In vitro evaluation of methyl methacrylate (MMA) release from different temporary denture base materials

INTRODUCTION: Residual methyl methacrylate (MMA) released from temporary denture base materials is of clinical concern due to its potential biological effects. Recently, light polymerized and 3D-printed denture base resins have emerged as alternatives to conventional cold-polymerized acrylics. This study aimed to compare the in vitro MMA release levels of three clinically relevant temporary denture base materials. MATERIALS AND METHODS: Three materials were tested: cold-polymerized acrylic resin, light-polymerized baseplate resin, and 3D-printed denture base resin. Ten samples were prepared for each group (n=10), standardized to 0.05 g per specimen. Samples were immersed in 2 mL and 5 mL of artificial saliva and incubated at 37°C. MMA release was quantified using high-performance liquid chromatography (HPLC) at 15 minutes, 30 minutes, 1 hour, and 24 hours. Data distribution was analyzed with the Shapiro-Wilk test; the effects of time, material, and saliva volume were assessed using two-way ANOVA and Tukey post-hoc tests (p<0.05). RESULTS: No MMA release was detected before 24 hours in the 3D-printed and light-polymerized groups. The cold polymerized acrylic group showed progressive MMA release starting from 15 minutes, with a significant increase over time (p<0.001). At 24 hours, it exhibited the highest MMA levels among all groups. A significant difference between 2 mL and 5 mL saliva volumes was observed only in the cold-cure group. The 3D-printed resin showed the most stable performance across all time points. CONCLUSION: Temporary denture base materials should be selected with consideration of residual monomer release. The results support the biocompatibility of 3D-printed resins for short-term clinical applications, especially when early MMA release and toxicity are of concern.