Enhanced penetration and antibacterial efficacy of calcium hydroxide modified with titanium dioxide nanoparticles

This study evaluated the effect of incorporating titanium dioxide nanoparticles (TNPs) into calcium hydroxide (CH) on its physicochemical properties, intratubular penetration, and antibacterial efficacy. An experimental nano-modified CH formulation was prepared by blending 1 wt% of TNPs (20 nm) with CH. Twenty-four extracted human premolars were disinfected and randomly allocated to two groups: CH and nano-modified CH (n = 12/group). Material characterization was performed using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Biocompatibility was assessed via MTT assay, while pH was measured using a digital pH meter. Antibacterial activity against Enterococcus faecalis was evaluated through an agar diffusion assay, and intratubular penetration was assessed using SEM. Statistical analysis was conducted using repeated measures ANOVA for penetration depth and independent t-tests for pH and antibacterial activity. Nano-modified CH exhibited a significantly higher pH (mean difference = 0.54; p < 0.05), greater antibacterial activity (mean inhibition zone = 12.67 ± 0.61 mm; p < 0.001), and deeper penetration in the coronal, middle, and apical thirds of dentin (p < 0.001) compared to CH. These findings support the potential of nano-modified CH as an advanced intracanal medicament with superior antimicrobial and diffusion characteristics, warranting further investigation for clinical application.