” DOUBLE STEP REVERSE”( DSR): A NEW PROTOCOL IN POLYVINYLSILOXANES( PVS) IMPRESSION- TAKING PROCESS- TWO CASE REPORTS
Figure 3. Dies made from an Ultimate impression( U) and from Aquasil XLV + monophase( A)
Figure 4. The duralay post ready to be transformed in a“ Bio-HPP” post
Figure 5. Endorsal x-rays that shows the space between posts and dies( Left: DRS impression, Right: traditional impression)
Reverse), requires the operator to place the intrasulcular tip straight into the sulcus for a direct material“ wash” placement and leave the material wash to fully set. Exploiting the power of airpressure, the clinician is able to precisely place the wash material over the margins in a single step without having to retract the tissues with any retraction cord or astringent paste. Once set, the wash material is ready to be taken away from the mouth, by inserting an impression tray( with a“ tray material”) and positioning in patient’ s mouth, over the wash material. After the recommended setting time( 3 minutes), the operator removes the tray and performs a visual inspection. The hypothesis of this work is the clinical verification of the results obtained by applying either the new DSR technique and the well-known protocol 3-6, 8-9. Putty-wash 1-step that instead recommends to place the wash material( type 3) on the preparations then the heavy-viscosity or monophase material( type 1- 2).
2. Cases Reports 2.1. Case Report n ° 1 Tooth # 13 shows a very old ceramic crown with a considerable misfit, which hides a damaged and aged core structure so that it requires a thorough
186 STOMA. EDUJ( 2016) 3( 2)