INTRODUCTION: This study aimed to determine the correlation between proximal caries and the extent and site of pulp canal obliteration (PCO) in cone-beam computed tomographic (CBCT) scans of mandibular molar teeth. METHODS: A total of 1491 CBCT scans of patients 18-49 years of age were selected from the database (2002-2022). From them, 328 teeth with proximal caries and satisfying inclusion criteria were evaluated by 2 calibrated evaluators. PCO was observed in the sagittal and coronal planes. PCO and proximal caries were compared concerning different age groups, sexes, and sites using an independent sample t test. RESULTS: The prevalence of PCO among patients with proximal caries is 47%. In mesial proximal caries, the extent of PCO is significantly greater in the distal root canal (73.4%), whereas in distal proximal caries, PCO is more often found in the mesial canal (77.3%). The mean extent of intraradicular calcification was higher in the distal canal (P <
.001). Moreover, mesial proximal caries showed a greater extent of intraradicular obliteration (P <
.001). The probability of developing PCO was significantly higher in females (P = .003). CONCLUSIONS: Within the limitations of this study, it can be concluded that the extent of calcification is more common on the opposite side of the location of the proximal caries. Moreover, such intraradicular calcification is greater in a distal canal compared to a mesial canal. Sex plays a significant role in the calcification process, showing higher predilection in females compared to males.