残存歯冠形態とレジンアバットメントおよびファイバーポストが静的および動的破壊抵抗性に及ぼす影響

Influence of remaining coronal tooth morphology with resin abutment and fiber post on static and dynamic fracture resistances.

抄録

本研究は，歯内療法を施した歯冠残存歯根に築造したレジンアバットメントの破壊抵抗を，静的負荷試験および繰返し負荷試験により明らかにすることを目的とした．歯内療法を施した牛歯根のうち，引張側で歯冠残存歯が円周の1/4と1/2を占めるもの，または引張側と圧縮側の両方で円周を覆うものを作製し，レジンアバットメントを築造した．歯軸に対して30°の荷重をかけ，静的負荷試験および繰返し負荷試験により耐破折性を評価した．歯冠残存歯の半周は有意に高い静的破折荷重と生存率を示した．圧縮側の歯冠残存歯は，重度破折に伴う動的破折抵抗を改善した．歯冠残存歯の占有面積と位置は，静的および動的破壊抵抗に影響した．

This study aimed to clarify the fracture resistance of resin abutments built on endodontically treated roots with the remaining coronal teeth via static and cyclic loading tests. Endodontically treated bovine roots, which had a remaining coronal tooth covered with an occupied area for a quarter and half of the circumference at the tensile side or covered the circumference at both the tensile and compressive sides, were fabricated to build up to the resin abutment. Fracture resistance was evaluated via static and cyclic loading tests by applying a load of 30° to the tooth axis. Half of the circumference of the remaining coronal tooth showed a significantly higher static fracture load and survival rate. The remaining coronal tooth on the compressive side improved the dynamic fracture resistance associated with severe fractures. The occupied area and location of the remaining coronal tooth affected the static and dynamic fracture resistances.