Influence of intraoral scanner and finish line location on the fabrication trueness and margin quality of additively manufactured laminate veneers fabricated with a completely digital workflow

Gülce Çakmak; Jad Chebaro; Mustafa Borga Donmez; Deniz Yılmaz; Hyung-In Yoon; Çiğdem Kahveci; Martin Schimmel; Burak Yilmaz

doi:10.1016/j.prosdent.2023.10.026

Influence of intraoral scanner and finish line location on the fabrication trueness and margin quality of additively manufactured laminate veneers fabricated with a completely digital workflow

J Prosthet Dent. 2024 Feb;131(2):313.e1-313.e9. doi: 10.1016/j.prosdent.2023.10.026. Epub 2023 Nov 17.

Authors

Gülce Çakmak¹, Jad Chebaro², Mustafa Borga Donmez³, Deniz Yılmaz⁴, Hyung-In Yoon⁵, Çiğdem Kahveci⁶, Martin Schimmel⁷, Burak Yilmaz⁸

Affiliations

¹ Senior Resarch Associate, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
² Predoctoral student, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland; and Private Practice, Bellinzona, Switzerland.
³ Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Istinye University, İstanbul, Turkey; and ITI Scholar, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland. Electronic address: mustafa-borga.doenmez@unibe.ch.
⁴ Lecturer, Department of Prosthodontics, Faculty of Dentistry, Alanya Alaaddin Keykubat University, Antalya, Turkey.
⁵ Associate Professor, Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea; and Adjunct Professor, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
⁶ Prosthodontist, Ordu Oral and Dental Health Center, Ordu, Turkey.
⁷ Professor and Head, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland; and External Research Associate, Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland.
⁸ Associate Professor, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland; Associate Professor, Department of Restorative, Preventive and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland; and Adjunct Professor, Division of Restorative and Prosthetic Dentistry, The Ohio State University, Columbus, Ohio.

PMID: 37978007
DOI: 10.1016/j.prosdent.2023.10.026

Abstract

Statement of problem: Knowledge of the fabrication trueness and margin quality of additively manufactured (AM) laminate veneers (LVs) when different intraoral scanners (IOSs) and finish line locations are used is limited.

Purpose: The purpose of this in vitro study was to evaluate the fabrication trueness and margin quality of AM LVs with different finish line locations digitized by using different IOSs.

Material and methods: An LV preparation with a subgingival (sub), equigingival (equi), or supragingival (supra) finish line was performed on 3 identical maxillary right central incisor typodont teeth. Each preparation was digitized by using 2 IOSs, (CEREC Primescan [PS] and TRIOS 3 [TS]), and a reference LV for each finish line-IOS pair (n=6) was designed. A total of 90 LVs were fabricated by using these files and urethane acrylate-based definitive resin (Tera Harz TC-80DP) (n=15). Each LV was then digitized by using PS to evaluate fabrication trueness (overall, external, intaglio, and marginal surfaces). Each LV was also qualitatively evaluated under a stereomicroscope (×60), and the cervical and incisal margin quality was graded. Fabrication trueness and cervical margin quality were evaluated by using 2-way analysis of variance, while Kruskal-Wallis and Mann Whitney-U tests were used to evaluate incisal margin quality (α=.05).

Results: The interaction between the IOS type and the finish line location affected measured deviations at each surface (P≤.020). PS-sub and TS-supra had higher overall trueness than their counterparts. and the subgingival finish line resulted in the lowest trueness (P≤.005). PS and the subgingival finish line led to the lowest trueness of the external surface (P≤.001). TS-sub had the lowest intaglio surface trueness among the TS subgroups, and PS-sub had higher trueness than TS-sub (P<.001). PS-sub and PS-supra had higher marginal surface trueness than their TS counterparts (P<.001). TS resulted in higher cervical margin quality (P=.001).

Conclusions: Regardless of the IOS tested, subgingival finish lines resulted in the lowest trueness. The effect of IOS on the measured deviations varied according to the surface evaluated and finish line location. The cervical margin quality of AM LVs was higher when TS was used.

MeSH terms

Computer-Aided Design*
Dental Impression Technique
Imaging, Three-Dimensional*
Models, Dental
Workflow