Effects of Implant Angulation and Impression Coping Type on the Dimensional Accuracy of Impressions.

Abstract

To analyze the accuracy of impressions in relation to implant angulation and type of impression coping. Three metal master models with 2 implants of 3 different angulations (parallel, mesiodistal, and buccolingual) were fabricated. Nine groups of experimental models were fabricated to duplicate the 3 master models using 3 types of impression copings: transfer, pick-up, and hybrid. The distance between the analogs for each model was measured using a video measuring system. The influence of angulation and type of impression coping was analyzed by a two-way ANOVA (P < 0.05). There were significant differences in error rates in relation to implant angulation and type of impression coping (P < 0.05). Impressions of buccolingually divergent implants with transfer copings showed statistically higher error rates than other groups (P < 0.05). Buccolingual divergence can be a variable that influences the impression accuracy of transfer copings compared with pick-up and hybrid copings. Hybrid copings demonstrate reasonable reproducibility similar to that of pick-up copings.