ABSTRACT
<p><b>OBJECTIVE</b>To analyze the amount and tendency of methyl methacrylate (MMA) released from autopolymerized denture base polymer (self-curing resin) during processing using time-of-flight mass spectrometer (TOF-MS).</p><p><b>METHODS</b>Self-curing resin was mixed in the container using a ratio of 2 g of powder to 1 g of liquid in accordance with the manufacturer's instructions for 40 s as a specimen. The amount of MMA released from the specimen was continuously monitored and simultaneously recorded every minute by TOF-MS since immediately after mixing. A total of five specimens were monitored.</p><p><b>RESULTS</b>The amount of MMA increased dramatically at 11 min [(45.2 ± 3.5) mg/L] after mixing, and reached the highest level at 13 min [(228.9 ± 22.6) mg/L], then become stable at 23 min [(8.8 ± 2.3) mg/L] after mixing.</p><p><b>CONCLUSIONS</b>The releasing tendency of MMA could be analyzed accurately with continuously monitoring during processing. The amount of MMA released from self-curing resin changed rapidly and the processing was complicated and changeful.</p>