下顎前歯の歯内療法後におけるケイ酸カルシウム系シーラーの象牙細管への浸透に及ぼす封鎖技術の影響

Effect of obturation technique on penetration of calcium silicate-based sealer into dentinal tubules after endodontic retreatment of mandibular premolars.

抄録

研究目的:

共焦点レーザー顕微鏡（CLSM）を用いて，2種類の封鎖方法を用いて再治療後の歯内シーラーの歯頸管への浸透を検討した．

OBJECTIVE: Confocal laser scanning microscopy (CLSM) was used to investigate the penetration of endodontic sealers into the dentinal tubules after retreatment using two different obturation techniques.

材料および方法:

30本の下顎前歯をインスツルメントF3（ProTaper Universal, Dentsply）まで作製し，シングルコーン法を用いてEndofillを充填した．管腔はMtwoインスツルメントを使用して再治療した．バイオCシーラーに蛍光色素（Fluo-3）を混合し，ラテラルコンデンセーション法（LC群）またはシングルコーン法（SC群）で再着手を行った（n＝15）．歯根端から2,4,6mmの位置で切開し，CLSMで分析し，管腔周囲へのシーラーの浸透と象牙細管へのシーラーの最大浸透深さを評価した．データはANOVA，Student-t検定，Holm-Sidak検定を用いて解析した．

MATERIALS AND METHODS: Thirty mandibular premolars were prepared up to instrument F3 (ProTaper Universal, Dentsply) and filled with Endofill using the single cone technique. The canals were retreated using Mtwo instruments. Reobturation was performed with the Bio-C sealer mixed with a fluorophore dye (Fluo-3) using either the lateral condensation technique (group LC) or the single cone technique (group SC) (n = 15). Teeth were sectioned 2, 4, and 6 mm from the apex and analyzed with CLSM to assess the penetration of the sealer into the canal perimeter and the maximum depth of penetration of the sealer into the dentinal tubules. Data were analyzed using ANOVA and the Student-t and Holm-Sidak tests.

結果:

先端部では，SC群に比べLC群で有意に浸透量が多かった（p＜0.05）．中・頸部では，有意差は認められなかった（p＞0.05）．浸透深度に関しては、調査したどのセグメントでも有意差は認められなかった（p>0.05）。

RESULTS: In the apical segment, the penetrated perimeter was significantly higher in the LC group than in the SC group (p < 0.05); no significant difference was found in the middle and cervical segments (p > 0.05). In terms of penetration depth, no significant differences were found for any of the segments studied (p > 0.05).

結論:

LC 法は SC 法に比べ，歯内療法後の先端セグメントにおいて，シーラーの浸透する管周の割合が高いことが示された．

CONCLUSION: The LC technique promoted a higher percentage of canal circumference penetrated by the sealer than the SC technique in the apical segment after endodontic retreatment.

臨床的意義:

CLSMにより，再治療後の下顎前歯部において，LC法はSC法よりもバイオCシーラーを浸透させた管腔周囲長の割合を高くすることが示された．

CLINICAL RELEVANCE: CLSM demonstrated that the LC technique promoted a higher percentage of canal perimeter penetrated by the Bio-C sealer than the SC technique in the apical segment of mandibular premolars after retreatment.