This surgical bone preparation instrument (1) comprises a main body (5)terminatedby a contacting surface (50) adapted to abut on a bone (B), and a sliding body(7)equipped with a cutting element (3) and which is movable in translation withrespect to themain body (5). The bone preparation instrument (1) includes a cutting depthcontrol ring(11) that is adjustable by a single hand, which forms an abutment surface(110) againstthe movement of one of the main body (5) and the sliding body (7) when thesliding body(7) reaches an adjusted cutting depth (D) corresponding to an adjustmentposition of thecontrol ring (11)
