Effects of three food-simulating liquids on the roughness and hardness of CAD/CAM polymer composites

Rua Babaier; David C Watts; Nick Silikas

doi:10.1016/j.dental.2022.04.001

Effects of three food-simulating liquids on the roughness and hardness of CAD/CAM polymer composites

Dent Mater. 2022 May;38(5):874-885. doi: 10.1016/j.dental.2022.04.001. Epub 2022 Apr 15.

Authors

Rua Babaier¹, David C Watts², Nick Silikas³

Affiliations

¹ Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Prosthetic Dental Sciences, College of Dentistry, King Saud University, Saudi Arabia.
² Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Photon Science Institute, University of Manchester, UK. Electronic address: david.watts@manchester.ac.uk.
³ Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK. Electronic address: nick.silikas@manchester.ac.uk.

PMID: 35431089
DOI: 10.1016/j.dental.2022.04.001

Abstract

Objective: Implant-supported frameworks constructed from high-performance polymer CAD/CAM composites are exposed to liquids from the oral environment and routine care maintenance. Therefore, this study investigated the effect of food-simulating liquids (FSLs) on surface properties of three CAD/CAM polymer composite blocks.

Methods: The composites investigated were (i) a carbon fibre-reinforced composite (CarboCAD 3D dream frame; CC), (ii) a glass fibre-reinforced composite (TRINIA; TR), and (iii) a reinforced PEEK (DentoKeep; PK). The filler contents were determined by thermo-gravimetry. The surface properties were roughness, Vickers hardness (HV), properties measured by Martens force/depth indentation, namely: hardness (HM), modulus (E_IT) and creep (C_IT). Property measurements were made at baseline on polished specimens and then, where possible, after 1- and 7-days storage at 37 ℃ in three different media: water, 70% ethanol/water and MEK (methyl ethyl ketone). Specimens were selected for light and scanning electron microscopy. Statistical analysis was performed by two-way repeated measures ANOVA, one-way ANOVA, and multiple comparison tests (α = 0.05).

Results: The baseline roughness and hardness (HV, HM) and modulus (E_IT) correlated approximately with filler content (wt%), with the fibre-reinforced composites being rougher, harder and stiffer than PK. At baseline, roughness (Sa) ranged from 0.202 to 0.268 µm; HV from 23.1 to 36.9; HM from 224.5 to 330.6 N/mm²; E_IT: from 6 to 9.8 GPa. After ageing in 70% ethanol and MEK, more pronounced roughness and hardness changes were observed than in water. MEK caused greater deterioration for the FRC than 70% ethanol, while PK specimens showed slight changes in 70% ethanol.

Significance: Storage media adversely affected the surface and mechanical properties of each CAD/CAM composite. However, during ageing, the reinforced PEEK showed greater relative stability in these properties. Nevertheless, the deterioration may indicate the need for full protection by a veneer material on each surface of an implant-supported framework.

Keywords: Ageing; CAD/CAM composites; Food-simulating liquid; Martens hardness; Surface roughness; Vickers hardness.

Publication types

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

MeSH terms

Composite Resins*
Computer-Aided Design
Dental Materials
Ethanol
Hardness
Materials Testing
Polymers*
Surface Properties
Water

Substances

Composite Resins
Dental Materials
Ethanol
Polymers
Water