GAP Australasian-Dentist-May June 2019

Category AustrAlAsiAn Dentist 81 STEP 3 Vertys easy putty application Over the two first layers, a third layer of harder silicone material was then applied. this is to create the fit to the flask (Furbo). this material is used in lieu of the plaster that ensures the fit to the flask. the silicone-packed impression was then tightly screwed into place with fixation screws using the dynamometric key. ‘Dynamo Block’ guarantees a regular and reproductible pressure when making the duplicate. STEP 4 Removing the models When fully hardened, the silicone was removed, the wax was boiled out and the teeth removed. injection channels and access for free flow of the acrylic were created. STEP 5 Injecting Vertys prothesis excel acrylic Before injection, the stock teeth were carefully positioned in the mould. the syringe was then filled. When doing this it is essential to expel all air from the syringe. time should be taken to do this stage with care. During injection the pressure was kept constant and the injection was done in one constant motion without pause until the acrylic had filled the flask. Prothesis excel is a heat-curing acrylic. it was cured at 50°C for 30 minutes with two bars of pressure. A cooling time of ten minutes was then required. Curing must be done in a suitable curing device – here the Vertysytem Asterix was used. STEP 6 Removal and finishing the first set of dentures were then gently removed and finished. the occlusion was a perfect match with the wax-up. the sculpting that was done in the wax had been preserved and reproduced perfectly. Furthermore, there was virtually no flash, so the finishing was extremely fast. note the remarkable shine that was obtained with just a quick, light polish. STEP 7 Fabrication of the duplicate denture When fabricating the duplicate denture, we did not use stock teeth, since those used for the primary denture had been ground and modified at the chairside. instead a dentine acrylic would be injected at a later stage. this allowed us to respect the recorded morphology. First the silicone moulds were pre p a red for the injection of the excel acrylic. the flasks were closed and the acrylic was injected – at this stage we also injected the teeth in pink acrylic – these would be modified later. the curing was done in the same way as for the original denture. lInICal Result after deflasking.