Evaluation of trabecular bone structure using fractal analysis in patients with peri-implant health and disease

Peri-implant diseases are associated with inflammatory changes affecting the peri-implant bone; however, objective radiographic markers for assessing trabecular bone structure are limited. Fractal dimension (FD) analysis is a noninvasive method for measuring trabecular complexity. This study aimed to assess peri-implant trabecular architecture using FD and to investigate its relationship with clinical parameters of peri-implant health and disease.

Patients with dental implants were examined at a university periodontology clinic. Plaque index (PI), gingival index (GI), bleeding on probing (BOP), and probing depth (PD) were recorded at six sites for each implant. Implants were classified as having peri-implant health, mucositis, or peri-implantitis based on a combination of clinical and radiographic criteria. According to this classification, 75 mandibular implants were included in the study using panoramic images. Regions of interest (ROI) were determined to evaluate the trabecular bone in the mesial and distal vicinities of the implants, and mean FD values were calculated using standardized box-counting methods.

FD values progressively decreased from peri-implant health to mucositis and peri-implantitis (p < 0.01). FD showed a weak but statistically significant negative correlation with PD and BOP (p < 0.05), whereas correlations with PI and GI did not reach statistical significance. Peri-implantitis areas exhibited the lowest FD values and the highest inflammation load.

Decreased trabecular bone complexity, as assessed by FD, was associated with peri-implant disease severity. FD can serve as a complementary radiographic marker in the assessment of peri-implant bone changes and can support the clinical evaluation of peri-implant disease in practice.