D De Santis

Adult human bone cells from jaw bones cultured on plasma-sprayed or polished surfaces of titanium or hydroxylapatite discs

Adult human bone cells isolated from jaw bone biopsies were cultured either on Thermanox® coverslips or on polished or plasma-sprayed surfaces of titanium or hydroxylapatite and the levels of their various metabolic functions were compared after 2 and 5 days of staying in culture. Thus, jaw bone cells grown on hydroxylapatite proliferated very little, while expressing discrete levels of alkaline phosphatase activity and of osteocalcin secretion into the growth medium. On the other hand, bone cells seeded onto titanium surfaces proliferated much more intensely than those on Thermanox®, besides expressing alkaline phosphatase (very intensely after 5 days) and secreting osteocalcin. Thus, both kinds of titanium surfaces greatly enlarged the size of both populations of pre-osteoblastic precursors and of pre-osteoblasts in vitro, but plasma-sprayed titanium surfaces elicited, between day 2 and 5 in culture, greater increases in bone cell numbers markedly enhancing their proliferative and alkaline phosphatase activities, along with their osteocalcin secretion into the growth medium, and thus favouring the expression of the mature osteoblastic phenotype. These preliminary findings show that studies correlating the physical surface features of various biomaterials with the corresponding expression of specific differentiation markers by the bone cells cultured on these same surfaces can provide information relevant to the clinical application of biomaterials.

Fibromatosis of the mandible: case report and review of previous publications

The term fibromatosis is used to denote two main pathological entities: juvenile fibromatosis and adult fibromatosis. It is also possible to distinguish between superficial fibromatosis of the aponeurosis and deep fibromatosis of the muscle-aponeurosis. Histopathological findings have indicated that fibromatosis is an invasive neoformation of fibromatous connective tissue involving adjacent structures. It does not metastasize, though recurrence rates vary. Treatment is based on either excision of the mass, or radiotherapy and chemotherapy if the condition is inoperable. We describe a case of fibromatosis of the mandible in a young girl. The growth was excised completely and she was still disease-free four years later.