Objectives: this study was conducted to compare the adaptation accuracy of three different denture base materials for the edentulous maxilla; compression molded heat cured polymethyl methacrylate (PMMA), injection molded thermoplastic resin and versacryl.
Methodology: a completely edentulous model for the upper arch was duplicated to 15 stone casts, then divided equally into three groups: group I (compression molded PMMA), group II (injection molded thermoplastic resin), group III (versacryl). The dentures on their respective casts were sectioned 5 mm anterior to the posterior border and the gap distance between the denture base and the cast was measured using a traveling microscope at the mid-palatal and crestal regions. The data was collected and statistically analyzed.
Results: the least gap measurement was found in group II at the crestal and mid-palatal sections, while the highest gap measurement was found in group I followed by group II. A statistically significant difference was found between the three groups at the crestal and mid-palatal sections, and between the crestal and mid-palatal measurements within each group.
Conclusions: injection molded thermoplastic resin showed the highest adaptation accuracy as measured by gap distance, followed by versacryl and then compression molded heat cured PMMA.