Mesquita Filipe Teles Ximenes, Vilela Handially Dos Santos, Trinca Rafael Bergamo, Braga Roberto Ruggiero
University of São Paulo School of Dentistry, Department of Biomaterials and Oral Biology, Av. Prof. Lineu Prestes, 2227, São Paulo, SP 05508-000, Brazil.
University of São Paulo School of Dentistry, Department of Biomaterials and Oral Biology, Av. Prof. Lineu Prestes, 2227, São Paulo, SP 05508-000, Brazil.
Dent Mater. 2025 Jun;41(6):658-665. doi: 10.1016/j.dental.2025.03.309. Epub 2025 Apr 5.
To investigate the influence of experimental variables on Ca release from experimental resin-based materials containing dicalcium phosphate dihydrate (DCPD) particles.
Experimental materials were prepared, both with BisGMA and TEGDMA and either 25 % or 50 % DCPD (by volume). Ca release in deionized water (DW) was quantified using induced coupled plasma-optical emission spectrometry (ICP-OES, n = 3) according to the variables (1) frequency of DW renewal (weekly, biweekly, monthly or no renewal in 8 weeks), (2) volume of DW (5 mL, 10 mL or 50 mL) and (3) specimen dimensions (in mm, 9×2, 10x1, 5×4 or 5×1). Release kinetics was described using the semi-empirical Peppas-Sahlin model. Data were analyzed by two-way ANOVA/Tukey test (alpha: 5 %).
Weekly and/or biweekly DW renewal increased Ca release compared to monthly and no renewal (p < 0.001). Ca release was higher in 50 mL compared to 10 mL (50 % DCPD) and 5 mL (25 % DCPD) (p < 0.001). The specimen with the highest area-to-volume ratio (5×1 mm) presented the highest release expressed in μg/cm or as fractional (i.e., % of the total Ca in the specimen, p < 0.001). At early stages and high DW volumes, diffusion was the main release mechanism, particularly for the 25 % DCPD material. Polymer relaxation becomes more important than diffusion over time, most noticeably for the 50 % DCPD material.
Researchers and clinicians must be aware of the fact that ion release is influenced by a large number of experimental variables, including (but not limited to) immersion medium renewal frequency, volume of immersion medium and specimen dimensions.
