Evaluation of the Effectiveness of Systemic and Local Vitamin D Administration in Maxillary Sinus Lift Procedures: An Animal Study.

PURPOSE: This study compared the effects of local and systemic calcitriol administration on bone regeneration in a xenograft-based rabbit maxillary sinus augmentation model. MATERIALS AND METHODS: Eighteen New Zealand rabbits were randomly assigned to three groups (n = 6 per group at baseline): control (xenograft only), local calcitriol (xenograft hydrated with 0.1 µg/kg calcitriol per sinus), and systemic calcitriol (single intravenous dose of 0.2 µg/kg). After 10 weeks, histomorphological scoring, RT-qPCR quantification of VEGF and BMP-2, and serum 25(OH)D measurements were performed. RESULTS: Osteoblast activity was significantly higher in the local calcitriol group than in the control group (p = 0.024). Ossification scores showed a numerical trend toward higher values in the local group but did not reach statistical significance (p = 0.061). VEGF and BMP-2 expression were approximately 17.2-fold and 29.3-fold higher in the local group compared with controls (Bonferroni-corrected p < 0.001 for both); the systemic group showed intermediate expression without reaching corrected significance. Serum 25(OH)D levels showed no significant between-group differences at any time point. CONCLUSIONS: Local calcitriol delivery was associated with significantly greater osteoblast activity and VEGF and BMP-2 expression, along with a non-significant trend toward higher ossification scores. Local application via routine graft hydration may represent a practical, low-cost strategy to enhance bone regeneration without systemic exposure, warranting confirmation in larger clinical studies.