Determination of the Accuracy of Four Interocclusal Recording Materials

Click on images to view full size.

Objectives: Through selection of accurate bite registration materials, errors in the interocclusal relationship of mounted casts can be minimized. Thus, this study was done to determine the three-dimensional accuracy of four interocclusal recording materials. Methods: This quasi-experimental study measured and compared three dimensional errors of modeling wax (Cavex; Holland), polyether (Impregum, ESPE; Germany), impression compound (Kerr; Italy) and an autopolymerizing acrylic resin (Duralay, Resielance Dental Mfg. Co). A dentoform was mounted on a semiadjustable arcon articulator. The samples of each material were prepared (n=10) and stored (24 hours). Following a variety of modifications on the articulator, the three dimensional deviations of maxillary dentoform member due to interocclusal records, were measured on the outer surface of the condylar housings (sagital and vertical directions) and on incisal table (transversal direction). This measurement was performed under suitable magnification (Photoshop 8.0 software).The mean errors of materials were statistically analyzed in each direction (one way ANOVA,Tukey's). Results: Significant differences were found between recording materials in all directions (P<0.01). In multiple comparisons significant differences were: 1. Right sagital- polyether with wax and resin, compound and wax with resin; 2. Left sagital- resin with wax and polyether and compound; 3. Right vertical- polyether with compound and wax, resin with compound and wax; 4. Left vertical- polyether with resin and compound and wax; 5. Transverse- compound with wax and resin, polyether with resin and wax, wax with resin. Conclusion: The least three dimensional errors were recorded in polyether. So, polyethers can be used as one of the most accurate bite registration materials.