CAD-CAM complete denture resins: an evaluation of biocompatibility, mechanical properties, and surface characteristics

Murali Srinivasan; Nicole Kalberer; Porawit Kamnoedboon; Mustapha Mekki; Stéphane Durual; Mutlu Özcan; Frauke Müller

doi:10.1016/j.jdent.2021.103785

CAD-CAM complete denture resins: an evaluation of biocompatibility, mechanical properties, and surface characteristics

J Dent. 2021 Nov:114:103785. doi: 10.1016/j.jdent.2021.103785. Epub 2021 Aug 20.

Authors

Murali Srinivasan¹, Nicole Kalberer², Porawit Kamnoedboon², Mustapha Mekki³, Stéphane Durual³, Mutlu Özcan⁴, Frauke Müller⁵

Affiliations

¹ Clinic of General, Special Care, and Geriatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland; Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland. Electronic address: murali.srinivasan@zzm.uzh.ch.
² Clinic of General, Special Care, and Geriatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
³ Division of Fixed Prosthodontics and Biomaterials, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland.
⁴ Division of Dental Biomaterials, Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
⁵ Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland.

PMID: 34419480
DOI: 10.1016/j.jdent.2021.103785

Abstract

Objectives: This study evaluated the biocompatibility, mechanical properties, and surface roughness of CAD-CAM milled and rapidly-prototyped/3D-printed resins used for manufacturing complete dentures.

Methods: Six groups of resin specimens were prepared, milled-base (MB), milled-tooth shade (MT), printed-tooth shade (PT), printed-base with manufacturer-recommended 3D-printer (PB1), printed-base with third-party 3D-printer (PB2), printed-base in a vertical orientation (PB2V). Human epithelial (A-431) and gingival (HGF-1) cells were cultured and tested for biocompatibility using Resazurin assays. Three-point bending and nanoindentation tests measured the mechanical properties of the resin groups. Surface roughness was evaluated using a high-resolution laser profilometer. ANOVA and post-hoc tests were used for statistical analyses (α = 0.05).

Results: There were no significant differences in biocompatibility between any of the investigated groups. MB revealed a higher ultimate strength (p = 0.008), elastic modulus (p = 0.002), and toughness (p = 0.014) than PB1. MT had significantly higher elastic modulus than PT (p < 0.001). Rapidly-prototyped resin samples with a manufacturer-recommended 3D-printer (PB1) demonstrated higher ultimate strength (p = 0.008), elastic modulus (p < 0.001), hardness (p < 0.001) and a reduced surface roughness (p < 0.05) when compared with rapidly-prototyped groups using a third-party 3D-printer (PB2). Rapidly-prototyped samples manufactured with a vertical printing orientation (PB2V) revealed a significantly lower elastic modulus than samples groups manufactured using horizontal printing orientation (PB2) (p = 0.011).

Conclusions: Within the limits of this present study, CAD-CAM milled and rapidly-prototyped complete denture resins performed similarly in terms of biocompatibility and surface roughness. However, the milled denture resins were superior to the rapidly-prototyped denture resins with regard to their mechanical properties. Printing orientation and type of 3D-printer can affect the resin strength and surface roughness.

Keywords: Biocompatibility; CAD-CAM; Complete dentures; Geriatric dentistry; Mechanical properties; Surface roughness.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Computer-Aided Design*
Denture, Complete*
Elastic Modulus
Humans
Materials Testing
Surface Properties