Developing a core outcome set for periodontal trials.

BACKGROUND: There is no agreement which outcomes should be measured when investigating interventions for periodontal diseases. It is difficult to compare or combine studies with different outcomes; resulting in research wastage and uncertainty for patients and healthcare professionals. OBJECTIVE: Develop a core outcome set (COS) relevant to key stakeholders for use in effectiveness trials investigating prevention and management of periodontal diseases. METHODS: Mixed method study involving literature review; online Delphi Study; and face-to-face consensus meeting. PARTICIPANTS: Key stakeholders: patients, dentists, hygienist/therapists, periodontists, researchers. RESULTS: The literature review identified 37 unique outcomes. Delphi round 1: 20 patients and 51 dental professional and researchers prioritised 25 and suggested an additional 11 outcomes. Delphi round 2: from the resulting 36 outcomes, 13 patients and 39 dental professionals and researchers prioritised 22 outcomes. A face-to-face consensus meeting was hosted in Dundee, Scotland by an independent chair. Eight patients and six dental professional and researchers participated. The final COS contains: Probing depths, Quality of life, Quantified levels of gingivitis, Quantified levels of plaque, Tooth loss. CONCLUSIONS: Implementation of this COS will ensure the results of future effectiveness trials for periodontal diseases are more relevant to patients and dental professionals, reducing research wastage. This could reduce uncertainty for patients and dental professionals by ensuring the evidence used to inform their choices is meaningful to them. It could also strengthen the quality and certainty of the evidence about the relative effectiveness of interventions. REGISTRATION: COMET Database: http://www.comet-initiative.org/studies/details/265?result=true.

Exploring a temporal relationship between biofilm microbiota and inflammatory mediators during resolution of naturally occurring gingivitis.

BACKGROUND: This study uses multiple, contemporary methodologies to expand our knowledge of the temporal relationship between host-microbial interactions and clinical signs of gingivitis. METHODS: Subgingival plaque and crevicular fluid samples were collected from 31 systemically healthy adults with naturally occurring plaque-induced gingivitis. Professional prophylaxis was administered and participants were followed over 7 weeks. Microbial characterization was performed using a bead-based hybridization assay and cytokine analysis using bead-based flow cytometry. RESULTS: The provision of sequential interventions, oral hygiene instruction, and subsequent professional prophylaxis brought about significant reduction of plaque and resolution of gingivitis at all post baseline time points (P < 0.0001). Candidate cytokines that increased significantly (95% level) were interleukin (IL)-1ß, matrix metalloproteinases (MMP)-1, MMP-3, MMP-8, MMP-9, from baseline to week 2; regulated on activation, normal T cell expressed and secreted (RANTES) at week 4 and week 8; macrophage inflammatory protein (MIP)-1α and MIP-1ß at week 8. Resolution of inflammation was accompanied by a shift in the microbiological flora toward those species associated with health. CONCLUSIONS: This study provides further evidence of the dynamic relationships that exist between the overt clinical signs, the microbial biofilm, and the host response in gingivitis and upon resolution following clinical interventions. Understanding the interactions between the host immune system and subgingival microbial communities during the resolution of established gingivitis continues to evolve as additional knowledge is achieved through using new analytical technologies. The present study confirms a critical effect of oral hygiene measures on restoration of microbial eubiosis in subgingival communities, confirming the important role for home care and professional intervention in maintaining oral health.

Improving the Quality of Dentistry (IQuaD): a cluster factorial randomised controlled trial comparing the effectiveness and cost-benefit of oral hygiene advice and/or periodontal instrumentation with routine care for the prevention and management of periodontal disease in dentate adults attending dental primary care.

