Use TCS Twist Drills to create diatoric retention.
Diatorics holes must be made in “T” shape and must connect in the middle.
On pre-molars create diatorics as far lingual as possible.
On molars use a thick Twist Drill to create bigger diatoric holes to ensure material locks in firmly.

Select the correct Twist Drill Bur.
Twist Drills come in different diameters, select according to the size/type of tooth to create diatorics/mechanical retention.
Meso-distal retentions are made as lingual as possible to avoid interference with the aesthetics of the appliance.
Mechanical retentions for anterior teeth are created in a V shape, from lingual to the middle of the neck of the tooth, with the purpose of not interfering with the aesthetics of the appliance.

Drill two holes.
One from the mesial to distal and through the tooth.
Another in the center of the neck of the tooth until it is intercepted with the meso-distal retention.
