Periodontal diseases have been recognized and treated for at least 5000 years. Clinicians have recognized for many years that there are apparent differences in the presentation of periodontal diseases and have attempted to classify these diseases. Systems of classifications of disease have arisen allowing clinicians to develop structures which can be used to identify diseases in relation to aetiology, pathogenesis and treatment. It allows us to organize effective treatment of our patients' diseases. Once a disease has been diagnosed and classified, the aetiology of the condition and appropriate evidence-based treatment is suggested to the clinician. Common systems of classification also allow effective communication between health care professionals using a common language. Early attempts at classification were made on the basis of the clinical characteristics of the diseases or on theories of their aetiology. These attempts were unsupported by any evidence base. As scientific knowledge expanded, conventional pathology formed the basis of classification. More recently, this has been followed by systems of classification based upon our knowledge of the various periodontal infections and the host response to them. Classification of periodontal diseases has, however, proved problematic. Over much of the last century clinicians and researchers have grappled with the problem and have assembled periodically to review or develop the classification of the various forms of periodontal disease as research has expanded our knowledge of these diseases. This has resulted in frequent revisions and changes. A classification, however, should not be regarded as a permanent structure. It must be adaptable to change and evolve with the development of new knowledge. It is expected that systems of classification will change over time. This review examines the past and present classifications of the periodontal diseases.

AIMS This audit aimed to assess the effect of implementing referral criteria on the quality and content of referral letters sent by general dental practitioners (GDPs) to the periodontal department of a teaching hospital. METHODS Retrospective data were collected from a total of 450 referrals made in:(i) 1997, prior to any changes;(ii) 2000/2001, after referral guidelines were implemented; and (iii) 2004/2005, after referral criteria were redefined and circulated via Primary Care Trusts. A standardised data-collection form was used to record the information that was provided in the referral letters. This information was also compared to the findings at initial hospital consultations. RESULTS There was a small improvement in the administrative details provided in the referral communications in 2000/2001 and 2004/2005. Medical history was often incomplete and was mentioned in 31-34% of referral letters. Use of the Basic Periodontal Examination (BPE) score increased from 17%(1997) to 57%(2004/2005). The information on clinical details otherwise increased in 2000/2001 with a tendency to decrease in 2004/2005. There was little agreement between the clinical details in the referral communications and the findings at consultation in the periodontal department. CONCLUSIONS Following implementation of referral criteria, there was an increase in the clinical details provided in referral letters. However, the validity of the information provided by the GDPs was often questionable. The number of referrals that provided medical history details remained unchanged. Use of a pro forma was not associated with an improvement in the quality of referrals in this audit.

INTRODUCTION Identifying which patients are at risk of significant periodontal breakdown and may need specialist care is a process fraught with problems. This paper summarises factors that should be considered by referring clinicians, describes a system to assist them, and presents the results of two sequential audits carried out in general dental practice using the system. AIMS, MATERIALS AND METHODS: The author aims to present the system and the results of two sequential audits, carried out in the same eight general dental practices by 23 general dental practitioners (GDPs) after training from a specialist in periodontics. The system is based on the use of the Basic Periodontal Examination (BPE), a constant pressure periodontal probe, and a computer screen that prompts the clinician who is performing periodontal screening. A series of risk factors, including smoking, presence of relevant systemic disease and age, is used to modulate the score. Patients are then classified into one of three complexity groups. Those in the Complexity 3 group are deemed to be potentially at risk of significant periodontal breakdown and in need of referral for specialist advice and/or care, in accordance with the published British Society of Periodontology guidelines. In each audit a random sample of the records of ten dentate patients over the age of 20 years, who attended for recall or new examinations by each of the 23 GDPs over a calendar month, were assessed to see whether or not BPE scores had been recorded and whether or not those classified as Complexity 3 (and in need of referral) had been correctly identified and referred. RESULTS In both audits the total random sample of patient records was 225 (ten for 22 dentists and five for the remaining dentist who only worked for a short time during the months of the audit). In the first audit cycle 139 (62%) of the random sample of records included a BPE score and 11 (8%) of the patients concerned were identified as Complexity 3 and referred for specialist advice and/or treatment. All 11 accepted the referral and when examined by the specialist in periodontics were confirmed as Complexity 3. In the second audit cycle, which took place seven months later, 179 (80%) of the random sample of patient records included a BPE score and 14 patients were assessed by their GDPs as being Complexity 3. All 14 accepted a referral and were deemed to be Complexity 3 when they were subsequently examined by the specialist in periodontics. CONCLUSION Although the full potential of the system was not investigated during the two audits, these preliminary results suggest that it may assist referring clinicians in identifying which patients to refer and encourage clinicians to perform periodontal screening.

