Dental photon-counting computed tomography for the assessment of Peri-Implant structures

Abstract Purpose To assess the diagnostic performance of photon-counting computed tomography (PCCT) in the imaging of peri-implant bone structures and to compare it quantitatively and qualitatively to cone-beam computed tomography (CBCT). Methods Thirty titanium implants were placed in ten porcine mandibles. CBCT and PCCT scans were acquired and compared quantitatively regarding image noise and CT-values. Additionally bone thickness was compared to a gold standard at 60 standardized locations by one calibrated investigator in both modalities. Measurement accuracy was assessed by Bland–Altman analysis. Two experienced raters performed qualitative assessments of anatomic structures around the implant using a 5-point visibility scale. These included the bone-implant interface around the implant surface, the bone at the implant shoulder as well as the oral and vestibular bone lamella. Inter-rater agreement was assessed using ICC. Results Across all evaluated implants, CT-values in a soft-tissue region of interest adjacent to the implant increased by 11.7 ± 3.9% for CBCT acquisitions, whereas they decreased by 5.3 ± 1.3% for PCCT acquisitions. Similarly, image noise in the respective ROIs is increased by a factor of 63 ± 13% in case of CBCT acquisitions and only by 23 ± 5% in case of PCCT acquisitions. Bone thickness deviations were smaller for PCCT (mean ± SD: 0.06 ± 0.08 mm) than for CBCT (0.39 ± 0.34 mm). Qualitative assessments consistently favored PCCT ( p 0.75 ) in almost all categories. Conclusions PCCT enables superior visualization of peri-implant bone structures with fewer artifacts and improved diagnostic accuracy.