Comparison of the accuracy of different impression procedures in case of multiple and angulated implants

Abstract

Abstract Background There is no consensus in the literature regarding the impression procedures in the presence of multiple and angulated implants. Methods Three maxillary master models with 6 implants bilaterally positioned in anterior, premolar and molar regions were fabricated. In model 1, all implants were placed in parallel; in models 2 and 3, anterior implants were buccally inclined and posterior implants were distally inclined in 10- and 20-degrees, respectively. Three different impression copings (hexed, non-hex, multi-unit) and two different impression techniques (splinting and non-splinting) were tested. A total of 180 impressions (n = 10 per group) were made using mono-phase vinyl poly-siloxane. Master models and duplicate casts were scanned by a 5-axis laboratory scanner and data were transferred to a software program for the alignment of master and duplicate copings. Coronal and angular deviations were calculated, and data were statistically analyzed. Results For angulated models, the lowest deviation values were detected at the splinted non-hex coping group (P < 0.05). Conclusions Implant angulation, impression coping type, and splinting the impression copings had significant effects on the accuracy of impressions. Trial registration Not applicable.