Fokkinga Wietske A, Kreulen Cees M, Le Bell-Rönnlöf Anna-Maria, Lassila Lippo V J, Vallittu Pekka K, Creugers Nico H J
Department of Oral Function and Prosthetic Dentistry, College of Dental Science, University Medical Centre Nijmegen, Nijmegen, the Netherlands.
Eur J Oral Sci. 2006 Jun;114(3):250-6. doi: 10.1111/j.1600-0722.2006.00357.x.
The in vitro fracture behavior of severely damaged premolars, restored with metal crowns with limited ferrule and several post-and-core systems, was investigated. Crowns of maxillary premolars were removed and canals were prepared with Gates Glidden drills and with Parapost drills. Groups of 11 samples were each treated with cast post-and-cores (Parapost XP, Wironium Plus) (group 1), prefabricated metal posts (Parapost XH) (group 2), prefabricated glass fiber posts (Parapost FiberWhite) (group 3), and custom-made glass fiber posts (EverStick Post) (group 4). Posts and composite cores and metal crowns in groups 2, 3, and 4 were adhesively cemented. Post-and-cores and crowns in group 1 were cemented with phosphate cement. Thermocycling was performed (6,000x, 5-55 degrees C). Two static load tests (30 degrees ) were applied. During the first load test (preloading) no failures occurred. Failure modes from the second load test were categorized into favorable and unfavorable failures. Mean failure loads among the four groups (group 1, 1,845 N; group 2, 1,718 N; group 3, 1,812 N; and group 4, 1,514 N) were not significantly different. Unfavorable failures were root fractures and favorable failures were postcrown displacements. No differences in frequencies of unfavorable/favorable failures were seen among the groups. The results suggest that different post-and-core systems have no influence on the fracture behavior of severely damaged premolars restored with metal crowns with limited ferrule.
研究了用带有限制性箍的金属冠和几种桩核系统修复的严重受损前磨牙的体外断裂行为。去除上颌前磨牙的牙冠，用盖茨·格利登钻和帕拉桩钻制备根管。将11个样本分为几组，分别用铸造桩核（帕拉桩XP、维罗镍合金增强型）（第1组）、预成金属桩（帕拉桩XH）（第2组）、预成玻璃纤维桩（帕拉桩纤维白）（第3组）和定制玻璃纤维桩（爱固桩）（第4组）进行处理。第2、3和4组中的桩、复合树脂核和金属冠采用粘结剂粘结。第1组中的桩核和牙冠用磷酸锌水门汀粘结。进行热循环（6000次，5 - 55摄氏度）。施加两次静态载荷试验（30度）。在第一次载荷试验（预加载）期间未发生失效。第二次载荷试验的失效模式分为有利失效和不利失效。四组的平均失效载荷（第1组，1845牛；第2组，1718牛；第3组，1812牛；第4组，1514牛）无显著差异。不利失效为牙根折断，有利失效为桩冠移位。各组之间不利/有利失效的频率无差异。结果表明，不同的桩核系统对用带有限制性箍的金属冠修复的严重受损前磨牙的断裂行为没有影响。