BACKGROUND: Periodontal disease is preventable but remains the most common oral disease worldwide, with major health and economic implications. Stakeholders lack reliable evidence of the relative clinical effectiveness and cost-effectiveness of different types of oral hygiene advice (OHA) and the optimal frequency of periodontal instrumentation (PI). OBJECTIVES: To test clinical effectiveness and assess the economic value of the following strategies: personalised OHA versus routine OHA, 12-monthly PI (scale and polish) compared with 6-monthly PI, and no PI compared with 6-monthly PI. DESIGN: Multicentre, pragmatic split-plot, randomised open trial with a cluster factorial design and blinded outcome evaluation with 3 years' follow-up and a within-trial cost-benefit analysis. NHS and participant costs were combined with benefits [willingness to pay (WTP)] estimated from a discrete choice experiment (DCE). SETTING: UK dental practices. PARTICIPANTS: Adult dentate NHS patients, regular attenders, with Basic Periodontal Examination (BPE) scores of 0, 1, 2 or 3. INTERVENTION: Practices were randomised to provide routine or personalised OHA. Within each practice, participants were randomised to the following groups: no PI, 12-monthly PI or 6-monthly PI (current practice). MAIN OUTCOME MEASURES: Clinical - gingival inflammation/bleeding on probing at the gingival margin (3 years). Patient - oral hygiene self-efficacy (3 years). Economic - net benefits (mean WTP minus mean costs). RESULTS: A total of 63 dental practices and 1877 participants were recruited. The mean number of teeth and percentage of bleeding sites was 24 and 33%, respectively. Two-thirds of participants had BPE scores of ≤ 2. Under intention-to-treat analysis, there was no evidence of a difference in gingival inflammation/bleeding between the 6-monthly PI group and the no-PI group [difference 0.87%, 95% confidence interval (CI) -1.6% to 3.3%; p = 0.481] or between the 6-monthly PI group and the 12-monthly PI group (difference 0.11%, 95% CI -2.3% to 2.5%; p = 0.929). There was also no evidence of a difference between personalised and routine OHA (difference -2.5%, 95% CI -8.3% to 3.3%; p = 0.393). There was no evidence of a difference in self-efficacy between the 6-monthly PI group and the no-PI group (difference -0.028, 95% CI -0.119 to 0.063; p = 0.543) and no evidence of a clinically important difference between the 6-monthly PI group and the 12-monthly PI group (difference -0.097, 95% CI -0.188 to -0.006; p = 0.037). Compared with standard care, no PI with personalised OHA had the greatest cost savings: NHS perspective -£15 (95% CI -£34 to £4) and participant perspective -£64 (95% CI -£112 to -£16). The DCE shows that the general population value these services greatly. Personalised OHA with 6-monthly PI had the greatest incremental net benefit [£48 (95% CI £22 to £74)]. Sensitivity analyses did not change conclusions. LIMITATIONS: Being a pragmatic trial, we did not deny PIs to the no-PI group; there was clear separation in the mean number of PIs between groups. CONCLUSIONS: There was no additional benefit from scheduling 6-monthly or 12-monthly PIs over not providing this treatment unless desired or recommended, and no difference between OHA delivery for gingival inflammation/bleeding and patient-centred outcomes. However, participants valued, and were willing to pay for, both interventions, with greater financial value placed on PI than on OHA. FUTURE WORK: Assess the clinical effectiveness and cost-effectiveness of providing multifaceted periodontal care packages in primary dental care for those with periodontitis. TRIAL REGISTRATION: Current Controlled Trials ISRCTN56465715. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 38. See the NIHR Journals Library website for further project information.

Core outcomes in periodontal trials: study protocol for core outcome set development.

