Showing papers in "Evidence-based Dentistry in 2003"

Not all evidence is created equal — so what is good evidence?

Abstract: We are living in the information age, bombarded from every side by bits and bytes of information. How do we know how good any of it is? One of the aims of Evidence-Based Dentistry is to help the practitioner identify the best evidence. Therefore, we identify here the differing levels of evidence and explain how we will be using these in the journal in future.

I know nothing

Abstract: In this issue of Evidence-Based Dentistry we look at a number of systematic reviews published as the result of an initiative by the European Federation of Periodontology. These represent a commitment by the Federation and its members to clarify the evidence-base of periodontology. The production of these reviews — as with any systematic review — represents a great deal of work. This is not just in terms of the review itself but also the training necessary to bring all the participants up to speed. The results summarised in the journal have also been produced over a relatively short timescale for systematic reviews (less than a year). This owes much to the enthusiastic core group of authors and the support of Ian Needleman and David Moles, who are the Director and Deputy Director respectively of the International Centre for Evidence-based Periodontology, based at the Eastman Dental Institute in London, UK. The reviews provide answers to some questions that periodontologists have been debating for some time. Nevertheless, as with most reviews that have been completed in dentistry to date, they leave us with further questions remaining to be resolved. Even in the case of periodontology, which has been leading dentistry in the number of randomised controlled trials it produces, the review teams found few trials of good quality and comparable outcomes, limiting their ability to combine studies. There are a variety of reasons for this, and there is a need for the dental research community to address these issues, and not just in periodontal studies. Many people question the value of systematic reviews because they often seem to be inconclusive. This is a negative interpretation of the valuable role they perform. Systematic reviews locate, appraise and synthesise evidence and thus provide a valuable benchmark of the current state of the dental evidence. They are a retrospective exercise of necessity, and they can only summarise the evidence that is available. If researchers do not like the message, ‘‘don’t shoot the messenger’’. Clarifying dental evidence is a primary role of the systematic review: in doing this such reviews inform us of the strength of evidence on which our current practice is based (good or bad), and any potential negative effect of treatment. They also identify obvious knowledge gaps requiring future research. All of these features are important to practitioners and to those who provide services, researchers and funding, as well as to patients. In his text book Evidence-based Health Care, Muir Gray categorised three types of treatment and their impact on patients: those that do more good than harm; those that do more harm than good; and those of unknown effect. The number of treatments that have good evidence that they do more good than harm in dentistry is limited and I would suggest that the majority currently fall into the category of unknown effect. I imagine that many members of the dental profession today believe that most of what they do is of benefit to their patients either in the short or long term. Perhaps the wisest amongst us should realise that, as Socrates suggested, we must first accept that we know very little about the effectiveness of our treatments. This issue of EBD also outlines the career of Helen Worthington, who has been made Professor of Evidence-based Care at Manchester University. This honour is richly deserved because Helen is one of the unsung driving forces behind the Cochrane Oral Health Group. I would like to add my personal congratulations on her appointment. Helen is one of those rare resources within dentistry in the UK: a dental statistician. Perhaps her appointment will lead to more statistical input in dental research within other dental research groups in the UK — preferably at the study design stage rather than just after the data collection has been completed. Perhaps then we can begin to address some of the quality issues within study design in dentistry.

Sources of evidence

Abstract: In the last issue we looked at levels of evidence.1 In this article we take an overview of the sources of this evidence in this information age. In later articles we will then look in more depth at some of these sources themselves.

Power and glory

Abstract: Two Cochrane systematic reviews of consumer-oriented products were previewed at an Evidence-based Dental Conference held at the Forsyth Institute in Boston earlier this year. The media reaction to one was negligible while the other prompted hundreds of stories, why the difference?

Fluoride toothpaste prevents caries

Abstract: Data sources The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials, MEDLINE (1966–January 2000) and several other databases were sources. Journals and reference lists of articles were handsearched and selected authors and manufacturers were contacted.

