Comparative analysis of denture base adaptation performance between pour and other conventional fabrication techniques.

STATEMENT OF PROBLEM: Studies assessing the comparative denture base adaptation performance of the pour technique for various palatal vault depths are sparse.

PURPOSE: The purpose of this in vitro study was to investigate the denture base adaptation performance of the pour technique compared with other conventional fabrication techniques (light-polymerization, injection, compression molding) for shallow and deep palatal vault depths.

MATERIAL AND METHODS: Edentulous maxillary study models with 2 palatal vault depths were prepared. Based on the power analysis, the sample size of each conventional fabrication technique was 12 (N=96). After denture bases for each technique had been fabricated on the casts according to the manufacturers' recommendations, the casts and the intaglio surfaces of the denture bases were scanned by using a laboratory scanner (InEos X5). The standard tessellation language (STL) files of the casts and the intaglio surfaces of acrylic resin bases were transferred into a software program (Romexis, version 5.0), and the software superimposed each cast and its corresponding denture base scan with the reference pyramids semi-automatically. After superimposition, the mean gap distances (mm) were calculated by using the software and recorded from the identified 4 specific regions (denture border apex, palate, ridge crest, and posterior palatal seal). A statistical analysis was performed by using the 3-factor factorial ANOVA. Post hoc comparisons among the subgroups were performed by using the Tukey HSD test.

RESULTS: Two- and 3-way interactions among palatal vault depth, polymerization technique, and location variables were statistically significant (P<.05). For shallow palatal vault depth, injection and pour polymerization techniques demonstrated similar mean gap distances irrespective of location (P>.05). The light-polymerization technique showed the highest mean gap distances among the tested polymerization techniques in all regions except for the posterior palatal seal area (P<.05).

CONCLUSIONS: The pour technique showed similar denture base adaptation to compression molding and injection. Light-polymerization exhibited the highest mean gap distance between the denture base and the cast for both palatal vault depths for most of the locations. A deep palatal vault depth led to inferior denture base adaptation performance for light-polymerization in the ridge crest and compression molding in the posterior palatal seal location.