CBCT-Based Volumetric Assessment of Tooth Roots in the Context of Alveolar Ridge Preservation

Background/Objectives: Alveolar ridge preservation (ARP) is commonly performed following tooth extraction to minimize post-extraction dimensional changes. However, limited information is available regarding root-volume variations among different tooth types. This study aimed to assess the root volumes of maxillary and mandibular teeth using cone-beam computed tomography (CBCT) and to compare the measured root volumes with commonly available graft-material package volumes in the context of ARP. Methods: CBCT scans from 53 patients meeting the eligibility criteria were retrospectively evaluated. Fourteen teeth per scan were assessed using a split-mouth approach, resulting in a total of 742 teeth. Root boundaries were identified by two trained and calibrated dentists, and root volumes were calculated using OsiriX MD v13.0.3 software. Statistical comparisons were performed using paired and independent t-tests. Results: Root volumes varied according to tooth type and arch. The maxillary first molar demonstrated the highest mean root volume (0.55 ± 0.10 cm3), whereas the mandibular central incisor demonstrated the lowest (0.11 ± 0.02 cm3). Maxillary teeth showed significantly greater root volumes than their mandibular counterparts. Gender-related differences were limited to the maxillary second premolar and mandibular second molar and were considered of limited clinical relevance. For illustrative comparison, the measured root volumes were considered in relation to commonly available graft-material package volumes, including 0.25 and 0.50 cc; these comparisons do not represent clinically validated graft requirements. Conclusions: This study provides CBCT-derived reference root-volume values for different tooth types and demonstrates variations according to tooth type and arch. Comparison of these measurements with commonly available graft-material package volumes may provide a descriptive volumetric reference in the context of ARP. However, root volume does not directly represent post-extraction socket volume or the quantity of graft material required clinically. Therefore, these comparisons should not be interpreted as recommendations for graft quantity, and prospective clinical studies comparing root volume with actual socket volume and graft utilization are required before clinical application.