Tabriz University of Medical Sciences Journal of Dental Research, Dental Clinics, Dental Prospects 2008-210X 20 3 2026 09 30 Innovation in Glass-Ionomer Cement Modified with Fibroin Nanoparticles: Evaluation of Mechanical, Surface, and Microbiological Properties 176 184 10.34172/joddd.44408 EN Veridiana de Oliveira Mantovani https://orcid.org/0000-0002-9108-3248 Rogério Valentim Gelamo Evandro Watanabe Rodrigo Galo Maria Cristina Borsatto Journal Article 10.34172/joddd.44408 2025 11 24 2026 08 21 Introduction: Silk fibroin (SF), due to its biocompatibility and strength, can act as an additive to optimize glass-iono m e r cement (GIC). This study aimed to incorporate 0.5% SF nanoparticles into restorative GIC (Maxxion® R) to improve its mechanical, surface, and microbiological properties. Methods: Compression, diametral tensile strength, microhardness, surface roughness, and microbiological tests involving Streptococcus mutans (bacterial adhesion, in vitro biofilm formation, and inhibition halo) were conducted, along with scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The specimens were randomly divided into three groups: G1: GIC without SF nanoparticle incorporation; G2: GIC with SF nanoparticles incorporated only into the liquid; and G3: GIC with SF nanoparticles incorporated into both the liquid and powder. Results: Incorporating nanoparticles into GIC resulted in favorable outcomes, with statistically significant differences in compression tests (P=0.048), surface roughness (P=0.03), and microbiological evaluation. CFU counts differed significantly between groups (P=0.049), while differences in inhibition halo (IH) measurements were descriptive without statistical comparison. Diametral tensile strength tests (P=0.598) and microhardness (P=0.241) showed no statistically significant differences, although values increased numerically with SF incorporation. SEM analysis suggested reduced biofilm formation on the surfaces of groups G2 and G3. FTIR indicated that the incorporation did not interfere with the acid–base setting reaction of the GIC. Conclusion: Incorporating SF nanoparticles improved GIC performance in terms of compressive strength, surface roughness, and antimicrobial activity against S. mutans.