Is human papillomavirus a risk factor for oral squamous cell carcinoma

Abstract: Data sources Sources used were MEDLINE (January 1980–August 1998) and bibliographies of review articles.

Decision-making for preradiation dental extractions is based primarily on experience and opinion

Abstract: Decision-making for preradiation dental extractions is based primarily on experience and opinion

Powered toothbrushes show a modest benefit over manual toothbrushes

Abstract: Data sources Sources were the Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials, Medline, EMbase and CINAHL. In addition, manufacturers of powered toothbrushes were contacted for further published and unpublished trials. Study selection Trials were selected if there was random allocation of participants, they were conducted within the general public, subjects had uncompromised manual dexterity, and supervised manual and powered toothbrushing was compared for at least 4 weeks with the primary outcome of change in plaques and gingivitis over the period. Data extraction and synthesis Six reviewers independently extracted information in duplicate. Indices for plaque and gingivitis were expressed as standardised values for each study. The effect measure for each meta-analysis was the standardised mean difference with the appropriate 95% confidence intervals using random-effect models. Potential sources of heterogeneity were examined, along with sensitivity analyses for the items assessed for quality and publication bias. Results A total of 29 trials (including 2547 participants) provided data for the meta-analysis. Brushes that worked with a rotation–oscillation action removed more plaque and reduced gingivitis more effectively than manual brushes in the short- and long-term (Figure 1). At 3 months this represented an 11% reduction in plaque and a 6% reduction in gingivitis. At over 3 months there was a 7% reduction in plaque and a 17% reduction in gingivitis. Sensitivity analyses revealed the results to be robust when selecting trials of high quality. There was no evidence of any publication bias. Conclusions Powered toothbrushes with a rotation–oscillation action achieve a significant, though modest, reduction in plaque and gingivitis compared with manual toothbrushing. Observation of methodological guidelines and greater standardisation of design would benefit both future trials and meta-analyses.

No conclusive evidence favouring cast over direct post and core preparations

Abstract: Data sources English, French or German articles were identified in Medline and EMbase, and in the reference lists of retrieved articles. Study selection The in-vitro studies were of single rooted teeth (no resin analogues) and load angles of 130–135°. In-vivo studies were of ⩾3 years’ duration. These included teeth that could be identified separately with complete crown restoration including fixed partial denture abutments and detectable information regarding success or failure. Data extraction and synthesis For in-vitro studies, primary outcome was load-to-failure. For in-vivo studies, failure was defined as a need for recementing, a new restoration of any kind, or tooth extraction. A qualitative synthesis of all included in-vitro and in-vivo studies was performed along with a meta-analysis of four in-vitro studies. Results Ten in-vitro and six in-vivo studies were included. The meta-analysis of four in-vitro studies revealed no significant difference in fracture load. There was also little difference in the mode of fracture across the 10 in-vitro studies. For three of the in-vivo studies it was possible to construct a life table that indicated the survival rate for cast posts was between 87 and 88% and for direct posts was 86% at 72 months. Conclusions There is no conclusive evidence favouring cast over direct post and core preparations or vice versa. The literature on the clinical success of post-retained cores is scare and randomised controlled trials are needed.

Is grafting biomaterials or biological agents more effective than open-flap debridement in treating deep intraosseous defects?

Abstract: Is grafting biomaterials or biological agents more effective than open-flap debridement in treating deep intraosseous defects?

