Inaccurate fit of implant superstructures. Part II: Efficacy of the Preci-disc system for the correction of errors.

The Preci-disc prosthetic system for dental implants is designed to compensate for casting inaccuracies and to reduce stresses generated on the superstructure and implant components. This laboratory study compared stresses induced on the implant superstructure with various sizes of vertical discrepancy of fit, with and without the application of the Preci-disc system. A series of test casts carrying four abutment replicas were fabricated incorporating various sizes of discrepancies (10 to 100 micrometers) relative to a master superstructure. The stress generated on the superstructure was quantified using photoelastic stress analysis. It was found that the Preci-disc system was effective in reducing stresses induced on the surface of the implant superstructure particularly with greater discrepancies of fit (60 to 100 micrometers).