To investigate the molecular effects of the periodontopathogens Fusobacterium nucleatum (FN) and Porphyromonas gingivalis (PG) on the oral epithelium, the H400 oral epithelial cell line was cultured in the presence of non-viable bacteria. Following confirmation of the presence of transcripts for the bacterial pattern recognition receptors in H400 cells, Toll-like receptors -2,-4 and -9, and components of the NF-kappaB signalling pathway, immunocytochemical analyses were performed showing that NF-kappaB was activated within 1 h of exposure to both periodontopathogens. A significantly greater number of NF-kappaB nuclear translocations were apparent following H400 cell exposure to FN as compared with PG. Gene expression analyses indicated that transcripts known to be regulated by the NF-kappaB pathway, including cytokines/chemokines TNF-alpha, IL-1beta, IL-8, MCP-1/CCL2 and GM-CSF, were up-regulated following 4 and 24 h of exposure to both periodontopathogens. In addition, H400 periodontopathogen exposure resulted in differential regulation of transcripts for several cytokeratin gene family members. Consistent with the immunocytochemical data, microarray results indicated that FN induced a greater number of gene expression changes than PG following 24 h of exposure, 609 and 409 genes, respectively. Ninety-one genes were commonly differentially expressed by both periodontopathogens and represented biological processes commonly associated with periodontitis. Gene expression analyses by reserve transcriptase-polymerase chain reaction (RT-PCR) of molecules identified from the microarray data sets, including Heme oxygenase-1, lysyl oxidase, SOD2, CCL20 and calprotectin components, confirmed their differential expression profiles induced by the two periodontopathogens. FN and PG have clearly different molecular effects on oral epithelial cells, potentially highlighting the importance of the composition of the plaque biofilm in periodontitis pathogenesis.

BACKGROUND Oxidative stress is implicated in the pathogenesis of periodontitis. The total antioxidant capacity (TAOC) of gingival crevicular fluid volume (GCF) and plasma appears compromised in periodontitis, but it is unclear whether this predisposes to, or results from the inflammatory process. AIM To investigate longitudinal changes in GCF and plasma TAOC following reductions in periodontal inflammation with successful non-surgical therapy. MATERIALS AND METHODS Two longitudinal studies were run in series on non-smokers with chronic periodontitis (CP). Study-1 (n=17) assessed index sites with mild disease; Study-2 (n=18) investigated deep sites. GCF sampling and clinical measures were performed at baseline and 3 months post-therapy. Plasma and GCF TAOC was determined by enhanced chemiluminescence and 32 age/sex-matched periodontally healthy controls were used. RESULTS Therapy improved clinical outcomes consistent with the literature. There were no differences in plasma TAOC between periodontitis patients (507+/-92 microMTeq) and controls (520+/-100 microMTeq; p=0.57) at baseline, but GCF TAOC was lower (p<0.0001) in CP patients (680+/-371 microMTeq) than controls (1129+/-722 microMTeq). Successful periodontal therapy did not alter plasma TAOC (p=0.56), but GCF TAOC increased (by 449+/-722 microMTeq, p<0.001) to control subject levels (p=0.47) CONCLUSIONS Local total antioxidant capacity in CP appears to reflect increased oxygen radical activity during periodontal inflammation and can be restored to control subject levels by successful non-surgical therapy.

