the mean PPD was 5.6 +/- 1.3 mm and the mean CAL 10.1 +/- 1.5 mm. The histological analysis showed in the EMD group a mean 2.6 +/- 1.0 mm of new attachment (i.e. new cementum with inserting collagen fibers) and a mean 0.9 +/- 1.0 mm of new bone. In this group, the formation of new attachment was not always followed by bone regeneration. In the GTR group, the mean new attachment was 2.4 +/- 1.0 mm and the mean new bone 2.1 +/- 1.0 mm. In every case treated with GTR, the formation of new attachment was followed by a varying amount of new bone. After both types of regenerative treatment the newly formed cementum displayed a predominantly cellular character. The findings of the present study indicate that the treatment of intrabony defects with enamel matrix proteins or with bioabsorbable membranes enhances the formation of a new connective tissue attachment in humans.

Twenty years of enamel matrix derivative: the past, the present and the future

BACGROUND

On June 5th, 2015 at Europerio 8, a group of leading experts were gathered to discuss what has now been 20 years of documented evidence supporting the clinical use of enamel matrix derivative (EMD). Original experiments led by Lars Hammarström demonstrated that enamel matrix proteins could serve as key regenerative proteins capable of promoting periodontal regeneration including new cementum, with functionally oriented inserting new periodontal ligament fibres, and new alveolar bone formation. This pioneering work and vision by Lars Hammarström has paved the way to an enormous amount of publications related to its biological basis and clinical use. Twenty years later, it is clear that all these studies have greatly contributed to our understanding of how biologics can act as mediators for periodontal regeneration and have provided additional clinical means to support tissue regeneration of the periodontium.

AIMS

This review article aims to: (1) provide the biological background necessary to understand the rational for the use of EMD for periodontal regeneration, (2) present animal and human histological evidence of periodontal regeneration following EMD application, (3) provide clinically relevant indications for the use of EMD and (4) discuss future avenues of research including key early findings leading to the development of Osteogain, a new carrier system for EMD specifically developed with better protein adsorption to bone grafting materials.

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 effect of diabetes mellitus on osseous healing

Diabetes mellitus and, in particular, type 1 diabetes has been associated with impaired osseous wound healing properties. The scope of the present review is to discuss the clinical evidence supporting a higher rate of complications during fracture healing in diabetic patients and the histological evidence indicating impaired potential for intramembranous and endochondral ossification in the presence of uncontrolled experimental diabetes. The article further provides a synthesis of our current understanding of the plausible molecular mechanisms underlying the diabetic bone healing pathophysiology and of the role of insulin treatment in promoting osseous healing in the diabetic status.

Biomaterials and regenerative technologies used in bone regeneration in the craniomaxillofacial region: Consensus report of group 2 of the 15th European Workshop on Periodontology on Bone Regeneration

BACKGROUND AND AIMS

To review the regenerative technologies used in bone regeneration: bone grafts, barrier membranes, bioactive factors and cell therapies.

MATERIAL AND METHODS

Four background review publications served to elaborate this consensus report.

RESULTS AND CONCLUSIONS

Biomaterials used as bone grafts must meet specific requirements: biocompatibility, porosity, osteoconductivity, osteoinductivity, surface properties, biodegradability, mechanical properties, angiogenicity, handling and manufacturing processes. Currently used biomaterials have demonstrated advantages and limitations based on the fulfilment of these requirements. Similarly, membranes for guided bone regeneration (GBR) must fulfil specific properties and potential biological mechanisms to improve their clinical applicability. Pre-clinical and clinical studies have evaluated the added effect of bone morphogenetic proteins (mainly BMP-2) and autologous platelet concentrates (APCs) when used as bioactive agents to enhance bone regeneration. Three main approaches using cell therapies to enhance bone regeneration have been evaluated: (a) "minimally manipulated" whole tissue fractions; (b) ex vivo expanded "uncommitted" stem/progenitor cells; and (c) ex vivo expanded "committed" bone-/periosteum-derived cells. Based on the evidence from clinical trials, transplantation of cells, most commonly whole bone marrow aspirates (BMA) or bone marrow aspirate concentrations (BMAC), in combination with biomaterial scaffolds has demonstrated an additional effect in sinus augmentation and horizontal ridge augmentation, and comparable bone regeneration to autogenous bone in alveolar cleft repair.

Treatment of intrabony defects with guided tissue regeneration and enamel-matrix-proteins. An experimental study in monkeys

BACKGROUND

Enamel matrix proteins (EMD) have recently been introduced in regenerative periodontal treatment. However, no histological data are yet available concerning the effect of treating intrabony periodontal defects with EMD, and no histological comparisons have been made comparing the result of treatment of intrabony defects with EMD with that of the treatment with guided tissue regeneration (GTR).

AIM

Therefore, the aim of the present study was to evaluate histologically in monkeys the effect of treating intrabony defects with EMD, GTR or combined EMD and GTR.

