Comparative Evaluation of the Accuracy and Dimensional Stability of Three Interocclusal Recording Materials- An In Vitro Study

AIMS: To compare accuracy and dimensional stability of 3 inter occlusal recording materials , as a function of time. Method of study 3 commercially available inter occlusal recording materials investigated in this study were chemically bite registration wax, bis acrylic and polyvinylsiloxane. A mold of ADA specification no 19 was used. Samples of 10 specimen each were made. Specimen were disc shaped ,0.3 cm in thickness and 3cm in diameter ,with 3 parallel lines on surface A, B, C equally separated by 2.5 mm. They were immersed in 36±1 ̊ C, water bath for setting time plus 3 minutes. Distance between lines A and C were measured with universal measuring microscope at 1, 24, 48, 72, 168 hr time intervals and the values were statistically analysed. RESULTS: Polyvinyl siloxane was found to be the most accurate and dimensionally stable followed by bis acrylic and bite registration wax. CONCLUSION: All materials exhibited maximum accuracy and dimensional stability in the initial stages but decreased as the time factor increased. Dimensional stability was influenced by both material and time factors, and difference exhibited by the materials were statistically significant at 1 ,24 and 48 hrs