Investigation of the extent of post-extraction bone contraction and bone remodeling after 4 months. A prospective pilot study

Objectives: Aim was to investigate a correlation between the serum levels of 25(OH)D and the resorption of the alveolar bone walls and regeneration of the alveolar space after tooth extractions. Methods: 14 adults in need of extraction of hopeless teeth were enrolled. An intraoral digital impression was performed using CS3600 scanner, and each patient was tested to assess serum vitamin D levels. Subsequently, extraction of teeth and contextual guided bone regeneration was performed using porcine origin graft material and a resorbable collagen membrane to covert the defect. After 4 months, an impression was taken, and the model was scanned using a professional scanner for lab. At the same time, a CBCT exam was performed to perform implant insertion through fully digital computer guided surgery. Bone was collected to perform histological and histomorphometric analysis. Pre and postoperative scans were compared using a specific software GOM Inspect, GOM GmbH, Germany) to estimate the volumetric changes. GLM tests were applied to investigate the relationship between the different predictor variables and the outcome variables. Results: 14 patients were divided in 3 groups depending on the serum Vit-D levels, identifying three ranges corresponding to low (lower than 20), medium (between 20-30), and optimal vitamin D levels (higher than 30). Volumetric contraction after extraction was observed for all patients without any significant difference. Focusing on the post-extraction regeneration, patients belonging to the group with lower levels of Vit-D displayed lower and more disorganized levels of bone. Immunohistochemistry analysis showed that Col1A1 and Osteocalcin had no physiological alteration. Osteopontin could be identified near the external surface of bone tissue granules. Runx2 signals were detected near the margins of bone trabeculae. Conclusions: Serum vit-D levels do not appear to influence the extent of post-extraction bone contraction. On the contrary, it seems to significantly influence the post-extraction regeneration. Clinical significance: Vit D serum levels may influence the regenerative aspect during post-extraction turn-over. This might suggest controlling and (in case of low levels) recommend Vit D supplement in the patient diet in case of extraction.