Evidence map›Paper›PMID 41555346›Full record

ArticleBMC oral health2026

Electronic apex locator 'apical constriction' reading versus micro-computed tomography landmarks in molars: an in vitro study.

Hongtao Hu, Mingwen Liu, Jingwen Yang, Lingxin Zhu, Yi Min, Qian Yang

Abstract readComparative Study
In one paragraph

Article in BMC oral health, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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4 · The record

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5 · Who and what money

Authors and funding

6 authors.

Hongtao HuState Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China.
Mingwen LiuState Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China.
Jingwen YangState Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China.
Lingxin ZhuState Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China.
Yi MinState Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China. minyi795@whu.edu.cn.
Qian YangState Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China. yangqianendo@whu.edu.cn.

Funding

the Natural Science Foundation of Hubei Province of China No. 2024AFB721
6 · The paper itself

Abstract

backgroundThe aim of this in vitro study was to use micro-computed tomography (µCT) to determine the anatomical position corresponding to the 'apical constriction' (AC) reading of three different electronic apex locators (EALs) in extracted human molars. MATERIALS AND

methodsFifty-six extracted human molars (138 canals) were scanned using µCT to assess apical morphology (presence/absence of a single AC) and, for canals with a single AC, to measure the distance from the major apical foramen (AF) to the narrowest diameter (Md). Using a modified mounting model (MM), the distance from the AF to the EAL's 'AC' reading (Ld) was measured for three devices: Root ZX II, Raypex 6, and Elements Apex Locator. Ld values were compared among the EALs within morphological subgroups using one-way analysis of variance (ANOVA) and the Least Significant Difference (LSD) post-hoc test. Significance was set at P < 0.05.

resultsNo statistically significant differences were found among the mean Ld readings of the three EALs, either overall or within the 'AC present' and 'AC absent' morphological subgroups (P > 0.05). Within the 'AC present' group, mean Ld values for the Elements Apex Locator and Raypex 6 were significantly shorter (coronal) than the mean µCT-measured distance Md (P = 0.005 and P = 0.008, respectively). In contrast, the mean Ld for Root ZX II did not differ significantly from the mean Md (P = 0.095).

conclusionsThe 'AC' reading of the three EALs generally indicated a position slightly coronal to the major apical foramen, irrespective of AC presence. While the three EALs provided comparable readings relative to each other, their accuracy in corresponding to the anatomical AC (when present) varied in this in vitro model, with Root ZX II showing closer agreement with µCT findings.

Indexed as

Dental Pulp CavityMolarOdontometryTooth ApexX-Ray MicrotomographyHumansIn Vitro TechniquesRoot Canal PreparationApical constrictionElectronic apex locatorMicro-computed tomographyMolarRoot canal anatomy

Identifiers

PMID41555346
PMCPMC12905839

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.