[ Periodontal ]
[ Prosthodontics ]
[ Orthodontics ]
[ Oral/Maxillofacial Surgery ]
Evidence based dentistry - abstracts 2
1. How long do multirooted teeth with furcation involvement survive with treatment? 2 Multifaceted strategy needed to improve dentists' adherence to evidence-based guidelines 3 A patient-randomised controlled trial (RCT) and a cluster RCT of the same intervention 4 The best treatment for avulsed permanent teeth 5 Treatment of ankylosed permanent teeth 6 Enamel matrix derivative for direct pulp capping 7 Predicting successful outcomes of complete denture therapy 8 Implant-supported cantilevered fixed partial dentures 9 Survival rates of short-span implant-supported cantilever fixed dental prostheses 10 Patients undergoing craniofacial tumour ablation surgery may benefit from having the implants.. 11 Surgical or nonsurgical treatment for teeth with existing root fillings? 12 Drug treatment for oral submucous fibrosis 13 Socioeconomic status and head and neck cancer Summary Review/Periodontal Disease Evidence-Based Dentistry (2010) 11, 38-39. doi:10.1038/sj.ebd.6400714 How long do multirooted teeth with furcation involvement survive with treatment? Question: In people undergoing periodontal treatment of multirooted teeth with furcation involvement, what is the survival rate and incidence of complication at 5 years? Address for correspondence: Giovanni E Salvi, Department of Periodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, CH-3010 Bern, Switzerland. E-mail: firstname.lastname@example.org Ian Needleman1 1International Centre for Evidence-Based Oral Health and Unit of Periodontology, Division of Restorative Dental Sciences, University College London Eastman Dental Institute, London, UK Huynh-Ba G, Kuonen P, Hofer D, Schmid J, Lang NP, Salvi GE. The effect of periodontal therapy on the survival rate and incidence of complications of multirooted teeth with furcation involvement after an observation period of at least 5 years: a systematic review. J Clin Periodontol 2009; 36: 164-176 Top of pageAbstract Data sources A Medline search and handsearching of the following journals were carried out: International Journal of Periodontics and Restorative Dentistry, Journal of Clinical Periodontology, Journal of Periodontal Research and Journal of Periodontology as well as reference lists of publications selected. Study selection To be eligible for inclusion in this review, studies had to be longitudinal in nature. Prospective and retrospective cohort studies were considered. Studies were screened and quality assessed independently by two reviewers. Review articles, case reports and studies of fewer than 5-years' duration were excluded, as were those not providing information on tooth survival or furcation involvement. Data extraction and synthesis Data was abstracted independently by two reviewers. Owing to the heterogeneity of the data, a meta-analysis could not be performed. A qualitative synthesis was conducted grouping the studies into the following areas: nonsurgical furcation therapy; surgical therapy not involving tooth structures; tunnelling surgical resective therapy (eg, root resection and/ or root separation); and guided tissue regeneration (GTR) and grafting procedures. Results Twenty-two publications met the inclusion criteria. The survival rate of molars treated nonsurgically was >90% after 5-9 years. The corresponding values for the different surgical procedures were: surgical therapy, 43.1-96% (observation period, 5-53 years); tunnelling procedures, 42.9-92.9% (observation period, 5-8 years); surgical resective procedures including amputation(s) and hemisections, 62-100% (observation period, 5-13 years); and GTR, 83.3-100% (observation period, 5-12 years). The most frequent complications included caries in the furcation area after tunnelling procedures and root fractures after root-resective procedures. Conclusions Good long-term survival rates (up to 100%) of multirooted teeth with furcation involvement were obtained following various therapeutic approaches. Initial furcation involvement (degree I) could be successfully managed by nonsurgical mechanical debridement. Vertical root fractures and endodontic failures were the most frequent complications observed following resective procedures. Summary Trial/Effective Practice Evidence-Based Dentistry (2010) 11, 40. doi:10.1038/sj.ebd.6400715 Multifaceted strategy needed to improve dentists' adherence to evidence-based guidelines Question: In dental practice are