BACKGROUND: There are a large number of clinical outcome measures used to assess the effectiveness of prevention and management strategies of periodontal diseases. This heterogeneity causes difficulties when trying to synthesise data for systematic reviews or clinical guidelines, reducing their impact. Core outcome sets are an agreed, standardised list of outcomes that should be measured and reported in all trials in specific clinical areas. We aim to develop a core outcome set for effectiveness trials investigating the prevention and management of periodontal disease in primary or secondary care. METHODS: To identify existing outcomes we screened the Cochrane systematic reviews and their included studies on the prevention and management of periodontal diseases. The core outcome set will be defined by consensus of key stakeholders using an online e-Delphi process and face-to-face meeting. Key stakeholders involved in the development will include: patients, dentists, hygienists/therapists, specialists, clinical researchers and policy-makers. Stakeholders will be asked to prioritise outcomes and feedback will be provided in the next round(s). Stakeholders will have an opportunity to add outcomes found in the Cochrane review screening process at the end of the first round. If consensus is not reached after the second round we will provide feedback prior to a third round. Remaining outcomes will be discussed at a face-to-face meeting and agreement will be measured via defined consensus rules of outcome inclusion. DISCUSSION: The inclusive consensus process should provide a core outcome set that is relevant to all key stakeholders. We will actively disseminate our findings to help improve clinical trials, systematic reviews and clinical guidelines with the ultimate aim of improving the prevention and management of periodontal diseases. TRIAL REGISTRATION: COMET ( http://www.comet-initiative.org/studies/details/265?result=true ). Registered on August 2012.

Gingival recession and root caries in the ageing population: a critical evaluation of treatments.

AIM: To review evidence for the treatments of gingival recession and root caries in older populations. MATERIALS & METHODS: A systematic approach was adopted to identify reviews and articles to allow us to evaluate the treatments for gingival recession and root caries. Searches were performed in PubMed, Medline and Embase, the Cochrane trials register and bibliographies of European and World Workshops. OBSERVATIONS: Gingival recession: We identified no articles that focussed specifically on older populations. Conversely, no evidence suggested that Miller class I and II lesions should be managed differently in older patients when compared to younger cohorts. Six systematic reviews included older patients and suggested that connective tissue grafts are the treatment of choice, alone or in combination with enamel matrix derivative. Root caries can be controlled at the population level by daily brushing with fluoride-containing toothpastes, whilst active decay may be inactivated using professional application of fluoride varnishes/solutions or self-applied high-fluoride toothpaste. Active root caries lesions that cannot be cleaned properly by the patient may be restored by minimally invasive techniques. CONCLUSIONS: Gingival recession and root caries will become more prevalent as patients retain their teeth for longer. Whilst surgical (gingival recession) and non-operative approaches (root caries) currently appear to be favoured, more evidence is needed to identify the most appropriate strategies for older people.

The impact of structured plaque control for patients with gingival manifestations of oral lichen planus: a randomized controlled study.

AIM: To evaluate the impact of a structured plaque control intervention on clinical and patient-centred outcomes for patients with gingival manifestations of oral lichen planus. MATERIALS AND METHODS: Eighty-two patients were recruited into a 20-week randomized controlled trial. The intervention was structured plaque control comprising powered tooth brushing and inter-dental cleaning advice. Control subjects continued with their normal dental plaque control regimen. The primary outcome measure was the oral health impact profile (OHIP) with secondary outcomes of pain, plaque index, mucosal disease score and cost-effectiveness. RESULTS: Overall, the intervention patients showed statistically significant improvements in OHIP sum ordinal and OHIP dichotomous scores compared with control. There were improvements in the functional limitation, psychological discomfort and physical disability domains at 4- and 20-weeks and in the psychological disability domain at 20-weeks. The intervention was successful in reducing plaque compared to control (p < 0.001) and improvements were observed using the mucosal disease indices at the 4- and 20-week follow-ups (p < 0.001). CONCLUSION: A structured plaque control intervention was effective in improving the oral health-related quality of life and clinically observed gingival lesions. This study provides evidence to include intensive plaque control within patients' initial and on-going management.

Evidence for the occurrence of gingival recession and non-carious cervical lesions as a consequence of traumatic toothbrushing.

