Degradation of Printed Polymethyl Methacrylate Denture Base Materials under Simulated Oral Conditions: A Systematic Review and Meta-analysis

Aim: To investigate the effects of artificial aging on the mechanical, physical, and chemical characteristics of polymethyl methacrylate (PMMA) denture base materials.Materials and methods: This systematic review and meta-analysis of in vitro studies searched five databases until December 2025.This was reported in accordance with the preferred reporting items for systematic reviews and meta-analyses 2020 (PRISMA 2020) guidelines.Selected studies evaluated heat-cured, computer-aided design/computer-aided manufacturing (CAD/CAM)-milled, and three-dimensionally (3D)-printed PMMA denture base materials.All these used artificial aging protocols.Random-effects meta-analysis was applied wherever necessary.Results: Artificial aging resulted in a significant decrease in flexural strength after aging.There were small to moderate decreases in mean values based on fabrication method and aging protocol applied.Computer-aided design/computer-aided manufacturing-milled PMMA consistently showed the highest flexural strength values before and after aging.Hardness and roughness were not affected by standard thermocycling protocols.There was some variability with coffee or staining aging protocols.Three-dimensionally printed PMMA showed higher water sorption values than milled or conventional PMMA.The levels of residual monomer released were low for all fabrication techniques.Conclusion: Artificial aging resulted in small to moderate decreases in the flexural strength of PMMA denture base materials.Computer-aided design/computer-aided manufacturing-milled PMMA showed the least change with aging.Three-dimensionally printed PMMA exhibited the greatest change.Clinical significance: Denture base material selection should account for the method of fabrication and expected aging effects, especially in patients with high denture loading.