Penetration of shearing and nonshearing pins into dentin.

An in vitro study was made of the penetration into human dentin of the shearing and nonshearing portions of TMS Minim two-in-one pins when placed manually and mechanically. It was found that the penetration of the first (shearing) portion of the pin was unaffected by the placement method. In contrast, the second (nonshearing) pin always penetrated further than the shearing pin. Mechanical placement resulted in better seating.