Antibacterial effect of metallic nanoparticles on Streptococcus mutans bacterial strain with or without diode laser (970 nm)

Abstract

Thirty freshly a traumatically extracted premolars human tooth were collected, and cylindrical cavity in crowns with 4 mm diameter and 5 mm depth was prepared and inoculated with S. mutans for 24 h. The tooth were randomlly divided into equal expermintal groups (6 each): group 1, positive control group by S. mutans bacterial strain; group 2, irrigation with silver nanoparticles (AgNPs) for 3 min; group 3, irrigation with gold nanoparticles (AuNPs) for 3 min; group 4, 3 ml AgNPs + irradiation with diode laser for 60 s; and group 5, 3 ml AuNPs + irradiation with diode for 60 s. The specimens were collected from the teeth sample, and colony-forming units (CFU’s) were observed by counting the bacteria colony on plates. A significant difference was found among all the groups in comparison to the control group (p < 0.05). The greatest reduction in CFU’s was observed in combination of AgNPs with diode laser group.