Background <p>Locating calcified canals in teeth with pulp canal obliteration remains particularly challenging. The absence of data from randomized controlled trials conducted in vivo has been a critical gap. The objective of this study was to comprehensively assess the accuracy of static-guided endodontics in addressing the challenges of pulp canal obliteration through a randomized controlled clinical trial, as well as pain during treatment and clinical outcomes.</p> Methods <p>Eighty patients with pulp canal obliteration were selected from July 2020 to March 2022 and randomly divided into two groups. In the freehand group, patients underwent contemporary freehand access cavity preparation. Patients in the static-guided group underwent innovative access cavity preparation using three-dimensional-printed endodontic guides for precise root canal localization. The quantitative accuracy was subsequently evaluated through meticulous assessment of indirect impression scans obtained from the access cavities. Moreover, pain during treatment and clinical outcome were investigated.</p> Results <p>All participants were randomly assigned to treatment groups. The static-guided group showed high accuracy, with average deviations of 0.14 ± 0.08&#xa0;mm at the coronal entry point, 0.35 ± 0.16&#xa0;mm at the apical point, and an angular deviation of 1.75 ± 0.30 °. These deviations were significantly lower than those in the freehand group (<i>P</i> &lt; 0.0001). No significant difference were found between the groups regarding pain during treatment and clinical outcomes after one year (<i>P</i> &gt; 0.05).</p> Conclusion <p>This study demonstrates, within its limitations, the static endodontics guides represent an accurate method in locating root canals for pulp canal obliteration through a randomized controlled clinical trial.</p> Trial registration <p>The Chinese Clinical Trial Registry, NO. ChiCTR2000037260 (27/08/2020, retrospectively registered).</p>