Benefits of Using Magnification in Access Cavity Preparation by Undergraduate Dental Students: A Micro-Computed Tomography Study

Introduction: Access cavity preparation is a critical step in endodontic treatment, impacting the success of subsequent procedures. Magnification devices are proposed to improve visualisation and precision, but their effectiveness among undergraduate students remains largely unexplored. This study evaluated the benefits of magnification on access cavity preparation accuracy by undergraduate dental students using Micro-computed tomography (Micro-CT) imaging for quantitative assessment. Methods: Thirty-two undergraduate dental students participated, performing access cavity preparations on plastic maxillary molars under three conditions: unaided vision (group 1), dental loupes (group 2) and a dental operative microscope (DOM) (group 3). Micro-CT scans were used to evaluate the quality and accuracy of the access cavities. Results: The DOM group exhibited the highest percentage of proper access cavity outlines (50.0%) and ideal locations (78.1%). However, no significant differences were found in preparation time (p = 0.274) or gouging frequency (p = 0.139) across groups. Gouging size also showed no significant difference (p = 0.839). Complete removal of the pulp chamber roof was comparable in the loupes and dom groups (both 34.4%) and slightly higher than that in the no-magnification group (25%), with no significant difference in residual pulpal roof thickness among groups (p = 0.477). Conclusion: Magnification enhances access cavity preparation precision and quality in undergraduate students. To further validate these findings and inform best practices in dental education, larger-scale studies and clinical trials are needed.