Weak evidence for a benefit of Emdogain in the treatment of intrabony defects

Abstract: Data sources Sources were the Cochrane Oral Health Group's Trials Register (to January 2003), the Cochrane Central Register of Controlled Trials, Medline (1966 to January 2003) and EMBASE (1980 to January 2003). The International Journal of Periodontics and Restorative Dentistry, Journal of Clinical Periodontology, Journal of Dental Research, Journal of Periodontal Research, Journal of Periodontology and the bibliographies of papers and review articles were searched by hand. Authors, personal contacts and manufacturers were contacted in an attempt to identify unpublished or ongoing trials. There were no language restrictions. Study selection The studies included were clinical randomised controlled trials (RCT) that considered enamel matrix derivative (EMD; Emdogain) [Biora, Malmo, Sweden] with at least 1 year follow-up. Data extraction and synthesis Data were extracted by two reviewers independently, using specially designed data extraction forms. Results were expressed as random-effect models using weighted mean differences for continuous outcomes and relative risk for dichotomous outcomes with 95% confidence intervals (CI). Heterogeneity was investigated including both clinical and methodological factors. Results No difference in tooth loss was observed. Meta-analysis of eight trials showed that EMD-treated sites displayed statistically significant probing attachment level (PAL) improvements (mean difference, 1.3 mm; 95% CI: 0.8–1.8) and probing pocket depth (PPD) reduction (1 mm; 95% CI: 0.5–1.4) compared with flap surgery. Six trials compared EMD with guided tissue regeneration (GTR), GTR showing a statistically significant reduction of PPD (0.6 mm) and increase of gingival recession (0.5 mm). No difference in postoperative infections was observed. Conclusions EMD is able to significantly improve PAL levels (1.3 mm) and PPD reduction (1 mm) compared with flap surgery, but these results may not have a great clinical impact since it has not been shown that more periodontally compromised teeth could be saved. There was no evidence of clinically important differences between GTR and EMD.

Peri-implantitis — absence of evidence to support specific treatment protocols

Abstract: Data sources Medline was searched to January 2002. Manual searches were made of the Journal of Periodontology, Journal of Clinical Periodontology, International Journal of Maxillofacial Implants, Clinical Oral Implants Research and Clinical Implant Dentistry and Related Research dated to December 2001, and of bibliographies of all relevant articles. There were no language restrictions. Study selection Human studies were included if they provided a clinical diagnosis and treatment of peri-implantitis. Animal experiments on the treatment of peri-implantitis were also included. Data extraction and synthesis Information regarding quality and study characteristics was extracted independently by two reviewers. A qualitative summary of included studies was carried out. Results No clinical randomised controlled trials (RCT) were available. Six human and 15 animal studies were identified. A multitude of treatment regimens, including anti-infective therapy, was reported. The antibiotic regimens varied between studies. No standardised medication protocol was used. Type of antibiotic, dosage, duration and time for initiation of antibiotic treatment were different for all studies, but details were not always reported. A nonmedicated control group was reported in one animal experiment only. The outcomes following anti-infective treatment of peri-implantitis are highly variable. Conclusions Several anti-infective treatment strategies have demonstrated a beneficial clinical effects in humans but there is insufficient evidence to support a specific treatment protocol. All studies had only a small number of subjects and the study periods, in general, were relatively short. No evidence exists on the significance of anti-infective treatment for the longevity of the implant. Clinical RCT for the treatment of peri-implantitis should be conducted.

Treatment of odontogenic keratocysts by enucleation with adjunctive therapy has lower recurrence rates

Abstract: Data sources Index Medicus, MEDLINE were searched, as well as the bibliographies of identified studies. Study selection Papers selected were those in which odontogenic keratocysts (OKC) was diagnosed histologically, the patient selection process was adequately described, there was consecutive, adequate description of the follow-up period, and where detailed treatment information and recurrence rates were included and assessed using eight defined criteria. Data extraction and synthesis The treatment method and recurrence rates were extracted and tabulated. Results Fourteen papers met the criteria. These were restricted to retrospective consecutive case-series. The type of treatment and recurrence rates are shown in the Table 1. Conclusions The literature is limited to retrospective study designs and prospective studies need to be initiated. It appears, however, that resection or enucleation with adjunctive therapy is associated with lower recurrence rates than enucleation alone.

