A device for use in an endodontic root canal, performed using a dental drill hand set has a first upper unit coupled to the drill hand set. The first upper unit is cylindrical in shape and has a first drill shank shaft therethrough. The upper unit has a first threading on its outside surface. A second bottom unit, cylindrical in shape, is also provided, having a second drill shank shaft therethrough. The second bottom unit has a second corresponding threading on its inside surface. When the second bottom unit is screwed onto the first upper unit a root canal jig is formed having a set height and allowing a shank from the drill hand set to pass through the first and second drill shank shafts, such that when the drill shank of the drill hand set is drilled into an affected tooth for a root canal, the drill shank is prevented from drilling along its entire length into the root of the affected tooth when the bottom of the root canal jig contacts the top of the tooth.