Low-dose cone-beam CT in implant dentistry: a clinical validation of diagnostic sufficiency

To validate the diagnostic sufficiency of a low-dose (LD) cone-beam CT (CBCT) protocol for dental implant assessment by comparing it to a standard-dose (SD) protocol in a clinical setting. The study evaluated linear measurement accuracy, subjective clarity of anatomical landmarks, and the impact on bone microarchitecture assessment.

This retrospective study analyzed preoperative (SD) and postoperative (LD) CBCT scans from 37 patients (37 SD and 37 LD scans for both maxillary and mandibular sites). The LD protocol achieved a 76.7% dose reduction by decreasing tube current and exposure time. The diagnostic utility was assessed: (1) subjective clarity scoring of the mandibular canal and maxillary sinus floor; (2) objective linear measurements of key anatomical dimensions; and (3) quantitative analysis of bone microstructural parameters (trabecular number [Tb.N], trabecular separation [Tb.Sp], trabecular thickness [Tb.Th], bone volume fraction [BV/TV]). Reliability assessment was also performed for clarity scoring and quantitative measurements. Statistical comparisons were performed using Chi-square and paired-samples t-tests.

No statistically significant differences were found between the LD and SD protocols in the subjective clarity of anatomical structures (P > .05) or in the accuracy of linear measurements (P > .05). However, all 4 bone microstructural parameters showed statistically significant differences between the 2 protocols in both the maxilla and mandible (P < .05 for all). Intra- and inter-examiner assessments demonstrated substantial to good consistency across all qualitative (weighted Kappa >0.611) and quantitative (intra-class correlation coefficient [ICC] >0.702) parameters.

This study provides clinical evidence that for the specific CBCT unit tested, the optimized LD CBCT protocol reduces patient radiation exposure by over 76.7% for dental implant assessment without compromising the diagnostic accuracy required for linear measurements and visualization of key anatomical landmarks. Therefore, for the tested model, the LD protocol is sufficient for preoperative CBCT scanning in implant dentistry. This offers a clinically validated method for enhancing patient safety in this specific context, effectively applying the As Low As Diagnostically Acceptable, Indication-oriented, and Patient-specific (ALADAIP) principle.