This video illustrates a simple way to get rid of air bubbles that often occur when fabricating flexible partials.
After you design and block out on the master model, duplicate it twice. Then, begin the wax up for the framework and clasps on one of the duplicates. Wax in a uniform way, we recommend 1.5mm - 2.5mm. Depending on the desired flexibility, thickness will vary. Do not set up the teeth.
Invest and flask the waxed up model you worked on. Use proper sprue placement, close, pour/set, and boil out. Then, open the flask and clean out any excess wax to prepare for the first injection. Since we are injecting Karadent, be sure to use a high quality acrylic separator and let it dry completely (not peeling) before injecting. TCS recommends injecting a medium Karadent cartridge in shade (N) Clear first, to create the transparent framework base. Be sure to inject with a hot flask and the correct Karadent time and temp for your TCS unit.
After injection, trim the sprues and clean up the framework. Optional: Drill holes to create mechanical retention on the area where the teeth will go. Then, snap the framework on to the second duplicate model and wax up for the teeth setup. Drill diatorics in the teeth and setup as normal.
When you finish waxing and setting up the teeth, flask the case by covering everything except for the waxed area. Run sprues to the wax site, close the flask, and then pour the 2nd half. Once the stone sets, continue with the boil out. For optimal results, synchronize your final injection with the boil out to have approximately 5 minutes before you need to inject. The flask will be hot, which allows for the fusing liquid to work best. After you boil out, clean out the excess wax and paint a high quality separator only on the stone surface. Do not paint separator on the bonding areas where you will apply fusing liquid.
After you apply separator, apply fusing liquid to the areas that will fill with new material. Use a small brush or Q-tip to assist you in adding the fusing liquid accurately and evenly. Covering the entire bonding site in Fusing Liquid is key to making the new material bond with the old material. Let the Fusing Liquid stand for 3 minutes before injecting. Ideally this step should occur 5 minutes after the boil out to keep the flask hot for injection.
Carefully close the hot flask and inject a medium Karadent cartridge in shade (2) St. Pink or (4) Dark Pink using the correct time/temp for your unit. This case will require a medium sized cartridge but, cartridge size is dependent on the size of the area being covered. Once the flask cools (~20min), open and process to finish and polish.