Drill sleeve (1) for a dental drill (70) having a hollow and cylindrical shape and a longitudinal axis A, a circular inner surface (10) for guiding the dental drill (70), and an outer surface (15) intended to be inserted into a template (50). The outer surface (15) of the drill sleeve (1) has at least one longitudinal flattened or concave area (20, 120), the circular inner surface (10) is essentially parallel to the longitudinal axis A, and the drill sleeve (1) is thin-walled.