Objectives: This study aimed to compare the diagnostic accuracy of cone beam CT (CBCT) units with different voxel sizes with the digital intraoral scanning technique in terms of the detection of periodontal defects. Methods and materials: The study material comprised of 12 dry skulls with maxilla and mandible. Artificial defects were created on teeth separately using burs randomly on dry skulls. In total 46 dehiscences, 10 fenestrations, 17 furcations, 12 wall defects and 13 without periodontal defect were used in the study. Each tooth with and without defects was imaged at various vertical angles using each of the following modalities: a Veraviewepocs 3D R100 CBCT device and a 3D Shape TRIOSㄾ Color P13 Shade Intraoral Scanner. Results: The κ values for interobserver agreement between observers ranged between 0.29 and 0.86 for the CBCT 10 × 8 cm field of view (FOV) with 0,160 mm³ voxel size; 0.35 and 1 for the CBCT 8 × 8 cm FOV with 0,125 mm3 voxel size; and 0.30 and 1 of intraoral scans. The κ values for detecting defects on anterior teeth were the least, following premolar and molar teeth both CBCT and intraoral scanning. Conclusions: Smaller voxel sizes and smaller CBCT FOV has the highest sensitivity and diagnostic accuracy for detecting various periodontal defects among the scanner modalities examined. Advances in knowledge: Adequate evaluation of the condition of the alveolar bone and periodontal tissues is important for the diagnosis, treatment, and prognosis of periodontal disease. Limited examination methods, such as palpation, inspection, and periodontal probe examination, may provide insufficient information for the diagnosis of periodontal diseases.

Impacted mandibular third molar surgery is one of the most common procedures in oral and maxillofacial surgery, and an accurate preoperative assessment of surgical difficulty remains clinically important. The Pederson difficulty index is widely used for radiographic difficulty estimation, whereas fractal dimension analysis provides a quantitative assessment of trabecular bone complexity. This retrospective observational study aimed to evaluate the relationship between the Pederson difficulty index and the fractal dimension of the alveolar bone surrounding impacted mandibular third molars on panoramic radiographs. A total of 207 impacted mandibular third molars were obtained from 113 patients. Demographic data, tooth side, and Pederson difficulty categories were recorded. Each impacted tooth was classified as easy, moderate, or difficult according to the Pederson difficulty index (PDI). Fractal dimension measurements were performed in three predefined regions of interest: mesial, apical, and distal alveolar trabecular bone. The study population had a mean age of 22.63 ± 4.36 years, and the tooth-side distribution was balanced between teeth 38 and 48. No significant association was found between sex or tooth side and the Pederson difficulty category. Mesial, apical, and distal fractal values did not differ significantly according to sex or Pederson difficulty category. Panoramic radiography-based fractal dimension measurements were not significantly associated with Pederson difficulty categories for impacted mandibular third molars.