Accuracy of Conventional and Digital Impressions for Complete-Arch Implant-Supported Restorations
- VernacularTitle:无牙颌种植修复中传统和数字化印模的精度研究
- Author:
Changhong ZHENG
1
;
Lei LI
Author Information
- Keywords: Edentulous; Implant-supported restoration; Digital impression; Conventional impression; Accuracy
- From: Journal of Sichuan University (Medical Sciences) 2025;56(3):778-784
- CountryChina
- Language:Chinese
- Abstract: Objective To evaluate the accuracy of conventional impression techniques,intraoral scanning,and two stereophotogrammetry systems(PIC and ICam4D)for complete-arch implant restorations,and to analyze the influence of varying interimplant distance and implant angulation on the accuracy of each impression method.Methods A total of 6 edentulous maxillary all-on-four casts were fabricated with varying posterior implant parameters,including anterior-posterior(A-P)distances of 20 mm and 35 mm and distal implant angulations of 0°,15°,and 25°.Impressions were obtained using conventional impression techniques,intraoral scanning,and two stereophotogrammetry systems(PIC and ICam4D).The three-dimensional deviations of the impression techniques were measured using reverse-engineering software to evaluate trueness and precision.Results The accuracy of intraoral scanning technology exhibited a declining trend with increasing A-P distance and implant angulation.The maximum deviations in trueness and precision were observed in the posterior region with an A-P distance of 35 mm and a distal implant angulation of 25°,measuring(76.90±43.32)μm and(99.43±74.39)μm,respectively.The conventional impression techniques exhibited stable performance,with mean accuracy deviation values consistently falling below 50 μm.The ICam4D stereophotogrammetry system exhibited the highest precision across all conditions(P<0.05).The maximum precision deviation for PIC system occurred in the right anterior region with an A-P distance of 20 mm and a distal implant angulation of 15°([28.10±18.73]μm),while the maximum trueness deviations for both PIC and ICam4D were observed in the anterior region with an A-P distance of 20 mm and a distal implant angulation of 25°,measuring(62.63±9.40)μm and(83.61±1.76)μm,respectively.The PIC system showed better overall trueness than ICam4D did when distal implant angles were≥15°(P<0.05).Conclusion For complete-arch implant rehabilitation,the accuracy of different impression methods varies depending on implant-related factors.The inter-implant distance and angulation were critical determinants of accuracy for intraoral scanning,whereas conventional impression techniques and the two stereophotogrammetry systems exhibited no clear correlation with these parameters.
