# Narrative Review on Methods of Activating Irrigation Liquids for Root Canal Treatment
## 6 Discussion  
The state of knowledge about techniques and biomaterials used in modern medicine changes rapidly nowadays. It is one of the clinicians' tasks to constantly educate and search for the best possible solutions for their patients. To gain the latest and most reliable knowledge about clinical procedures, also in the field of endodontic treatment, clinicians may follow instructions provided by leading endodontic associations. They offer verified and actual knowledge presented in the formula of guidelines.  
In 2006 European Society of Endodontology presented a guideline about endodontic treatment [94]. The authors enumerate the following aims of the irrigation--elimination of microorganisms, flushing out debris, lubrication of root canal instruments, and dissolution of the organic debris. Attention is paid to not irritating the periradicular tissues by using a suitable syringe and the exact amount of the irrigant. No specific data is given. The possibility of using ultrasonic or sonic systems is also outlined.  
British Endodontic Society remarks that the success of the endodontic treatment depends on accurate diagnosis and completion of each stage of treatment to a high standard [95]. In the guide presented in 2022, it is noticed that the primary objective of endodontic treatment is the elimination of microorganisms from the root canal system and preventing reinfection. The aims of the irrigation are defined as antibacterial action, tissue dissolving capabilities, reduction of the friction between the instrument and dentine, improving the cutting effectiveness of the files, lowering the operation field's temperature, and a washing effect to flush out debris. Most importantly, irrigation is the only way to impact areas of the root canal untouched by mechanical instrumentation. Irrigants recommended by the British Endodontic Society include sodium hypochlorite solution (0.5% to 5.25%), EDTA (17%), and Chlorhexidine (2%). Activation of irrigants is also recommended. They can be enhanced using dynamic agitation, ultrasonic activation, negative pressure irrigation, or with heat.  
Considering modern studies, we may conclude that sodium hypochlorite is the primary irrigant of choice. Usage of the chelator is also necessary in order to dissolve hard-tissue debris created during instrumentation or the inorganic components of the smear layer [31]. The same study concludes that there is no evidence, that long-term clinical success of endodontic treatment can be improved by irrigants' activation. However, it is noted that delivering NaCl and EDTA by a syringe and ultrasonic activation is the most popular and efficient protocol of irrigation during root canal treatment. Such an approach is promoted in the review from 2012. The paper, based on many in vitro studies, emphasizes the role of ultrasonic irrigation as having a positive effect on chemical, biological, and physical debridement of the root canal system [96]. The study, which analyzed articles available on MEDLINE and Cochrane bases, concludes that to fully compare different methods of activation, there is a need for protocols' standardization and further tests are necessary to obtain a complete state-of-the-art. Another review on the effectiveness of ultrasonically activated irrigation from 2018 comparing 15 studies came to a similar conclusion as presented above [97]. Authors notice that ultrasonic irrigant activation is more efficient in microorganism reduction compared to other irrigant activation techniques.