Thermogravimetric Characterization of the Microstructui Composition of Polyamide Injection Molded Denture Base Material vs Conventional Compression Molded Heat-cured Denture Base Material.

BACKGROUND: Thermoplastic resin polymers are widely used in medicine due to their biostability and hypoallergenic properties, making them a possible alternative to poly-methylmethacrylate (PMMA). The current research examined the microstructure of a rapid injection molding system thermoplastic resin for construction of flexible denture compared with that of heat-cured PMMA. MATERIALS AND METHODS: A total of 40 disk-shaped specimens (25 mm in diameter and 3 mm in thickness) were prepared and divided into two groups of 20 disks each (group I samples were of thermoplastic acrylic resin while group II was heat-cured PMMA resin). RESULTS: In group I, thermogravimetric analyzer showed that increasing the temperature up to 169 degrees C resulted in about 1.3% of the material loss, and after that the material remains thermally stable up to 200 degrees C. Group 11 showed 2.24% weight loss at 171 degrees C, and further weight loss (12.025%) was observed on heating to 230 degrees C. Fourier transform infrared (FTIR) spectrophotometer analysis in the range of 400-4000 cm(-1) detected the presence of an amine group (N-H) in group I samples and the presence of methylene group attached to inorganic Si as reinforcement filler (Si-CH3). CONCLUSION: Thermoplastic resin displayed excellent thermal stability and the absence of residual monomer within the polymerized material, suggesting its suitability for the fabrication dentures.