DEVICE FOR MAKING, DUPLICATING AND FIXING DENTAL MODELS IN ARTICULATOR, in the field of dentistry, comprising a dental articulator to be used with dental replicas made of plaster or other material, upper and lower, adjusted to accurately reproduce the patient's bite, allowing the creation and use of a pair of articulated and related dental models in said existing articulator by adding some bases and pins to said dental replicas, in that the pins have fixing means to said bases and by platens that have protruding from their surface, arranged in position to join said pins and make a separable connection with them, keeping said elements of each arm of said articulator, wherein - it comprises at least three of said pins and a minimum of three fixing elements, said pins have a protrusion or lower cavity for centering in the body of said fixing element that respectively has a cavity and/or antagonistic protrusion; - it comprises a tray, made of relatively elastic material, such as rubber, configured for emptying or pouring plaster or material to make a mold for duplicates, which is a container in the bottom of which there are one or more holes, said fixing elements fitting in said holes and in which said pins can be placed fixed by said fixing elements thereby plugging said holes; - said articulator further comprises having in its arms base surfaces aimed at receiving said platens, also having stops to the maximum closure of the articulator, in which said arms are arranged in a position parallel to each other thus maintaining a separation or height (h) or "master" predefined between the end surfaces of said fixing elements of said platens; - it further comprises a double positioner formed by a hollow body inside which said dental replicas are arranged and adjusted to the patient's bite; - it further comprises a platen positioner that has two extreme parallel surfaces, formed by planes in the shape of a geometric figure with a minimum of three vertices, there being In each of said vertices of both end surfaces a fixing and/or positioning element compatible with said fixing elements; - it keeps said detachable connection a pre-established and reproducible relationship. - it comprises at least three of said pins and a minimum of three fixing elements, said pins have a protrusion or lower cavity for centering in the body of said fixing element that respectively has a cavity and/or antagonistic protrusion; - it comprises a tray, made of relatively elastic material, such as rubber, configured for emptying or pouring plaster or material to make a mold for duplicates, which is a container in the bottom of which there are one or more holes, said fixing elements fitting in said holes and in which said pins can be placed fixed by said fixing elements thereby plugging said holes; - said articulator further comprises having in its arms base surfaces aimed at receiving said platens, also having stops to the maximum closure of the articulator, in which said arms are arranged in a position parallel to each other thus maintaining a separation or height (h) or "master" predefined between the end surfaces of said fixing elements of said platens; - it further comprises a double positioner formed by a hollow body inside which said dental replicas are arranged and adjusted to the patient's bite; - it further comprises a platen positioner that has two extreme parallel surfaces, formed by planes in the shape of a geometric figure with a minimum of three vertices, there being In each of said vertices of both end surfaces a fixing and/or positioning element compatible with said fixing elements; - it keeps said detachable connection a pre-established and reproducible relationship.