In vitro osteogenic potential of bone debris resulting from placement of titanium screw-type implants

Histological sections of preclinical animal studies have shown that new bone formation around dental implants frequently contains debris derived from the original bone. Whether such debris by itself is osteogenic, i.e., can influence the process of new bone formation after implant placement, is still unknown. We therefore aim to investigate if such debris does have osteogenic potential.

To substantiate our hypothesis, we performed an in vitro study in which titanium screws were placed into animal bone, and immediately removed. Without additional treatment these were placed into a cell culture medium provided with beta-glycerophosphate. We used Von Kossa staining and scanning electron microscopy to examine calcifications on the surface of the implants. Additionally, total DNA analysis, alkaline phosphates activity, and calcium content were assessed on the screw surface.

Light and electron microscopy revealed the increasing presence of calcified matter on the implant surface. DNA amounts doubled from days 1 to 6, while alkaline phosphatase activity and calcium content showed a pronounced increase over the entire incubation time. None of these phenomena occurred on the control samples in the same medium.

From these results, we proved that bone debris, which arises from dental implant placement, and which is moved along by the inherent roughness of the implant, by itself has osteogenic potential.