AIM: To identify the best available evidence for the effect of toothbrushing on the initiation and progression of gingival recession and non-carious cervical lesions (NCCLs). METHODS: A protocol was developed for the questions: Does traumatic toothbrushing, compared to normal toothbrushing, lead to an increased prevalence of non-inflammatory gingival recession? [FQ1] and NCCLs? [FQ2]. The search covered four electronic databases. Bibliographies of review articles, relevant texts, World and European Workshops were screened. Hand searches were performed of the Journals of Clinical Periodontology, Periodontology, Periodontal Research and IADR abstracts. RESULTS: A meta-analysis included 159 subjects and showed that subjects who used MTBs (manual toothbrush) had greater gingival recession after 12 months when compared with those using PTBs (powered toothbrush). Thirteen cross-sectional studies identified the most frequent toothbrushing factors associated with gingival recession as being toothbrushing frequency, a horizontal or scrub toothbrushing method, bristle hardness, toothbrushing duration and the frequency of changing a toothbrush. The principal toothbrushing factors associated with NCCLs were toothbrushing method and frequency. CONCLUSION: The data to support or refute the association between toothbrushing and gingival recession and NCCLs remain largely inconclusive.

IQuaD dental trial; improving the quality of dentistry: a multicentre randomised controlled trial comparing oral hygiene advice and periodontal instrumentation for the prevention and management of periodontal disease in dentate adults attending dental primary care.

BACKGROUND: Periodontal disease is the most common oral disease affecting adults, and although it is largely preventable it remains the major cause of poor oral health worldwide. Accumulation of microbial dental plaque is the primary aetiological factor for both periodontal disease and caries. Effective self-care (tooth brushing and interdental aids) for plaque control and removal of risk factors such as calculus, which can only be removed by periodontal instrumentation (PI), are considered necessary to prevent and treat periodontal disease thereby maintaining periodontal health. Despite evidence of an association between sustained, good oral hygiene and a low incidence of periodontal disease and caries in adults there is a lack of strong and reliable evidence to inform clinicians of the relative effectiveness (if any) of different types of Oral Hygiene Advice (OHA). The evidence to inform clinicians of the effectiveness and optimal frequency of PI is also mixed. There is therefore an urgent need to assess the relative effectiveness of OHA and PI in a robust, sufficiently powered randomised controlled trial (RCT) in primary dental care. METHODS/DESIGN: This is a 5 year multi-centre, randomised, open trial with blinded outcome evaluation based in dental primary care in Scotland and the North East of England. Practitioners will recruit 1860 adult patients, with periodontal health, gingivitis or moderate periodontitis (Basic Periodontal Examination Score 0-3). Dental practices will be cluster randomised to provide routine OHA or Personalised OHA. To test the effects of PI each individual patient participant will be randomised to one of three groups: no PI, 6 monthly PI (current practice), or 12 monthly PI.Baseline measures and outcome data (during a three year follow-up) will be assessed through clinical examination, patient questionnaires and NHS databases.The primary outcome measures at 3 year follow up are gingival inflammation/bleeding on probing at the gingival margin; oral hygiene self-efficacy and net benefits. DISCUSSION: IQuaD will provide evidence for the most clinically-effective and cost-effective approach to managing periodontal disease in dentate adults in Primary Care. This will support general dental practitioners and patients in treatment decision making. TRIAL REGISTRATION: Protocol ID: ISRCTN56465715.

Cost-effectiveness of personalized plaque control for managing the gingival manifestations of oral lichen planus: a randomized controlled study.

