Scanning accuracy with splinted and unsplinted implant scan bodies for the edentulous arch at implant level: an in vitro study

Antoanela Garbacea; Ali F Alqahtani; Brian Goodacre; Abdulaziz Alhelal; Jaime Lozada; Mathew T Kattadiyil

doi:10.1563/aaid-joi-D-21-00293

Scanning accuracy with splinted and unsplinted implant scan bodies for the edentulous arch at implant level: an in vitro study

J Oral Implantol. 2022 Jul 11. doi: 10.1563/aaid-joi-D-21-00293. Online ahead of print.

Authors

Antoanela Garbacea¹, Ali F Alqahtani², Brian Goodacre³, Abdulaziz Alhelal⁴, Jaime Lozada⁵, Mathew T Kattadiyil⁶

Affiliations

¹ Loma Linda University School of Dentistry Assistant Professor Prosthodontics and Implant Dentistry 11092 Anderson street UNITED STATES Loma Linda CA 92350 9092068096 Assistant Professor, Advanced Specialty Education Program in Prosthodontics and Implant.
² Faculty, Department of Periodontics and Community Dentistry, College of Dentistry, King Khalid University, Abha, Saudi Arabia.
³ Assistant Professor, School of Dentistry, Loma Linda University, Loma Linda, California, USA.
⁴ Assistant Professor, Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
⁵ Professor and Director, Advanced Education Program in Implant Dentistry, School of Dentistry, Loma Linda University, Loma Linda, California, USA.
⁶ fProfessor and Director, Advanced Specialty Education Program in Prosthodontics, School of Dentistry, Loma Linda University, Loma Linda, California, USA.

PMID: 35816623
DOI: 10.1563/aaid-joi-D-21-00293

Abstract

Accuracy of completely edentulous arch scanning with implant scan bodies has not been completely validated for intraoral scanners. For desktop laboratory scanners validations were found in the literature. The aim of this in vitro study was to compare the dimensional accuracy of scanning with splinted and unsplinted scan bodies on a completely edentulous maxillary arch with 6 implants. A maxillary edentulous master cast with 6 implants was used as control for all implant level impressions. 6 implants were digitally planned and placed at different angulation of 0, 0 17° and 30°. A contact coordinate measuring machine (CMM) was used to generate baseline linear measurements of the master cast. Four test groups included: 2 intraoral scanners Trios (3shape, Copenhagen, Denmark) and True Definition (3M ESPE, St Paul, MN), one industrial scanner Atos (Core optical 3D scanner) and one conventional impression group scanned with laboratory scanner Dental Wings 7 Series. Each scan recording was made with splinted and unsplinted scan bodies. Digital datasets of all measurements were compared with the CMM baseline values using PolyWorks® InnovMetric Software in order to assess the linear and angular deviations and determine the accuracy of complete arch digital impression. Factorial ANOVA showed significant effect with splinting, scanner type, inter-implant distance and implant angulation for linear deviations. Splinted scan bodies revealed elevated linear and angular deviation values for all scanners with significantly highest deviations for True Definition scanner. Significant correlation was found between inter-implant distance and linear deviation (r =0.45, P =<0.001) with increased linear deviations among all scanners, regardless of splinting. ( P <0.05). Significant effect on accuracy was seen for angular deviation with splinting, scanner type and implant angulation; significant difference was found between 0° and 30° implant angulation ( P =0.035) with more deviation with 30° implant angulation. The accuracy of the complete arch implant digital impression using splinted scan bodies was significantly reduced for measurements that crossed the arch midline. The digital impression technique using a broad splint design to connect scan bodies was not found to improve the scan accuracy for intraoral scanners.

Keywords: 3D printed splint, scan bodies, complete edentulous arch scanning at the implant level.