This burr looks like a small ice pick.  It has grooves cut diagonally on the distal end.  It is quite sharp and pointed.  Therefore, it can get right into an inflamed nail groove and not damage the soft tissue.  You insert the burr as far proximal, and as deep in the nail groove as possible.  Run the drill as slow as it will go to keep noise and vibration to a minimum.  Start filing a groove in the nail coming out distally as you do.  In other words, you do the same as you would with a nail splitter only in the opposite direction.  Use very little pressure, and give the nail plenty of chances to cool from the grinding.  This will cut a groove in the nail.  This burr will cut the groove in a smooth straight line.  You may follow up this procedure with either the small spicule, or a very thin splitter, or nail nipper as you desire to remove the nail spicule.

 

NOTE:  This burr bends easily and is very easy to loose.