Can transfer type and implant angulation affect impression accuracy? A 3D in vitro evaluation

Abstract

Impression accuracy is fundamental to achieve a passive fit between implants and the superstructure. Three transfer types were tested to evaluate the differences in impression accuracy and their efficiency in case of different implant angles. A master model with four implant analogues placed at 0°, 15° and 35° was used. 27 impressions were taken with three different types of impression coping: closed tray technique coping (CT), open tray technique coping (COT) and telescopic open tray coping (TOT). The impressions were poured. Analogues were matched with scan bodies to be scanned and exported in STL. An implant bar was designed from each STL and another one from the master model. A comparison between these bars was obtained. Linear and angular measurements for every type of coping were calculated for different angulations. The collected data were analyzed with ANOVA test (95% of confidence). Student’s t test showed a significative discrepancy (p ≤ 0.001) on linear and angular measurements on Δx, Δy, Δz with different transfer types as well as diverse implant positioning angles (p ≤ 0.001). Within the limitations of this study, it can be concluded that the coping type and the implants divergence may be significant parameters influencing the impression accuracy.

Accuracy of digital implant impressions in clinical studies: A systematic review

“…While restoring natural teeth, minor inaccuracies can be compensated by their inherent mobility, which is not possible in case of implants as they have a 10‐fold lower inherent mobility than natural teeth (Chang et al, 2012; Winter, Klein, & Karl, 2013a,b). Thus, implant impressions play a key role in achieving a passive fit of implant‐supported prosthodontic restorations (Farronato et al, 2021), as the prosthetic restoration is fabricated on the basis of the digital or conventional models. However, passive fit can only be guaranteed if prosthodontic restoration can be inserted without any tension, which requires an accurate model (Abu Ghofa & Onoral, 2021).…”

Accuracy of multiple implant impressions using different combinations of impression materials using closed tray technique

“…The goal of achieving an accurate, passively fitting prosthesis[ 1 ] is by replicating the intraoral connection of implants through impression processes that act as a permanent record in the creation of a dental restoration or prosthesis. [ 2 ] Other than recreating surface detail, it is of main concern to preserve the 3D orientation of the implant same as present intraorally for successful implant prosthodontic treatment.…”