A computer-assisted learning programme to reduce caries detection variability

Abstract: Design A randomised controlled trial using block design was devised. Intervention A computer-assisted learning (CAL) programme, with feedback, was tested. Outcome measure Sensitivity and specificity of caries diagnosis, and the summary receiver operating characteristic (SROC) method for summarising true-positive ratio (sensitivity) and false-positive ratio (1 — specificity), were used to analyse the dichotomous data. Results The mean sensitivity for dentine caries detection was 76.3% (standard deviation (SD), 13.0%) for the experimental group and 66.9% (SD, 14.8%) for the control group (P=0.005). Mean false-positive ratios were similar (experimental 28.1% and control 28.7%; P=0.5). The area under the SROC curve was 0.832 for the experimental group and 0.773 for the control group (P=0.002). Conclusions The CAL programme does improve diagnostic performance. Improving the cognitive feedback provided by the programme should be considered before implementation.

Computer-aided learning programmes in teaching dental students

Abstract: Data sources Sources were MEDLINE, the Cochrane Library, Embase, ERIC (Educational Resources Information Centre), CINHAL (Cumulative Index to Nursing and Allied Health), LISA (Library and Information Science Abstracts), Psycinfo (Psychological Information) and IPA (International Pharmaceutical Abstracts). Study selection Randomised controlled trials (RCT) that compared computer-aided learning (CAL) programmes with any other method of instruction were considered. Only studies within dentistry were included. The quality of studies was assessed using a checklist. Data extraction and synthesis Both qualitative and quantitative outcomes from studies were recorded, and qualitative synthesis of the results was undertaken because of the diverse nature of the outcomes. Results Twelve studies were identified (five in endodontics, three in orthodontics and one each in oral anatomy, restorative, geriatric and prosthetic dentistry). Conclusions For the most part, CAL is either more effective than or equally effective as other methods of education.

Does chewing xylitol gum result in suppression of mutans streptococci

Abstract: Design Randomised controlled trail using a health-centre population in Finland. Intervention 195 pregnant women with high mutans streptococci counts were randomised into three groups, xylitol (X; n=127), chlorhexidine varnish (CHX; n=32) or fluoride varnish (F; n=36). In group X, mothers were recommended to chew xylitol gum two to three times per day, starting at 3 months from delivery and continuing until their child was 3 years of age. The CHX- and F-group mothers received chlorhexidine or fluoride varnish at 6, 12 and 18 months after the birth of the child. Children received routine dental care (oral hygiene instruction, dietary advice fluoride treatment and restorative treatment) where necessary. Standardised plaque and salivary sampling was undertaken. Outcome measure Mutans streptococcus levels in plaque and saliva. Results Loss to follow-up was 19% at 3 years and 25% at 6 years. The reported proportion of the children who were colonised by mutans streptococci are shown (see Table 1) with a calculated worst-case scenario analysis assuming the best possible outcomes for groups CHX and F and the worst for group X. Numbers-needed-to-treat are presented comparing groups X and F. Conclusions Chewing xylitol gum by mothers who have high mutans streptococcus counts results in long-term suppression of the bacterium in their offspring.

There is more to continuing professional development than just scoring hours

Abstract: This issue introduces a new service for readers to enable them to record and verify the time they have spent studying articles in this journal. Around the world, dental registration bodies are beginning to demand that dentists keep up-to-date and be able to prove it. Whereas some states and countries have had a formalised system for a number of years, others so far have not. It is quite clear that in the future dentists will not be able to coast along once they have their basic qualification but will be expected to stay abreast of current knowledge.

Presence or absence of periodontal pathogens does not distinguish between chronic and aggressive periodontitis

Abstract: Data Sources Data sources were Medline, with hand searches of the Journal of Dental Research, Journal of Clinical Periodontology, Journal of Periodontal Research and Journal of Periodontology dated from 1990 up to July 2001, and the reference lists of articles selected for inclusion Study selection Studies included were cross-sectional or longitudinal with microbiological data from at least two cohorts Data extraction and synthesis Information regarding quality and study characteristics was extracted independently by two reviewers Kappa scores determined their agreement Sensitivity and specificity of the microbiological tests were calculated for each selected study individually, with values being expressed as a Receiver Operator Characteristic (ROC) diagram Results The presence or absence of Actinobacillus actinomycetemcomitans could be evaluated in 11 papers; of Porphyromonas gingivalis in seven papers; and of Prevotella intermedia in six studies Bactericides forsythus and Campylobacter rectus were each analysed in two papers ROC diagrams indicated the limited discriminatory ability of all of the test parameters to identify subjects with aggressive periodontitis An additional assessment showed that the highly leukotoxic variant of A actinomycetemcomitans was uniquely associated with patients suffering from aggressive periodontitis In a high proportion of patients diagnosed with the aggressive form of the condition, however, the presence of this variant could not be detected Conclusions The presence or absence of A actinomycetemcomitans, P gingivalis, P intermedia, B forsythus and C rectus could not distinguish subjects with aggressive periodontitis from those with the chronic form

