The invention relates to a pilot drill ( 1 ) for producing a pilot bore in a human jaw bone in preparation for its enlargement into a step bore, achieved by means of a first step drill ( 2 ) or if the step bore is further enlarged, by means of second and third step drills ( 2 ). The prepared step bore is designed to receive a dental implant, preferably in screw form. The pilot drill ( 1 ) and the first step drill ( 2 ) form a drill set. The pilot guide ( 11 ) on the pilot drill ( 1 ), comprising a step ( 124 ) lying in the transition region leading to the drill neck ( 12 ), positions the drill at the commencement of drilling in the corticalis, whereby the drilling direction can be corrected prior to the continued drilling down to the maximum depth of the pilot bore. The pilot guide ( 11 ) has a drill diameter (b 1 ), whereas the step ( 124 ) leads into an enlarged drill diameter (b 2 ). The step guide ( 21 ) of the first step drill ( 2 ) has a drill diameter (b 2' ) that corresponds to the drill diameter (b 2 ). The drill diameter (b 3 ) at the drill neck ( 22 ) of the first step drill ( 2 ) corresponds to the drill diameter at the step guide ( 21 ) of the second step drill ( 2 ). The second step drill corresponds in a similar manner to the third step drill ( 2 ). The advantages of the invention are that it requires a reduced number of drilling tools, that the implant bed can be prepared in a precise, gentle manner and that the inserted implants achieve a primary stability.
