フラグメント再付着か直接修復か？in vitroでの検討

Fragment reattachment or direct restoration? An in vitro study.

抄録

背景・目的:

フラグメント再付着術を受ける歯の耐破折性は、中間材料を用いて同術を行うことで向上する可能性がある。本研究の目的は、予熱されたコンポジットレジンを含む様々なボンディング材が、コンポジットレジン直接修復と比較して、再付着術を受けた歯の破壊抵抗に与える影響を評価することであった。

BACKGROUND/AIMS: The fracture resistance of teeth subjected to fragment reattachment may improve when the technique is performed using intermediate materials. The aim of this study was to evaluate the influence of different bonding materials, including pre-heated composite resin, on the fracture resistance of teeth subjected to the reattachment technique compared with a direct composite resin restoration.

材料および方法:

歯牙の破折を模擬した後，各試料を以下の中間材料（n=15）のいずれかを用いて再付着させた．G0：ネガティブコントロール（健全歯）；G1：Z100；G2：予熱Z100；G3：フィルテックZ350 XT；G4：予熱フィルテックZ350 XT；G5：フィルテックZ350 XT Flow；およびG6：RelyX Veneer．これらの中間材料は，歯牙破折を模擬した後，各試験片の再着に使用された．G7では，Filtek Z350 XTコンポジットレジンを用いて直接クラスIV修復を行った．耐破折性は万能試験機を用い，1mm/minの圧縮荷重で評価した．一元配置分散分析（ANOVA）およびポストホックTukey test（5%）を行った．

MATERIALS AND METHODS: After simulating a tooth fracture, each specimen was reattached by using one of the following intermediate materials (n=15): G0, negative control (sound teeth); G1, Z100; G2, pre-heated Z100; G3, Filtek Z350 XT; G4, pre-heated Filtek Z350 XT; G5, Filtek Z350 XT Flow; and G6, RelyX Veneer. In G7, direct class IV restorations were performed using Filtek Z350 XT composite resin. The fracture resistance was evaluated using a universal testing machine under a compressive load of 1 mm/min. One-way analysis of variance (ANOVA) and the post hoc Tukey test (5%) were conducted.

結果:

G0は最も高い破壊抵抗を示し，G2およびG4を除く他の実験群とは統計的に有意な差を示した（p＜0.05）．G1とG6の間には，統計的に有意な差が認められた（one-way ANOVA，p=0.04）．G1およびG2では，予熱を伴う場合と伴わない場合で有意差が認められた（p＜0.05）．G3，G4では，この差は認められなかった（p>0.05）．再接着群と直接修復群との間には，統計的に有意な差は認められなかった（t-test，p＝0.53）．

RESULTS: G0 showed the highest fracture resistance, and this was statistically different from the other experimental groups (p<0.05) except for G2 and G4, in which the fragments were bonded using pre-heated resins. A statistically significant difference was found between groups G1 and G6 (one-way ANOVA, p=0.04). For G1 and G2, a significant difference was found between bonding with or without pre-heating (p<0.05). This difference was not observed in G3 and G4 (p>0.05). No statistically significant difference was found between the reattached and directly restored groups (t-test, p=0.53).

結論:

予熱されたコンポジットレジンを用いた再着歯法では，健全歯群と同程度の耐破折性を示した．フラグメント再着手法と直接コンポジットレジン法との間に差は認められなかった．

CONCLUSION: The tooth reattachment technique using pre-heated composite resin showed fracture resistance values similar to those of the sound tooth group. No difference was found between the fragment reattachment and direct composite resin techniques.