Light irradiation activates a range of cellular processes in a variety of cell types, including stem cells, and can promote tissue repair. This study investigated the effects of light-emitting diode (LED) exposure on dental pulp cells (DPCs). Dose response analysis at 20-second intervals up to 120 seconds demonstrated that a LED array emitting 653-nm red light stimulated significantly increased cell growth at 3 and 7 days post-irradiation with 40 (149 mJ/cm(2)) and 60 (224 mJ/cm(2)) seconds of radiant exposure. Double-dosing cells at days 1 and 4 of a 7-day culture period with 60-second (224 mJ/cm(2)) LED exposure significantly increased cell growth compared with a single dosing regime. BrdU analysis demonstrated significantly increased proliferation rates associated with significantly increased ATP, nitric oxide (NO), and mitochondrial metabolic activity. LED-stimulated NO levels were not reduced by inhibition of NO-synthase activity. Light exposure also rescued the inhibition of mitochondrial dysfunction and increased levels of in vitro mineralization compared with control. Media exchange experiments indicated that autocrine signaling was not likely responsible for red-light-induced DPC activity. In conclusion, data analysis indicated that 653-nm LED irradiation promoted DPC responses relevant to tissue repair, and this is likely mediated by increased mitochondrial activity.

OBJECTIVE Malignant tumours of the nasal cavity and paranasal sinuses are rare and late presentation of a maxillary sinus tumour is common due to the vague nature of the symptoms which can delay diagnosis. METHODS We report a female with a maxillary sinus tumour who was initially diagnosed with chronic idiopathic facial pain (CIFP) and sinusitis, which subsequently led to a delay in diagnosis and treatment of her tumour. RESULTS There was no clinical extra- or intra-oral pathology, however, she had varying clinical presentations of facial pain, anosmia, loss of gustatory function, and infra-orbital nerve paraesthesia. CT and MRI scans confirmed obliteration of the left maxillary sinus by a solid mass involving ethmoid and sphenoid sinuses and some cranial nerves. Biopsy confirmed a poorly differentiated carcinoma of the ethmoid and sphenoid sinuses and invasion of the cavernous sinus. CONCLUSION A morbid, but hidden tumour was left undiagnosed due to the unusual presentation of the patient's symptoms. It is essential that all patients are managed holistically and thorough historical, clinical and radiographic examination and appropriate investigations are carried out to prevent unnecessary and potentially time-wasting treatment.

Neutrophil extracellular traps (NETs) comprise extracellular chromatin and granule protein complexes that immobilize and kill bacteria. NET release represents a recently discovered, novel anti-microbial strategy regulated non-exclusively by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase generation of reactive oxygen intermediates (ROIs), particularly hydrogen peroxide. This study aimed to characterize the role of ROIs in the process of NET release and to identify the dominant ROI trigger. We employed various enzymes, inhibitors and ROIs to record their effect fluorometrically on in vitro NET release by human peripheral blood neutrophils. Treatment with exogenous superoxide dismutase (SOD) supported the established link between hydrogen peroxide and NET production. However, treatment with myeloperoxidase inhibitors and direct addition of hypochlorous acid (HOCl; generated in situ from sodium hypochlorite) established that HOCl was a necessary and sufficient ROI for NET release. This was confirmed by the ability of HOCl to stimulate NET release in chronic granulomatous disease (CGD) patient neutrophils which, due to the lack of a functional NADPH oxidase, also lack the capacity for NET release in response to classical stimuli. Moreover, the exogenous addition of taurine, abundantly present within the neutrophil cytosol, abrogated NET production stimulated by phorbol myristate acetate (PMA) and HOCl, providing a novel mode of cytoprotection by taurine against oxidative stress by taurine.

