مقالات

:PURPOSE

The aim of this in vitro study was to compare the accuracy of two different impression techniques for the All-on-Four implant therapy protocol

:MATERIALS AND METHODS

An acrylic resin analog for an edentulous maxilla with four internal connection implants (Replace Select, Nobel Biocare) was fabricated according to the All-on-Four protocol. A total of 40 impressions were made with different techniques (open and closed tray) at abutment and implant levels and poured in type IV dental stone. A coordinate measuring machine was used to record the x, y, and z coordinates and angular displacement. The measurements were compared with those obtained from the reference model. Data were analyzed with analysis of variance and t test at α = .05

:RESULTS

There was less linear and rotational displacement for the open-tray technique when compared with the closed-tray technique (P = .02 and P < .001, respectively). Impressions made at abutment level produced fewer linear and rot