Characterization of experimental resin composites with cholesteryl methacrylate organic matrix – Part 2

• Published in: Dental materials 2024-11, Vol.40 (11), p.e63-e71
• Main Authors: Silva, Julyana Dumas Santos, de Almeida, Letícia Nunes, Machado, Antônio Silva, de Oliveira, Amanda Alves, Cardoso, Luiza Santos, Gonçalves, Cristhiane, de Macêdo, Isaac Yves Lopes, de Souza Gil, Eric, Veríssimo, Crisnicaw, de Aleluia Batista, Karla, Lião, Luciano Morais, Estrela, Carlos, Menegatti, Ricardo, Lopes, Lawrence Gonzaga
• Format: Article
• Language: English
• Subjects: Cholesterol Esters; Composite Resins; Methacrylates; Polymerization; Polymers
• ISSN: 0109-5641; 1879-0097; 1879-0097
• DOI: 10.1016/j.dental.2024.07.037

The aim of this study was to evaluate the degree of conversion (%), flexural strength (MPa), elastic modulus (GPa), compressive strength (MPa), Knoop microhardness (KHN), post-gel shrinkage (%) and prediction of ideal concentration of cholesteryl methacrylate (CM) in experimental resins. Four formulations were manipulated (F): F1, control group, (0 % CM); F2 (15 % CM); F3 (19.8 % CM) and F4 (30 % CM). Bis-GMA and CM percentages were determined using Statistica™ software. For the degree of conversion test, Raman spectroscopy was used. To testing flexural strength, elastic modulus and compressive strength, a universal testing machine was used. For the Knoop microhardness test five indentations were made in each sample. Post-gel shrinkage was determined using the strain gauge method. Statistica™ software processed all data obtained in this study. Results were submitted to one-way ANOVA and Tukey's post hoc tests (α = 0.05). Better performance was observed for F2 (15 % CM) and F3 (19,8 % CM) for degree of conversion, elastic modulus and post-gel shrinkage. For Knoop microhardness F2 (15 % CM), F3 (19,8 % CM) and F4 (30 % CM) showed higher values than F1 (0 % CM). For flexural strength F1 (0 % CM) and F3 (19,8 %) were similar and F4 showed the lowest values and for compressive strength F1 (0 % CM) showed the highest values. For mixture designs analysis data, concentrations ≤ 25 % of CM would provide better results. Addition of CM at concentrations lower than 30 % contributed to a significant increase in the degree of conversion, microhardness values, elastic modulus and reduction of post-gel shrinkage. •Cholesteryl methacrylate proved to be a promising polymer for improving composites.•An endocyclic double bond can be an additional site for photochemical cycloaddition.•Concentrations ≤ 25 % cholesteryl methacrylate enhance composite resins.•Post-gel shrinkage performed better with 15 %, 19.8 % and 30 % cholesteryl methacrylate.•Knoop microhardness was higher with 15 %, 19.8 %, and 30 % cholesteryl methacrylate.