Authors: Abou-Rass M, Piccinino MV.
Title: The effectiveness of four clinical irrigation methods on the removal of root canal debris.
Journal: Oral Surg Oral Med Oral Pathol
Date: Sep 1982
Citation: 54(3):323-8
Category: Irrigants and Medicaments
Evidence-based Ranking: 5
Purpose/Objectives: To investigate the effect of four methods of irrigation of the root canal on removal of dental debris.

Materials and Methods: 48 mesial roots of mandibular molars were used. 24 teeth (48 canals) were prepared with a step back technique to a size 25. The other half were prepared to a size 40 and which would allow a D-11 1 mm from the apex. During preparation the teeth were irrigated with 2.5% NaOCl and RC Prep. Dentin shavings from extracted teeth were mixed with radiopaque contrast medium Renografin-60, and introduced into the canals, which was confirmed with radiographs. The teeth were then irrigated 4 different times with 1. 3ml of tap water introduced in to the chamber and stirred with a 15 file. 2. 3ml of tap water with a 23-gauge endodontic needle. 3. 1.8 ml of anesthetic solution from a 30-gauuge needle. 4. 1.5ml of 3% H2O2 and 1.5 ml of 2.5% NaOCl via a 23 gauge needle. The teeth were than radiographed and scored by 1/3, 2/3. or 3/3 depending on the amount of flushing. Results: In canals C/S to a size 40, method 3 was statistically significant compared to the others (45 out of 46 completely cleared, compared to 24, 32, and 22 respectively) In method 3, the needle was able to reach an average of 17.4 mm in to an average of 20.4 m teeth. In case of step back preparation, the results were similar with method 3 being superior. (43 cleared compared to 26, 29, and 25).

AuthorÂ’s Conclusions: The proximity of the delivering needle plays an important role, and must be in close proximity. Narrow canals prepared to a size 25 can be properly irrigated, if the taper allow needle penetration close to the apex. The use of a 30-gauge anesthetic needle is more effective than a 23-gauge Endo needle, and alternating solutions of peroxide and NaOCl were no more effective than other methods, ReviewerÂ’s Comments: Interesting design and some decent conclusions, but it seems the author wants to claim the proximity of the needle is more important than the irrigant used. It might be in a flushing action, but from a chemical evaluation, I do not believe that can be deduced from a radiographic study. Volume, needle proximity and type of irrigant all play important roles in thoroughly cleaning the root canal system.