multifaceted guideline-implementation strategies more effective than dissemination alone? Address for correspondence: Department of Preventive and Restorative Dentistry, College of Oral Sciences, Radboud University, Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands. E-mail: email@example.com Debora C Matthews1 1Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, Canada Mettes TG, van der Sanden WJ, Bronkhorst E, Grol RP, Wensing M, Plasschaert AJ. Impact of guideline implementation on patient care: a cluster RCT. J Dent Res 2010; 89: 71-76 Top of pageAbstract Design This was a cluster-randomised clinical trial (RCT) of incomplete block design. Intervention The interventions comprised an online 'patient-simulated clinical case' assessment, guideline dissemination, an interactive educational meeting, and flow chart reminders. All participants received feedback on individual as well as group scores for the patient-simulated clinical case assessment. Reminders with particular information and guideline-algorithm flow diagrams were provided 2 months before post-intervention measurements. Outcome measure The primary outcome measure was guideline-adherent recall interval assignment, and the secondary outcome measure was guideline-adherent bitewing frequency prescription. Results For low-risk patients, guideline-adherent recall increased in the intervention group (+8%), which differed from the control group (-6.1%; P 0.01). Guideline-adherent bitewings showed mixed results. Conclusions Multifaceted intervention had a moderate but relevant effect on the performance of general dental practitioners, which is consistent with other findings in primary care. Summary Trial/Oral Health Promotion Evidence-Based Dentistry 11, 41 (2010) | doi:10.1038/sj.ebd.6400716 Abstract A patient-randomised controlled trial (RCT) and a cluster RCT of the same intervention were conducted independently of each other. Intervention The evidence-based intervention (a powered toothbrush and behavioural advice on timing, method and duration of toothbrushing) was framed to target oral hygiene self-efficacy (Social Cognitive Theory) and action plans (Implementation Intention Theory) to influence oral hygiene behaviour and therefore clinical outcomes. The content and the delivery of the intervention were standardised as a series of steps-altogether taking approximately 5 min. The control groups received routine care, even if that included oral hygiene advice. Outcome measure The primary outcome measures were behavioural (timing, duration and method of toothbrushing) matching the advice given in the intervention. Secondary outcomes were cognitive measures of self-efficacy and planning, and clinical measures of plaque and gingival bleeding. Results The study included 87 dental practices and 778 patients (patient RCT, 37 dentists and 300 patients; cluster RCT, 50 dentists and 478 patients). Controlled for baseline differences, pooled results showed that trial participants who experienced the intervention had better behavioural (timing, duration, method), cognitive (confidence, planning), and clinical (plaque, gingival bleeding) outcomes. Clinical outcomes were only significantly better in the cluster RCT, however. Conclusions A simple, theory-based intervention delivered within the constraints of a primary care environment was more effective than routine care in influencing patients' oral hygiene cognitions, behaviour and health. As clinical outcomes were significantly better only in the cluster RCT, the impact of trial design on results needs to be further explored. Summary Review/Paediatric Dentistry Evidence-Based Dentistry (2010) 11, 42-43. doi:10.1038/sj.ebd.6400717 The best treatment for avulsed permanent teeth Question: What is the best treatment option for permanent teeth with avulsion injuries? Address for correspondence: Luisa Fernandez Mauleffinch, Review Group Co-ordinator, Cochrane Oral Health Group, MANDEC, School of Dentistry, University of Manchester, Higher Cambridge Street, Manchester M15 6FH,UK. E-mail: firstname.lastname@example.org Aronita Rosenblatt1 1University of Pernambuco, Recife, Pernambuco, Brazil and Forsyth Institute and Children's Hospital Boston, Harvard School of Dental Medicine, Boston, Massachusetts, USA Day P, Duggal M. Interventions for treating traumatised permanent front teeth: avulsed (knocked out) and replanted. Cochrane Database Syst Rev 2010; issue 1 Data Sources The Cochrane Oral Health Group's Trials Register, Cochrane CENTRAL, Medline