In Vitro Comparison Between Complete-Arch Implant Supported Frameworks Using Intraoral Scanning and Photogrammetry.

Abstract

Purpose: To compare the vertical microgap of complete arch implant supported frameworks (ISF) obtained from one intraoral scanner (IOS) and two different photogrammetry (PG) systems.

Materials and methods: An edentulous mandibular model with four implants (BioHorizons) served as reference. Multi-unit abutments (BioHorizons) were inserted and torqued to 30 Ncm. A digital reference cast (Control group) was obtained by scanning the model with a laboratory scanner (inEosX5, Dentsply Sirona). Three test groups were investigated: PS (Primescan, Dentsply Sirona), ICam (ICam4D, Imetric4D Imaging Sàrl), and PIC (PIC System, PIC Dental). All scans were exported as Standard-tessellation language (STL) files and virtual bars were designed and milled out of titanium (n=2 per test group). The modified Sheffield test was used to quantitatively assess vertical microgaps. Differences between all groups were analyzed using Kruskal-Wallis test (a=0.05). Analysis of variance (ANOVA) was used to compare vertical microgaps at each respective implant position across groups (a=0.05).

Results: Mean vertical microgaps varied across acquisition devices, with lowest values in the control group (22.65±7.279 µm), followed by ICam (24.10±7.991 µm), PIC (30.52± 9.809 µm), and PS (33.21±13.84 µm). Statistically significant differences were detected between Control and PS as well as Control and ICam. No statistically significant difference occurred between the two PG groups. Vertical microgaps were the highest at implant site 44, predominantly observed in groups PS and PIC.

Conclusions: Frameworks fabricated from digital impressions of PG groups showed lower vertical microgaps than those fabricated using the IOS.