Residual monomers and volatile leachable substances of conventional and CAD/CAM-fabricated denture base materials — GC-MS analysis and surface characterization

Abstract Objectives Methacrylic acid ester-based resins for denture fabrication release residual monomers and leachable substances that may interact with oral tissues. With increasing adoption of CAD/CAM technologies, a systematic comparison of leachable substance profiles and surface characteristics across polymerization methods is needed. Materials and methods This study compared the chemical composition and profiles of leachable substances of four denture materials – autopolymerized, thermal polymerized, milled, and 3D-printed – using gas chromatography–mass spectrometry (GC–MS). Surface roughness was evaluated by confocal microscopy. Results GC–MS screening detected 24 distinct compounds in the solid specimens. Among the MMA/PMMA-based materials, methyl methacrylate content was highest in the thermally polymerized resin, followed by the autopolymerized and milled materials, and absent from the 3D-printed resin, consistent with its MMA-free formulation. MMA levels in the extracts did not exceed those of the negative control in any group. Surface roughness was comparable on the polished face (R a ≈ 0.21–0.25 μm), consistent with SEM findings but material-dependent on the unpolished, tissue-contacting face (R a 0.37–1.03 μm). Conclusions Both fabrication method and material formulation influence the volatile and semi-volatile extractables of denture resins. As the present GC–MS screening may not reliably capture high-molecular-weight dimethacrylates such as Bis-EMA and UDMA, novel CAD/CAM materials require additional, complementary toxicological evaluation. Clinical relevance The leachable substance profiles of CAD/CAM denture resins, particularly the distinct compounds detected in the 3D-printed material, underscore the need for material-specific biocompatibility data to support informed clinical material selection and patient safety.