Comparative evaluation of fiber and metal posts on mandibular bone microstructure: a fractal dimension analysis

The aim of this study was to quantitatively evaluate the effects of prefabricated fiber and metal posts on mandibular trabecular bone microarchitecture by comparing fractal dimension values derived from panoramic radiographs at pre-treatment and post-treatment time points.

A cohort of 101 individuals (50 fiber posts, 51 metal posts) was analyzed. To ensure comparability, both groups were matched regarding age, gender (p > 0.05). Digital panoramic radiographs were obtained at pre-treatment and post-treatment time points. Images were saved in uncompressed Tagged Image File Format and processed using ImageJ software. Bone complexity was quantified using the White and Rudolph box-counting method. Standardized Regions of Interest (50 × 50 pixels) were precisely defined in the peri-radicular bone, strictly excluding anatomical landmarks such as the mandibular canal and mental foramen. Intra-observer reliability was verified via the Intraclass Correlation Coefficient. Due to the non-normal distribution (Shapiro-Wilk test), data were analyzed using Mann-Whitney U and Wilcoxon signed-rank tests.

There was no statistically significant difference between pre- and post-treatment fractal dimension values within the fiber and metal post groups (p > 0.05). Inter-group comparisons revealed no significant disparity in trabecular bone complexity between the two post systems (p > 0.05). Furthermore, gender did not exert a significant influence on the fractal metrics. Sensitivity power analysis confirmed that the sample size was sufficient to detect clinically relevant changes.

The findings indicate that prefabricated fiber and metal posts produce similar short-term effects on mandibular trabecular bone microarchitecture, with no significant difference in fractal dimension values either within or between groups. From a clinical perspective, fractal analysis did not reveal a detectable difference in peri-radicular trabecular bone complexity between the two post systems over a one-year follow-up; this radiograph-based observation may provide an additional consideration for material selection when esthetic, financial considerations are weighed.