Root-End Bevel Angle and Dentinal Tubular Permeability: The Influence of Age and Radiographic Outcomes.

OBJECTIVES: To evaluate the effect of age and root-end bevel angle on dentinal tubular permeability following apical root resection in vitro and to assess the relationship between bevel angle and radiographic healing after endodontic microsurgery using CBCT images. METHODS: Permeability was evaluated using dye penetration. Forty-nine extracted single-rooted teeth from 2 age groups (≤30 years and ≥60 years) were instrumented to Protaper Gold F4 and evaluated using crystal violet dye penetration following sequential root-end resections at 30°, 0°, and 30° bevels. Dye penetration surface area and maximum penetration depth were measured in the buccal, lingual, mesial, and distal directions using digital microscopy and ImageJ analysis. Canal dimensions were also assessed. Statistical analysis was performed using Kruskal-Wallis testing with Bonferroni correction (p<0.05). The radiographic healing relative to bevel angle was evaluated with a retrospective CBCT analysis after a minimum of 7 months of follow-up. RESULTS: Fifty-five cross-sections from the ≤30 age group and 68 from the ≥60 age group were analyzed. The ≤30 age group demonstrated significantly greater dye penetration surface area and maximum penetration depth than the ≥60 age group across all bevels (p<0.05). Minimal bevel effects were identified, with only greater distal penetration observed in Bevel 3 compared with Bevel 1 in the ≤30 age group. Limited directional differences were observed. The buccolingual-to-mesiodistal canal ratio was significantly greater in younger teeth (p=0.045). CBCT analysis of 29 roots demonstrated no significant association between bevel angle and radiographic healing. CONCLUSIONS: Age significantly influenced dentinal tubular permeability following root-end resection, whereas bevel angle demonstrated minimal effect on dye penetration or radiographic healing. Age-related dentinal sclerosis may play a greater role in permeability than bevel angle during endodontic microsurgery. CLINICAL SIGNIFICANCE: Root-end bevel angle may have limited influence on tubular permeability and healing outcomes when contemporary microsurgical principles are followed.