Histological aspects in bone regeneration of an association with porous hydroxyapatite and bone marrow cells

The osteogenic potential of an association of two kinds of hydroxyapatite ( HA) porous ceramics with autologous bone marrow cells cultured with or with out dexamethasone (10(-8)M) addition in the culture medium and non-cultured rabbit marrow stromal stem cells (MSCs) was tested after 4 weeks of implan tation in the dorsal muscles of spine in rabbit. A significantly higher num ber of rabbits with implants containing bone tissue inside pores were obtai ned with 10(7) cells ml(-1) cultured treated with Dex. In the HA porous cer amic using naphtalen as porogen agent, the bone recolonization remains only at the periphery of implants and in the second row of pores, while in the HA porous ceramic using polymethacrylate (PMMA) microbeads as porogen agent , the bone recolonization is observed in the depth of implants. In the PMMA HA group, the Kruskal-Wallis variance analysis between the rabbits is sign ificantly different with the percentage of number of occupied pores and occ upied pores with bone tissue is different (p<0.05). (C) 1999 Kluwer Academi c Publishers.