Need for the study:

 The success of endodontic treatment is highly related to the elimination or reduction of post-endodontic pain, many clinical studies have reported varying degrees of pain, ranging from 25 to 40%. Postoperative pains in patient undergoing root canal treatment is an undesirable complication in dental practice for both patient and dentist. The agent that triggers these events may have different origins, such as physic, chemical or microbiological; however, the latter seems to be the main cause of postoperative pain. The intensity of the inflammatory reaction can be influenced by several factors such as the degree of existing pathological changes in the periapical region, presence of certain bacterial species in the root canal.

Current literature on number of visits for root canal treatment provides conflicting opinions and recommendations. However, single-visit root canal treatment has become a common practice and offers several advantages, including decreased number of operative procedures, less time consuming, more economical for busy patients and no risk of inter-appointment leakage through temporary restorations. The disadvantages of single visit procedures are also obvious as it eliminates some of the controls available in the multiple visit procedures, such as culturing to check the effectiveness of the biomechanical preparation. But with meticulously instrumentation and irrigation in a single-visit root canal treatment a better disinfection and pain management can be achieved.

In endodontics, root canal irrigation is an integral part of preparation, which plays an important role in disinfection and removal of the debridement. The ideal irrigant should be strongly antimicrobial, able to dissolve the necrotic tissues, the remaining organic tissues, and be non-toxic to the periapical tissues if extruded through the apex. Not only irrigation solution but also the irrigation technique plays a crucial role in successful endodontic treatment. Therefore, newer irrigation solutions and techniques have to be tested to achieve this goal.

 One such new generation of the disinfectant agents is ozone; a powerful oxidizing agent used to eliminate bacteria in root canals. Recent investigations of aqueous ozone have indicated that it is a powerful antimicrobial agent against oral pathogens and even resistant microorganisms too. One of the crucial properties of aqueous ozone is its non toxicity to oral cells in vitro than all other known antiseptics. However, the most important disadvantage of aqueous ozone is its unstable concentration in a long time. Consequently, aqueous ozone should be used as soon as possible after obtaining the ozone generator.   

 Irrigant exchange can be further improved in a number of ways, including pressure alteration, sonics, and ultrasonics. The simplest is manual dynamic agitation technique in which the obturating gutta-percha cone is pumped up and down in the canal.  The literature is scarce on studies that evaluate whether efficacy of Ozone can be optimized by the use of the ultrasonic, pro-agitator tip system (PATS) or manual dynamic agitation.

 Hence, the present study will aim to evaluate and compare the post-treatment pain after single-visit endodontics with three different Ozone application techniques (manual and ultrasonic and pro agitator tip system (PATS).