Adaptation Accuracy of Cast Metallic Single Tooth Restorations

Achieving metallic frameworks of single tooth restorations involves obtaining high precision parts. Adaptation accuracy is one of the main factors that influence single tooth restorations long-term reliability. The purpose of the study was to test innovative methods for adaptation accuracy evaluation of different single tooth cast restorations. Acrylic teeth were prepared for single tooth cast restorations using traditional preparation methods. Ni-Cr alloy frameworks were obtained through classical laboratory procedures. Light silicone was inserted between each restoration and tooth preparation. Subsequently two distinct working methods were chosen: the introduction of light silicone in putty silicone respectively introduction of the whole complex restoration-preparation-silicone in acrylic resin. Marginal and internal fit for all restorations were measured on cross-sections. It was noticed that the first method is of choice for intracoronal restorations, and the second for cast post-and-core. Featheredge preparations showed the best accuracy for cast metallic restorations. Using base metal alloys for restorations, the discrepancies were smaller for extracoronal restorations, than for intarcoronal. Key-Words: single tooth restorations, metallic frameworks, adaptation accuracy, marginal fit, internal fit, crosssections, discrepancies.