Accuracy of a complete arch noncalibrated splinting implant scanning technique with a palatal orientation recorded by using different intraoral scanners.

Abstract

Statement of problem: The accuracy of noncalibrated splinting implant scanning techniques that include horizontal implant scan bodies (ISBs) positioned connecting the implants by following the shape of the dental arch have previously been analyzed. A novel horizontal ISB connected in the center of the arch has been introduced; however, the accuracy of this noncalibrated splinting implant scanning technique with a palatal orientation is unknown.

Purpose: The purpose of this in vitro study was to compare the accuracy of a nonsplinting and noncalibrated splinting implant scanning technique recorded using 5 intraoral scanners (IOSs).

Material and methods: A laboratory scan (reference scan) of an edentulous stone cast with 6 implant abutment analogs (MultiUnit Abutment Plus Replica) was acquired (T710). Five groups were created based on the IOS tested: TRIOS5, Primescan, i700, Aoralscan3, and iTero Element 5D. Two subgroups were defined based on the implant scanning technique used to record complete arch implant scans: a nonsplinted (NS-ISB subgroup) or noncalibrated splinting (NCS-IOC group) implant scanning technique (n=10). In the NS-ISB subgroup, an ISB (TrueScan Body) was positioned on each implant abutment, and complete arch implant scans were recorded and exported in standard tessellation language (STL) format. In the NCS-IOC subgroup, a horizontal ISB (IOConnect) was positioned on each implant abutment connecting them in the center of the palate. Implant scans were recorded, capturing only the section of the horizontal ISBs located in the center of the arch. Then, the scans were processed by a specific program (TruSuite), and the STL of the scans were exported. A program (Geomagic) was used to perform linear and angular measurements among the ISBs in the control scan and each specimen. The measurements obtained in the control scan were used as a reference to measure the scanning distortion of each specimen. The 2-way ANOVA Welch and pairwise multiple comparison Tukey tests were used to analyze trueness (α=.05). The Levene and pairwise multiple comparison Wilcoxon rank tests were used to analyze precision (α=.05).

Results: Linear trueness discrepancies were found among the groups (P<.001) and subgroups (P<.001), with a significant interaction group×subgroup (P=.002). The NCS-IOC group had significantly better linear trueness than the NS-ISB group. The TRIOS5, Primescan, and Aoralscan3 systems had significantly better linear trueness than the i700 device. The Levene test revealed that the NCS-IOC group had significantly better linear precision than the NS-ISB group. Additionally, angular trueness discrepancies were revealed among the groups (P<.001) and subgroups (P<.001), with a significant interaction group×subgroup (P<.001). The NCS-IOC group had significantly better angular trueness than the NS-ISB group. The i700 and Aoralscan3 systems had the best angular trueness. Additionally, the NCS-IOC group had significantly better angular precision than the NS-ISB group. The TRIOS5 and Aoralscan3 had the best angular precision.

Conclusions: The implant scanning technique used and IOS selected impacted the trueness and precision of complete arch implant scans.