and Embase were consulted, along with the websites www.clinicaltrials.gov and www.controlled-trials.com and reference lists of identified articles. There were no language restrictions. Study selection Only randomised controlled trials that included a minimum followup period of 12 months for interventions dealing with avulsed and replanted permanent teeth were considered. Data extraction and synthesis Two review authors independently extracted data and assessed trial quality and the risk of bias in studies to be included. Results Three studies (involving, in total, 162 patients and 231 teeth) were included. Study one (high risk of bias) investigated the effect of extra-oral endodontics. This showed no significant difference in radiographic resorption compared with intra-oral endodontics provided at week 1 for teeth avulsed for longer than 60 min dry time. Study two (moderate risk of bias) investigated a 10-min soaking in thymosin alpha 1 prior to replantation and then its further use as a daily gingival injection for the first 7 days. They reported a strong benefit at 48 months (14% with periodontal healing in the control group versus 77% for the experimental group). Study three (high risk of bias) investigated a 20-min soaking with gentamycin sulphate for both groups prior to replantation and then the use of hyperbaric oxygen daily in the experimental group for 80 min for the first 10 days. They reported a strong benefit at 12 months (43% periodontal healing versus 88% for the experimental group). There was no formal reporting of adverse events. Conclusions The available evidence suggests that extra-oral endodontic treatment is not detrimental for teeth replanted after more than 60 min dry time. Studies with moderate/ high risk of bias indicate that soaking in thymosin alpha 1 and gentamycin sulphate followed by hyperbaric oxygen may be advantageous but these strategies have not previously been reported as interventions for avulsed teeth and await further validation. More evidence with low risk of bias is required and, with the low incidence of avulsed teeth, collaborative multicentre trials are indicated. Summary Review/Paediatric Dentistry Evidence-Based Dentistry (2010) 11, 16-17. doi:10.1038/sj.ebd.6400718 Treatment of ankylosed permanent teeth Question: In people who have ankylosed permanent anterior teeth, what treatment options are effective? Address for correspondence: Luisa Fernandez Mauleffinch, Review Group Co-ordinator, Cochrane Oral Health Group, MANDEC, School of Dentistry, University of Manchester, Higher Cambridge Street, Manchester M15 6FH,UK. E-mail: email@example.com Nicky Stanford1 1Glasgow Dental School and Hospital, University of Glasgow, Glasgow, Scotland, UK de Souza RF, Travess H, Newton T, Marchesan MA. Interventions for treating traumatised ankylosed permanent front teeth. Cochrane Database Syst Rev 2010; issue 1 Data Sources The Cochrane Oral Health Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase and LILACS . There were no language restrictions. Study selection Randomised controlled trials (RCT) were considered that compared any intervention for treating displaced ankylosed permanent front teeth in individuals of any age. Data extraction and synthesis Two independent review authors screened studies in duplicate. Although no studies were ultimately included, the authors had planned to extract data independently and to assess risk of bias following Cochrane Collaboration methods. Results The search retrieved 77 references to studies. None matched the inclusion criteria and therefore were excluded. Conclusions There is no evidence from RCT about the comparative effectiveness of the different treatment options for ankylosed permanent front teeth. The lack of high-level evidence for the management of this health problem emphasises the need for well-designed clinical trials. Summary Trail/Caries Evidence-Based Dentistry (2010) 11, 45-46. doi:10.1038/sj.ebd.6400719 Enamel matrix derivative for direct pulp capping Question: Is enamel matrix derivative as effective as calcium hydroxide for direct pulp capping of primary molars? Address for correspondence: Dr Amaury de Jesús Pozos Guillén, Facultad de Estomatología, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava #2, Zona Universitaria, C.P. 78290, San Luis Potosí, México. E-mail: firstname.lastname@example.org Nicola Innes1 1Preventive and Children's Dentistry Section, Dundee Dental Hospital and School, Dundee, Scotland, UK Garrocho-Rangel A, Flores H, Silva-Herzog D, Hernandez-Sierra F, Mandeville P, Pozos-Guillen AJ. Efficacy of EMD versus calcium hydroxide in direct pulp capping of primary molars: a randomized controlled clinical trial. