今回は根管洗浄針と根管洗浄法に関する文献です。
48本の下顎大臼歯を半数ずつ2グループに分けています。
1つは根管をMAF25号でステップバック形成し
他方はMAF40号でスプレッダーD11の規格化されたサイズに形成しています。
.
それぞれの根管にX線造影剤を充填し、
その後4種の方法で根管洗浄を行い
X線撮影にて造影剤の除去効果を評価しています。
.
洗浄法1
根管内に水道水を満たし15号ファイルを回転させて
洗浄した後
1.5mlの水道水で23ゲージの根管洗浄針を用いて洗浄
.
洗浄法2
3mlの水道水で23ゲージの根管洗浄針を用いて洗浄
.
洗浄法3
1.8mlの麻酔液で30ゲージの根管洗浄針を用いて洗浄
.
洗浄法4
それぞれ0.75mlの3％過酸化水素水と次亜塩素酸ナトリウム溶液を
23ゲージの根管洗浄針で2回繰り返して交互洗浄
.
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).
Authors 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.
Reviewers 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.
.
つまり、30ゲージの先の細い洗浄針を用いた方が除去効果が高く
ステップバック形成法でテーパーを付与すれば、MAF25号の細い根管形成でも
MAF40号とほぼ同様の洗浄を行えた
ということです。
.
根管洗浄針が根尖付近まで到達しない場合には
テーパーを付けて根管形成することが根管洗浄に有効であることが分かりました。
.
引用文献
Abou-Rass M, Piccinino MV.
The effectiveness of four clinical irrigation methods on the removal of root canal debris.
Oral Surg Oral Med Oral Pathol 1982 ;54(3):323-8.