Objective: The aim of this study was to compare radiographically thermoplastic and conventional heat cured acrylic resin as denture base material for mandibular conventional type implant retained complete overdentures and evaluate the effect of this difference on the implants stability.

Materials and methods: Fourteen edentulous patients were selected to construct two implants retained mandibular overdenture. The patients were equally divided into two groups according to material of denture base: group I, patients with thermoplastic resin constructed by injection moulding technique; and group II, patients with denture bases constructed by conventional heat curing acrylic resin. Radiographic and implant stability parameters were evaluated 1 year study.

Results: There was no statistically significant difference between the thermoplastic and conventional heat cured denture bases for implant retained mandibular overdenture in bone resorption and stability of the implants.
Conclusion: There was no statistically significant difference between the thermoplastic and conventional heat cured implant overdenture bases. Both denture bases have beneficial effect on implant osseointegration and stability.