RCTs in periodontology do not meet current recommendations on quality

Abstract: Data sources Cochrane Oral Health Group specialised register of RCT, limited to the Journal of Clinical Periodontology, Journal of Periodontology and Journal of Periodontal Research from 1996 to 1998. Study selection Studies included were RCT of treatment conducted in humans and with a full journal publication available. Data extraction and synthesis Information was extracted about randomisation, allocation concealment methods and the blinding of patient, caregiver and examiner. This was conducted independently by two reviewers. Results A total of 91% of trials were described as randomised, of which 17% had adequate methods of randomisation and 7% adequate allocation concealment. Blinding was adequate for the caregiver in 17% and for the examiner in 55% of studies. A clear accounting of all participants was present in 56% of reports. Conclusions The quality of periodontology RCT, judged by their publications, frequently does not meet recommended standards. If this quality is reflected in actual study conduct, fundamental errors could have a significant impact on the outcomes of these trials. It is likely that other fields of dentistry are similarly affected.

Evidence suggests that orthodontic treatment as a child is not related to later TMD

Abstract: Design Prospective cohort study of 402 randomly-selected individuals aged 7, 11 and 15 years at baseline. A total of 320 completed a questionnaire after 20 years of which 100 patients, who were aged 15 at initial examination, were re-examined. Orthodontic treatment in the oldest age group was scrutinised by individual case records. Outcome measure The questionnaire dealt with the presence of symptoms such as headaches, frequent stress or depression, previous trauma to the face, experience of temporomandibular disorders (TMD) during the 20 years of observation and current demand for TMD treatment. The clinical examination was conducted to measure any TMD signs and symptoms including limitation to range of movement, temporomandibular joint sounds and pain. Tooth wear was recorded on a five-point scale where 1 indicated no wear and 5 indicated wear of more than one-third of the clinical crown. Results One hundred and two patients had received orthodontic treatment, 192 no orthodontic treatment and 26 did not know. Correlations between signs and symptoms of TMD and different malocclusions were weak. Lateral forced bite and unilateral crossbite were correlated with TMD signs and symptoms at the 10- and 20-year follow-ups (r2=0.38, P<0.05 and r2=0.34, P<0.01, respectively). Subjects who had malocclusion over a long period of time tended to report more symptoms of TMD and to show a higher dysfunction index, compared with subjects with no malocclusion at all. Conclusions There were no statistically-significant differences in the prevalence of TMD signs and symptoms between subjects with or without previous experience of orthodontic treatment.

Infection control in dentistry: compliance with guidelines needs more work

Abstract: Data sources Data sources were MEDLINE, EMbase, BIDS Science Citation Index and Social Sciences Citation Index, the Cochrane Library, NHS EED (NHS Economic Evaluation Database), SIGLE (System for Information on Grey Literature in Europe), British Dental Association Library, reference lists of identified studies and hand searches of the International Dental Journal, Community Dentistry and Oral Epidemiology and Journal of the American Dental Association. Study selection Randomised controlled trials (RCT), controlled clinical trials, controlled before-and-after studies, interrupted time series, observational studies, surveys and reports were selected. A wide range of outcome measures, both observed and self-reported, were considered, for example, glove use, mask use, wearing of protective clothing and eye wear and vaccination against hepatitis B virus. Data extraction and synthesis Two reviewers independently selected studies and the quality was assessed using a checklist. Disagreements were resolved by discussion. Due to the degree of heterogeneity, a qualitative synthesis was performed. Results Only 71 studies met the inclusion criteria and their overall quality was poor. The results were summarised under several headings: knowledge and attitudes, personal protective equipment, immunisation, sterilisation and disinfection, waste disposal, and occupationally acquired injuries. They revealed substantial improvements in compliance in some areas of infection control such as glove wearing, but other aspects, such as the effective management of needlestick injuries, remains problematic. Conclusions More rigorously designed studies are needed to accurately assess dental team members' adherence to infection control guidelines.

