Crestal-Lift-Control is used for a minimally invasive, closed sinus-floor elevation within the scope of internal sinus lifts. Lifting the Schneiderian membrane already takes place during the transcrestal drilling procedure. The atraumatic design of the crestal drill serves to safely shape a conical bone flap. The head of the 4-blade crestal drill, which is curved inwards, can also be used to collect bone graft material in an ideal manner. In addition, the adapted stop sleeve system provides protection against membrane injuries.