Aluminum zirconate nanoparticles in etch and rinse adhesive to caries affected dentine: An in-vitro scanning electron microscopy, elemental distribution, antibacterial, degree of conversion and micro-tensile bond strength assessment.

To incorporate different concentrations of AlOZr (1%, 5%, and 10%) nanoparticles (NP) into the ER adhesive and subsequently assess the impact of this addition on the degree of conversion, μTBS, and antimicrobial efficacy. The current research involved a wide-ranging examination that merged various investigative techniques, including the application of scanning electron microscopy (SEM) for surface characterization of NP coupled with energy-dispersive x-ray spectroscopy (EDX), Fourier-transform infrared (FTIR) spectroscopy, μTBS testing, and microbial analysis. Teeth were divided into four groups based on the application of modified and unmodified three-step ER adhesive primer. Group 1 (0% AlOZr NPs) Control, Group 2 (1% AlOZr NPs), Group 3 (5% AlOZr NPs), and Group 4 (10% AlO9Zr3 NPs). EDX analysis of AlOZr NPs was performed showing elemental distribution in synthesized NPs. Zirconium (Zr), Aluminum (Al), and Oxides (O). After primer application, an assessment of the survival rate of Streptococcus mutans was completed. The FTIR spectra were analyzed to observe the characteristic peaks indicating the conversion of double bonds, both before and after the curing process, for the adhesive Etch and rinse containing 1,5,10 wt% AlOZr NPs. μTBS and failure mode assessment were performed using a Universal Testing Machine (UTM) and stereomicroscope respectively. The μTBS and S.mutans survival rates comparison among different groups was performed using one-way ANOVA and Tukey post hoc (p = .05). Group 4 (10 wt% AlOZr NPs + ER adhesive) specimens exhibited the minimum survival of S.mutans (0.11 ± 0.02 CFU/mL). Nonetheless, Group 1 (0 wt% AlOZr NPs + ER adhesive) displayed the maximum surviving S.mutans (0.52 ± 0.08 CFU/mL). Moreover, Group 2 (1 wt% AlOZr NPs + ER adhesive) (21.22 ± 0.73 MPa) samples displayed highest μTBS. However, the bond strength was weakest in Group 1 (0 wt% AlOZr NPs + ER adhesive) (14.13 ± 0.32 MPa) study samples. The etch-and-rinse adhesive exhibited enhanced antibacterial activity and micro-tensile bond strength (μTBS) when 1% AlOZr NPs was incorporated, as opposed to the control group. Nevertheless, the incorporation of AlOZr NPs led to a decrease in DC. RESEARCH HIGHLIGHTS: 10 wt% AlOZr NPs + ER adhesive specimens exhibited the minimum survival of S.mutans. 1 wt% AlOZr NPs + ER adhesive samples displayed the most strong composite/CAD bond. The highest DC was observed in Group 1: 0 wt% AlOZr NPs + ER adhesive.