AIM: To undertake cost-effectiveness and cost-benefit analyses of an intervention to improve oral health in patients presenting with the gingival manifestations of oral lichen planus (OLP). MATERIALS & METHODS: Eighty-two patients were recruited to a 20-week randomized controlled trial. The intervention was personalized plaque control comprising powered tooth brushing and inter-dental cleaning advice. The primary outcome measure was the oral health impact profile (OHIP) with secondary outcomes of pain, plaque index, mucosal disease score and cost-effectiveness. Private cost data and stated willingness-to-pay (WTP) values for treatment were obtained from intervention patients at 20 weeks. RESULTS: Overall, 81% of intervention patients showed improvement in both plaque index and mucosal disease score at 20 weeks compared to 30% of controls that continued with their usual plaque control regimen. All intervention group patients stated a positive WTP value. The mean net value of the treatment was £172 compared to the incremental cost of the treatment estimated at £122.75. The cost-effectiveness analysis resulted in an incremental cost-effectiveness ratio of £13 per OHIP point. CONCLUSIONS: The tailored plaque control programme was more effective than control in treating the gingival manifestations of oral lichen planus. The programme is cost effective for modest values placed on a point on the OHIP scale and patients generally valued the treatment in excess of the cost.

Effects of smoking cessation on the outcomes of non-surgical periodontal therapy: a systematic review and individual patient data meta-analysis.

AIM: To conduct an individual patient data (IPD) meta-analysis to assess the effect of smoking cessation (SC) on clinical outcomes following the non-surgical periodontal treatment in patients with chronic periodontitis. METHODS: MEDLINE, EMBASE and CENTRAL were searched up to, and including, August 2012. Prospective cohort studies of at least 6 months' duration were included if the participants met the following criteria: (1) smokers who had expressed an interest in quitting the habit; and (2) a diagnosis of periodontitis. Search was conducted by two independent reviewers. IPD meta-analyses were undertaken using multiple linear or Poisson regression to evaluate the impact of SC on five different dependent variables. RESULTS: Of 2455 potentially eligible articles, two studies were included. The two studies found that SC seems to promote additional beneficial effects in reducing probing depths (PD) and improving attachment level following non-surgical periodontal treatment. The IPD approach allowed data combination but it might not have usefully added strength to the data in this review. CONCLUSION: SC seems to be an important component of periodontal therapy, and smokers should be encouraged to quit as part of their overall periodontal management; however, only a limited base of evidence was available for analysis.

Compromised periodontal status in an urban Sri Lankan population with type 2 diabetes.

AIM: To determine the prevalence of periodontitis in an urban population of Sri Lankans with type 2 diabetes (T2DM) and to compare the data with those from a population of adults without diabetes. METHODS: Demographic data and a diabetes profile were recorded for a population of urban Sri Lankan adults with T2DM including duration of diabetes, blood pressure; percentage glycosylated haemoglobin, fasting blood glucose level, total cholesterol; triglycerides, low- and high-density lipoproteins. The clinical examination comprised an oral soft tissue examination, full-mouth probing depths (PD), gingival recession (GR), clinical attachment levels and bleeding on probing (BoP). RESULTS: Two hundred and eighty-five individuals with T2DM and 72 controls were examined. 33.3% of T2DM patients were diagnosed with chronic periodontitis compared with 21.7% of controls (p=0.077). Subjects with T2DM had significantly more sites with PD>or=4 and >or=5 mm (p<0.01), and higher mean GR and BoP scores (p<0.01). CONCLUSION: This urban Sri Lankan population of subjects with T2DM demonstrated a compromised periodontal status compared with non-diabetic controls.

Response of subgingival bacteria to smoking cessation.

It has been demonstrated that smoking cessation alters the subgingival microbial profile; however, the response of individual bacteria within this ecosystem has not been well studied. The aim of this investigation, therefore, was to longitudinally examine the effect of smoking cessation on the prevalence and levels of selected subgingival bacteria using molecular approaches for bacterial identification and enumeration. Subgingival plaque was collected from 22 smokers at the baseline and 12 months following periodontal nonsurgical management and smoking cessation counseling. The prevalence and abundance of selected organisms were examined using nested PCR and multiplexed bead-based flow cytometry. Eleven subjects successfully quit smoking over 12 months (quitters), while 11 continued to smoke throughout (smokers). Smoking cessation led to a decrease in the prevalence of Porphyromonas endodontalis and Dialister pneumosintes at 12 months and in the levels of Parvimonas micra, Filifactor alocis, and Treponema denticola. Smoking cessation also led to an increase in the levels of Veillonella parvula. Following nonsurgical periodontal therapy and smoking cessation, the subgingival microbiome is recolonized by a greater number of health-associated species and there are a significantly lower prevalence and abundance of putative periodontal pathogens. The results indicate a critical role for smoking cessation counseling in periodontal therapy for smokers in order to effectively alter the subgingival microbiome.

