Influence of the calcium orthophosphate:glass ratio and calcium orthophosphate functionalization on the degree of conversion and mechanical properties of resin-based composites

Author(s)

Campos, Amanda Lopes ; Fronza, Bruna Marin ; Rodrigues, Marcela Charantola ; Souza Chiari, Marina Damasceno E. ; Braga, Roberto Ruggiero

• Document type: Journal article
• Source: JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS; v. 111, n. 1, p. 8-pg., 2023-01-01.

Abstract

The study verified the influence of calcium orthophosphate (CaP):glass ratio on the degree of conversion and mechanical properties of resin-based composites containing either TEGDMA-functionalized dicalcium phosphate anhydrous (DCPA) or non-functionalized DCPA particles. The null hypotheses were that the evaluated variables are not affected by (1) CaP:glass ratio or (2) DCPA functionalization. DCPA particles were synthesized and half of them were functionalized with TEGDMA. Particle characterization included x-ray diffraction, elemental analysis, laser scattering, helium picnometry and scanning electron microscopy. Two series of composites were prepared containing either DCPA-NF (non-functionalized) or DCPA-F (functionalized), with total inorganic content of 50 vol % and DCPA:silanized barium glass (BG) ratios from 10:40 to 50:0. A composite containing 50 vol % BG was tested as control. DC was determined using FTIR spectroscopy. Biaxial flexural strength and modulus were tested after 24 h in water. Data were analyzed using Kruskal-Wallis/Dunn (flexural properties) or analysis of variance/Tukey tests (DC). Materials with similar actual DCPA contents were compared using Student's t test (alpha: 0.05). DC was higher for materials with DCPA-F, except for the 10:40 ratio. DCPA-F resulted in higher strength than DCPA-NF only at 40:10 ratio. Modulus was not affected by functionalization. Materials with similar actual DCPA contents showed differences in DC (F > NF), while no difference in flexural properties was observed between materials with 28%-30% DCPA. Both null hypotheses were rejected. (AU)

• FAPESP's process: 19/01701-9 - Development of functionalized calcium phosphate particles for use in remineralizing restorative composites
• Grantee: Bruna Marin Fronza
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 20/04537-2 - Influence of the functionalization of calcium orthophosphate particles on the mechanical properties of experimental composites
• Grantee: Amanda Lopes Campos
• Support Opportunities: Scholarships in Brazil - Scientific Initiation