Accuracy of tooth-implant impressions: Comparison of five different techniques.

Abstract

To compare the accuracy of five different tooth-implant impression techniques. In this in vitro, experimental study, an acrylic model containing one bone-level Straumann dental implant at the site of maxillary first molar and an adjacent second premolar prepared for a porcelain fused to metal restoration was used. Impressions were made from the model using five different one-step tooth-implant impression techniques including scanning with an intraoral scanner, occlusal matrix, wax relief, closed-tray, and open-tray techniques. Each technique was repeated 15 times. The impressions were poured with dental stone, and the obtained casts were scanned by a laboratory scanner. The scan file of each technique was compared with the scan file of the original acrylic model by Geomagic Design X software. Data were analyzed by one-way analysis of variance, and Tamhane's post-hoc test (α = 0.05). For dental implant, intraoral scanning had the highest accuracy (0.1004 mm2 ) followed by open-tray (0.1914 mm2 ), occlusal matrix (0.2101 mm2 ), closed-tray (0.2422 mm2 ), and wax relief (0.2585 mm2 ) techniques (p < 0.05). For the prepared tooth, wax relief (0.0988 mm2 ) had the highest accuracy followed by occlusal matrix (0.1211 mm2 ), open-tray (0.1663 mm2 ), closed-tray (0.1737 mm2 ), and intraoral scanning (0.4903 mm2 ) technique (p < 0.05). For both dental implant and prepared tooth, occlusal matrix (0.2431 mm2 ) had the highest accuracy followed by open-tray (0.2574 mm2 ), wax relief (0.2693 mm2 ), closed-tray (0.2862 mm2 ), and intraoral scanning (0.3192 mm2 ) technique (p > 0.05). The compared simultaneous tooth-implant impression techniques had comparable accuracy with no significant difference.