Proof-of-concept study of magnesium and ciprofloxacin-loaded zeolite incorporated into dental composites

A magnesium-based zeolite filler (Mg-X) was prepared and loaded with the antibiotic ciprofloxacin (Mg-X-CF) to enhance resin-based composites (RBCs). The fillers were characterized using scanning electron microscopy, X-ray diffraction, nitrogen adsorption isotherms, FTIR microscopy, and thermogravimetric analysis, confirming the effectiveness of both preparation steps. These zeolites were then incorporated as fillers (65 % vol., 48–49 % wt.) into light-cured RBCs. Two composite formulations were examined—one without CF (Mg-X-c) and one containing CF (Mg-X-CF-c). Key properties were assessed, including degree of conversion (DC), depth of cure (DOC), polymerization shrinkage (PS), compressive (CS) and flexural strength (FS), water sorption (SP), solubility (SL), magnesium ion release, surface roughness, and antibacterial activity against Staphylococcus aureus and Escherichia coli. Mg-X-c and Mg-X-CF-c showed high DC at the surface: 67.36 ± 3.48 % and 68.37 ± 4.72 %, slightly decreasing at 2 mm depth to 65.40 ± 2.60 % and 68.51 ± 2.71 %, and significantly dropped to 5.98 ± 2.71 % and 14.78 ± 3.94 % at the bottom. DOC reached 2.14 ± 0.04 mm and 1.93 ± 0.07 mm; PS was 4.40 ± 0.20 % and 4.27 ± 0.28 %; CS was 226.30 ± 9.55 MPa and 208.21 ± 12.41 MPa; FS was 59.18 ± 5.79 MPa and 58.26 ± 5.97 MPa; SP was 52.7 ± 3.3 and 58.1 ± 4.8 μg mm −3 ; SL was −4.0 ± 1.3 and 4.2 ± 0.9 μg mm −3 , respectively. Both composites released Mg 2+ for over 28 days. Their surface roughness (RMS) was beneficially below 0.2 μm. Antibacterial activity was observed against S. aureus (Mg-X-CF-c) and E. coli (both composites). Ciprofloxacin retained its antibacterial properties within the composite and conferred them to the material, while only slightly affecting its physicochemical properties. • Magnesium zeolite with ciprofloxacin was used as a filler in dental composites. • Composites released Mg 2+ ions for at least 28 days. • Antibacterial activity was observed against E. coli and S. aureus . • Antibiotic addition increased bactericidal and slightly affected material properties. • Composites showed new functions, but also high sorption and low flexural strength.