A systematic review of methods used to sample and analyse periradicular tissue fluid during root canal treatment

Abstract

Aim The primary aim was to identify techniques used to sample and analyse periradicular tissue fluid (PTF) in permanent teeth diagnosed with apical disease during root canal treatment. Secondly, to identify the types of inflammatory mediators studied using this approach. Methodology Data Sources: PubMed, EMBASE, Cochrane Library, Science Direct, Web of Science and OpenGrey. Eligibility Criteria: Clinical studies published until 1 June 2018 which utilized orthograde techniques to sample and analyse PTF were included. Cell culture, laboratory or animal studies and those concerned with investigating inflammatory mediator activity from within healthy or diseased pulp tissue, and not periradicular tissues, were excluded. Study appraisal and methods: In accordance with PRISMA guidelines, data were extracted on study characteristics, target mediators, sampling and assay techniques and the parameters associated with the PTF sampling and eluting protocol. A qualitative synthesis was conducted, and studies were critically appraised using a modified version of the Cochrane risk of bias tool. Results Study Characteristics: From 251 studies, 33 were eligible for inclusion. Sampling techniques included the use of paper points (n = 27), fine needle aspiration (n = 4) and filter strips (n = 2). Assay techniques included enzyme‐linked immunosorbent assay (n = 18), quantitative polymerase chain reaction (n = 9), radioimmunoassay (n = 4), colorimetric assay (n = 2), immunofluorometric assay (n = 1) and cytometric bead array (n = 1). Forty‐five different inflammatory mediators were targeted at the proteomic/metabolomic (n = 25) or transcriptomic level (n = 9). Limitations: Significant heterogeneity exists within the methodology, and only 5 studies disclosed unambiguous information about their PTF sampling and eluting protocols. Conclusions Paper points and proteomic/metabolomic analysis are currently the preferred methods for studying and analysing PTF during root canal treatment. The most studied analytes were IL‐1β and TNF‐α. Implications: Further research is required to develop an optimized PTF sampling and eluting protocol to overcome methodological heterogeneity, and future studies are advised to follow a standardized approach to reporting their methodology.

Clinical influence of calcium hydroxide and N‐acetylcysteine on the levels of resolvins E1 and D2 in apical periodontitis

“…2015, 2016, 2018, Virdee et al . 2019). Safavi & Rossomando (1991) were the first study to sample PTF to investigate inflammatory mediators sampled through the root canal using a paper point.…”

“…More recently, in a systematic review, Virdee et al . (2019) reported that although several other methods have been explored, such as direct surgical access, fine needle aspiration and absorption with methylcellulose filter points, paper points remain the most commonly used approach. Traditional methods such as direct surgical access are invasive, technique sensitive, and do not permit longitudinal analyses (Torabinejad et al .…”

Preferred reporting items for systematic reviews and meta‐analyses for abstracts: best practice for reporting abstracts of systematic reviews in Endodontology

“…Cell culture, laboratory or animal studies and those concerned with investigating inflammatory mediator activity from within healthy or diseased pulp tissue, and not periradicular tissues, were excluded’ (Virdee et al . ). Example 3c : ‘Three electronic databases (Medline, Embase and PubMed) were searched to identify human studies from 1966 to October 2009 in 5 different languages (English, French, German, Italian and Spanish)’ (Setzer et al . ). Example 3d : ‘A literature search was performed in the MEDLINE and EBSCOhost databases until June 2017 with no language restriction’ (Nagendrababu et al .…”

“…Cell culture, laboratory or animal studies and those concerned with investigating inflammatory mediator activity from within healthy or diseased pulp tissue, and not periradicular tissues, were excluded’ (Virdee et al . ).…”

Therapeutic irrigation procedures to treat apical periodontitis - TIPTAP

“…A recent literature review conducted by our group has revealed the most common approach for sampling and analysing the concentrations of periradicular inflammatory mediators during NSRCT is using paper points and proteomic molecular analysis techniques respectively (Virdee et al 2019). Through in vitro experimentation, our group has optimised the sampling and elution procedure so that the maximum amount of PTF is absorbed onto the paper point, and the maximum amount of cytokine is recovered during elution.…”