Comparative evaluation of the effects of implant position, impression material, and tray type on implant impression accuracy.

Purpose: To evaluate the effect of implant position, impression, and tray material on the accuracy of implant impressions of edentulous arches with multiple implants.

Materials And Methods: Four experimental groups were produced; medium-viscosity polyvinyl siloxane (PVS) was used in 3 groups and polyether was used in 1 group. In PVS groups, different tray types were used; metal stock trays, custom acrylic tray, and full-arch perforated plastic trays. In polyether group, custom acrylic trays were used. The discrepancies in 3 dimensions were measured.

Results: The casts obtained exhibited small deviations (7.50-9.71 µm) from the master cast. There was no statistically significant difference between the polyether and PVS groups. Similarly, different tray materials did not produce any statistically significant discrepancies within the PVS groups. There was no significant difference among the groups when the accuracy of anterior implants were compared, but within-the-group comparisons showed that except group 1 (GR1), the posterior implants demonstrated more accuracy than anterior ones.

Conclusions: Polyether and PVS can safely be used for the impressions of the edentulous arches with multiple implants and different tray types produce similar accuracy results.