Comparison of Ultrasonic vs 980-nm Diode Laser Irrigant Activation for Reducing Residual Bacterial DNA in Necrotic Teeth

This randomized clinical trial aimed to compare residual oral bacterial DNA detection after ultrasonic irrigant activation and 980-nm diode laser irrigant activation during root canal treatment of necrotic single-rooted teeth. Sixteen patients requiring endodontic treatment were randomly assigned into two groups: ultrasonic activation or 980-nm diode laser activation. Root canals were prepared using standardized chemomechanical procedures and irrigated with 3% sodium hypochlorite activated by the assigned method. Microbial samples were collected before treatment and after irrigant activation. Bacterial DNA was identified using 16S rRNA polymerase chain reaction (PCR) sequencing. The primary outcome was the presence or absence of detectable oral bacterial DNA after treatment, while the secondary outcome was the taxonomic pattern of detected bacteria before and after activation. The study was designed to explore the comparative antibacterial effects of ultrasonic and diode laser activation in infected root canals.