Biosynthesized TiO₂ Nanoparticles to Enhance the Mechanical and Antibacterial Properties of Type-II Glass Ionomer Cement for Dental Restorative Applications.
- 2025-12-02
- Cureus 17(12)
- Shubha P
- Harini Ks
- Ganesh S
- Anubhav Jannu
- Preethi Kusugal
- Zarir Ruttonji
- PubMed: 41487806
- DOI: 10.7759/cureus.98281
Titanium dioxide (TiO₂) and its nanoforms are highly valued in dentistry for their biocompatibility, antimicrobial effects, and photocatalytic properties, making them useful functional additives in restorative materials. In this study, TiO₂ nanoparticles (TiO₂ NPs) were synthesized using bio-assisted methods and incorporated into type-II glass ionomer cement (GIC) to investigate their effect on the mechanical and antimicrobial performance of the cement. The modified GICs were evaluated for setting time, compressive strength, antimicrobial activity against Streptococcus mutans and Lactobacillus acidophilus, and antioxidant potential. The study explores whether incorporating bio-assisted TiO₂ NPs can enhance the functional and therapeutic properties of conventional GICs. TiO₂ NPs were synthesized using Piper betle aqueous extract and Ocimum sanctum hydroalcoholic extract using hydrothermal and microwave-assisted synthesis methods, respectively. Synthesized TiO₂ NPs were subsequently subjected to physicochemical characterization and in vitro hemolysis and cytotoxicity assessments. Further, TiO₂ NPs were incorporated into type-II GIC powder to formulate four modified cement groups (F2-F5), along with an unmodified control group (F1), at two nanoparticle weight ratios. Compressive strength was measured using a universal testing machine (UTM) at a crosshead speed of 0.5 mm/min until the samples fractured. Antimicrobial activity was determined by exposing GIC discs (5 × 2 mm) to S. mutans (Microbial Type Culture Collection (MTCC) 890) and L. acidophilus (MTCC 10307) cultures, followed by plating and colony counting after incubation at 37°C for 24 and 72 hours. The antioxidant activity of F1-F5 formulations was also evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. A significant reduction in the setting time was observed in GIC formulations containing 100 mg/g of TiO₂ NPs regardless of the synthesis method, with the difference in mean setting time between the control and TiO₂-incorporated groups being statistically significant (p < 0.05). Incorporation of 100 mg/g TiO₂ NPs also resulted in a notable increase in compressive strength (F3: 290 ± 11 MPa; F5: 301 ± 12 MPa), whereas the 50 mg/g formulations did not show statistically significant improvement. Antimicrobial evaluation revealed that even the control GIC exhibited low colony counts (<300) with no apparent increase after 72 hours; however, the addition of TiO₂ NPs provided a modest enhancement in antibacterial effects at both 24- and 72-hour timelines. TiO₂ NPs showed less than 20% antioxidant activity, likely due to residual phytoconstituents as indicated by Fourier transform infrared (FTIR) analysis. Formulations F3 and F5 displayed slightly higher antioxidant activity than the pure GIC (still <10%), although the differences were not considerable at the tested concentrations. Overall, the results of our research indicate that plant-mediated synthesis resulted in TiO₂ NPs with favorable morphology, enhanced antibacterial effects, and good cytocompatibility. When incorporated into type-II GIC, TiO₂ NPs contributed to both increased compressive strength and decreased setting time. The TiO₂ NP-modified GICs also exhibited a slight improvement in antimicrobial activity and mild antioxidant effects, indicating their potential suitability as restorative materials after elaborate research on other required mechanical properties and pilot clinical performance.
Research Insights
| Supplement | Health Outcome | Effect Type | Effect Size |
|---|---|---|---|
| Lactobacillus acidophilus L-92 | No Applicable Outcome Reported | Neutral | Small |
| Lactobacillus acidophilus L-92 | Reduced Bacterial Viability in Dental Plaque | Beneficial | Small |