Table 2.

Antimicrobial properties of dental nanomaterials: studies on nano-PLA and zinc oxide nanofiller denture base resins.

Sl. no	Author and Year	Study design	Methodology used	Antimicrobial Testing	Microorganisms Tested	Antimicrobial properties of nano- PLA & zinc oxide nanofiller denture base resins
1.	Kamonkhantikul et al., 2017 (10).	In Vitro	Preparation of denture base resin samples with nano-PLA & zinc oxide nanofillers. Characterization of physical and mechanical properties.	Agar diffusion method, biofilm formation analysis, and zone of inhibition testing.	Streptococcus mutans, Candida albicans, and Escherichia coli.	Enhanced antimicrobial activity with significant reduction in biofilm formation and clear zones of inhibition against all tested microorganisms.
2.	Shafiee Nasab et al. 2018 (20).	Experimental in vitro study	Fabrication of denture base resins with nano-PLA and zinc oxide nanofillers; characterization using SEM, FTIR, and XRD	Disc diffusion method; MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) tests	Staphylococcus aureus, Candida albicans, Escherichia coli, Pseudomonas aeruginosa	Nano-PLA and zinc oxide nanofiller resins exhibited significant antimicrobial activity against tested microorganisms; showed effective inhibition of bacterial and fungal growth; enhanced mechanical properties compared to control resins
3.	Lipovsky et al., 2011 (6).	Experimental	Synthesis and characterization of nanofillers; incorporation into resins; testing	Growth inhibition, minimum inhibitory concentration (MIC), colony counting	Candida albicans, Staphylococcus aureus, Escherichia coli	Nano-PLA and ZnO nanofillers exhibit enhanced antimicrobial activity against tested microorganisms, with ZnO showing greater efficacy.
4.	Mousavi et al., 2020 (15).	Experimental study	Incorporation of Ag, ZnO, and chitosan nanoparticles into tissue conditioners; antimicrobial testing via turbidity measurements	Spectrophotometric assessment of microbial growth inhibition at various nanoparticle concentrations and incubation times	Candida albicans, Streptococcus mutans, Enterococcus faecalis, Pseudomonas aeruginosa	Effective in reducing growth of tested microorganisms; optimal inhibition at 5% concentration
5.	Abd Alwahab et al. 2020 (21).	Experimental study	Preparation of PMMA with varying percentages of Nano ZrO2 and ZnO; Testing for thermal conductivity, compression, and roughness.	Not conducted	Not tested	The study focused on thermal conductivity, compression strength, and surface roughness, not on antimicrobial properties.
6.	Fahmi et al. 2019 (16).	Experimental study	Addition of ZrO2 to PMMA at 0.5%, 1%, 3% concentrations	Not tested	Not tested	Not applicable
7.	Collares et al. 2020 (22).	In vitro study	Formulation of methacrylate-based dental sealers with ZnO nanostructures; physical, chemical, and antibacterial evaluations	Agar diffusion test, CFU count	Enterococcus faecalis	ZnO nanostructures provided significant antimicrobial effects, particularly at higher concentrations (30% and 40%).
8.	Raj et al. 2018 (23).	Experimental study	Fabrication of denture base resins with varying concentrations of nano-PLA and zinc oxide nanofillers	Agar diffusion method	Candida albicans and Streptococcus mutans	Nano-PLA and zinc oxide nanofillers enhanced antimicrobial properties against C. albicans and S. aureus, with higher concentrations showing increased effectiveness.