Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Oct;109(4):884-894.
doi: 10.1007/s10266-021-00619-y. Epub 2021 Jun 1.

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

Davide Farronato  1 , Pietro Mario Pasini  1 , Veronica Campana  2 , Diego Lops  3 , Lorenzo Azzi  4 , Mattia Manfredini  5
Affiliations

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

Davide Farronato et al. Odontology. 2021 Oct.

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.

Keywords: Dental implants; Implant angulation; Implant impression technique; Impression accuracy; Impression coping.

PubMed Disclaimer

Conflict of interest statement

The study was funded by Kristal (Kristal S.r.l, Trezzano sul Naviglio, Italy) and conducted independently by University Insubria Varese with the support of an external technical structure (LaStruttura SPA, Cassano Magnago, Italy), also disinterested. A disclosure agreement states that results and publications won’t be anyway influenced by any commercial purpose. The authors declare the absence of any conflict of interest.

Figures

Fig. 1
Fig. 1
The three transfers under analysis: TOT A, COT B and CT C, respectively
Fig. 2
Fig. 2
A The digital project of the master model and of the individual impression tray. B A section of the two structures showing their matching and the holes direction
Fig. 3
Fig. 3
A The master model with two sample transfers in place, at 0° (CO) and 15° (T15). B An example of impression, with VPS material and its corresponding type IV die stone cast with analogues in place. C A cast with scan bodies matched to the analogues under analysis. D An STL file revealing the implant’s position referred by the two transfers under analysis
Fig. 4
Fig. 4
A 3 points alignment between the virtual scan bodies and the real one acquired from the cast. B A section of the scan body used to verify the matching reliability. C A bar projected from the implant’s position acquired. D The chromatic scale used to verify the differences in micron during alignment
Fig. 5
Fig. 5
A Measurement of the linear and angular displacement of TB compared to RB in X-, Y- and Z-axes. The linear one is lead considering the distance between the center of the outermost circumference of RB and TB’s cylinders. B The angular one is obtained from the distance, on plane x–z, between the axis of the two outermost circumferences (one belonging to the RB and one to the TB)
Fig. 6
Fig. 6
The results of the measurements considering both the transfer types (TOT, COT and CT) and the angle of implant’s position. It is considered a linear and angular displacement
See this image and copyright information in PMC

References

    1. Buzayan MM, Yunus NB. Passive fit in screw retained multi-unit implant prosthesis understanding and achieving: a review of the literature. J Indian Prosthodont Soc. 2014;14(1):16–23. doi: 10.1007/s13191-013-0343-x. - DOI - PMC - PubMed
    1. Guichet DL, Caputo AA, Choi H, Sorensen JA. Passivity of fit and marginal opening in screw- or cement-retained implant fixed partial denture designs. Int J Oral Maxillofac Implants. 2000;15:239–246. - PubMed
    1. Karl M, Taylor TD, Wichmann MG, Heckmann SM. In vivo stress behavior in cemented and screw-retained five-unit implant FPDs. J Prosthodont. 2006;15:20–24. doi: 10.1111/j.1532-849X.2006.00064.x. - DOI - PubMed
    1. Maiorana C, Farronato D, Pieroni S, Cicciu M, Andreoni D, Santoro F. A four-year survival rate multicenter prospective clinical study on 377 implants: correlations between implant insertion torque, diameter, and bone quality. J Oral Implantol. 2015;41(3):e60–e65. doi: 10.1563/AAID-JOI-D-13-00206. - DOI - PubMed
    1. Abduo J, Judge RB. Implications of implant framework misfit: a systematic review of biomechanical sequelae. Int J Oral Maxillofac Implants. 2014;29(3):608–621. doi: 10.11607/jomi.3418. - DOI - PubMed

Substances