A comparison of different methods and materials for establishing maximal intercuspal position: A clinical study

Abstract

Statement of problemWhich method or material used to record the intercuspal position yields the best accuracy of location of the maxillary and mandibular casts is unclear. PurposeThe purpose of this clinical study was to determine the most reliable method of recording a patient’s maximal intercuspal position by comparing 2 common methods with 2 popular registration materials. Material and methodsComplete-arch impressions were made of both jaws with a polyvinyl siloxane impression material in a metal stock tray followed by 4 interocclusal registrations for each of the 17 participants. Two registration techniques were used. More than 1 record was obtained in the first technique, as the participant had to close through a wax sheet or a polyvinyl siloxane material. In the second technique, a polyvinyl siloxane material was injected from the buccal aspect between occluded tooth surfaces. Casts were made from Type 4 stone and vertical measurements of the casts were carried out by using digital vernier calipers, accurate to 100 μm. Hand articulation of the casts was used as the control. Consistency of measurement was assessed by the intraclass correlation coefficient, and comparisons were made by using repeated-measures regression analysis. ResultsStatistical analysis showed significant discrepancies when the participant closed through both wax and polyvinyl siloxane material (P<.001). No statistically significant differences to the control group were present when polyvinyl siloxane was injected laterally after closure. ConclusionsHand articulation was the most accurate method of reproducing the maximal intercuspal position in a completely dentate individual with horizontal and vertical occlusal stability and was therefore considered the control. Recording the position after the participant had closed by using a polyvinyl siloxane material was the most accurate.