Endodontic treatment aims to retain teeth, by maintaining pulp vitality and/or health of periapical tissues by preventing and treating infection, and comprises a fundamental part of everyday dental practice. The scope of the treatment includes, but is not limited to, non-surgical and surgical root canal treatment (RCTx) and vital pulp treatment (VPT).
RCTx is indicated in teeth in which the dental pulp is severely inflamed (irreversible pulpitis) or when the pulp becomes necrotic with or without infection [1]. The treatment involves removing infection primarily from the root canal system, by cleaning, shaping and filling of the root canals. Although complex, the treatment is highly successful when performed to a high standard [2][3]. The outcome of RCTx is generally assessed by clinical and radiographic examination using a range of criteria. These assessment tools are largely clinician-centred, rather than patient-centred. If primary RCTx fails, teeth can be retreated conventionally or surgically. The outcomes of retreatment are assessed in the same way as primary treatment, with clinical and radiographic examination using various criteria [4]. Some studies reporting outcomes of surgical and non-surgical RCTx use clinical and radiographic criteria individually or as a combined outcome [2][5]. Others have reported tooth survival or need for further treatment as the outcome [6]. Within the clinical criteria, there is often marked variation in the way clinical outcomes are reported. Radiographic examination is often carried out using conventional imaging, but recently outcomes are also reported using cone beam tomography (CBCT) [7]. There is marked heterogeneity in the reporting of outcomes in published studies and a lack of consistency in reporting the outcomes of randomised controlled trials (RCT).
VPT is a re-emerging minimally invasive endodontic treatment that aims to maintain vitality of all or part of the dental pulp. There are two main VPT modalities for treating teeth with deep caries and compromised pulp; pulp capping and pulpotomy. Pulp capping (direct or indirect) is a type of VPT generally indicated for teeth with deep caries in which the pulp is not pathologically exposed or is mildly symptomatic [8]. Pulpotomy is indicated for teeth in which the pulp is cariously-exposed, and the procedure involves removal of a small part of the inflamed pulp (partial pulpotomy) or amputation of the coronal pulp (complete pulpotomy) depending on the extent of inflammation and patient symptoms [8]. The outcome of VPT depends on the treatment modality and, as with RCTx, various outcomes including clinical and radiographic outcomes are reported to indicate its success; but with a lack of standardised outcome measures.
A biologically based endodontic therapy known as revascularization or revitalization that aims to promote normal physiological development in immature permanent teeth with pulpal necrosis is an emerging endodontic treatment modality [9]. Like other endodontic treatments, various outcomes are reported for revascularisation procedure that are mainly clinician focused with no consensus [10].
The absence of standardised outcomes is reflected in the quality of many systematic reviews reporting the effects of endodontic treatment [2][11][12] and has been acknowledged in the European Society of Endodontology (ESE) position statement on the management of deep caries and exposed pulp [8]. For RCTx, the principal outcome reported is periapical health, diagnosed clinically and radiographically. The same also applies to surgical endodontics where healing of periapical tissue is generally regarded as an important outcome. In VPT, maintenance of pulp vitality is considered the primary outcome. There are, however, other outcomes that are often inconsistently reported including tooth survival [13][6], integrity of restoration, pathological changes (calcification, resorption etc.) [14], and patient reported outcomes such as symptoms and oral health related quality of life measures (OHRQoL).
Why are core outcome sets important in Endodontics?
Core outcome sets (COS) are defined as an agreed standardised set of outcomes that should be measured and reported as a minimum in all trials in a particular field [15]. COS should be registered to support the selection of outcomes and outcome measures in clinical trials, the delivery of routine care [16] and the quality of systematic reviews [17].
The selection of appropriate outcomes is essential if clinical studies are to enable direct comparison between the effects of different interventions with minimal bias. Development and implementation of COS minimise bias in the selection and reporting of outcomes, thereby facilitating evidence synthesis for systematic reviews [18][15]. Indeed, the bulk of the systematic reviews on the outcome of endodontic treatment reported problems when comparing outcome measures [2][19][11]. Outcome reporting bias is likely to affect not only systematic reviews but applies to published research in general, with a resultant negative impact on clinical guideline development and ultimately patient care. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) group, supported by Cochrane [20] and the World Health Organization (WHO) [21] for the development of guideline recommendations recognizes the need to identify a relevant COS for use in the research that will underpin those recommendations.
In dentistry, COS has been or is being developed for various dental treatments including traumatic dental injuries [22], periodontology [23] and orthodontics [24]. Endodontology is an important field in dentistry for which COS are needed. Recently the ESE developed a focused but limited COS for S3 level clinical practice guidelines [25] This process was limited to the guideline steering group and was not representative of all stakeholders particularly, service users and patients. There is therefore a need for the development of COS which include full representation of stakeholders so that clinicians, researchers, patients, the general public, policymakers, and public health professionals will benefit.
Aim
The aim of this study is to develop a COS suitable for assessing endodontic treatment outcomes after any form of endodontic treatment including non-surgical and surgical RCTx, VPT and revitalisation procedures.
Scope
The COS is designed for use in both research and clinical practice, including any health-care setting in which endodontic treatment for adults with pulpal and periapical disease is carried out.
Objectives
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Perform scoping reviews to identify a list of potentially important outcomes from published studies investigating various endodontic treatment modalities.
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Identify a list of potentially important outcomes reported by patients in semi-structured interviews to augment the list generated from the scoping review process.
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To reach consensus regarding the most important outcomes from the perspective of patients and clinicians by using consensus.
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To identify appropriate outcome measurement instruments (OMIs) to be used in the reporting of the COS and the appropriate time points at which the outcomes should be measured.