METHOD

Intrabony periodontal defects were produced surgically at the distal aspect of teeth 14, 11, 21, 24, 34, 31, 41 and 44 in 3 monkeys (Macaca fascicularis). In order to prevent spontaneous healing and to enhance plaque accumulation metal strips were placed into the defects. After 6 weeks the defects were exposed using a full-thickness flap procedure. The granulation tissue was removed and the root surfaces were debrided by means of hand instruments. Subsequently, the defects were treated using one of the following therapies: (i) GTR, (ii) EMD, or (iii) combination of EMD and GTR. The control defects were treated with coronally repositioned flaps. After 5 months, the animals were sacrificed and perfused with 10% buffered formalin for fixation. Specimens containing the defects and surrounding tissues were dissected free, decalcified in EDTA and embedded in paraffin. 8 microm thick histological sections were cut and stained and subsequently examined under the light microscope.

RESULTS

In the control specimens, the healing was characterized by a long junctional epithelium and limited periodontal regeneration (i.e., new periodontal ligament, new cementum with inserting connective tissue fibers and new bone) in the bottom of the defect. The GTR-treated defects consistently presented periodontal regeneration when the membranes were not exposed whereas the sites treated only with EMD presented regeneration to a varying extent. The combined therapy did not seem to improve the results.

CONCLUSION

It can be concluded that all 3 treatment modalities favor periodontal regeneration.

Treatment of intrabony defects with enamel matrix proteins and guided tissue regeneration

BACKGROUND

Utilisation of enamel matrix proteins (EMD) and application of the guided tissue regeneration principle (GTR) are treatment modalities which both have been shown to result in periodontal regeneration. However, it is yet unknown whether the combination of EMD and GTR may additionally favor the regeneration process.

AIM

The aim of the present controlled study was to evaluate clinically the treatment effect of EMD, GTR, combination of EMD and GTR, and flap surgery (control) on intrabony defects.

MATERIAL AND METHODS

56 patients each of whom displaying one intrabony defect of a depth of at least 6 mm were randomly treated with one of the treatment modalities. Prior to surgery and at one year after, the following parameters were evaluated by a blinded examiner: Plaque index (PlI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), gingival recession (GR) and clinical attachment level (CAL). No statistical significant differences between the four groups were observed at baseline for any of the investigated parameters.

RESULTS

At 1 year after therapy, the sites treated with EMD demonstrated a mean PPD reduction of 4.1 +/- 1.7 mm and a mean CAL gain of 3.4 +/- 1.5 mm (p<0.001). The sites treated with GTR showed a mean PPD reduction of 4.2 +/- 1.9 mm and a mean CAL gain of 3.1 +/- 1.5 mm (p<0.001). The sites treated with the combined treatment showed a mean PPD reduction of 4.3 +/- 1.4 mm and a mean CAL gain of 3.4 +/- 1.1 mm (p<0.001). In the control group, the mean PPD reduction was 3.7 +/- 1.4 mm (p<0.001) and the mean CAL gain measured 1.7 +/- 1.5 mm (p<0.01). All 4 treatments led to statistically significant PPD reduction and CAL gain. All three regenerative treatments led to higher CAL gain than the control treatment (p<0.05). No statistical significant differences in PPD reduction and CAL gain were observed between the three regenerative treatments.

CONCLUSION

It may be concluded that (a) all 3 regenerative treatment modalities may lead to higher CAL gain than the control one, and (b) the combined treatment does not seem to improve the outcome of the regenerative procedure.

Comparison of enamel matrix proteins and bioabsorbable membranes in the treatment of intrabony periodontal defects. A split-mouth study

BACKGROUND

Enamel matrix proteins (EMP) have recently been introduced as a new modality for regenerative periodontal treatment. However, limited information is available concerning the comparison of the treatment of intrabony periodontal defects with enamel matrix proteins and other regenerative treatment alternatives.

METHODS

The aim of the present controlled clinical trial was to compare the treatment of deep intrabony periodontal defects with EMP to that with guided tissue regeneration (GTR) with bioabsorbable membranes. Sixteen patients, each of whom displayed one pair of intrabony defects located contralaterally in the same jaw, were randomly treated with EMP or with a bioabsorbable membrane. Prior to surgery and 8 months later the following parameters were evaluated by a blinded examiner: Plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), and clinical attachment level (CAL). Antibiotics (amoxicillin and metronidazole) were given during the first 10 days after surgery. No statistical significant differences in any of the investigated parameters between the 2 groups were observed at baseline.

RESULTS

No serious adverse events (e.g., allergic reactions or abscesses) after any of the treatments were noted during the entire observation period. Membrane exposure occurred in 7 out of the 16 GTR treated sites. Clinical examination was performed again 8 months postoperatively. Sites treated with EMP demonstrated a reduction of PD from 8.1+/-1.7 mm to 4.3+/-1.2 mm (P <0.001) and a change in CAL from 10.3+/-1.8 mm to 7.2+/-1.2 mm (P <0.001). The sites treated with GTR showed a reduction of PD from 8.3+/-1.7 mm to 4.3+/-0.7 mm (P <0.001) and a change of CAL from 10.1+/-1.9 mm to 7.1+/-1.7 mm (P <0.001). Both treatment procedures led to significant improvements of PD and CAL. However, no statistically significant differences in any of the investigated parameters were observed between the test and control group.

