Abstract: In the making of fixed dental prosthesis, a model is employed, which is an accurate replica of the patient's teeth and gums. For reinforcement, the model is fixed to a base. A model comprises a replica of the teeth remaining in the patient's mouth and a replica of teeth to be prepared by restorative dentistry. For preparing the teeth by restorative dental techniques, a die is used. It is desired that the die be removed from and replaced in the model with facility, be indexed accurately relative to the model and have stability while positioned in the model against forces applied in the practice of prosthesis, and also be removable from the base on which the model is secured. Toward this end, a pin is fixed in the die having a locating leg and an indexing leg interconnected by an arcuate portion of the pin. The legs extend outwardly from the die to be received by the base to which the model is secured.