Effect of the voxel size on the accuracy of endodontic length measurements using cone-beam computed tomography: A systematic review conducted according to the PRISMA guidelines and Cochrane Handbook for Systematic Reviews of Interventions.

Abstract

Background: The accurate determination of the working length (WL) is imperative for endodontic success.

Objectives: Our objective was to systematically analyze the available evidence on the impact of voxel size variation on the estimation of WL using cone-beam computed tomography (CBCT).

Material and methods: An electronic search of the PubMed, Scopus, Embase, and Web of Science databases was conducted according to specific inclusion and exclusion criteria in March 2022. Studies published in English, comparing the influence of 2 or more voxel sizes on the CBCT assessments of WL in human teeth against physical or electronic methods qualified for inclusion. Multiple authors independently carried out study selection, data extraction and quality assessment.

Results: We included 4 studies involving the assessment of 220 teeth. There were some concerns with regard to the risk of bias in all studies, owing to methodological insufficiencies. Voxel sizes can affect the accuracy of CBCT measurements. All 4 studies reported that the voxel size in CBCT measurements was closely correlated with the estimation of WL. The smallest voxel sizes showed a greater correlation with the actual length (AL). Larger voxel sizes can reduce accuracy by ±0.05 mm. The differences may be clinically irrelevant. Cone-beam computed tomography assessments correlate strongly with the endodontic WL as measured by electronic apex locators (EALs), but are associated with a larger radiation dose in comparison with periapical radiographs.

Conclusions: Based on the limited evidence available, it can be stated with low certainty that voxel sizes may impact CBCT accuracy. However, the differences may be clinically irrelevant. The pre-existing CBCT scans may be useful in the estimation of WL, rather than additional periapical radiographs.