Abstract
We attempt to improve the adaptability of denture base resins by initiating the polymerization from the mucosal side using selective microwave-heating of the model and investing stones.
We also attempted to develop resins suitable for microwave polymerization.
This investigation used differential scanning calorimetry (DSC) to evaluate the relationship between the heating rate and initiation temperature of polymerization. We also controlled the initiation temperature of polymerization by adding an activator, dimethyl-p-toluidine (DMPT) and an inhibitor, hydroquinone (HQ) to freshly-distilled methylmethacrylate (MMA).
The results were summarized as follows.
1. The initiation temperature of polymerization increased with the heating rate. Acron had the highest initiation temperature for polymerization, followed by freshly-distilled MMA containing 0.0050 wt% HQ, while freshly-distilled MMA and Quick Acron did the lowest. The difference in the initiation temperature between resins remained constant irrespective of the heating rate.
2. The initiation temperature for polymerization increased 10℃ with increments in the HQ concentration up to 0.0050 wt%.
3. The initiation temperature for polymerization decreased 35℃ with increments in the DMPT concentration up to 1.00 wt%.
4. The effect of the dual addition of HQ and DMPT on the initiation temperature for polymerization did not differ significantly from the effect of single additions of HQ and DMPT.