CONCLUSIONS

It may be concluded that both therapies led to shortterm improvements of the investigated clinical parameters. Further studies of much higher power are needed to support equivalence.

Temporal sequence of hard and soft tissue healing around titanium dental implants

The objective of the present review was to summarize the evidence available on the temporal sequence of hard and soft tissue healing around titanium dental implants in animal models and in humans. A search was undertaken to find animal and human studies reporting on the temporal dynamics of hard and soft tissue integration of titanium dental implants. Moreover, the influence of implant surface roughness and chemistry on the molecular mechanisms associated with osseointegration was also investigated. The findings indicated that the integration of titanium dental implants into hard and soft tissue represents the result of a complex cascade of biological events initiated by the surgical intervention. Implant placement into alveolar bone induces a cascade of healing events starting with clot formation and continuing with the maturation of bone in contact with the implant surface. From a genetic point of view, osseointegration is associated with a decrease in inflammation and an increase in osteogenesis-, angiogenesis- and neurogenesis-associated gene expression during the early stages of wound healing. The attachment and maturation of the soft tissue complex (i.e. epithelium and connective tissue) to implants becomes established 6-8 weeks following surgery. Based on the findings of the present review it can be concluded that improved understanding of the mechanisms associated with osseointegration will provide leads and targets for strategies aimed at enhancing the clinical performance of titanium dental implants.

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 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.

Oxidative stress, chronic inflammation, and telomere length in patients with periodontitis

The aim of this study was to determine leukocyte telomere length (LTL) in individuals with periodontitis and controls, exploring its relationship with systemic inflammation and oxidative stress. Five hundred sixty-three participants were recruited for this case-control study: 356 subjects with and 207 subjects without periodontitis. LTL was measured by a qPCR technique from leukocytes' DNA. Global measures of oxidative stress (reactive oxygen metabolites) and biological antioxidant potential in plasma were performed together with high-sensitivity assays for C-reactive protein (CRP). Leukocyte counts and lipid profiles were performed using standard biochemistry. Cases had higher levels of CRP (2.1±3.7mg/L vs 1.3±5.4mg/L, P<0.001) and reactive oxygen metabolites (378.1±121.1 U Carr vs 277.4±108.6 U Carr, P<0.001) compared to controls. Overall, cases had shorter LTL with respect to controls (1.23±0.42 vs 1.12±0.31T/S ratio, P=0.006), independent of age, gender, ethnicity, and smoking habit. When divided by subgroup of periodontal diagnosis (chronic, n=285; aggressive, n=71), only chronic cases displayed shorter LTL (P=0.01). LTL was negatively correlated with age (P=0.001; R=-0.2), oxidative stress (P=0.008; R=-0.2), and severity of periodontitis (P=0.003; R=-0.2) in both the whole population and the subgroups (cases and controls). We conclude that shorter telomere lengths are associated with a diagnosis of periodontitis and their measures correlate with the oxidative stress and severity of disease.

Association of serum interleukin-6 concentration with a functional IL6 -6331T>C polymorphism

BACKGROUND

Interleukin-6 (IL-6) concentrations vary substantially among individuals. This study aimed to identify novel genetic markers to explain these differences.

METHODS

We sequenced a region 6-kb upstream of the IL6 [interleukin 6 (interferon, beta 2)] transcription start site in a search for functional variants and detected 3 common variants: -6331T>C, -6101A>T, and -5617/-5616C/A>T/G. IL6 -6331T>C (C allele frequency, 0.20; 95% confidence interval, 0.16-0.24) showed strong negative linkage disequilibrium with -174G>C (D' = -0.97) and was studied further in 309 individuals who underwent coronary artery bypass grafting.

RESULTS

Patients with the TT genotype had higher IL-6 concentrations 6 h after surgery than those with the CC genotype (mean, 199.4 ng/L vs 114.9 ng/L; P = 0.02). A similar association was seen in a cohort of 173 patients who underwent intensive periodontal therapy: Individuals with the CC genotype had significantly lower IL-6 concentrations 24 h after therapy than TT patients (mean, 0.78 ng/L vs 5.00 ng/L; P < 0.0001). A similar trend was observed in 203 healthy individuals from northern Europe (1.29 ng/L for the TT genotype vs 0.89 ng/L for the CC genotype; P = 0.07). Reporter assays that used a sequence flanking the -6331 single-nucleotide polymorphism spliced upstream to the IL-6 minimal promoter driving luciferase gene expression demonstrated a 1.3-fold increase in promoter activity (P < 0.01) for constructs containing -6331T. Electrophoretic mobility shift assays revealed enhanced binding of transcription factor Oct-1 to the T allele.

CONCLUSIONS

IL6 -6331T is associated with increased IL-6 concentrations in an acute inflammatory state via a mechanism involving binding of the Oct-1 transcription factor. This finding may help resolve conflicting studies based on the IL6 -174G>C variant.