Effect of supramucosal height of a scan body and implant angulation on the accuracy of intraoral scanning: An in vitro study

Elena Sicilia; Gabriela Lagreca; Panos Papaspyridakos; Matthew Finkelman; Juan Cobo; Wael Att; Marta Revilla-León

doi:10.1016/j.prosdent.2023.01.018

Effect of supramucosal height of a scan body and implant angulation on the accuracy of intraoral scanning: An in vitro study

J Prosthet Dent. 2023 Feb 22:S0022-3913(23)00060-4. doi: 10.1016/j.prosdent.2023.01.018. Online ahead of print.

Authors

Elena Sicilia¹, Gabriela Lagreca², Panos Papaspyridakos³, Matthew Finkelman⁴, Juan Cobo⁵, Wael Att⁶, Marta Revilla-León⁷

Affiliations

¹ PhD Candidate, Department of Prosthodontics and Occlusion, School of Dentistry, University of Oviedo, Oviedo, Spain. Electronic address: elenasicilia72@gmail.com.
² Assistant Professor, Department of Prosthodontics, Tufts University School of Dental Medicine, Boston, Mass.
³ Associate Professor, Department of Prosthodontics, Tufts University School of Dental Medicine, Boston, Mass.
⁴ Associate Professor, Department of Public Health and Community Service, Tufts University School of Dental Medicine, Boston, Mass.
⁵ Director of Orthodontics, Department of Surgery and Medical-Surgical Specialties, Area of Orthodontics, Medical and Dental School, Instituto Asturiano de Odontologia, University of Oviedo, Oviedo, Spain.
⁶ Department Chair, Department of Prosthodontics, Tufts University School of Dental Medicine, Boston, Mass.
⁷ Director of Research and Digital Dentistry, Kois Center, Seattle, Wash.

PMID: 36828728
DOI: 10.1016/j.prosdent.2023.01.018

Abstract

Statement of problem: Intraoral scanners (IOSs) provide a digital alternative to conventional implant impression techniques. However, the effect of the supramucosal height of the scan body and implant angulation on the accuracy of IOSs remains unclear.

Purpose: The purpose of this in vitro study was to measure the impact of the supramucosal height of the scan body and implant angulation on the accuracy (trueness and precision) of intraoral digital implant scans in partially edentulous models.

Material and methods: Two maxillary partially edentulous casts with 4 implant analogs were fabricated, 1 with 4 parallel implants (P-groups) and 1 with 2 implants distally inclined 18 degrees (A-groups). An implant scan body was positioned on each implant analog (CARES RC Mono Scanbody). For each cast, 3 subgroups were determined based on the soft tissue moulage fabricated for each reference cast exposing 3 mm (P-3 and A-3 subgroups), 5 mm (P-5 and A-5 subgroups), and 7 mm (P-7 and A-7 subgroups) of the implant scan bodies. The 2 reference casts were registered by using a coordinate measurement machine and desktop scanner (7 Series Dental Wings) and then scanned using an IOS (TRIOS 4) (n=15). Linear and angular discrepancy values and root mean square (RMS) error values between the implant scan bodies measured on the reference and experimental scans were computed with an inspection software program (Geomagic). Mann-Whitney U tests with Bonferroni correction were applied for planned comparisons (α=.05/9 ≈ .006).

Results: For linear discrepancies, statistically significant differences were found between groups P-3 and A-3 (P=.004) and between P-7 and A-7 (P=.005). For angular discrepancies, statistically significant differences were found between groups A-3 and A-5 (P=.002) and between P-7 and A-7 (P=.003). The RMS error analysis found no statistically significant differences among the groups.

Conclusions: Implant angulation of 18 degrees did not significantly affect the accuracy of the intraoral scans in terms of 6 of the 9 planned comparisons, although the angled groups had lower mean values. Also, the supramucosal height of the scan body did not significantly affect the accuracy of the intraoral scans in terms of 17 of the 18 planned comparisons. Results may vary with different implant scan body designs.