Method and tool for creating a perforation or cavity in a bone or bone structure in contact with a membrane

Method for creating a perforation or cavity in a bone or bone structure in contact with a membrane, the method comprising:

• drilling said bone or bone structure by a drill;
• and
• providing a liquid under pressure at a free end and through a channel of said drill such that said liquid flows partially into and through the bone or bone structure toward the membrane while drilling the bone or bone structure with the drill, and causing a progressive detachment of the membrane when the drill is close to the membrane while still being inside the bone or bone structure, and before completely piercing the bone or bone structure.

Kit of drills for creating a perforation or cavity in a bone or bone structure in contact with a membrane, said kit comprising a plurality of drills including a first drill and a second drill, each drill of said plurality of drills having a free end and a channel adapted for supplying a liquid under pressure to said free end, said channel having an inner diameter, each said drill being adapted for receiving an insert for supplying said liquid to said channel, wherein an outer diameter of said insert is smaller than an inner diameter of said channel, thus creating an open space between said insert and said channel for backflow of a portion of said liquid supplied to said channel;

• wherein said first drill has a first drilling length and said second drill has a second drilling length longer than the first drilling length, and wherein said first drill has a first inner diameter of said channel and said second drill has a second inner diameter of said channel larger than said first diameter.