Purpose: A die stone jig was evaluated as to its ability to clinically verify the position of the abutment replicas on the master cast. Materials and Methods: A clinical evaluation was made on 58 edentulous arches necessitating rehabilitation with fixed partial dentures. Any broken jigs detected were replaced with a new set of jigs and clinically retested. Data were statistically confirmed. Results: Fifty-five percent of the 58 jigs broke, with a 95% confidence interval (CI) of 42.5 to 67.3; after replacement, there were no breakages (95% CI: 0 to 6.2). Conclusions: The jig detected misfits in clinical trials, according to the parameters defined in the literature.