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 107: 733-738 Top of pageAbstract Design A split-mouth randomised controlled trial (RCT) was conducted. Intervention Standard noncarious pulp exposures were treated with either enamel matrix derivative (EMD) or calcium hydroxide and restored with a preformed metal crown (PMC). Patients were followed up at 1, 6 and 12 months. Outcome measure The appearance of any of the following was considered to signify treatment failure: internal dentin resorption, spontaneous pain, gingival abscess (sinus tract), external root resorption, or pathologic mobility. Results In total, 90 direct pulp capping (DPC) treatments were performed (45 in the experimental group and 45 in the control group) and followed for 12 months. There were 88 successful treatments at the end of this period, with only two failures (one in each study group) Conclusions Both capping materials showed a similar effectiveness in this pulp procedure with a postoperative observation time of 12 months. On the basis of this study, we recommend the use of DCP treatment on primary molars as a standard technique. Summary Review/Restorative Dentistry Evidence-Based Dentistry (2010) 11, 47. doi:10.1038/sj.ebd.6400720 Predicting successful outcomes of complete denture therapy Question: What are the indicators for success in prosthodontic treatment? Address for correspondence: Janice S Ellis, Department of Restorative Dentistry, School of Dental Sciences, Framlington Place, Newcastle University, Newcastle upon Tyne, UK. E-mail: email@example.com Asim Al-Ansari1 1Dental Department, Armed Forces Hospital, Dhahran, Saudi Arabia Critchlow SB, Ellis JS. Prognostic indicators for conventional complete denture therapy: a review of the literature. J Dent 2010; 38: 2-9 Top of pageAbstract Data sources Ovid databases searched for relevant material for the review. Study selection Studies were limited to the English language and all identified articles were included. Data extraction and synthesis A narrative review was conducted. Results Three RCT were identified that related directly to conventional dentures. Nineteen clinical experimental studies and seven nonexperimental clinical studies were therefore also included because of the lack of higher ranking studies in this area. All studies that were identified have been included within this review. Conclusions There remains a paucity of research in this area. From the best available data, construction of technically correct dentures, a well-formed mandibular ridge and accuracy of jaw relations are positive indicators for success. Patient neuroticism and a poorly formed mandibular ridge are negative indicators for success. Other prognostic indicators have not been shown to be of significant value. There exists a minority of patients who will never adapt to any conventional complete denture. This problem is more acute in the mandible than the maxilla. There is need for further research in this area. Summary Review/Restorative Dentistry Evidence-Based Dentistry (2010) 11, 48-49. doi:10.1038/sj.ebd.6400721 Implant-supported cantilevered fixed partial dentures Question: How do the survival and complication rates of implant-supported fixed partial dentures with cantilevers compare with implanted-supported single tooth and implanted-supported fixed partial dentures without cantilevers? Address for correspondence: José Zurdo, Institute for Postgraduate Dental Education, Greenbank Building, Room 304, University of Central Lancashire, Preston, Lancashire, UK. E-mail: firstname.lastname@example.org Ben Balevi1 1Private practitioner, affiliated with Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada Zurdo j, Romao C, Wennstrom JL. Survival and complication rates of implant-supported fixed partial dentures with cantilevers: a systematic review. Clin Oral Implant Res 2009; 20 (suppl. 