Effect of clutch surface changes on the computerized pantographic reproducibility index and the Fischer angle

This study of eight patients compared the pantographic numeric data obtained with a concave clutch with those obtained with a flat clutch. The slight alterations that resulted were insignificant and varied with each patient. The only difference between Depoorter's study and this one is the manual calculation of the EPRI compared with the computerized calculation of CPRI. Small variation was found in the value of the Fischer angle when the studies were compared. As shown in Depoorter's work, the shape of the clutch does not produce any significant changes in the recording of the posterior determinants. This conclusion is confirmed by this study for both the CPRI and the value of the Fischer angle. The concave clutch and the flat clutch reproduced similar results in both studies. By altering the central bearing pin and obtaining the same interclutch distance for both clutches, we obtained results in this study that refute the findings of Scortecci that a concave clutch was superior to a flat clutch.