Effect of the association between the tray and impression techniques on angulated implants using the All-on-Four system

Abstract

Background: Due to the circular shape and smaller diameter of dental implants in comparison with the walls of natural teeth, it is difficult to determine how to build an artificial crown with an abutment system that is similar to a natural tooth. Purpose: This study aimed to analyze the effect of the association between the tray and impression techniques on angled implants in a prefabricated master cast in CAD-CAM. Methodology: The experimental groups were divided as follows: (G1) pour-up with plaster type IV Fuji Rock EP and Matrix CAD/CAM, (G2) pour-up with plaster type IV Durone and Matrix CAD/CAM; and (G3) Metallic Tray. For each group, we used an impression technique with squared, non-splinted copings (S) and an impression technique with squared, splinted copings using metal drill burs and Pattern resin (SS) in an edentulous jaw containing 2 angulated posterior implants (defined by letters A and D) and 2 parallel anterior implants (B and C). To evaluate the extensions of gaps, an analysis of variance (ANOVA) with two main factors was used. This analysis was complemented by multiple comparisons of means by Tukey's test, with a significance level of 5% for decision-making. Results: The repeated-measures ANOVA showed a significant interaction among all factors (p <0.001). The significant differences between means were only similar in A and C. For Analog A, the mean was significantly different from the control, while for the analog C, only the mean of group G2-S was higher than the control. This same analysis showed no significant effect of the group (mode of impression), the impression technique or the interaction between them (p> 0.05). Conclusion: There was no statistically significant difference between the groups compared with the master cast.