A Survey on Root Canal Irrigation at the University School of Dentistry in Japan

<p> Introduction: Although endodontic treatment has markedly changed due to the improvement of instruments and materials, mechanical cleaning remains insufficient to control intracanal infection. Root canal irrigation and intracanal medication are considered necessary. In the present study, a questionnaire survey regarding root canal irrigation methods used in clinical settings at dental university hospitals in Japan was conducted.</p><p> Method: A questionnaire titled “A survey regarding root canal irrigation methods used in clinical settings” was sent to 34 endodontic departments in Japan.</p><p> Results: The response rate to the questionnaire was 88%, and all departments performed root canal irrigation. The timing of root canal irrigation was as follows: Performed every time (root canal enlargement): 30%, Performed as needed (root canal enlargement): 80%, Performed after, not during, root canal enlargement (before root canal application): 3%.</p><p> Instruments used for root canal irrigation were as follows: Syringe: 93%, Passive ultrasonic irrigation: 87%, Sonically activated irrigation: 13%, Others: 3%. Types of syringe were as follows: Root canal syringe: 32%, Syringe and open-ended flat needle: 64%, Syringe and side-vented needle: 32%. Irrigants used were as follows: Sodium hypochlorite solution: 96%, EDTA solution: 96%, Hydrogen peroxide solution: 32%, Saline: 32%, Sterile water: 4%, Citric acid solution: 4%.</p><p> Conclusion: All endodontic departments in dental university hospitals in Japan that answered the questionnaire regarding root canal irrigation performed root canal irrigation. There was a common awareness that root canal irrigation is necessary. Many departments have introduced not only a syringe but also passive ultrasonic irrigation and sonically activated irrigation. As for root irrigation agents, many departments have introduced sodium hypochlorite and EDTA solutions.</p>