Luigi Canullo1, Gaia Pellegrini2, Elena Canciani3, Friedhelm Heinemann4, Emanuela Galliera2, Claudia Dellavia3. 1. Private Practice, Rome, Italy. Electronic address: luigicanullo@yahoo.com. 2. Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy; IRCCS Galeazzi Orthopaedic Institute, Milan, Italy. 3. Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy. 4. Private Practice, Morsbach, Germany; Greifswald University Hospital, Department of Prosthodontics, Gerodontology and Dental Materials, Greifswald, Germany.
Abstract
BACKGROUND: There is a lack of evidence in the literature on the correlation between histomorphometric findings and gene/protein expression markers for bone metabolism. AIM: Evaluation of the histological features, changes in protein expression and gene activation for specific markers of bone metabolism following application of the alveolar ridge preservation technique with magnesium-enriched hydroxyapatite (MgHA). MATERIALS AND METHODS: For each patient (n=15), bone samples were harvested after tooth extraction and processed for immunohistochemical and gene expression analysis (T0). Then, all alveolar sockets were grafted with MgHA. After 4 months (T1), bone samples were harvested for histomorphometrical, immunohistochemical and gene expression analysis. Gene expression and protein expression were evaluated for: RANK, RANKL, OPG, IL-6, TNF-α. RESULTS: For all markers, gene expression increased, but not significantly, from T0 to T1. The mean RANKL/OPG ratio was 1.88±1.24. Protein expression increased significantly (p<0.05) for TNF-α, IL-6, RANK and RANKL. Histomorphometrical features at T1 were not significantly related to protein expression at T0. CONCLUSIONS: After ridge preservation with MgHA, markers for bone catabolism were activated. No significant correlation was found between histomorphometrical features of the regenerated tissue and protein expression at baseline.
BACKGROUND: There is a lack of evidence in the literature on the correlation between histomorphometric findings and gene/protein expression markers for bone metabolism. AIM: Evaluation of the histological features, changes in protein expression and gene activation for specific markers of bone metabolism following application of the alveolar ridge preservation technique with magnesium-enriched hydroxyapatite (MgHA). MATERIALS AND METHODS: For each patient (n=15), bone samples were harvested after tooth extraction and processed for immunohistochemical and gene expression analysis (T0). Then, all alveolar sockets were grafted with MgHA. After 4 months (T1), bone samples were harvested for histomorphometrical, immunohistochemical and gene expression analysis. Gene expression and protein expression were evaluated for: RANK, RANKL, OPG, IL-6, TNF-α. RESULTS: For all markers, gene expression increased, but not significantly, from T0 to T1. The mean RANKL/OPG ratio was 1.88±1.24. Protein expression increased significantly (p<0.05) for TNF-α, IL-6, RANK and RANKL. Histomorphometrical features at T1 were not significantly related to protein expression at T0. CONCLUSIONS: After ridge preservation with MgHA, markers for bone catabolism were activated. No significant correlation was found between histomorphometrical features of the regenerated tissue and protein expression at baseline.