Palmer LJ, Chapple ILC, Wright HJ, Roberts A, Cooper PR. Extracellular deoxyribonuclease production by periodontal bacteria. J Periodont Res 2011; doi: 10.1111/j.1600-0765.2011.01451.x © 2011 John Wiley & Sons A/S Background and Objective:  Whilst certain bacteria have long been known to secrete extracellular deoxyribonuclease (DNase), the purpose in microbial physiology was unclear. Recently, however, this enzyme has been demonstrated to confer enhanced virulence, enabling bacteria to evade the host's immune defence of extruded DNA/chromatin filaments, termed neutrophil extracellular traps (NETs). As NETs have recently been identified in infected periodontal tissue, the aim of this study was to screen periodontal bacteria for extracellular DNase activity. Material and Methods:  To determine whether DNase activity was membrane bound or secreted, 34 periodontal bacteria were cultured in broth and on agar plates. Pelleted bacteria and supernatants from broth cultures were analysed for their ability to degrade DNA, with relative activity levels determined using an agarose gel electrophoresis assay. Following culture on DNA-supplemented agar, expression was determined by the presence of a zone of hydrolysis and DNase activity related to colony size. Results:  Twenty-seven bacteria, including red and orange complex members Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Parvimonas micra, Prevotella intermedia, Streptococcus constellatus, Campylobacter rectus and Prevotella nigrescens, were observed to express extracellular DNase activity. Differences in DNase activity were noted, however, when bacteria were assayed in different culture states. Analysis of the activity of secreted DNase from bacterial broth cultures confirmed their ability to degrade NETs. Conclusion:  The present study demonstrates, for the first time, that DNase activity is a relatively common property of bacteria associated with advanced periodontal disease. Further work is required to determine the importance of this bacterial DNase activity in the pathogenesis of periodontitis.

OBJECTIVE To investigate microbiological biofilm contamination of retrieved bone-anchored hearing aids. MATERIALS AND METHODS Nine failed, retrieved bone-anchored hearing aids and 16 internal screws were examined by scanning electron microscopy. A fixture from a failing implant, which had been removed and disassembled under aseptic conditions, was cultured. Finally, an internal screw from a new, unimplanted fixture was examined by scanning electron microscopy. RESULTS Debris was seen on the fixture and abutment of all bone-anchored hearing aids, and on the heads of the 16 internal screws. On eight screws, biofilm extended down the shaft to the threads, where it was several micrometres thick. Culture of a failing fixture yielded staphylococcus. The new, unimplanted fixture internal screw showed evidence of scratching and metallic debris on the threads, which may interfere with close fitting of the screw and subsequently facilitate microleakage. CONCLUSION There may be a link between internal microbial contamination and failure of bone-anchored hearing aids.

AIM: Periodontitis results from the loss of a delicate balance between microbial virulence factors and a proportionate host response. Nutritional factors have been implicated in several chronic inflammatory diseases that are associated with periodontitis. This manuscript reviews the evidence for nutritional exposures in the etiology and therapeutic management of periodontitis, and makes recommendations for daily nutritional intake for vitamin C (ascorbic acid), vitamin D, calcium, and antioxidants. RESULTS AND CONCLUSION: Periodontitis is associated with low serum/plasma micronutrient levels, which may result from dietary and/or life-style factors as well as nutrigenetic characteristics. Early evidence suggests beneficial outcomes from nutritional interventions; supporting the contention that daily intake of certain nutrients should be at the higher end of recommended daily allowances. For prevention and treatment of periodontitis daily nutrition should include sufficient antioxidants, vitamin D, and calcium. Inadequate antioxidant levels may be managed by higher intake of vegetables, berries, and fruits (e.g. kiwi fruit), or by phytonutrient supplementation. Current evidence is insufficient to support recommendations of mono-antioxidant vitamin supplements and randomised controlled double-blind intervention studies are needed to provide evidence to underpin future recommendations. Inadequate supply of vitamin D and calcium may be addressed by implementing changes in diet/life style or by supplements.

