Socket and ridge preservation using a mixture of nano-hydroxyapatite, polylactic and polyglycolic acid: Histological evaluation. [Preservazione dell'alveolo e della cresta mediante nanoidrossiapatite in miscela con acido polilattico e poliglicolico: valutazioni istologiche]

OBJECTIVES. The aim of this study was to histologically evaluate the results obtained with alveolar bone volume maintenance techniques using a bio-based material made of nano-hydroxyapatite conveyed by polylactic and polyglycolic acid. MATERIALS AND METHODS. Two clinical cases were presented, in which the patient was subjected to tooth extraction and alveolus filling with a mixture of nano-hydroxyapatite granules (70 nm diameter) and of polylactic and polyglycolic acid copolymers (Fisiograft® nano-HA.reinforced, Ghimas SpA, Casalecchio di Reno, Bologna, Italy). About 6 months later, at the time of implant surgery, bone samples were harvested for histological examination. RESULTS. At six monthsfrom surgery, the bio-material placed in the alveolus appeared homogeneous and integrated into the new bone formation. Histomorphometric quality assessment allowed to quantify the percentage of newly formed bone (70,82%), of residual nano-hydroxyapatite (3.80%) and of bone marrow spaces (25.38%) in the reqenerated sites. CONCLUSIONS: The use of nano-hydroxyapatite in socket and ridge preservation techniques seems to allow a [arger newlyformed bone quantity as compared with slow resorption materials.