Abstract: An instrument which verifies whether the distance between two teeth is the minimum adequate distance for the placement of one or two implants, verifies that marks made with a surgical splint have amongst them the minimum adequate distance, and centers edentulous space for placement of an implant or divides equidistantly the space for the placement of two implants, the instrument having a first rectangular sheet with a central perforation joined by an extension from one side to one side of a second, larger rectangular sheet having two perforations and an opposite side from which a handle extends is improved by stops extending from opposite ends of at least one of the one side of the first rectangular sheet or the opposite side of the second rectangular sheet for engaging the teeth in a position that verifies whether the distance between two teeth is the minimum adequate distance for the placement of one or two implants, verifies that marks made with a surgical splint have amongst them the minimum adequate dist