Closed versus open tray technique | 合法醫療器材資訊網

The open tray technique for making a definitive impression is one of two choices (the other being a closed tray impression) in the fabrication of a fixed complete denture. The open tray technique is specifically indicated, when the implants are not sufficiently parallel[1] to allow an impression to be withdrawn from multiple impression copings.

The temporary copings can be connected using flowable composite, impression plaster or acrylic resin (Fig 1). Connecting the copings[2] may assist in improving the accuracy of the definitive impression and cast and may facilitate fabrication of a verification jig.

The impression tray is coated with adhesive and loaded with heavy-body impression material. Concurrently light-body impression material is expressed around the copings to capture the morphology of the soft tissue (Fig 2). Monophase impression material&n...