Alveolar socket preservation technique: Effect of biomaterial on bone regenerative pattern

Background: There is a lack of evidence in the literature on the correlation between histomorphometricfindings and gene/protein expression markers for bone metabolism.Aim: Evaluation of the histological features, changes in protein expression and gene activation for specificmarkers of bone metabolism following application of the alveolar ridge preservation technique withmagnesium-enriched hydroxyapatite (MgHA).Materials and methods: For each patient (n = 15), bone samples were harvested after tooth extractionand processed for immunohistochemical and gene expression analysis (T0). Then, all alveolar socketswere grafted with MgHA. After 4 months (T1), bone samples were harvested for histomorphometrical, immunohistochemical and gene expression analysis. Gene expression and protein expression wereevaluated for: RANK, RANKL, OPG, IL-6, TNF-.Results: For all markers, gene expression increased, but not significantly, from T0 to T1. The meanRANKL/OPG ratio was 1.88 ± 1.24. Protein expression increased significantly (p < 0.05) for TNF-, IL-6,RANKandRANKL. Histomorphometricalfeatures at T1 werenot significantly related to proteinexpressionat 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 proteinexpression at baseline