Three-dimensional processing deformation of three denture base materials

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Prosthodontics

Background:

• Heat-polymerized polymethyl methacrylate denture bases are prone to deformation during and after polymerization.
• This processing deformation can negatively impact the clinical performance and fit of complete dentures.

Purpose of the Study:

• To investigate and quantify the processing deformation of three different denture base materials.
• To evaluate deformation on a standardized anatomical model using advanced scanning and software analysis.

Main Methods:

• Four groups of denture bases were fabricated using different materials (polymethyl methacrylate-based, urethane dimethacrylate-based) and techniques (compression molding, injection molding, light-polymerization).
• A contact scanner and surface-matching software were employed to measure dimensional changes between casts and fabricated denture bases.
• Statistical analysis (Kruskal-Wallis, Mann-Whitney U) was performed with P<.01 significance level.

Main Results:

• Significant differences in processing deformation were found between polymethyl methacrylate-based and urethane dimethacrylate-based resins.
• No significant deformation differences were observed between compression and injection molding techniques for polymethyl methacrylate.
• Similarly, manual adaptation alone and combined with compression molding showed no significant differences.

Conclusions:

• Urethane dimethacrylate-based resins exhibited greater processing deformation compared to polymethyl methacrylate-based resins.
• Compression and injection molding yielded comparable results for polymethyl methacrylate resins.
• The study highlighted complex deformation patterns exceeding linear measurement accuracy.