4): S59-S66 Top of pageAbstract Data sources Medline was used to search for relevant material for the review. Study selection Systematic reviews and longitudinal prospective/ retrospective studies (randomised controlled trials, controlled clinical trials and cohort studies) were chosen that reported outcomes following treatment with implant-supported fixed partial denture prostheses (FPDP) with cantilever extensions, after a mean function time of at least 5 years. Two independent reviewers preformed screening and data abstraction. Data extraction and synthesis Five-year survival and technical complication rates were extracted, which included: loss of prosthesis, loss of implants, complications with supra-construction (fractures or deformations of the framework or veneers, loss of retention and screw or abutment loosening) and marginal bone loss. Data from included studies were pooled and summarised as a weighted mean. Disagreement regarding data extraction was resolved by discussion and consensus. Results Only three studies met the inclusion criteria for final analysis. Two of the studies had a prospective or retrospective case control design, whereas the third was a prospective cohort study. The 5-year survival rate of cantilever FPDP varied between 89.9 and 92.7% (weighted mean, 91.9%), with implant fracture as the main cause for failure. The corresponding survival rate for FPDP without cantilever extensions was 95.3 to 96.2% (weighted mean, 95.8%) . Technical complications related to the supra-construction in the three included studies were reported to occur at a frequency of 13-26% (weighted mean, 20.3%) for cantilever FPDP, compared with 0-12% (weighted mean, 9.7%) for noncantilever FPDP. The most common complications were minor porcelain fractures and bridge-screw loosening. For cantilever FPDP, the 5-year event-free survival rate varied between 66.7 and 79.2% (weighted mean, 71.7%) and between 83.1 and 96.3% (weighted mean, 85.9%) for noncantilever FPDP. No statistically significant differences were reported with regard to peri-implant bone-level change between the two prosthetic groups, either at the prosthesis or at the implant level. Conclusions Data on implant-supported FPDP with cantilever extensions are limited and therefore survival and complication rates should be interpreted with caution. The incorporation of cantilevers into implant-borne prostheses may be associated with a higher incidence of minor technical complications Summary Review/Restorative Dentistry Evidence-Based Dentistry (2010) 11, 50-51. doi:10.1038/sj.ebd.6400722 Survival rates of short-span implant-supported cantilever fixed dental prostheses Questions: What are the survival rates of short-span implant-supported cantilever fixed dental prostheses and the incidence of technical and biological complications over 5 years? Address for correspondence: Giovanni E Salvi, Department of Periodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, CH-3010 Bern, Switzerland. E-mail: email@example.com Gary L Stafford1 - 1Department of General Dental Sciences, Marquette University School of Dentistry, Milwaukee, Wisconsin, USA Aglietta M, Siciliano VI, Zwahlen M, et al. A systematic review of the survival and complication rates of implant supported fixed dental prostheses with cantilever extensions after an observation period of at least 5 years. Clin Oral Implant Res 2009; 20: 441-451 Data sources Publications were sought using Medline, and searches were made by hand of the journals Clinical Oral Implants Research, International Journal of Periodontics and Restorative Dentistry, Journal of Periodontology, Journal of Clinical Periodontology and the International Journal of Oral and Maxillofacial Implants, along with reference lists of identified articles. Study selection Titles and abstracts were initially screened by two independent reviewers to identify prospective or retrospective longitudinal cohort studies or controlled studies reporting on implantsupported cantilever fixed dental prostheses (ICFDP) with a mean followup period of at least 5 years. A clinical examination had to be performed at the end of the followup. For multiple publications reporting on the same population, only the most recent report was included. Data extraction and synthesis Data for the meta-analysis were extracted by two independent reviewers. Information regarding survival and complication rates of both implants and ICFDP were extracted. Implant survival was considered if the implant was present at the followup examination; ICFDP survival was considered if the prosthesis was present at the followup visit without any modifications . Peri-implantitis and soft tissue complications were included in the category of biological complications. As for technical complications, all the events affecting the implant and/ or the meso- and/ or the suprastructures' integrity were considered. Among them, the following categories were defined: