” DOUBLE STEP REVERSE”( DSR): A NEW PROTOCOL IN POLYVINYLSILOXANES( PVS) IMPRESSION- TAKING PROCESS- TWO CASE REPORTS
Figure 6. The sequence that leads to the definitive crown
Figure 7. Before and after the prosthetic procedures
Figure 8. Teeth 16 and 17 are in need of prosthetic treatments
replacement.( Fig. 1) We removed the metal post by means of an ultrasonic insert and then it is time to take a couple of impressions. The First one is made following the protocol of the“ DSR” technique: the“ Wash material”( Aquasil Ultimate Wash), after being left for 3 minutes within the root canal, is covered and firmly bonded by the“ Tray material”. These two materials, after their setting time, are ready to be removed from the arch. The Second impression is made of an eXtra-Light
Viscosity( Aquasil XLV) in a monophase technique, where a lentulo is used to push the XLV material deep inside the root canal, gaining more push from the subsequent monophase material, delivered by an impression tray.( Fig. 2) At this time, two dies are made and tagged as“ U”( which stands for Ultimate) and as“ A”( for Aquasil Monophase)( Fig. 3); then sent to the laboratory where they make two duralay resin posts according to the plaster models. Through the process of thermocompression, the
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