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Title Apex Locator Gives Similar Results as Periapical Radiograph for Working Length Determination in Endodontic Treatment
Clinical Question Does using an apex locator gives more accurate measurements than using conventional periapical radiographs in measuring working length in endodontic treatment?
Clinical Bottom Line For root canal treatment of permanent teeth or pulpectomy of primary teeth, using either apex locator or periapical radiograph will give similar results in measuring the working length. This is supported by few clinical studies which also agreed that apex locator would give extra benefit by reducing exposure to radiation, less time and minimize the cost compared to radiography.
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 22193485Jarad/201146 adult patients with minimal and moderate difficulty of proposed tooth required root canal treatments according to the American Association of Endodontics Pilot randomized controlled clinical trial
Key resultsNo significant difference was found between working lengths determined using apex locator (AL) combined with a master cone GP radiograph or using periapical radiograph (PA). Inter and intra-examiner reliability: kappa= 0.8 & 0.89, respectively with acceptable measurements were 91% for AL and 74% for PA. Mean length from the tip of the master cone GP to radiographic apex was 1.06 mm (SD=0.67) for AL compared to 1.23 (SD=0.73) for PA group (mean difference-0.18mm, 99% confidence interval - 0.60 to 0.25). The differences were not statistically significance at the 5% level.
#2) 20951282Ravanshad/201084 teeth with 188 canals from patients aged 20 to 65 years old who presented for primary endodontic therapy.Consort randomized clinical trial
Key resultsThe measurement using electronic apex locator (group 2) is comparable to radiographic length measurement (group 1) and better in reducing overestimation. The acceptable cases: master cone radiography (group 2=90.4% and group 1= 82.1%); final radiography (group 2=90.4% and group 1 = 85.7) and short cases: master cone radiography (group 2=8.7% and group 1= 7.1%); final radiography (group 2=1% and group 1 = 1.2). Overestimation were 10.7% in group 1 whereas only 1% in group 2(χ2, p = 0.00). No significant difference for final obturation where group 1=13.1% and group 2=8.7%.
#3) 22016313Neena/201190 canals from 30 primary teeth indicated for pulpectomy in patients age 5-11 yearsIn-vivo prospective within subjects comparative study
Key resultsApex locator is comparable to conventional radiographs in determining the working length in the primary teeth. There is no significant difference in the mean root length measurements from the three techniques: apex locator = 11.79 (SD=1.70), digital radiography = 11.98 (SD=1.70) and conventional radiograph = 11.76 (SD=1.67) (P > 0.05).
Evidence Search Apex locator[All Fields]) AND periapical radiograph (All Fields) AND endodontics[MeSH Terms] AND therapy[All Fields] OR treatment[All Fields] and related citations (Jarad)
Comments on
The Evidence
Validity: The randomized clinical trial studies were done in well controlled, blinded and randomized. None of the studies did mention sensitivity, specificity, PPV or NPV; so a quantitative assessment of the validity is unknown. The gold standard is acceptable when all use conventional radiograph which is reliable and reproducible. Perspective: All three studies are clinical studies which are good for showing what might happen in clinical practice rather than just simulation. Ravanshad used a bisecting technique for taking periapical radiograph which is less reproducible than paralleling technique and might have affected the results. The studies considered many factors such as the use of latest generation of apex locator and the film type. All three studies agree that the use of apex locator will give similar result as conventional radiograph in determination of working length.
Applicability Apex locators should be used routinely to minimize radiation exposure to patients, especially children, when taking periapical radiographs during endodontic therapy. Their use could also minimize the timing of treatment, difficulty in technique, cost of device and complex room set-up for radiology and high maintenance of the radiograph system. The price of apex locator is also reasonably affordable by general practitioner.
Specialty/Discipline (Endodontics) (General Dentistry) (Restorative Dentistry)
Keywords Apex locator, periapical radiograph, endodontic treatment
ID# 2539
Date of submission: 08/01/2013spacer
E-mail wanbaker@uthscsa.edu
Author Wan Zaripah Wan Bakar
Co-author(s) Erin Wyrick
Co-author(s) e-mail wyrick@livemail.uthscsa.edu
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