Chemical and mechanical properties of dual-polymerizing core build-up materials

Abstract

Objectives To investigate the chemical (degree of conversion (DC)) and mechanical properties (Martens hardness (HM), elastic indentation modulus (EIT), and biaxial flexural strength (BFS)) of four dual-polymerizing resin composite core build-up materials after light- and self-polymerization. Materials and methods Round specimens with a diameter of 12 mm and a thickness of 1.5 mm were manufactured from CLEARFIL DC CORE PLUS (CLE; Kuraray), core·X flow (COR; Dentsply Sirona), MultiCore Flow (MUL; Ivoclar Vivadent), and Rebilda DC (REB; VOCO) (N = 96, n = 24/material). Half of the specimens were light-polymerized (Elipar DeepCure-S, 3 M), while the other half cured by self-polymerization (n = 12/group). Immediately after fabrication, the DC, HM, EIT, and BFS were determined. Data was analyzed using Kolmogorov–Smirnov, Mann–Whitney U, and Kruskal–Wallis tests, Spearman’s correlation, and Weibull statistics (p < 0.05). Results Light-polymerization either led to similar EIT (MUL; p = 0.119) and BFS (MUL and REB; p = 0.094–0.326) values or higher DC, HM, EIT, and BFS results (all other groups; p < 0.001–0.009). When compared with the other materials, COR showed a high DC (p < 0.001) and HM (p < 0.001) after self-polymerization and the highest BFS (p = 0.020) and Weibull modulus after light-polymerization. Positive correlations between all four tested parameters (R = 0.527–0.963, p < 0.001) were found. Conclusions For the tested resin composite core build-up materials, light-polymerization led to similar or superior values for the degree of conversion, Martens hardness, elastic indentation modulus, and biaxial flexural strength than observed after self-polymerization. Among the tested materials, COR should represent the resin composite core build-up material of choice due to its high chemical (degree of conversion) and mechanical (Martens hardness, elastic indentation modulus, and biaxial flexural strength) properties and its high reliability after light-polymerization. The examined chemical and mechanical properties showed a positive correlation. Clinical relevance The chemical and mechanical performance of dual-polymerizing resin composite core build-up materials is significantly affected by the chosen polymerization mode.

Effects of Sr/F-Bioactive Glass Nanoparticles and Calcium Phosphate on Monomer Conversion, Biaxial Flexural Strength, Surface Microhardness, Mass/Volume Changes, and Color Stability of Dual-Cured Dental Composites for Core Build-Up Materials

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“…Dental composites are usually placed as dentine substitute material (core build-up restoration) for severely damaged teeth that require complex direct or indirect restorations [ 1 ]. The use of composites that can be polymerized via both light-activated and chemical-activated polymerization (dual-cured) is beneficial to ensure sufficient polymerization of the materials in a deep cavity [ 2 , 3 ]. The placement of definitive restorations for teeth temporized with core build-up materials may be delayed in some circumstances, such as ongoing orthodontic treatments or patients with limited budget/cooperation.…”

Evaluation of the Fracture Resistance of Different Designs of All-Resin Post and Core Systems: An In Vitro Study

“…The innovation of dual-polymerizing resin composites, incorporating both light and self-polymerization initiators, has broadened the applications of this material group. Consequently, adhesive luting of endodontic posts and subsequent core build-up can now be achieved with a single material, reducing treatment times and minimizing potential weaknesses in material interfaces and processing errors [ 18 ].…”

Designing stimuli-responsive upconversion nanoparticles based on a mimetic immunoassay for potential accurate diabetic nephropathy diagnosis

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