Title The presence of different irrigants in the root canal system can affect working length determination during root canal treatment.
Clinical Question For a patient receiving root canal treatment, does the absence of an irrigant in the root canal system result in successful determination of accurate working length compared to the presence of an irrigant?
Clinical Bottom Line For a patient receiving root canal treatment, the absence of an irrigant in root canal system is better for determining working length compared to the presence of an irrigant.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
26409810Tsesis/201510 studies including 1105 electronic apex locator (EAL) measurements using 4 EALs.Systematic Review and Meta-Analysis
Key resultsThis authors of this systematic review conducted a literature search between 1966 and January 2014 to evaluate the precision of electronic apex locators (EAL) for determining the apical constriction compared to a histologic evaluation of the apical constriction, while considering factors that could influence the results, including but not limited to the presence of endodontic irrigants. From 247 articles, 10 were chosen and included results from 4 EALs: Root ZX, Justy II, Endy 5000, Endox. One of the influencing factors evaluated and discussed was the presence irrigant and its effect on precise working length. Only two of the four apex locators (Root ZX and Justy II) were studied in the presence of irrigants: NaOCl and H2O2. The Root ZX measurements were further away from the apical constriction when compared to the Jusy II. Additionally, for both EALs, the distance measured between the file tip and the apical constriction was significantly shorter in the presence of H2O2 than in the presence of NaOCl with p<0.05. The authors claim the validity of this data to be higher due to the histological evaluation of the actual apical constriction, which was not performed in the other studies.
23551276Duran-Sindreu/201332 single-rooted human teeth scheduled for extractionRandomized Controlled Trial
Key resultsThis randomized controlled trial was performed on vital single rooted teeth planned for extraction for periodontal, prosthetic, endodontic or orthodontic reasons. All teeth were free of metallic restorations, fractures, root resorption or open apices. Two electronic apex locators, Root ZX and iPex, were tested in the presence of 2.5% NaOCl and 2.0% CHX endodontic irrigants. When evaluating the effect of the irrigants, the working lengths in the presence of either irrigant did not differ significantly for either apex locator (P>.05). However, when comparing one apex locator to the other, the iPex was considered to be significantly less accurate than the Root ZX with both irrigants (p<.05).
Evidence Search (("work"[MeSH Terms] OR "work"[All Fields] OR "working"[All Fields]) AND length[All Fields] AND ("analysis"[Subheading] OR "analysis"[All Fields] OR "determination"[All Fields]) AND ("dental pulp cavity"[MeSH Terms] OR ("dental"[All Fields] AND "pulp"[All Fields] AND "cavity"[All Fields]) OR "dental pulp cavity"[All Fields] OR ("root"[All Fields] AND "canal"[All Fields]) OR "root canal"[All Fields])) AND (systematic[sb] OR Meta-Analysis[ptyp]) (("work"[MeSH Terms] OR "work"[All Fields] OR "working"[All Fields]) AND length[All Fields] AND irrigant[All Fields] AND ("dental pulp cavity"[MeSH Terms] OR ("dental"[All Fields] AND "pulp"[All Fields] AND "cavity"[All Fields]) OR "dental pulp cavity"[All Fields] OR ("root"[All Fields] AND "canal"[All Fields]) OR "root canal"[All Fields])) AND (systematic[sb] OR Meta-Analysis[ptyp] OR Randomized Controlled Trial[ptyp])
Comments on
The Evidence
Validity: The first article is the highest level of evidence as a systematic review and meta-analysis. The search for articles included strict exclusion criteria and the abstracts of eligible articles were evaluated by two reviewers to select a preliminary list. Full text of eligible studies was read and the data was extracted independently by two reviewers. The selection criteria were well established and parameters such as allocation concealment, blinding, selection bias and sample size were verified before inclusion. The authors considered 3 out of 10 studies to have a low risk of bias, and 7 out of 10 studies to have a high risk of bias based on blinding of the outcome assessment. Meta-analysis was completed on the results of the data to conclude that the precision of the working length depends on the device used and the irrigant in the root canal system (H2O2 vs NaOCl). The second study was a randomized control trial with adequate exclusion criteria including metal restorations, root resorption, open apices, toot fractures and non-vital teeth. Type of irrigant was randomized but whether the operator was blinded to the irrigant was not indicated and the method of statistical analysis was not described. Perspective: The systematic review discusses the importance of keeping the root canal treatment within the root canal system, but does not specify the generally accepted value of 0.5 mm from the apex as being the gold standard for instrumentation and obturation in most cases. Although the two irrigants led to significantly different readings of the working length from each other, they both gave readings within 0.5 mm of the apical constriction, which is the standard established by endodontic literature. If a practitioner is unable to determine a precise working length with the apex locator in the presence of an irrigant, then it is recommended to dry the root canal system with a micro-suction and paper points and reattempt obtaining a working length.
Applicability This topic is applicable for dental practitioners performing endodontic treatment. The current gold standard is a working length to 0.5mm from the apical constriction. The evidence cited confirms this standard for both irrigants however, authors continue to recommend radiographic verification of apex as best practice.
Specialty (Endodontics) (General Dentistry)
Keywords Root canal, working length determination, irrigant
ID# 3301
Date of submission 12/11/2017
E-mail sandhusk@livemail.uthscsa.edu
Author Sukhpreet Sandhu, DDS
Co-author(s) Tyler Hawkins, DMD
Co-author(s) e-mail hawkinstk@livemail.uthscsa.edu
Faculty mentor
Faculty mentor e-mail
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
Comments and Evidence-Based Updates on the CAT
None available