Ion releasing direct restorative materials: Key mechanical properties and wear

Rawan Daabash; Abdulrahman Alshabib; Mohammed Q Alqahtani; Richard Bengt Price; Nick Silikas; Maan M Alshaafi

doi:10.1016/j.dental.2022.09.007

Ion releasing direct restorative materials: Key mechanical properties and wear

Dent Mater. 2022 Dec;38(12):1866-1877. doi: 10.1016/j.dental.2022.09.007. Epub 2022 Oct 3.

Authors

Rawan Daabash¹, Abdulrahman Alshabib², Mohammed Q Alqahtani¹, Richard Bengt Price³, Nick Silikas⁴, Maan M Alshaafi¹

Affiliations

¹ Department of Restorative Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
² Department of Restorative Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia. Electronic address: abdalshabib@ksu.edu.sa.
³ Department of Dental Clinical Sciences, Dalhousie University, Faculty of Dentistry, Halifax, Nova Scotia, Canada.
⁴ School of Medical Sciences, Division of Dentistry, University of Manchester, UK.

PMID: 36202659
DOI: 10.1016/j.dental.2022.09.007

Abstract

Objectives: To investigate the depth of cure (DoC), fracture toughness (K_IC) and wear of ion releasing resin-based composite (RBC) restorative materials.

Methods: Two ion releasing RBCs, Activa (ACT) and Cention-N (CN) were compared to a conventional RBC (Z350) and a resin-modified glass ionomer cement (Fuji-II-LC). The DoC was measured in a 10-mm deep semi-circular metal mold with a 2-mm internal radius (n = 8). The molds were irradiated from one end for 20-s. The Knoop hardness (KH) was measured at 0.5-mm intervals from the surface after the specimens had been stored at 37 °C for 24-h. To measure the K_IC, single-edge-notched specimens (n = 15/group) were prepared (25×5x2.5-mm) for a 3-point bending test and then stored for either 1 or 30-days in water at 37 °C. Disk-shaped specimens (n = 10) were subjected to 250,000-load cycles of 49-N using a chewing simulator against spherical steatite antagonists. DoC and wear data were analyzed by one-way ANOVA and Tukey post hoc tests (p ≤ 0.05). K_IC data were analyzed by two-way ANOVA and one-way ANOVA, and the Tukey post hoc test (p ≤ 0.05). In addition, an independent t-test was used to determine if storage time had any effect (α = 0.05) on the K_IC of each material.

Results: Maximum hardness value was the highest for Z350 and the lowest for ACT. The depth at which 80% of the maximum KH, was the highest for CN (9.2 mm) and the lowest for Z350 (2 mm). All tested materials met the manufacturers' claims for DoC. After 1-day, the highest K_IC values were recorded for ACT and the lowest for Fuji-II-LC. Water storage (30-days) significantly reduced the K_IC value for all materials except Fuji-II-LC. The highest wear rate values were recorded for CN followed by ACT.

Significance: All tested materials met their manufacturers' claims for DoC. Water storage for 30-days significantly reduced the fracture toughness for ACT and CN. Wear was significantly higher for ACT and CN.

Keywords: Depth of cure; Fracture toughness; Ion release; Resin composites; Water storage; Wear.

MeSH terms

Composite Resins*
Dental Materials
Glass Ionomer Cements*
Hardness
Materials Testing
Surface Properties
Water

Substances

Composite Resins
Glass Ionomer Cements
Dental Materials
Water