Degradation effects of dietary solvents on microhardness and inorganic elements of computer-aided design/computer-aided manufacturing dental composites

• Main Authors: Munusamy, Selva Malar, Helen-Ng, Lee Ching, Farook, Mohideen Salihu
• Format: Article
• Published: BioMed Central 2024
• Subjects: RK Dentistry
• Online Access: http://eprints.um.edu.my/45692/; https://doi.org/10.1186/s12903-024-03905-7

BackgroundComputer-aided design/computer-aided manufacturing (CAD/CAM) dental composites were introduced with superior mechanical properties than conventional dental composites. However, little is known on effects of dietary solvents on microhardness or inorganic elemental composition of CAD/CAM composites.ObjectivesThe objectives of this study were to evaluate the degradation effects of each dietary solvent on the microhardness of the different CAD/CAM dental composites and to observe the degradation effects of dietary solvent on the inorganic elements of the dental composites investigated.MethodsFifty specimens with dimensions 12 mm x 14 mm x 1.5 mm were prepared for direct composite (Filtek Z350 XT FZ]), indirect composite (Shofu Ceramage CM]), and three CAD/CAM composites (Lava Ultimate LU], Cerasmart CS], and Vita Enamic VE]). The specimens were randomly divided into 5 groups (n = 10) and conditioned for 1-week at 37 degrees C in the following: air (control), distilled water, 0.02 N citric acid, 0.02 N lactic acid and 50% ethanol-water solution. Subsequently, the specimens were subjected to microhardness test (KHN) using Knoop hardness indenter. Air (control) and representative postconditioning specimens with the lowest mean KHN value for each material were analyzed using energy dispersive X-ray spectroscopy (EDX). Statistical analysis was done using one-way ANOVA and post hoc Bonferroni test at a significance level of p = 0.05.ResultsMean KHN values ranged from 39.7 +/- 2.7 kg/mm2 for FZ conditioned in 50% ethanol-water solution to 79.2 +/- 3.4 kg/mm2 for VE conditioned in air (control). With exception to LU, significant differences were observed between materials and dietary solvents for other dental composites investigated. EDX showed stable peaks of the inorganic elements between air (control) and representative postconditioning specimens.ConclusionsThe microhardness of dental composites was significantly affected by dietary solvents, except for one CAD/CAM composite LU]. However, no changes were observed in the inorganic elemental composition of dental composites between air (control) and 1-week postconditioning.