The impact of powered and manual toothbrushing on incipient gingival recession.

AIM: To compare clinical effects of manual and powered toothbrushes on sites of localized gingival recession over 12 months. To evaluate patterns and the extent of toothbrush bristle wear. METHODS: A longitudinal, single-blind, randomized, parallel group clinical trial compared the effects of one manual and one powered toothbrush on incipient lesions of localized gingival recession. Toothbrush wear was evaluated concurrently by wear index and wear rating. RESULTS: Sixty patients were recruited and randomized to two groups with 52 (26 per group) attending the final visit at month 12. There were no differences between groups for full-mouth plaque index, pocket depth or bleeding on probing at baseline and month 12. There were no differences at target sites for clinical attachment level, pocket depth, bleeding on probing, plaque index, width of keratinized gingiva or maximal height of recession. There were no differences between the wear of the brushes as measured by wear index or wear rating. CONCLUSION: There was no progression of gingival recession in subjects using either toothbrush over 12 months. There was no difference in the overall wear of the powered and manual toothbrushes over successive 3-month periods.

Does tooth brushing influence the development and progression of non-inflammatory gingival recession? A systematic review.

AIM: The aim of this systematic review was to produce the best available evidence and pool appropriate data to evaluate the effect of tooth brushing on the initiation and progression of non-inflammatory gingival recession. MATERIAL AND METHODS: A protocol was developed a priori for the question: "Do factors associated with tooth brushing predict the development and progression of non-inflammatory gingival recession in adults?" The search covered six electronic databases between January 1966 and July 2005. Hand searching included searches of the Journal of Clinical Periodontology, Journal of Periodontal Research and the Journal of Periodontology. Bibliographies of narrative reviews, conference proceedings and relevant texts known to the authors were also searched. Inclusion of titles, abstracts and ultimately full texts was based on consensus between three reviewers. RESULTS: The full texts of 29 papers were read and 18 texts were eligible for inclusion. One abstract from EuroPerio 5 reported a randomized-controlled clinical trial [Level I evidence] in which the authors concluded that the toothbrushes significantly reduced recessions on buccal tooth surfaces over 18 months. Of the remaining 17 observational studies, two concluded that there appeared to be no relationship between tooth brushing frequency and gingival recession. Eight studies reported a positive association between tooth brushing frequency and recession. Other potential risk factors were duration of tooth brushing, brushing force, frequency of changing the toothbrush, brush (bristle) hardness and tooth brushing technique. None of the observational studies satisfied all the specified criteria for quality appraisal and a valid appraisal of the quality of the randomized-controlled trial was not possible. CONCLUSION: The data to support or refute the association between tooth brushing and gingival recession are inconclusive.

Periodontal maintenance in a specialist periodontal clinic and in general dental practice.

