No abstract

In medical surgery, bone drilling is an inevitable procedure. The thermal necrosis in the drilling process can affect post-operative recovery. In this study, the method of drill bit precooling is proposed in bone drilling with robot assisted system. The influence of process parameters on the drilling temperature were investigated and analyzed. The results showed that the method of drill bit precooling could reduce the drilling temperature. The drill bit starting temperature and the feed rate were more important parameters on the drilling temperature compared with rotational speed and cooling length of the drill bit. The quadratic regression model obtained from response surface experiments can predicted the drilling temperature correctly under the range of process parameters in this study. The optimal parameter combination is rotational speed = 1610 rpm, feed rate = 0.5 mm/s, the starting temperature of drill bit = 8°C, and the cooling length = 34.8 mm. The results provide an effective method to reduce thermal necrosis of bone cells in drilling.

No abstract

In surgery, the friction between the cortical bone and the metal instruments cause bone cells damage, which would affect the stability of intraosseous implants. In the present work, the tribological characterization of cortical bone against 316 stainless steel during dry sliding condition was investigated by pin-on-disk tests. Finite element method was used to monitor the change of friction temperature with vibration assistance. The wear mechanism of the bone sample and the 316 stainless steel had been analyzed and discussed. The results show that the friction coefficient decrease with the increasing of load, the wear rate and the friction temperature increase. While, the friction coefficient, the wear rate and the friction temperature are increased with the increase of sliding speed, respectively. Moreover, the friction temperature with vibration assisted is lower than that in the normal friction process. Adhesive and abrasive wear behavior are the main wear mechanisms of the cortical bone against 316 stainless steel during the test. The results in this paper provide guidance for the selection of parameters during bone cutting, which has great significance for the improvement of implant stability.