Antimicrobial Efficacy of Intracanal Medicaments Incorporated With Nanoparticles in Primary Teeth: An In Vitro Study

Placing an intracanal medicament helps in the disinfection of primary root canals, and nanoparticles enhance the material properties by increasing the physical and chemical reactivity. The study was aimed at assessing the efficacy of calcium hydroxide+calcium hydroxide nanoparticles and zinc oxide+zinc oxide nanoparticles as an intracanal medicament when compared with calcium hydroxide and zinc oxide eugenol in terms of antibacterial efficacy and penetration depth. Forty extracted human primary teeth were included in the study. Of these, 40 teeth were divided into two subgroups-Group A (to assess antibacterial efficacy) and Group B (to assess penetration depth). The teeth in Group A were contaminated with an <i>Enterococcus faecalis</i> biofilm for 7 days, and CFU count was determined. Calcium hydroxide (A1), calcium hydroxide with calcium hydroxide nanoparticles (A2), zinc oxide with zinc oxide nanoparticles (A3), and zinc oxide eugenol (A4) were placed in the canals. CFU count was determined on Day 7 and Day 14. The teeth in Group B were also divided into calcium hydroxide (B1), calcium hydroxide with calcium hydroxide nanoparticles (B2), zinc oxide with zinc oxide nanoparticles (B3), and zinc oxide eugenol (B4) groups. Two teeth from each group were subjected to SEM analysis. A statistically significant difference was noted in the CFU count reduction on Day 7 in Group A2, Group A3, and Group A4. The highest penetration depth was noted in Group B2. The authors concluded that the antibacterial efficacy and penetration depth into dentin improved on incorporating calcium hydroxide and zinc oxide nanoparticles. Based on this conclusion, the authors recommend further in vivo studies with nanoparticles incorporated intracanal medicaments in primary teeth to determine their safety of use and feasibility in a clinical scenario.