Related Experiment Video
Updated: Jun 8, 2026

Impact of Fabrication Techniques and Polishing Procedures on Surface Roughness of Denture Base Resins
Published on: January 17, 2025
Mechanical properties of injection-molded thermoplastic denture base resins
Ippei Hamanaka1, Yutaka Takahashi, Hiroshi Shimizu
1Division of Removable Prosthodontics, Fukuoka Dental College, Fukuoka, Japan.
Objective:
To investigate the mechanical properties of injection-molded thermoplastic denture base resins.
Material And Methods:
Four injection-molded thermoplastic resins (two polyamides, one polyethylene terephthalate, one polycarbonate) and, as a control, a conventional heat-polymerized polymethyl methacrylate (PMMA), were used in this study. The flexural strength at the proportional limit (FS-PL), the elastic modulus, and the Charpy impact strength of the denture base resins were measured according to International Organization for Standardization (ISO) 1567 and ISO 1567:1999/Amd 1:2003.
Results:
The descending order of the FS-PL was: conventional PMMA > polyethylene terephthalate, polycarbonate > two polyamides. The descending order of the elastic moduli was: conventional PMMA > polycarbonate > polyethylene terephthalate > two polyamides. The descending order of the Charpy impact strength was: polyamide (Nylon PACM12) > polycarbonate > polyamide (Nylon 12), polyethylene terephthalate > conventional PMMA.
Conclusions:
All of the injection-molded thermoplastic resins had significantly lower FS-PL, lower elastic moduli, and higher or similar impact strength compared to the conventional PMMA. The polyamide denture base resins had low FS-PL and low elastic moduli; one of them possessed very high impact strength, and the other had low impact strength. The polyethylene terephthalate denture base resin showed a moderately high FS-PL, moderate elastic modulus, and low impact strength. The polycarbonate denture base resin had a moderately high FS-PL, moderately high elastic modulus, and moderate impact strength.
Related Concept Videos
Classification and Mechanical Properties of Synthetic Polymers
Plastic Behavior
Mortar Properties
Residual Stresses
Polymer Classification: Architecture
Polymer Classification: Stereospecificity
