Effect of Voxel Size on Cone‐Beam Computed Tomography‐Based Assessment of Root Canal Anatomy: A Systematic Review and Meta‐Analysis

ABSTRACT Introduction Cone‐beam computed tomography (CBCT) has become an integral part of endodontic diagnosis and treatment, with voxel size being a critical parameter affecting spatial resolution and diagnostic outcomes. This systematic review and meta‐analysis examined the effect of voxel size on the diagnostic outcome of CBCT images for root canal anatomy assessment. Methods A search was conducted in PubMed, Web of Science, Embase, and Scopus databases without date restrictions. Studies comparing different CBCT voxel sizes for root canal anatomy evaluation using quantitative diagnostic outcomes were included. Two reviewers independently performed study selection, data extraction, and quality assessment using QUADAS‐2. Meta‐analysis was conducted using random‐effects models with subgroup analysis by voxel size categories (≤ 125 μm and > 125 μm). Results Fifteen studies met the inclusion criteria, evaluating voxel sizes from 75 to 400 μm across various anatomical structures. Seven studies were included in the meta‐analysis. Individual studies consistently demonstrated improved visualisation with smaller voxel sizes, particularly for larger structures such as second mesiobuccal canals in maxillary molars. Overall pooled diagnostic accuracy was 80% (95% CI: 75%–84%) with substantial heterogeneity ( I 2 = 86.74%). Subgroup analysis showed diagnostic accuracy of 75% (95% CI: 68%–82%) for voxel sizes > 125 μm and 85% (95% CI: 80%–90%) for voxel sizes ≤ 125 μm. The difference between the two groups was statistically significant ( p = 0.002). Moreover, meta‐regression showed a statistically significant association between voxel size and diagnostic accuracy ( p = 0.0086). Conclusions The current study's findings suggest that there is an association between reducing the voxel size and enhancing the diagnostic outcome of CBCT images in assessing root canal anatomy. Although the meta‐regression showed a statistically significant correlation, the results should be interpreted cautiously because of methodological heterogeneity, the complex interplay of imaging parameters beyond voxel size alone, and the lack of clinical studies. Future research should focus on standardised clinical studies to examine the impact of voxel size on the diagnostic outcome of CBCT images.