![]() ![]() Plastic stock tray with access window over the copings. The window must be wide enough to ensure proper space between tray and coping for impression material, so that impression copings get properly engaged in impression without any movement, which is very important for the passive fit of the prosthesis.įigure 5. An access window ( Figure 5) was created directly over the impression copings with the carbide trimming bur. Modified impression copings splinted with unmodified coping with autopolymerizing acrylic resin.Ī plastic stock tray which can be used for making impression of the partially edentulous patients was selected. To overcome this, the two impression copings were connected with auto polymerizing acrylic resin ( Figure 4, Rapid Repair acrylic resin. Insufficient space between two impression copings, preclude the flow of impression material between them, which may lead to movement of the impression coping resulting in an inaccurate impression. the complete seating of the impression copings was verified with a periapical radiograph. ![]() After modification, it was secured with long connecting/fastening screw to the respective implant. The other impression coping was modified by holding it with artery forcep and cut it with carborundum disc so that it fits properly over the other implant. ![]() Modified impression copings in proper position. Modified healing abutment in position.įigure 3. Direct impression coping (AlphaBio, Israel) was on one of the implants (SPI, AlphaBio, Israel) and secure it with long connecting screw ( Figure 3).įigure 2. Healing abutments were cleaned and removed from mouth ( Figure 2) and placed in a disinfecting solution. This article describes a modified direct impression coping technique to overcome the difficulties associated in making an impression in such conditions. ![]() Due to insufficient space, the direct transfer copings do not fit precisely over the implants, which requires the modification of one or both transfer copings. The fabrication of an accurate passive fit prosthesis from such an impression is not possible, which requires lot of adjustments during seating of the prosthesis and also create associated soft tissue problems.įor the fabrication of accurately fit implant supported prosthesis for the closely placed implants, a precise registration of the position of the implants is important. But most of the direct impression coping supplied by the manufacturer are bulky in upper part which may preclude the accurate seating of the impression coping to the respective implants, thereby resulting in an inaccurate replication of position of the implants on the cast. Radiograph – closely positioned implants.ĭirect impression coping (open tray) technique is usually preferred over indirect impression coping (close tray) technique for making an accurate Impression of the implants. Unplanned implant placement or change in angulations of the implants due to anatomic limitations 3, 4 such as mandibular canal, mental foramen, nasal floor, sinus cavities or roots of the adjacent teeth, might result in close approximation of the implants ( Figure 1), which poses tough challenges to the restorative dentist, who have to overcome certain technical difficulties for the fabrication of the prosthesis including making of a proper impression.įigure 1. So, careful performance of each and every laboratory and clinical step is important to minimize the positional discrepancies. The passive fit of the implant components is very critical for the long term success of the implant restorations 1 Component failure or biologic complications 2 may occur due to poor fit. ![]()
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