Pain after endodontic treatment is the biggest fear of an Endodontist and is a common complication, which affects approximately 3-58% of patients . The etiology of postoperative endodontic pain is multifactorial, generally induced by inflammatory mediators produced due to chemical, mechanical, or microbial injuries to the pulp & periapical tissues that result in acute inflammation. While analgesic remains a popular form of therapy, lasers can be proposed as an alternate yet competent form of pain management due to their evident side effects.

 Low-level laser therapy (LLLT) or Photobiomodulation has shown a comparable effect over NSAIDs in pain management as per studies. While photobiomodulation can be done in the 600nm - 1000nm wavelength range previous studies have been done with 970nm & a few studies with 640nm wavelength in root canal treatment and re-treatment cases.

Different laser parameters such as wavelength, power, duration, and frequency could provide different reduced pain intensity results and certain wavelengths can be more effective than others in managing post-operative pain ^.

According to the literature, there is no evidence on which wavelength of the Diode laser is more efficient & safer way of reducing post-operative pain for patients who require endodontic treatment. Hence the present study is designed to evaluate and compare the efficacy of photobiomodulatory effect with 660nm and 970nm wavelength of diode lasers in single visit endodontic treatment.