ACCURACY OF 3 INTEROCCLUSAL RECORDING MATERIALS USED TO MOUNT A WORKING CAST

When remaining occlusal contacts of a dental posterior quadrant have b een prepared to receive complete or partial coverage restorations, it is necessary to use an interocclusal recording material to approximate the casts for laboratory mounting procedures. Inaccuracy in working c ast approximation leads to occlusal discrepancies in the fabricated re storations that require correction by the dentist at the time of inser tion. Traditionally waxes, impression compounds, plasters, and zine ox ide-eugenol pastes have been used intraorally to record maxillomandibu lar relationships. Elastomeric materials have also been advocated. Man ufacturers of thermoplastic resins have recently suggested that these materials may be used with ease and accuracy for interocclusal records . This investigation measured and compared the accuracies of a thermop lastic resin, an acrylic resin, and a vinyl polysiloxane interocclusal recording material. A measuring method was developed in which a compu terized axiograph was used to record positional errors in three planes , next to the posterior teeth, with the interocclusal recording materi als listed.