drilling technique for optimal performance joel gillard karsten zuendel randy huebner portland,...
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Drilling Technique for Optimal Performance
Joel GillardKarsten ZuendelRandy Huebner
Portland, Oregon USA
SIGN Conference 2009
Drilling Performance Factors1. Cutting edge geometry for material drilling into:
bone vs metal 2. Cutting edge retention: hardness vs. toughness
Wood Bone Metal
Cutting Edge
Drilling Performance Factors
3. Drilling technique: feed & speed
Tool life & Bone temperatureAbove 47oC for over 1 minute bone necrosis
Eriksson et al 1984 Scand J Plast Reconstr Surg 18:261–268
Drill Testing Outcomes
• Feed & Speed for 3.5mm SIGN drill– Tool Life & Temp
• Practical drilling techniques
• Ideas for improving SIGN drill
Methods
•2 speeds: 400 & 1100 RPM•2 feeds: 7 lbs (3 kg) & 17 lbs (8 kg)•Synthetic bone & pig femur•3.5mm SIGN drill•Commercial general purpose 3.5mm drill
•Record time & temperature•Note wear of cutting edge
Discussion
RPM = 800
Bullet drill performs better than ortho equivalent drills, producing significantly less temperatures
Conclusion•Push on the drill (17 lbs / 8 kg): more is better than less•Faster RPM (1100) cuts quicker, but only if you push hard (17 lbs, 8 Kg), otherwise temp drill dulls•Pulse or Peck every 2 – 3 sec
•Clears debris•Reminder to push
Conclusion
•Some irrigation is better than none•Drill a small (2mm) hole first followed by 3.5mm•All drills will eventually become dull, but the can be resharpened, find a craftsman•Drills need to be properly used, cared for and maintain to have a long life