Jeffrey Caso Gone are the days of bur errors and short bur life. A few software versions ago we suffered through bad bur chucks, broken burs and errors after four mills that slowed us down and cost us money. Sure, there are still issues, some materials – specifically the temporary materials – still have their problems, but for the most part, we are seeing huge improvements in this regard.
The 12s cylinder and step burs are the work horses of our milling process. The all-in-one bur (where the chuck and bur are one unit) has been the main reason for this nice change. Make sure that you or your staff knows to never grease the threads when placing them. If you do, removal will be nearly impossible.
This extended bur life leads to a maintenance issue. You now need to keep an eye on your mill count, which you can see in the 4.0 software in the Step Menu located on the bottom of the screen when getting ready to mill. I will not let the burs go past 20 mills. At that point you will see mill times increase. Not the time on the screen, but the actual mill time. So, when you see a mill that is supposed to take six minutes and it actually takes 11, that's because your burs are getting dull. It could be other things like wireless interference, but generally it's the burs.
In addition, if I plan to do a big case or some thin veneers, I usually will use a new set of burs.
So, the take-home lesson is this: Watch the bur count so you will be less likely to get an error, a slow mill time or chipped margins. Make sure your water jets are pointed correctly. They should be hitting the tip of the bur. If not, bur life will be greatly affected. Also, super-smooth, free-flowing preps will help a great deal.
Keep an eye on these things or spend a minute with your staff to let them know that they need to keep an eye on these things for you. The advantage is saving time and money, but also avoiding aggravation. That, to me, as I get older, is the name of the game. Less aggravation. More happiness. Better days.