implant fractures, veneer fractures, framework fractures, abutment or screw fractures, loss of retention and screw loosening. Results The five studies included in the meta-analysis yielded an estimated 5- and 10-year ICFDP cumulative survival rate of 94.3% [95% confidence interval (CI), 84.1-98%] and 88.9% (95% CI, 70.8- 96.1%), respectively. Five-year estimates for peri-implantitis were 5.4% (95% CI, 2.0-14.2%) and 9.4% (95% CI, 3.3-25.4%) at implant and prosthesis levels, respectively. Veneer fracture (5-year estimate; 10.3%; 95% CI, 3.9-26.6%) and screw loosening (5-year estimate, 8.2%; 95% CI, 3.9-17.0%) represented the most common complications, followed by loss of retention (5-year estimate, 5.7%; 95% CI,1.9-16.5%) and abutment/ screw fracture (5-year estimate, 2.1%; 95%CI, 0.9-5.1%). Implant fracture was rare (5-year estimate, 1.3%; 95% CI, 0.2-8.3%); no framework fracture was reported. Radiographic bone level changes did not yield statistically significant differences either at the prosthesis or at the implant levels when comparing ICFDP with short-span implant-supported end-abutment fixed dental prostheses. Conclusions ICFDP represent a predictable and reliable treatment for the replacement of posterior missing teeth in partially edentulous patients. The most frequent technical complications included veneer fractures, followed by screw loosening and loss of retention. No detrimental effects on bone levels were observed around implants in the proximity of cantilever extensions. To date, however, evidence is still sparse on the effects of various prosthetic designs (eg, distal or mesial cantilever extension), number of implants supporting ICFDP and occlusal concepts on the incidence of complications in ICFDP. Summary Review/Oral Surgery Evidence-Based Dentistry (2010) 11, 52-53. doi:10.1038/sj.ebd.6400723 Patients undergoing craniofacial tumour ablation surgery may benefit from having the implants placed simultaneously instead of waiting Question: What is the effectiveness of primary insertion of dental implants in people who have head and neck cancer? Address for correspondence: AJ Barber, Department of Restorative Dentistry, University of Bristol Dental Hospital, Lower Maudlin Street, Bristol BS1 2LY, UK. E-mail: firstname.lastname@example.org Asbjørn Jokstad1 1University of Toronto, Faculty of Dentistry, Toronto, Canada Barber AJ, Butterworth CJ, Rogers SN. Systematic review of primary osseointegrated dental implants in head and neck oncology. Br J Oral Maxillofac Surg 2010 Data Sources Medline, Embase and the Cochrane Library were searched for studies and the reference lists of the full-text articles were checked for any additional studies. Study selection Included studies were randomised clinical trials (RCT) and non-RCT, cohort studies, case control studies, case reports, or reviews that addressed the placement of dental implants at the same time as primary oncological resection in people suffering from cancer of the head and neck (primary implant insertion); or addressed benign or malignant tumours and the placement of implants into the native maxilla, mandible and zygoma, and grafted tissue. Articles were restricted to those written in English. The title and abstracts were reviewed independently by two reviewers. Data extraction and synthesis Data extraction was conducted independently and a qualitative synthesis of the data presented. Results Three case reports, 13 reviews, and 25 clinical studies were selected. Eight of the clinical studies referred solely to the insertion of dental implants at the time of primary oncological resection, and only two were of a prospective design. Conclusions Published studies concerning primary dental implants were concisely summarised, so that the collected evidence base surrounding this approach to oral rehabilitation could inform head and neck cancer teams, particularly oncological surgeons, restorative dentists, and maxillofacial prosthodontists. Summary Review/Restorative Dentistry Evidence-Based Dentistry (2010) 11, 54-55. doi:10.1038/sj.ebd.6400724 Surgical or nonsurgical treatment for teeth with existing root fillings? Questions: In symptomatic patients who have previously had endodontic treatment, is nonsurgical treatment more effective than endodontic surgery? Address for correspondence: Mahmoud Torabinejad, Endodontic Residency Program, Department of Endodontics, School of Dentistry, Loma Linda University, Loma Linda CA 92350, USA. E-mail: email@example.com Toru Naito1, 1Department