Ion release mechanisms in composites containing CaP particles and hydrophilic monomers

Author(s)

Trinca, Rafael Bergamo ; Vela, Beatriz Fonseca ; Vilela, Handially dos Santos ; Braga, Roberto Ruggiero

• Document type: Journal article
• Source: Dental Materials; v. 40, n. 7, p. 9-pg., 2024-06-14.

Abstract

Objective To investigate the effect of hydrophilic/permeable polymer matrices on water sorption/solubility (WS/SL), Ca2+ release, mechanical properties and hydrolytic degradation of composites containing dicalcium phosphate dihydrate (DCPD) particles. Methods Six composites were tested, all with 10 vol% of glass particles and either 30 vol% or 40 vol% DCPD. Composites containing 1BisGMA:1TEGDMA in mols (at both inorganic levels) were considered controls. Four materials were formulated where 0.25 or 0.5 of the BisGMA/TEGDMA was replaced by pyromellitic dianhydride glycerol dimethacrylate (PMGDM)/ polyethylene glycol dimethacrylate (PEGDMA). Composites were tested for degree of conversion (FTIR spectroscopy), WS/SL (ISO 4049) and Ca2+ release (inductively coupled plasma optical emission spectroscopy). Fracture toughness (FT) and biaxial flexural strength/modulus (BFS/FM) were determined after 24 h and 60 days in water. The contributions of diffusional and relaxational mechanisms to Ca2+ release kinetics were analyzed using the semi-empirical Salim-Peppas model. Data were analysed by ANOVA/Tukey test (alpha: 0.05). Results WS/SL was higher for composites containing PMGDM/PEGDMA compared to the controls (p < 0.001). Only at 40% DCPD the 0.5 PMGDM/PEGDMA composite showed statistically higher Ca2+ release than the control. Relaxation diffusion was the main release mechanism. Initial FT was not negatively affected by matrix composition. BFS (both DCPD fractions) and FM (30% DCPD) were lower for composites with hydrophilic/permeable networks (p < 0.01). After 60 days in water, composites with PMGDM/PEGDMA presented significant reductions in FT, while all composites had reductions in BFS/FM. Significance Increasing matrix hydrophilicity/permeability significantly increased Ca2+ release only at a high DCPD fraction. (AU)

• FAPESP's process: 19/04737-4 - Dentin remineralization with the use of composite containing calcium orthophosphate particles associated with a Polymer-Induced Liquid Precursor (PILP): material development, in vitro and randomized clinical studies
• Grantee: Roberto Ruggiero Braga
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 21/09297-2 - Effect of the ratio between DCPD and barium glass particles on the fracture toughness (KIc) of experimental composites
• Grantee: Beatriz Fonseca Vela
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 20/13983-6 - Effect of temperature, pH and precursors concentrations on the synthesis of DCPD particles and its application on a remineralizing resin composite
• Grantee: Rafael Bergamo Trinca
• Support Opportunities: Scholarships in Brazil - Post-Doctoral