歯内療法治療歯におけるEnterococcus faecalisのマイクロリーク防止に対する歯頸部バリアの有効性

The efficacy of a cervical barrier in preventing microleakage of Enterococcus faecalis in endodontically treated teeth.

抄録

歯冠修復物の臨床的不具合は，歯内療法を行った歯の健全な歯周状態を損なう可能性がある．今回のex vivo試験の目的は，歯冠修復物の最終的な喪失に伴う細菌のマイクロリークを防止するための歯頸部バリアの有効性を評価することであった．スメア層を除去し，セメントエナメル接合部をガッタパーチャで封鎖した後，70本の単根下顎前歯をランダムに5群に分けた．グループ 1 は追加治療を行わず，グループ 2 とグループ 3 はそれぞれ 2 mm と 3 mm の歯根固めを除去し，歯根固めと同じ厚さの歯頸部バリアを設置した．第4群（ポジティブコントロール）では，根管にガッタパーチャのみを充填し，第5群（ネガティブコントロール）では，根管を完全に不透過化した後に閉塞した．充填した根管は，Enterococcus faecalisを微生物マーカーとしたSplit Chamber Model Systemに組み込んだ．根尖は下部のチャンバーに浮遊させた．漏出量は60日間毎日測定し，濁度を評価した．Fisherの正確検定によると，グループ2および3の子宮頸管バリアは，グループ1および4と比較して，E. faecalisの根管へのマイクロリークを防止していた．この結果は，グループ 5 の完全密封サンプルの結果と同様であった（p = 0.001）．

The clinical failure of coronal restorations can compromise the healthy periapical status of endodontically treated teeth. The purpose of the present ex vivo study was to assess the effectiveness of the cervical barrier in preventing bacterial microleakage in the eventual loss of the coronal restoration. Following removal of the smear layer and obturation to the cementoenamel junction using gutta-percha, 70 single-rooted mandibular premolars were randomly divided into five different groups: Group 1 received no additional treatment; Groups 2 and 3 had 2 mm and 3 mm of the obturation removed, respectively, followed by placement of a cervical barrier that was the same thickness as the obturation. In Group 4 (positive control), the root canals were filled only with gutta-percha, while in Group 5 (negative control), the root canals were completely impermeabilized following obturation. The filled root canals were incorporated into a split-chamber model system using Enterococcus faecalis as a microbial marker. The apices were suspended in the lower chambers. Leakage was determined daily for 60 days and evaluated for turbidity. According to Fisher's exact test, the cervical barrier in Groups 2 and 3 prevented the microleakage of E. faecalis into the root canals when compared with Groups 1 and 4. This result was similar to that for the completely sealed samples in Group 5 (p = 0.001).