Comparison of retention between maxillary milled and conventional denture bases: A clinical study.

STATEMENT OF PROBLEM: Clinical studies comparing the retention values of milled denture bases with those of conventionally processed denture bases are lacking. PURPOSE: The purpose of this clinical study was to compare the retention values of conventional heat-polymerized denture bases with those of digitally milled maxillary denture bases. MATERIAL AND METHODS: Twenty individuals with completely edentulous maxillary arches participated in this study. Definitive polyvinyl siloxane impressions were scanned (iSeries; Dental Wings), and the standard tessellation language files were sent to Global Dental Science for the fabrication of a computer-aided design and computer-aided manufacturing (CAD-CAM) milled denture base (group MB) (AvaDent). The impression was then poured to obtain a definitive cast that was used to fabricate a heat-polymerized acrylic resin denture base resin (group HB). A custom-designed testing device was used to measure denture retention (N). Each denture base was subjected to a vertical pulling force by using an advanced digital force gauge 3 times at 10-minute intervals. The average retention of the 2 fabrication methods was compared using repeated ANOVA (alpha=.05). RESULTS: Significantly increased retention was observed for the milled denture bases compared with that of the conventional heat-polymerized denture bases (P<.001). CONCLUSIONS: The retention offered by milled complete denture bases from prepolymerized poly(methyl methacrylate) resin was significantly higher than that offered by conventional heat- polymerized denture bases.