Proliferation and differentiation of bone marrow cells on titanium plates treated with a wire-type electrical discharge machine.

Abstract

For successful dental implants, it is necessary to obtain satisfactory osteointegration at the site of both the cortical and trabecular bones in the jaw. Bone marrow stromal cells differentiate into osteoblast-lineage cells and have an important role in bone remodeling. In this experiment, the responsiveness of bone marrow cells to a titanium plate with a rough surface was compared with that of a titanium plate with a smooth surface. The rough surface was created by treating with a wire-type electrical discharge machine, and the smooth plate was produced by polishing with 1.500-grade emery paper. The results indicated that, though bone marrow cells proliferated on both plates, the proliferation pattern and cell growing time on the plates were different. While the cells on the smooth plate proliferated along the grooves produced by polishing, the cells on the rough plate proliferated randomly and more rapidly. As bone marrow cells consisted of heterogeneous cell populations involving hematopoietic cells, we collected bone marrow mesenchymal stromal cells that proliferated on plastic dishes and studied the proliferation and differentiation of these cells. Stromal cells on the rough plate more actively proliferated than those on the smooth plate. In long-term culture, the cells on the rough plate showed higher alkaline phosphatase activity and produced cell nodules. The cells on the smooth plate were stripped off the plate without nodule formation. These results indicated that bone marrow stromal cells on the rough plate could more rapidly proliferate and differentiate into osteoblast-lineage cells compared with those on the smooth plate.