Dental prosthesis assembly comprising an ancillary fitting and/or removal system comprising at least one tool (3, 4), at least one implant provided with a first internal blind bore, comprising a first internal thread on a distal end portion over a given first distance d from the bottom of the first bore and a frustoconical proximal end portion for connection to at least one pillar, said pillar comprising an at least partly frustoconical distal end portion for connection to the proximal end portion of the implant, arranged so that the surface of said distal end portion of the pillar cooperates frictionally with the surface (S') of the connecting proximal end portion when the connection between implant and pillar is complete, said pillar being provided with a second internal bore for passage of the tool (3, 4), and comprising a second internal thread and a first shoulder forming a longitudinal stop for the tool, the second internal thread extending over a given length l from a distance D from the distal peripheral end of the pillar, the ancillary system comprising a first ancillary tool for fitting the pillar onto the implant and a second ancillary tool for removing the pillar from the implant, the two tools each being in the form of an elongate rod about an axis (8', 8") and each provided on one side with a gripping sleeve (33, 34), and on the other side, separated by an intermediate portion (39, 40), with an end portion (36, 36') arranged to cooperate with the distal end portion of the first bore of the implant, the end portion of the second ancillary removal tool having a transverse dimension or diameter smaller than the inside diameter of the first internal thread and extending over a distance y from the distal end of the end portion of the second tool, such that y > d, so that the distal end of the end portion can abut against the bottom of the bore of the implant when the second tool is inserted in the implant through the internal bore of the pillar, the intermediate portion of the second tool comprising a second external thread at the distal end situated at the distance y, said second external thread being arranged to cooperate with the second internal thread and cause the pillar to rise / to be removed relative to the implant upon screwing of the second tool into the pillar, when said distal end of the end portion of said second tool abuts against the bottom of the first bore of said implant, implant characterised in that the end portion of the first ancillary fitting tool comprises a first external thread arranged to cooperate with the first internal thread, and the intermediate portion comprises a second shoulder arranged to abut against the first shoulder of the pillar during screwing of said first external thread into the first internal thread of the implant during fitting, so as to forcefully lock the proximal end portion of the implant to the distal end portion of the pillar. the ancillary system comprising a first ancillary tool for fitting the pillar onto the implant and a second ancillary tool for removing the pillar from the implant, the two tools each being in the form of an elongate rod about an axis (8', 8") and each provided on one side with a gripping sleeve (33, 34), and on the other side, separated by an intermediate portion (39, 40), with an end portion (36, 36') arranged to cooperate with the distal end portion of the first bore of the implant, the end portion of the second ancillary removal tool having a transverse dimension or diameter smaller than the inside diameter of the first internal thread and extending over a distance y from the distal end of the end portion of the second tool, such that y > d, so that the distal end of the end portion can abut against the bottom of the bore of the implant when the second tool is inserted in the implant through the internal bore of the pillar, the intermediate portion of the second tool comprising a second external thread at the distal end situated at the distance y, said second external thread being arranged to cooperate with the second internal thread and cause the pillar to rise / to be removed relative to the implant upon screwing of the second tool into the pillar, when said distal end of the end portion of said second tool abuts against the bottom of the first bore of said implant,