The dimensional accuracy of four impression techniques with the use of addition silicone impression materials.
OBJECTIVE
The aim of this study was to assess the influence of impression technique selection on the dimensional accuracy of the produced casts.


METHODS
Four impression techniques (single-stage, two-stage, monophase, and heavy/wash technique) were used to make addition silicone impressions of a phantom head maxillary jaw. The impression materials used were Aquasil, Extrude, and Imprint. Measurements on casts were made for the inter-abutment distances to assess dimensional accuracy.


RESULTS
There was a significant difference (p < 0.05) for the anteroposterior distances with the single-stage technique. The crossarch distances were slightly increased compared with the master model for all techniques, but significant statistical differences were only recorded for the single-stage technique and the monophase technique. The monophase technique demonstrated irregular results. The heavy/wash technique showed no significant differences for all the measurements compared with the standard model.


CONCLUSIONS
The results suggest that the selection of impression technique is an important factor that can affect the dimensional accuracy of the subsequent models which are used for indirect restorations.
Al-Bakri
I A
IA
Department of Allied Dental Sciences and Dental Technology, Faculty of Applied Medical Science, Jordan University of Science and Technology, Irbid, Jordan.
Hussey
D
D
Al-Omari
W M
WM
D000704:Analysis of Variance; D003760:Dental Impression Materials; D003761:Dental Impression Technique; D003765:Models, Dental; D011145:Polyvinyls; D012826:Silicone Elastomers; D012833:Siloxanes
D003760:Dental Impression Materials; C102652:Extrude; C521416:Imprint II; D011145:Polyvinyls; D012826:Silicone Elastomers; D012833:Siloxanes; C480691:aquasil; C034183:vinyl polysiloxane