of Geriatric Dentistry , Fukuoka Dental College, Tamura 2-15-1, Sawara, Fukuoka, Japan Torabinejad M, Corr R, Handysides R, Shabahang S. Outcomes of nonsurgical retreatment and endodontic surgery: a systematic review. J Endod 2009; 35: 930-937 Data sources Data was sought using Medline and the Cochrane Library, and relevant chapters from three major endodontic texts were consulted: Principles and Practice of Endodontics (4th Edn; editors; Torabinejad and Walton; 2008); Pathways of the Pulp (9th edition; editors, Cohen and Hargreaves; 2006), and Endodontics (6th edition; editors, Ingle, Bakland and Baumgartner; 2008). Every issue was also searched of the most recent 2 years of the following major endodontic journals: International Endodontic Journal; Journal of Endodontics; and Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology along with the reference lists of identified articles. Study selection Articles were included from peer-reviewed journals if they were published in English, and reported clinical and/or radiographic outcome data for nonsurgical endodontic retreatment or for endodontic surgery, with followup data for a minimum of 25 teeth and a minimum 2-year mean followup period. Studies reporting outcomes based on individual roots as opposed to whole teeth, or that did not report clinical or radiographic outcomes, which were animal studies, or studies that reported histological data only, were excluded. Data extraction and synthesis When necessary, the reviewers recalculated success and failure rates when they were not directly provided in papers' tables or in the text, or when only particular data subsets met the inclusion criteria. To facilitate meta-analysis, the data were standardised according to a commonly applied classification system used to assess outcomes for nonsurgical retreatment and surgical endodontics: (1) Complete healing; (2) Incomplete healing; (3) Uncertain healing; and (4) Unsatisfactory healing (failures). When uncertainty existed regarding which of the above four categories correlated with those reported in a given article, the data were assigned to the lower healing category. For this review, success was defined as teeth categorised as showing complete healing or incomplete healing. Weighted success rates, pooled success rates, and 95% confidence interval (CI) estimates of outcomes were generated in the metaanalysis from compiled data from the included studies by using the DerSimonian-Laird random effects pooling method. Results Twenty-six endodontic surgery and eight nonsurgical retreatment articles were included. There were only four randomised controlled trials (one in the nonsurgical retreatment, and three in the endodontic surgery group). A significantly higher success rate was found for endodontic surgery at 2–4 years (77.8%) than for nonsurgical retreatment for the same followup period (70.9%; P <0.05). At 4–6 years, however, this relationship was reversed, with nonsurgical retreatment showing a higher success rate of 83.0%, compared with 71.8% for endodontic surgery (P <0.05). Insufficient numbers of articles were available to make comparisons after 6 years of followup. Endodontic surgery studies showed a statistically significant decrease in success with each increasing followup interval (P <0.05). The weighted success for 2–4 years was 77.8%, which declined at 4–6 years to 71.8% and further declined at >6 years to 62.9% (P <0.05). Conversely, the nonsurgical retreatment success rates demonstrated a statistically significant increase in weighted success at 2–4 years (70.9%) versus 4–6 years (83.0%; P <0.05). Conclusions On the basis of these results it appears that endodontic surgery offers more favourable initial success, but nonsurgical retreatment offers a more favourable long-term outcome. Summary Review/Oral Medicine Evidence-Based Dentistry (2010) 11, 56. doi:10.1038/sj.ebd.6400725 Drug treatment for oral submucous fibrosis Question: What drugs can be used to treat oral submucous fibrosis? Address for correspondence: Dr J Hu, Department of Oral and Maxillofacial Surgery, West China College of Stomatology, Sichuan University, Chengdu 610041, China. E-mail: firstname.lastname@example.org Punnya V Angadi1, 1Department of Oral and Maxillofacial Pathology, KLE VK Institute of Dental Sciences and Hospital, Belgaum, Karnataka, India Jiang X, Hu J. Drug treatment of oral submucous fibrosis: a review of the literature. J Oral Maxillofac Surg 2009; 67: 1510-1515. Data sources Searches were