Dilmener Faruk Taner, Sipahi Cumhur, Dalkiz Mehmet
Dental Sciences Center, Gulhane Military Medical Academy, Ankara, Turkey.
J Prosthet Dent. 2006 Feb;95(2):130-6. doi: 10.1016/j.prosdent.2005.11.013.
Despite their esthetic properties, the fracture resistance of newly introduced esthetic post-and-core systems has not been studied, restricting clinical use.
The purpose of this study was to determine and compare the fracture resistances of 3 recently introduced esthetic post-and-core systems with a cast metal post and core using a clinically related test method.
Forty recently extracted caries-free maxillary central incisors were selected, sectioned, and their roots endodontically treated. The roots were then embedded in acrylic resin blocks and assigned to 4 experimental groups (n = 10). The cast metal (Wiron 99) post-and-core group (CMDC) served as the control. Three experimental groups consisted of a stainless steel post/composite-resin (Charisma) core group (SCOM), zirconium dioxide post/composite-resin (Charisma) core group (ZCOM), and zirconium dioxide post/ceramic (Cosmopost) core group (ZCER). The post spaces were prepared, posts were seated, cores were formed, and 40 post-and-core foundations were cemented into the roots. Following thermal cycling (5000 cycles between 5 degrees C and 55 degrees C with a dwell time of 30 seconds), a compressive load was applied to the inclined surface of each specimen at a 130-degree angle to the specimen long axes in a universal testing machine at a crosshead speed of 1 mm/min until failure occurred. Force to failure (N) was recorded. Data were analyzed with a 1-way analysis of variance and Bonferroni tests to determine the difference between the groups (alpha=.05). For pairwise comparisons among group mean values, P < .0083 indicated statistical significance and established the overall confidence level at 95%.
Groups CMDC (738.6 N +/- 10.2) and ZCER (710.2 N +/- 5.3) exhibited the highest resistance to fracture. The ZCOM group showed the lowest fracture resistance (450.3 N +/- 5.7). The fracture resistance of the SCOM group (565 N +/- 7.2) was lower than the CMDC and ZCER groups, and higher than the ZCOM group. The differences among the groups were significant (P < .001) except for CMDC and ZCER (P < .016).
Within the limitations of this study, the cast metal post/core and zirconia post/ceramic core foundations were found to be more fracture resistant than the zirconia post/composite-resin core and stainless steel post/composite-resin core foundations. Aside from its desirable esthetic properties, the zirconia post/ceramic core combination demonstrated high resistance to fracture.
尽管新型美学桩核系统具有美学特性，但其抗折性尚未得到研究，这限制了其临床应用。
本研究的目的是使用临床相关测试方法，确定并比较3种最近推出的美学桩核系统与铸造金属桩核的抗折性。
选择40颗近期拔除的无龋上颌中切牙，进行切片并对其牙根进行根管治疗。然后将牙根嵌入丙烯酸树脂块中，并分为4个实验组（n = 10）。铸造金属（Wiron 99）桩核组（CMDC）作为对照组。三个实验组分别为不锈钢桩/复合树脂（Charisma）核组（SCOM）、二氧化锆桩/复合树脂（Charisma）核组（ZCOM）和二氧化锆桩/陶瓷（Cosmopost）核组（ZCER）。制备桩道，就位桩，形成核，将40个桩核基底粘固到牙根中。在进行热循环（在5℃至55℃之间循环5000次，每次停留时间为30秒）后，在万能试验机中以1mm/min的十字头速度，对每个试件与试件长轴呈130度角的倾斜表面施加压缩载荷，直至试件破坏。记录破坏时的力（N）。采用单因素方差分析和Bonferroni检验对数据进行分析，以确定各组之间的差异（α = 0.05）。对于组均值的两两比较，P < 0.0083表示具有统计学意义，并将总体置信水平设定为95%。
CMDC组（738.6 N ± 10.2）和ZCER组（710.2 N ± 5.3）表现出最高的抗折性。ZCOM组的抗折性最低（450.3 N ± 5.7）。SCOM组（565 N ± 7.2）的抗折性低于CMDC组和ZCER组，但高于ZCOM组。除CMDC组和ZCER组（P < 0.016）外，各组之间的差异具有统计学意义（P < 0.001）。
在本研究的局限性内，发现铸造金属桩/核和氧化锆桩/陶瓷核基底比氧化锆桩/复合树脂核和不锈钢桩/复合树脂核基底更具抗折性。除了其理想的美学特性外，氧化锆桩/陶瓷核组合还表现出较高的抗折性。