OBJECTIVES: To monitor the efficacy of periodontal maintenance whether conducted in a specialist periodontology clinic or in the practice of the referring general dentist. MATERIALS AND METHODS: Thirty-five subjects with a diagnosis of moderate-severe chronic periodontitis who were referred to the specialist clinic received periodontal non-surgical therapy. Following a 6-month healing phase, subjects were randomly allocated to one of two groups: A (n=18, periodontal maintenance provided within the specialist clinic) or B (n=17, periodontal maintenance provided by the referring general dentist in accordance with written instructions provided by the specialist). All subjects were examined at months 0 (corresponding to 6 months post-completion of non-surgical therapy), 6 and 12. Full-mouth plaque index (PI), % bleeding on probing (%BOP) and probing depth (PD) measurements were recorded. PDs were also recorded at eight test sites which, prior to non-surgical therapy, exhibited PD 5-8 mm, BOP and radiographic alveolar bone loss. Standardized radiographs were exposed at test sites at months 0 and 12, and bone changes assessed using digital subtraction radiography (DSR). RESULTS: As a result of the non-surgical therapy, statistically significant improvements in all clinical parameters were recorded. In the maintenance period, mean PI increased significantly from months 0 to 12 (p<0.05), but this increase did not differ significantly between groups A and B (p>0.05). No other clinical parameters changed significantly in the maintenance phase of the study. Reductions in %BOP, mouth mean PD and mean test sites PD achieved by the non-surgical therapy were maintained and did not differ significantly whether subjects were allocated to group A or group B (p>0.05). Current smokers had significantly deeper PD than non-smokers and former smokers at all time points (p<0.05), although otherwise, smoking status did not affect the outcomes of the study. DSR analysis identified statistically non-significant, slight, alveolar bone loss in both groups between months 0 and 12. CONCLUSION: In the short term, periodontal maintenance can be provided in general dental practice with the same expected outcomes compared with maintenance that is provided in a specialist clinic, providing that general dentists are given specific instructions regarding the maintenance regimen. A strong emphasis on effective plaque control is necessary.

Current concepts in periodontal pathogenesis.

Periodontal research over the last 40 years has been remarkably prolific. We now understand that severe periodontitis affects approximately 10-15% of the population (representing a large number of individuals in the UK) and gingivitis and mild periodontitis affect a majority of people. Microbiological research has identified some of the key pathogens that are implicated in periodontal disease. Plaque bacteria exist in biofilms, which have evolved to protect individual organisms within the subgingival bacterial community. For this reason, root surface instrumentation (RSI) remains the cornerstone of periodontal treatment, and is necessary to disrupt the subgingival biofilm mechanically and reduce the bacterial bioburden. Although bacteria are necessary for periodontal disease to occur, a susceptible host is also required. The immune-inflammatory response that develops in the gingival and periodontal tissues in response to the chronic presence of plaque bacteria results in destruction of structural components of the periodontium leading, ultimately, to the clinical signs of periodontitis. The nature of the host response is determined primarily by genetic factors and environmental and acquired factors such as smoking. The host response is essentially protective in nature, but both under-activity (hypo-responsiveness) and over-activity (hyper-responsiveness) of aspects of the host response can result in enhanced tissue destruction. The purpose of this paper is to review current thinking in periodontics with special reference to periodontal epidemiology, microbiology, and pathogenesis.

Prostaglandin E2 concentrations in gingival crevicular fluid: observations in untreated chronic periodontitis.

OBJECTIVES: We set out to monitor gingival crevicular fluid prostaglandin E2 (GCF-PGE2) concentrations longitudinally in a cohort of subjects with chronic periodontitis, given that we had noted an unexplained trend for GCF-PGE2 concentrations to gradually increase in control groups and placebo populations in previously published clinical trials. MATERIAL AND METHODS: 41 adults with moderate-severe chronic periodontitis were recruited. GCF samples were collected from 8 test sites (with 5-8 mm probing depths and attachment loss) every 30 days for 150 days, and assayed for PGE2. Clinical measurements (probing depths, attachment levels, bleeding on probing) were recorded at days 0 and 150. RESULTS: A gradual and statistically significant increase in GCF-PGE2 concentrations was observed over the course of the study, from 40.3 ng/ml to 83.1 ng/ml (p<0.001). When data were expressed as absolute PGE2 content, a similar statistically significant increase from baseline to day 150 was observed (p<0.001). GCF volumes did not vary significantly during the study (p>0.05). Over the same time period, no statistically significant changes in clinical parameters were recorded, with the exception of mean probing depths, which decreased slightly from 5.73 mm to 5.51 mm (p<0.05). CONCLUSION: A trend for gradually increasing GCF-PGE2 concentrations in the absence of any clinical signs of disease progression was noted in a group of patients monitored longitudinally. We suggest that this phenomenon is to be expected in longitudinal clinical trials, and propose a new model for the role of PGE2 in the pathogenesis of periodontal destruction. We feel that if GCF mediators are to be monitored in clinical studies, then both concentrations and absolute mediator content should be calculated, and a standardised sampling protocol should be employed.

