The article reviews the principles and antimicrobial efficacy of laser-activated irrigation (LAI), a technique that uses pulsed lasers to activate root canal irrigants. The physical mechanism of LAI involves the formation and implosion of vapor bubbles, driven by cavitation, which enhances the dynamics and distribution of the irrigant within the root canal. Key parameters influencing LAI efficacy include laser wavelength, pulse energy, pulse length, and fiber tip geometry. Er:YAG and Er,Cr:YSGG lasers are preferred due to their high absorption in water, leading to efficient cavitation. Laboratory studies suggest that LAI is superior to conventional irrigation in disinfecting root canals, with some studies showing higher antimicrobial efficacy compared to ultrasonic activation. Clinical evidence is limited, but studies indicate that LAI does not result in higher postoperative pain levels compared to other activation methods. The review also discusses the historical evolution of LAI, the challenges in standardizing its parameters, and the potential benefits of double-pulse LAI (SWEEPS) for enhancing shock wave emission. Overall, while LAI shows promise in improving root canal cleaning and disinfection, more clinical trials are needed to fully evaluate its effectiveness.The article reviews the principles and antimicrobial efficacy of laser-activated irrigation (LAI), a technique that uses pulsed lasers to activate root canal irrigants. The physical mechanism of LAI involves the formation and implosion of vapor bubbles, driven by cavitation, which enhances the dynamics and distribution of the irrigant within the root canal. Key parameters influencing LAI efficacy include laser wavelength, pulse energy, pulse length, and fiber tip geometry. Er:YAG and Er,Cr:YSGG lasers are preferred due to their high absorption in water, leading to efficient cavitation. Laboratory studies suggest that LAI is superior to conventional irrigation in disinfecting root canals, with some studies showing higher antimicrobial efficacy compared to ultrasonic activation. Clinical evidence is limited, but studies indicate that LAI does not result in higher postoperative pain levels compared to other activation methods. The review also discusses the historical evolution of LAI, the challenges in standardizing its parameters, and the potential benefits of double-pulse LAI (SWEEPS) for enhancing shock wave emission. Overall, while LAI shows promise in improving root canal cleaning and disinfection, more clinical trials are needed to fully evaluate its effectiveness.