14 research outputs found
Hammering K-wires is Superior to Drilling with Irrigation
Cooling during drilling Kirschner wires is not always effective in preventing thermal related damage. In this study, we used a human in vitro model and compared temperature elevation, insertion time, and extraction force between three Kirschner wire insertion methods—drilling with and without irrigation and pneumatic hammering. Forty five Kirschner wires were inserted into 15 fresh human cadaver metacarpals. All three insertion methods were applied in each metacarpal. Drilling without irrigation resulted in a temperature elevation of 67.25 ± 5.4 ºC with significantly lower values for drilling with irrigation (4.15 ± 0.6 ºC) and pneumatic hammering (31.52 ± 3.4 ºC). The insertion time for pneumatic hammering (47.63 ± 8.8 s) was significantly lower compared to drilling without irrigation (263.16 ± 36.5 s) and drilling with irrigation (196.10 ± 28.5 s). Extraction forces after drilling without irrigation, drilling with irrigation, and pneumatic hammering were 39.85 ± 4.1 N, 57.81 ± 6.5 N, and 62.23 ± 6.7 N, respectively. Pneumatic hammering is superior to drilling without irrigation, especially when irrigation is not possible
Temperature change in pig rib bone during implant site preparation by low-speed drilling
INVESTIGATION OF BONE DRILLING FOR SECURE IMPLANT FIXATION IN HUMAN FEMURS: TAGUCHI OPTIMIZATION AND PREDICTIVE FORCE MODELS WITH EXPERIMENTAL VALIDATION
Modelling and optimisation of temperature and force behaviour in high-speed bone drilling
Thermal osteonecrosis and bone drilling parameters revisited
INTRODUCTION: During the drilling of the bone, the temperature could increase above 47 degrees C and cause irreversible osteonecrosis. The result is weakened contact of implants with bone and possible loss of rigid fixation. The aim of this study was to find an optimal condition where the increase in bone temperature during bone drilling process would be minimal. ----- MATERIALS AND METHODS: Influence of different drill parameters was evaluated on the increase of bone temperature. Drill diameters were 2.5, 3.2 and 4.5 mm; drill speed 188, 462, 1,140 and 1,820 rpm; feed-rate 24, 56, 84 and 196 mm/min; drill point angle 80 degrees , 100 degrees and 120 degrees and external irrigation with water of 26 degrees C. ----- RESULTS: Combinations of drill speed and drill diameter with the use of external irrigation produced temperatures far below critical. Without external irrigation, temperature values for the same combination of parameters ranged 31.4-55.5 degrees C. Temperatures above critical were recorded using 4.5 mm drill with higher drill speeds (1,140 and 1,820 rpm). There was no statistical significance of different drill point angles on the increase or decrease of bone temperature. The higher the feed-rate the lower the increase of bone temperature. ----- CONCLUSIONS: The external irrigation is the most important cooling factor. With all combinations of parameters used, external irrigation maintained the bone temperature below 47 degrees C. The increase in drill diameter and drill speed caused increase in bone temperature. The changes in drill point angle did not show significant influence in the increase of the bone temperature. With the increase in feed-rate, increase in bone temperature is lower