In this study, Streptococcus mutans bacteria were tested on nickel–titanium archwires in the presence of silver nanoparticles (AgNPs) as coatings. As a growth control, a well containing the BHI broth and bacterial suspension without silver nanoparticles was inoculated. The test was carried out in triplicate. The NiTi archwires in the presence of artificial saliva were incubated at different exposure times between 0–24 h and 15–30 days, respectively. The archwires were then put in contact with S. mutans to evaluate the AgNPs bactericidal effect. The characterization of AgNPs with NiTi archwires was conducted using scanning electron microscopy (SEM), X-ray energy dispersive analysis (EDS), fast fourier transform (FFT), power spectral density (PSD), surface geometry analysis, metal relation analysis, and control process analysis. The results indicate that the bioelectric signal and chemical interaction of NiTi and Ag nanoparticles have an antibacterial effect. In this context, the high wavelength of 17.06 mm and the wave amplitude of 15.66 GL are representative of the light scattering and humidity of the system in which the bacteria and silver nanoparticles interact. The sizes of the Ag nanoparticles in the archwires were less than 150 nm. Under microaerophile conditions, the solution’s pH and temperature were 7.0 at 37 °C, respectively. The NiTi archwires AgNPs functionality and relation to the minimum inhibitory concentration, dominant wavelength in power spectral density, and fast fourier transform analyses were investigated. The analysis was of the interaction between the high and low frequencies of the AgNPs-NiTi archwires and the S. mutans bacteria. This approach opens up a new route for the assessment and management of bacterial growth in various fluids by utilizing alternative biologically acceptable materials.

In this work, titanium dioxide scaffolds were synthesized. Titanium isopropoxide (IV) was used as a precursor in its formation, using a polymeric network of galactopyranose as a template. The powder sample obtained was evaluated by scanning tunneling microscopy (STM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, and thermal gravimetric analysis (TGA-DTA). According to the results, it was found that these scaffolds can be successfully synthesized in solution using the sol-gel method. The synthesized scaffolds have diameters from 50 nm with porosity of approximately 0.3–10 nm. Important parameters, such as pH and the concentration of the metallic precursors, were optimized in this solution. The values of maximum average roughness R(max) and roughness value (Ra) were 0.50 and 1.45, respectively. XRD diffraction analysis shows the formation of crystalline phases in the TiO₂ scaffold at 700 °C. The use of biological polymers represents an alternative for the synthesis of new materials at low cost, manipulating the conditions in the production processes and making the proposed system more efficient.

Persistent endodontic infections are frequently associated with Enterococcus faecalis, a microorganism capable of penetrating dentinal tubules and surviving conventional disinfection procedures. This in vitro study evaluated the antimicrobial activity of Chihuahuan propolis against E. faecalis using planktonic and intratubular infection models. Propolis extract was tested at concentrations of 15, 35, and 70 mg/mL and compared with triple antibiotic paste (TAP) as a clinically relevant intracanal medicament. Antimicrobial efficacy was assessed by disk diffusion, minimum inhibitory concentration (MIC), colony-forming unit (CFU) reduction in infected dentinal tubules, and scanning electron microscopy (SEM). Chihuahuan propolis exhibited concentration-dependent antimicrobial activity, with a MIC of 17.5 mg/mL. In the intratubular model, propolis at 70 mg/mL achieved a CFU reduction comparable to TAP after seven days of application. SEM analysis confirmed a marked reduction of bacterial colonization within dentinal tubules. Within the limitations of this in vitro, monoespecies model, Chihuahuan propolis demonstrated antimicrobial efficacy against E. faecalis comparable to TAP, supporting its further investigation as a potential non-antibiotic intracanal medicament.