Nothdurft F P, Seidel E, Gebhart F, Naumann M, Motter P J, Pospiech P R
Department of Prosthetic Dentistry and Dental Materials Sciences, Dental School and Clinics, Saarland University, Homburg/Saar, Germany.
J Dent. 2008 Apr;36(4):287-93. doi: 10.1016/j.jdent.2008.01.007. Epub 2008 Feb 21.
The aim of the study was to evaluate the influence of different posts and types of cementation on the fracture load and fracture mode of crowned, endodontically treated premolars with class II cavities in an ex vivo setting.
Forty-eight single-rooted human premolars were endodontically treated and prepared with standardized MO (mesio-occlusal) cavities and a circular chamfer preparation. Eight teeth each received either no posts or were restored with screws (BKS), glass fiber posts (DentinPost), or quartz fiber posts (DT Light SL). Sixteen teeth were restored with zirconium dioxide posts (CeraPost). BKS-screws and eight zirconium dioxide posts were cemented conventionally with glass ionomer cement; Panavia F was used for all others. The specimens were restored with composite cores and crowns cast from a non-precious metal. Eight sound premolars served as the controls. After thermomechanical fatigue testing, the samples were loaded until fracture occurred at an angle of 45 degrees. All specimens were evaluated for fracture lines.
The sound teeth showed the significant highest fracture load (792.50+/-210.01 N). Conventionally cemented zirconium dioxide posts showed the lowest fracture load (327.00+/-45.84 N); the highest fracture load occurred with quartz fiber posts (421.75+/-90.19 N). Only the difference between these two groups was statistically significant. With glass fiber posts and conventionally cemented zirconia posts, restored teeth failed mostly in an "unfavourable" mode.
With respect to the fracture load, there was no statistical difference between the restoration of non-vital premolars with class II cavities with crowns and posts or crowns alone.
本研究旨在评估在体外环境下，不同桩及粘结类型对患有Ⅱ类洞型的根管治疗后带冠前磨牙的断裂载荷和断裂模式的影响。
48颗单根人前磨牙进行根管治疗，并制备标准化的近中咬合（MO）洞型及环形肩台预备。每组8颗牙齿，分别不使用桩、用螺丝桩（BKS）、玻璃纤维桩（DentinPost）或石英纤维桩（DT Light SL）修复。16颗牙齿用二氧化锆桩（CeraPost）修复。BKS螺丝桩和8颗二氧化锆桩用玻璃离子水门汀传统粘结；其他所有桩均使用Panavia F粘结。样本用复合树脂核和非贵金属铸造的全冠修复。8颗健康前磨牙作为对照。经过热机械疲劳测试后，样本以45度角加载直至发生断裂。所有样本均评估骨折线情况。
健康牙齿的断裂载荷显著最高（792.50±210.01 N）。传统粘结的二氧化锆桩显示出最低的断裂载荷（327.00±45.84 N）；石英纤维桩的断裂载荷最高（421.75±90.19 N）。只有这两组之间的差异具有统计学意义。使用玻璃纤维桩和传统粘结的氧化锆桩修复的牙齿大多以“不利”模式断裂。
对于Ⅱ类洞型的无活力前磨牙，带冠并使用桩修复与仅带冠修复在断裂载荷方面无统计学差异。
