Effect of calcium orthophosphate particle size and CaP:glass ratio on optical, mechanical and physicochemical characteristics of experimental composites

Author(s)

Trinca, Rafael Bergamo ; Oliveira, Beatriz Almeida ; Vilela, Handially dos Santos ; Braga, Roberto Ruggiero

• Document type: Journal article
• Source: Dental Materials; v. 39, n. 9, p. 9-pg., 2023-08-23.

Abstract

Objective: Evaluate light transmittance (%T), color change (Delta E), degree of conversion (DC), bottom-to-top Knoop microhardness (KHN), flexural strength (BFS) and modulus (FM), water sorption/solubility (WS/SL) and calcium release of resin composites containing different dicalcium phosphate dihydrate (DCPD)-to-barium glass ratios (DCPD:BG) and DCPD particle sizes. Methods: Ten resin-based composites (50 vol% inorganic fraction) were prepared using BG (0.4 mu m) and DCPD particles (12 mu m, 3 mu m or mixture) with DCPD:BG of 1:3, 1:1 or 3:1. A composite without DCPD was used as a control. DC, KHN, %T and Delta E were determined in 2-mm thick specimens. BFS and FM were determined after 24 h. WS/SL was determined after 7 d. Calcium release was determined by coupled plasma optical emission spectroscopy. Data were analyzed by ANOVA/Tukey test (alpha: 0.05). Results: %T was significantly reduced in composites with milled, compared to pristine DCPD (p < 0.001). Delta E > 3.3 were observed with DCPD:BG of 1:1 and 3:1 formulated with milled DCPD (p < 0.001). DC increased at 1:1 and 3:1 DCPD:BG (p < 0.001). All composites presented bottom-to-top KHN of at least 0.8. BFS was not affected by DCPD size but was strongly dependent on DCPD:BG (p < 0.001). Reductions in FM were observed with milled DCPD (p < 0.001). WS/SL increased with DCPD:BG (p < 0.001). At 3DCPD: 1BG, using small DCPD particles led to a 35 % increase in calcium release (p < 0.001). Significance: A trade-off between strength and Ca2+ release was observed. In spite of its low strength, the formulation containing 3 DCPD: 1 glass and milled DCPD particles is preferred due to its superior Ca2+ release. (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: 20/12761-0 - In vitro analysis of dentin remineralization using glass ionomer cement with or without calcium orthophosphate particles or with mineral trioxide aggregate
• Grantee: Handially dos Santos Vilela
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• 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