title: Strength of recommendation for single-visit root canal treatment: grading the body of the evidence using a patient-centred approach.
abstract: OBJECTIVE
  To identify, search for and critically interpret the results from clinical studies on single- versus multiple-visit root canal treatment in the light of an evidence-based paradigm. For that purpose, the quality of the available body of evidence was assessed using the SORT 'grade' - Strength of Recommendation Taxonomy.
  
  
  METHODS
  A protocol was followed including all aspects of the review methods: (i) search strategy, (ii) inclusion criteria for studies, (iii) screening methods, (iv) quality assessment, (v) data synthesis of the selected studies, and (vi) the assessment of quality of the body of evidence available by the means of the SORT 'grade'. An extensive search of recent biomedical literature was performed in PubMed (up to May, 2014), EMBASE (dating from 1980 to May 2014) and Cochrane databases with appropriate headings and keywords related to single- and multiple-visit root canal treatment. Selected studies were stratified according to their level of evidence using the SORT criteria: (i) quality - Level A high-quality evidence, Level B medium/low-quality evidence and Level C no evidence; (ii) degree of consistency - consistent, when most studies found a similar conclusion, or inconsistent, when there was considerable variation amongst study findings.
  
  
  RESULTS
  After the digital and manual searches, 246 studies were indentified. Two hundred and seven studies were eliminated by exclusion criteria, resulting in a yield of 39 articles that were selected for retrieval. Of the 39 articles, only 11 could be classified as Level 2 (B); the other 28 articles did not obey the criteria to be considered as real patient-oriented evidence; thus, they were classified as Level 3 (C). No studies were ranked as Level 1 because they did not obey the minimum standard to be considered as both good-quality research and patient-oriented evidence. Despite this, all of the selected Level B studies reported no significant differences between single- and multiple-visit treatments.
  
  
  CONCLUSIONS
  There is B-level (mid-level) evidence to confirm there is no difference between the two different treatments, based on research addressing clinical outcomes and using some consistent but limited-quality methods of scientific investigation. More studies focused on evaluating patient-centred outcomes are urgently required.
authors.affiliation: Federal Fluminense University (UFF), Niterói, Brazil.
authors.forename: G
authors.initials: G
authors.lastname: De-Deus
authors.affiliation: Department of Periodontology, Veiga de Almeida University (UVA), Rio de Janeiro, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Canabarro
mesh_terms: D004708:Endodontics / Q000379:methods; D055094:Evidence-Based Dentistry; D006801:Humans; D018802:Patient-Centered Care; D012390:Root Canal Therapy / Q000379:methods*
keywords: evidence-based dentistry; multiple-visit; patient-centred approach; root canal treatment; single-visit; strength of recommendation