Effect of layer thickness, build angle, and viscosity on the mechanical properties and manufacturing trueness of denture base resin for digital light processing

Won-Jun Lee; Ye-Hyeon Jo; Burak Yilmaz; Hyung-In Yoon

doi:10.1016/j.jdent.2023.104598

Effect of layer thickness, build angle, and viscosity on the mechanical properties and manufacturing trueness of denture base resin for digital light processing

J Dent. 2023 Aug:135:104598. doi: 10.1016/j.jdent.2023.104598. Epub 2023 Jun 24.

Authors

Won-Jun Lee¹, Ye-Hyeon Jo², Burak Yilmaz³, Hyung-In Yoon⁴

Affiliations

¹ Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea.
² Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea.
³ Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland; Department of Restorative, Preventive and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland; Division of Restorative and Prosthetic Dentistry, The Ohio State University, Columbus, Ohio, USA.
⁴ Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea; Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland. Electronic address: drhiy226@snu.ac.kr.

PMID: 37356562
DOI: 10.1016/j.jdent.2023.104598

Abstract

Objectives: To investigate effects of layer thickness, build angle, and viscosity on the mechanical properties and trueness of denture base resins used for digital light processing (DLP).

Methods: Two denture base resins for DLP in different viscosity (high and low) were tested by using two manufacturing parameters:1) layer thickness (LT) (50- or 100-μm) and 2) build angle (BA) (0-, 45-, and 90-degree). disk- and bar-shaped specimens were used to evaluate hardness and flexural strength, respectively. Denture base specimens were used to examine trueness, and the deviation was calculated as the root mean square. Three-way analysis of variance (ANOVA) was conducted to determine the interaction among the three factors (viscosity, LT, and BA). Statistical significance was set at P < .05.

Results: Effects of LT and BA on hardness differed according to viscosity, with significant interactions among three factors (P=.027). Regardless of LT or BA, the low-viscosity group had higher hardness than the high-viscosity group (P<.001). In terms of flexural strength, no significant interaction was detected between the factors (P=.212), however, the effects of LT and BA were significant (P=.003 and P<.001, respectively). Regarding trueness, a significant interaction was observed between viscosity and BA (P=.001). Low-viscosity group had higher trueness than high-viscosity group when the 45- and 90-degree BA were applied (P<.001).

Conclusions: LT and BA significantly affected the mechanical properties and trueness of the 3DP denture base, depending on the viscosity. For hardness and trueness, using low-viscosity resin and manufacturing with 50-μm LT and 45-degree BA are recommended.

Clinical significance: Resin viscosity affects the influence of LT and BA on the hardness, flexural strength, and trueness of DLP-generated denture bases. A 50-μm LT and 45-degree BA can be used with a low-viscosity resin to fabricate denture bases with higher hardness and trueness.

Keywords: Build angle; Digital light processing; Flexural strength; Hardness; Layer thickness; Trueness; Viscosity.

Publication types

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

MeSH terms

Denture Bases*
Flexural Strength*
Hardness
Materials Testing
Surface Properties
Viscosity