Mechanical behaviour of prosthodontic CAD/CAM polymer composites aged in three food-simulating liquids

Rua S Babaier; Julfikar Haider; Abdulrahman Alshabib; Nick Silikas; David C Watts

doi:10.1016/j.dental.2022.07.001

Mechanical behaviour of prosthodontic CAD/CAM polymer composites aged in three food-simulating liquids

Dent Mater. 2022 Sep;38(9):1492-1506. doi: 10.1016/j.dental.2022.07.001. Epub 2022 Jul 22.

Authors

Rua S Babaier¹, Julfikar Haider², Abdulrahman Alshabib³, Nick Silikas⁴, David C Watts⁵

Affiliations

¹ Division of Dentistry, School of Medical Sciences, University of Manchester, United Kingdom; Prosthetic Dental Sciences, College of Dentistry, King Saud University, Saudi Arabia.
² Division of Dentistry, School of Medical Sciences, University of Manchester, United Kingdom; Department of Engineering, Manchester Metropolitan University, Manchester, United Kingdom.
³ Restorative Dental Sciences, College of Dentistry, King Saud University, Saudi Arabia; Engr. Abdullah Bugshan Research Chair for Dental and Oral Rehabilitation, King Saud University, Saudi Arabia.
⁴ Division of Dentistry, School of Medical Sciences, University of Manchester, United Kingdom. Electronic address: nikolaos.silikas@manchester.ac.uk.
⁵ Division of Dentistry, School of Medical Sciences, University of Manchester, United Kingdom; Photon Science Institute, University of Manchester, United Kingdom. Electronic address: david.watts@manchester.ac.uk.

PMID: 35871980
DOI: 10.1016/j.dental.2022.07.001

Abstract

Objectives: This study investigated the effect of ageing in three food-simulating liquids (FSLs) on mechanical properties of three prosthodontic CAD/CAM polymer composites intended for construction of implant-supported frameworks.

Methods: Materials 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). Filler contents and microstructural arrangements were determined by thermo-gravimetry and tomography (µ-CT), respectively. Flexural properties (FS and E_f) were measured by 3-point bending (3PB) of 1 mm and 2 mm thick beam specimens. Fracture toughness (K_IC) was measured by single-edge-notched-bending (SENB). All measurements were made at baseline (dry) and after 1-day and 7-day storage at 37 ℃ in either water, 70 % ethanol/water (70 % E/W) or methyl ethyl ketone (MEK). Failed specimens were examined microscopically. Statistical analyses included four-way ANOVA, two-way ANOVA and multiple Tukey comparison tests (α = 0.05). Multiple independent t-tests were performed regarding thickness effects on FS and E_f (α = 0.05).

Results: At baseline, the mechanical properties increased in the sequence: PK< TR< CC (p < 0.001). FS ranged from 192.9 to 501.5 MPa; E_f from 4.2 to 18.1 GPa; and K_{IC f}rom 4.9-12.4 MPa.m^0.5. Fibre-reinforced composites (CC and TR) were significantly stronger than PK. However, all properties of CC and TR reduced after 1 d storage in 70 % E/W and MEK with FS ranging from 58.6 to 408 MPa; E_f from 1 to 15.4 GPa; K_IC from 6.87 to 10.17 MPa.m^0.5. Greater reductions occurred after 7 d storage. MEK was more detrimental than 70 % E/W and water on fibre-reinforced composites.

Significance: Mechanical properties of each CAD/CAM composite were strongly dependent upon media and ageing. Although the mechanical properties of PK were initially inferior, it was relatively stable in all FSLs. All three materials exhibited sufficient mechanical properties at 1 mm thickness, but thicker specimens were more tolerant to ageing.

Keywords: Ageing; CAD/CAM composite; Flexural strength; Food-simulating liquid; Fractographic analysis; Fracture toughness; Three-point bending.

Publication types

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

MeSH terms

Composite Resins* / chemistry
Computer-Aided Design
Materials Testing
Polymers*
Prosthodontics
Surface Properties
Water

Substances

Composite Resins
Polymers
Water
methylethyl ketone