Raman maps indicate the changes in enamel affected by the early demineralization process with the use of new parameters.

This study aims to synthesize, characterize, and evaluate calcium phytate (Ca-PA) and fluorinated calcium phytate (Ca-PA-F) as novel active fillers in resin-based dental composites (RBCs). The hypothesis assumes that these fillers will provide remineralization potential through calcium and fluoride ion release while maintaining satisfactory physicochemical properties. Ca-PA and Ca-PA-F fillers were synthesized, characterized using various spectroscopic and microscopic techniques, and incorporated into methacrylate-based RBCs at a filler fraction of 65 vol% (≈30 wt%). The composites were polymerized and evaluated for degree of conversion (DC), depth of cure (DOC), polymerization shrinkage (PS), mechanical properties (compressive strength [CS], flexural strength [FS]), water sorption (SP), solubility (SL), also after 35 days of incubation, color, opacity, and calcium and fluoride release over 35 days in saline. Both experimental composites exhibited high DC (>70 %), DOC (>3 mm), and moderate PS (4.18-6.19 %). Ca-PA-c showed superior CS (351.6 MPa) and FS (53.9 MPa), while Ca-PA-F-c had lower CS (246.3 MPa) and FS (43.5 MPa). Excessive SP (>40 µg·mm⁻³) and high SL after 35 days of incubation, especially for Ca-PA-F-c, were observed. Both materials released calcium ions, with Ca-PA-F-c also releasing fluoride, showing the remineralizing potential. Phytate-based fillers provide a promising alternative for RBCs with remineralization potential. However, improvements in filler dispersion, flexural strength, and long-term mass stability are needed. Future work should focus on filler silanization or hybridization with conventional fillers to enhance mechanical performance while maintaining the ability to ions release.

Hydroxyapatite modified with methacrylate groups-bearing polyhedral oligomeric silsesquioxane was for the first time applied as a filler in the experimental composite for dental applications. As the modifier changed the hydroxyapatite surface from hydrophilic to hydrophobic, it was predicted that the stability of the obtained composites would be improved in comparison with raw hydroxyapatite-filled composites. The stability in the oral imitating environment, basic physicochemical properties, and remineralizing potential understood as the ability to release calcium ions, were examined. The distribution of the fillers in the organic matrix, composites’ degree of conversion, depth of cure, flexural and compressive strengths, sorption, and solubility after 2 and 12 weeks of incubation, and the concentrations of calcium released were examined. The results were subjected to statistical analysis. The filler modification resulted in the improvement of the composites’ mass stability during long-term incubation with simultaneous beneficial more balanced calcium release profiles and comparable physicochemical properties. Graphical abstract