Abnormal neutrophil responses have been observed in periodontitis patients, including hyper-reactivity in terms of production of reactive oxygen species (ROS) following exposure to the key quorum-sensing plaque bacterium, Fusobacterium nucleatum. This study was designed to characterize the transcriptional response of neutrophils to F. nucleatum. Peripheral blood neutrophils were exposed to F. nucleatum, and gene expression was analysed using high-throughput transcriptomics. Microarray technology demonstrated differential expression of 208 genes (163 increased and 43 decreased relative to control genes), which identified regulation of several ontological classes, including signal transduction (13%), transcription regulation (7%) and ROS response (14%). Individual gene expression analysis of selected transcripts, including CSF, CXCL3, FOS, HMOX1, HSP40, SOD2, NFKB2 and GP91, in individual and pooled RNA samples from control and F. nucleatum-exposed neutrophils corroborated microarray data. Analysis of ROS generation, combined with transcript analysis, in response to a panel of proinflammatory stimuli (F. nucleatum, Porphyromonas gingivalis, Escherichia coli lipopolysaccharide and opsonized Staphylococcus aureus) identified significant differences in ROS and transcript regulatory control. Further analyses of neutrophils from periodontitis patients and periodontally healthy control subjects stimulated with F. nucleatum indicated significant differential induction of several ROS response-related transcripts. These data demonstrate that neutrophils are transcriptionally active in response to the periodontal pathogen F. nucleatum and that these changes in gene expression are likely to affect neutrophil function. The differential response of neutrophils to a range of stimuli combined with data demonstrating differences between patient and control neutrophils indicate the importance of this cell and its interaction with the local tissue environment in the pathogenesis of periodontitis.

Continuous professional development (CPD) in Periodontology refers to the overall framework of opportunities that facilitate a life-long learning practice, driven by the learner-practitioner and supported by a variety of institutions and individuals. CPD must address different needs for a great diversity of practitioners. It is clear that no particular methodology or technology is able to successfully accommodate the entire spectrum of CPD in Periodontology. Course designers must choose from and combine a wide array of methodologies and technologies, depending upon the needs of the learners and the objectives of the intended education. Research suggests that 'interactivity','flexibility','continuity' and 'relevance to learners' practice' are major characteristics of successful CPD. Various methods of mentoring, peer-learning environments and work-based learning have been combined with reflective practice and self-study to form the methodological backbone of CPD courses. Blended learning encompasses a wide array of technologies and methodologies and has been successfully used in CPD courses. Internet-based content learning management systems, portable Internet devices, powerful databases and search engines, together with initiatives such as 'open access' and 'open courseware' provide an array of effective instructional and communication tools. Assessment remains a key issue in CPD, providing learners with valuable feedback and it ensures the credibility and effectiveness of the learning process. Assessment is a multi-level process using different methods for different learning outcomes, as directed by current evidence and best practices. Finally, quality assurance of the education provided must follow CPD courses at all times through a structured and credible process.

Sinus barotrauma is a common disease in divers. However, it is not familiar to maxillofacial surgeon. We presented orbital fracture deterioration by sinus barotrauma in scuba diving and a review of literatures. We also discussed the clinical features, the prevention, and the possible mechanism of orbital fracture deterioration after scuba diving.

The Japanese Yohkoh satellite is now in orbit observing the sun with a set of x-ray imagers and x-ray and gamma-ray spectrometers. The data from this successful mission provide new information on solar flares and the sun's corona. This paper discusses the Yohkoh observations and presents a sample of the first scientific results from the mission.

Critical care patients are among the sickest in hospital and require extensive facilities and equipment, and skilled care. This article outlines the rationale behind the development of critical care outreach services and discusses evaluation of the service.

This paper discusses the rationale for the development of tissue engineering and associated therapies and provides observations on the emerging developments in these areas.

This brief outline in reproductive cloning describes the background to these studies and then discusses successive aspects of the subject. These include abnormalities in cloned animals, therapeutic cloning and the ethics of this subject. A reference to further reading is provided.

A major need in cancer chemotherapy is the availability of cancer cell-specific drugs. This paper discusses recent advances and perspectives in the field of selective drug recognition considering the key targets tyrosine kinases, DNA-topoisomerases and telomerase.

This paper discusses preventing and treating periodontal diseases in people with special needs.

This paper presents an overview of recent progress in the clinical study of opisthorchiasis and treatment. Details of clinical manifestations of opisthorchiasis, hepatobiliary diseases and liver functions, community-based ultrasound study, treatment efficacy, and future study are discussed.

In this introduction to the present issue, we give a brief description of the phenomenon. Subsequently, we discuss the major theoretical accounts, focusing on how these are related to the papers included in the issue.

DNA is considered as a nonlinear dynamical system in which solitary conformational waves can be excited. The history of the approach, the main results, and arguments in favour and against are presented. Perspectives are discussed pertaining to studies of DNA's nonlinear properties.