Supportive periodontal care: the effect of periodic subgingival debridement compared with supragingival prophylaxis with respect to clinical outcomes.

BACKGROUND: The programme of supportive periodontal care (SPC) is essential to the long-term stability of patients with chronic periodontitis. The clinical strategy for SPC is often determined according to 'clinical needs' of the patient and is thus determined by clinical observation and individual decision-making rather than being based on the best available clinical evidence. OBJECTIVE: To evaluate the effectiveness of supragingival prophylaxis vs. sub-gingival debridement for SPC following the treatment of chronic periodontitis. SEARCH STRATEGY: Computerized for Medline and the Cochrane Oral Health Group Specialty Trials Register. Hand searching of the Journals of Clinical Periodontology, Periodontal Research and Periodontology. Reference lists from relevant articles were scanned and the authors of eligible studies were contacted to obtain additional information. SELECTION CRITERIA: Studies were selected if they were designed as a prospective clinical trial in which patients with chronic periodontitis had followed a programme of SPC, which included at least one of the regimens of interest in part of the mouth, for a minimum of 12 months. DATA COLLECTION AND ANALYSIS: Information regarding methods, patients, interventions (SPC), outcome measures and results were extracted independently, in duplicate, by two reviewers (P.A.H., G.McC.). Absent data were recorded as such and incomplete data were sought from the researchers wherever possible. RESULTS: In all, 28 papers were identified by the manual and electronic searches; 11 papers were eligible for inclusion. Only one study reported a direct comparison of the two SPCs of interest. The data were reported as mean changes in probing depth and attachment level between baseline and the 12-month follow-up point. For coronal scaling DeltaPD = 0.59 mm [0.13], DeltaAL = -0.13 mm [0.19]. For subgingival debridement DeltaPD = 0.37 mm [0.15], DeltaAL = -0.14 mm [0.18]. There were no significant differences between the SPC regimens. The weighted mean DeltaPD [95% confidence intervals] for the five additional studies that reported supragingival prophylaxis as the SPC regimen was 1.15 mm [-0.17, 2.38]. The weighted mean DeltaPD [95% confidence intervals] for the four studies that reported subgingival debridement as the SPC regimen was 0.56 mm [0.37, 1.47]. The difference between the SPC treatments for the mean DeltaPD is therefore 0.23 mm. The confidence interval for the combined studies was very wide [0.37, 1.47] and very little additional information is gained unless some strong assumptions are made about the comparability of the populations from which the samples are drawn. Such an assumption was not considered appropriate. The weighted mean DeltaAL [95% confidence intervals] for the six additional studies that reported supragingival prophylaxis as the SPC regimen was 0.18 mm [-0.38, 0.74]. The weighted mean DeltaAL [95% confidence intervals] for the six additional studies that reported supragingival prophylaxis as the SPC regimen was 0.50 mm [0.11, 0.89]. The difference between the SPC treatments for mean DeltaAL is 0.32 mm. The confidence interval [-0.36, 1.00] is very wide and the data from the additional studies provide little extra information than that reported in the one study that compared the treatments directly. CONCLUSION: It is not possible to make any firm recommendations regarding clinical practice based on the crude meta-analysis and the review of these 11 studies. The best available evidence indicates that SPC regimens of supragingival prophylaxis and subgingival debridement are comparable with respect to the clinical outcomes of probing depth and attachment levels at 12 months post non-surgical treatment.