Evaluation of the efficiency of mini screw strengthening devices in the laboratory environment

The aim of this study was to evaluate the effect of the mini screw strengthening device which has a stable leg on it, on the force strength of the mini screws in vitro. In the study of using 120 mini screws and synthetic bone blocks from 4 different company, half of the screws were placed in blocks containing 1 mm cortical bone and the other half in blocks containing 2 mm cortical bone. 120 mini-screws placed in blocks containing cortical bone at 2 different thicknesses. The screws in the cortical bone groups were divided into three groups of mini screws, in which only the body portion of the screws were placed in the bone, the screws were placed in the bone together with the neck regions, and the screws were used together with the mini screw strengthening head. We used a small-scale loading device that applies force at a speed of 0,005 mm/sec for loading the screws and we determined the highest values of force that the screws stay stable in the bone where they are placed into and these data were examined by statistical analysis. The force strengths of the mini screws of different companies showed variability depending on the diffeerences between cortical bone thickness and abutment heights of the screws which are the parts of the screws outside the bone and a clear majority of these differences between force strengths were statistically significant. With the use of the mini screw strengthening head, the force strengths of the mini screws increased statistically significant to approximately 2.5 times (p<0.05). As a result of this study, we have demonstrated the effectiveness of the screw strengthening device on increasing the strength of the mini screws in vitro, which paved the way for further clinical trials. Both the force moment system and the cortical bone support of mini screws have been increased with the mini screw strengthening device.