No evidence to allow quantification of optimum orthodontic force

Abstract: Data sources Sources were MEDLINE (1966–December 2001) and hand searches of the main orthodontic and dental journals, along with bibliographies of selected articles. Study selection Studies were excluded if there was no quantification of magnitude of force, rate or amount of movement, no control group, a split mouth design, fewer than five experimental sites, or if there was an observation period of less than 1 week. Neither were studies included that used functional or extra-oral appliances, or where medication and surgical or physical interventions other than orthodontic were used. Human and animal studies were included. Data extraction and synthesis A range of data relating to the forces applied to the tooth and their measurement were extracted from the studies identified. A large variation in data from current literature made it impossible to perform a meta-analysis. Results Seventeen studies in animals and 12 in people were included. In eight human studies for canine retraction, initial forces of 800–1500 cN were used. Three studies of premolar tipping used forces from 50 to 200 cN, and two studies reported molar tipping forces of 100–500 cN. Conclusions No evidence about the optimal force level in orthodontics could be extracted from literature. Well-controlled clinical studies and more standardised animal experiments in the orthodontic field would provide more insight into the relation between the force applied and the rate of tooth movement.

Powered toothbrushes are more effective than manual toothbrushes in reducing gingival bleeding or inflammation

Abstract: Powered toothbrushes are more effective than manual toothbrushes in reducing gingival bleeding or inflammation

Information is meagre on aetiology of oral cancer in young people

Abstract: Data sources Searches were made of Medline, Cancerlit, the Institute for Scientific Information (ISI) databases of SCI-expanded and Social Sciences Citation Index (SciSearch), and of Embase (1980–present) and the International Bibliography of the Social Sciences both via BIDS. Relevant journals and indices were searched by hand. Study selection Only English-language articles published between 1957 and 2000 were included. Articles that did not include studies of squamous cell carcinoma or describing cancer of upper aerodigestive tract, oesophagus or larynx were excluded. Data abstraction and synthesis A qualitative synthesis of the studies included was carried out. Results A total of 46 articles exclusively considering young adults were identified, of which 28 examined potential risk factors. About 4–6% of oral cancers occur in people aged under 40 years. The usual male dominance does not appear to hold for younger patients. There are inconsistencies in the survival rates of younger patients compared with older patients but this may be due to small sample sizes and differences in treatment type and duration. Several studies suggest that many younger patients have never used tobacco or consumed alcohol or the duration of exposure is too short for malignant transformation too occur. There is insufficient research on association with occupation, immune defence, viral infections, diets low in fruit and vegetables or genetic factors. Conclusions There is mixed evidence regarding the role of alcohol and tobacco as risk factors in young people. There is limited research on other risk factors.

Craniofacial morphology is distinctive in parents of children with orofacial clefting

Abstract: Data sources Cochrane Library, Medline, HealthStar, POPLINE, SDLINE, SPACELINE, EMbase, Old Medline, CINHAL, ASKSAM, the orthodontic reference database (1950–1997), European Clearing House on Health Systems reform, UK National Research Register and hand searching of Cleft Palate-Craniofacial Journal and bibliographies of retrieved publications Study selection The search strategy was based on the key words, “parent”, “cephalometry” and “cleft” Studies written in any language were included but case-reports and case series were excluded Data extraction and synthesis A range of clinical parameters were extracted from the studies with statistical analysis when available Studies were assessed for quality but methodological variation and insufficient consistency in study design precluded synthesis of data Results Parental craniofacial morphology in OFC is distinctive Conclusions The parental craniofacial complex in OFC is distinctive in comparison with parents of children without cleft lip and palate but there is insufficient information to localise these differences The quality of available data is limited