made for relevant data using Medline and the International Poster Journal of Dentistry and Oral Medicine online database (see ipj.quintessenz.de). Study selection Meta-analyses, randomised controlled trials (RCT), clinical trials and other experimental designs were considered. Data extraction and synthesis Because of heterogeneity of study designs and drugs used, a qualitative synthesis was conducted. Results Seventeen publications were identified of which 15 were included. Of these, six were RCT, four were clinical trials/ controlled clinical trials, and five were other types experimental studies. The studies in total involved 1224 patients. The rate of those lost to followup reached 30% in some studies. The drugs used to treat oral submucous fibrosis (OSF) were categorised into steroids, enzymes, cardiovascular drugs, antioxidants, vitamins and microelements. Conclusions There are few high-quality studies available and the present drug treatments are in general empirical and treat only symptoms. There is a need for high-quality RCT in this area, especially studies involving combined and sequential therapy. Summary Case Control/Oral Cancer Evidence-Based Dentistry (2010) 11, 57-58. doi:10.1038/sj.ebd.6400726 Socioeconomic status and head and neck cancer Question: What are the socioeconomic risk factors for head and neck cancers? Address for correspondence: David I Conway, University of Glasgow, Faculty of Medicine, Dental School, Community Oral Health Section, 378 Sauchiehall Street, Glasgow G2 3JZ, Scotland, UK. E-mail: email@example.com Imad Al-Dakkak1, 1Centre for Evidence-based Dentistry, Oxford, UK Conway DI, McMahon AD, Smith K, et al. Components of socioeconomic risk associated with head and neck cancer: a population-based case control study in Scotland. Br J Oral Maxillofac Surg 2010; 48: 11-17 Design This was a population-based case control study. Case control selection Eligible patients were aged between 18 and 80 years and had a primary histopathological diagnosis made between April 2002 and December 2004. Diagnosis included malignant cancers of the oral cavity, oropharynx, hypopharynx or larynx. Incident cases were identified through weekly monitoring of head and neck cancer clinics in hospital departments and were confirmed by pathology department records. Controls matched by age (5-year age band) and sex were randomly selected from the lists of general practitioners. Data analysis Information about occupation, education, smoking and alcohol consumption was collected at personal interview. Socioeconomic circumstances were measured at an individual level (education, occupational social class, unemployment), and by areabased measures of deprivation. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were computed by unconditional logistic regression and were adjusted for age and sex. This model was repeated to assess for potential independent effects of the range of socioeconomic components after adjusting for smoking and alcohol consumption. Interactions between smoking and consumption of alcohol, and between individual and area-based measures for socioeconomic factors were tested by the likelihood ratio test. In addition, the most important behavioural risk factors and socioeconomic variables were entered into a stepwise multivariate logistic regression model. All statistical analyses were carried out using Statistical Analysis System (SAS; Cary, North Carolina, USA) software. Results The study population included 103 cancer patients (38 women and 65 men), and 91 controls (39 women and 52 men) Individuals living in the most deprived areas (OR, 4.66; 95% CI, 1.79 12.18) and those who were unemployed (OR, 2.27; 95% CI, 1.21 4.26) had a significantly higher risk of cancer than people who had high levels of educational attainment (OR, 0.17; 95% CI, 0.05 0.58). Significance was lost for all measures of social class when adjustments were made for smoking and consumption of alcohol. When the most important behavioural and socioeconomic factors were combined in a fully adjusted multivariate analysis, smoking was the only significant risk factor (OR, 15.53; 95% CI, 5.36 44.99) found to be independently associated with head and neck cancers. Conclusions A high risk of head and neck cancer was consistently associated with poor socioeconomic circumstances. There were strong links for specific components but smoking dominated the overall profile of risk. More detailed research into the nature of such associations is needed in the future.