Ion releasing direct restorative materials: Key mechanical properties and wear. Issue 12 (December 2022)

• Record Type: Journal Article
• Authors: Daabash, Rawan; Alshabib, Abdulrahman; Alqahtani, Mohammed Q.; Price, Richard Bengt; Silikas, Nick; Alshaafi, Maan M.
• Is Part Of: Dental materials. Volume 38:Issue 12(2022)
• Page Start: 1866
• Page End: 1877
• Publication Date: 2022-12
• Subjects: Resin composites -- Ion release -- Water storage -- Depth of cure -- Fracture toughness -- Wear; Dentistry -- Periodicals; Dental materials -- Periodicals; 617.695
• DOI: 10.1016/j.dental.2022.09.007
• Languages: English
• ISSNs: 0109-5641

Abstract

Abstract: Objectives: To investigate the depth of cure (DoC), fracture toughness (KIC ) 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 KIC, 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). KIC 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 KIC 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 KIC values were recorded for ACT and the lowest for Fuji-II-LC. Water storage (30-days) significantly reduced the KIC 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. Highlights: Depth of cure (DoC) was determined using Knoop microhardness profiles 24 h post cure. All tested materials met the manufacturers' claims for DoC. 30 d storage in 37 °C water significantly decreased KIC of ion releasing resin based composite. Ion releasing resin based composite showed less wear resistance after cyclic loading.