Over half all patients develop short-term root sensitivity after periodontal therapy

Abstract: Data sources MEDLINE and EMbase reference lists from relevant articles were hand-searched and a hand-search was made of selected journals dated up to April 2001. Study selection No randomised controlled trials (RCT) nor quasi-randomised clinical trials were identified, so the review focused on cross-sectional and prospective clinical trials in which periodontitis patients were periodontally treated and the intensity of root sensitivity was evaluated. Data extraction and synthesis Data extraction was carried out in duplicate using a predetermined appraisal form. Results The prevalence of root sensitivity was 9–23% before and 54–55% after periodontal therapy. An increase in the intensity of root sensitivity occurred 1–3 weeks following therapy, after which it decreased. Conclusions There were insufficient RCT to adequately address the stipulated question. Based on the scarce evidence from only two studies, root sensitivity occurs in approximately half of patients following subgingival scaling and root planing. The intensity of root sensitivity increases for a few weeks after therapy, after which it decreases. In clinical practice, it may be recommended that, prior to treatment, patients should be made aware of the potential for root sensitivity. In research, there is a need for RCT and prospective studies with both short and long follow-up periods. Studies are also required that investigate the effects and the relationship of root instrumentation with the aetiology of root sensitivity; the efficacy of preventive and therapeutic regimes for root sensitivity; the incidence and severity of root sensitivity by subjective patient-reporting; and the response to different modes of stimuli. Furthermore, protocols should follow the criteria used in dentine hypersensitivity studies.

Surgical endodontic retreatment success and failure are almost equivalent

Abstract: Data sources Medline, EMbase, Science Citation Index, US National Library of Medicine, along with searches made on the Internet. Study selection Studies were included if they: had a random research design; were peer-reviewed; follow-up was at least 1 year; and if retrofilling material, the healing group, age, sex and teeth/roots, the number of surgeons, and the age and sex of patients were identified. Data extraction and synthesis The outcome in each of the included studies was standardised to success, or to uncertain or unsuccessful outcome, and the weighted average was calculated. Results Eight eligible studies were identified, involving 2375 patients and 2788 teeth. The weighted average for success with initial surgery was 64.2% with 25.7% uncertain and 15.75% unsuccessful. For patients undergoing a second surgery the weighted average success rate was 35.7% with 26.3% uncertain and 38% unsuccessful. Conclusions In patients who underwent second surgery for radiographically-determined endodontic failure, 35.7% healed successfully.

Possible predictors of temporomandibular disorders

Abstract: Design Prospective cohort study of 402 randomly selected individuals aged 7-, 11- and 15-years' old at baseline. A total of 320 people completed a questionnaire after 20 years, with 100 patients who were aged 15 at initial examination being re-examined. Outcome measures The questionnaire included questions about the presence of symptoms such as headaches, frequent stress or depression, previous trauma to the face and experience of temporomandibular disorders (TMD) during the 20 years of observation, and current demand for TMD treatment. The clinical examination was conducted to measure any TMD signs and symptoms including limitation to range of movement, temporomandibular joint (TMJ) sounds and pain. Tooth wear was recorded on a 5-point scale where 1 was no wear and 5 was wear of more than one-third of the clinical crown. Results Data from the questionnaire and clinical examinations were combined and regression analysis performed. The presence of bruxism, oral parafunctions, TMJ clicking and deep bite at baseline were found to be significant predictors of TMD (see Table 1). Conclusions Some signs and symptoms appear to be predictors of TMD. More research is needed, however, to determine if any of these parameters can be used to predict TMD in the long-term.

Low risk of adverse effects from epinephrine in hypertensive patients, but relevant high-quality literature is sparse

Abstract: Low risk of adverse effects from epinephrine in hypertensive patients, but relevant high-quality literature is sparse