Menani Luiz Ricardo, Ribeiro Ricardo Faria, Antunes Rossana Pereira de Almeida
Dental Materials and Prosthesis Department, Ribeirao Preto School of Dentistry, University of Sao Paulo, Sao Paulo, Brazil.
J Prosthet Dent. 2008 Feb;99(2):141-7. doi: 10.1016/S0022-3913(08)60030-X.
In vitro studies on the retentive strengths of various cements used to retain posts have reported conflicting results.
The purpose of this study was to compare the tensile strength of commercially pure titanium and type III cast gold-alloy posts and cores cemented with zinc phosphate or resin cement.
Forty-two extracted human canines were endodontically treated. The root preparations were accomplished using Largo reamers (10 mm in depth and 1.7 mm in diameter). Acrylic resin patterns for the posts and cores were made, and specimens were cast in commercially pure titanium and in type III gold alloy (n=7). Fourteen titanium cast posts and cores were submitted to surface treatment with Kroll acid solution and to scanning electron microscopy (SEM), before and after acid etching. The groups (n=7) were cemented with zinc phosphate cement or resin cement (Panavia F). Tensile strengths were measured in a universal testing machine at a crosshead speed of 0.5 mm/min. The results (Kgf) were statistically analyzed by 2-way ANOVA (alpha=.05).
The 2-way ANOVA indicated that there were no significant differences among the groups tested. Retentive means for zinc phosphate and Panavia F cements were statistically similar. The bond strength was not influenced by the alloy, the luting material, or the etching treatment. SEM analysis indicated that the etched surfaces were smoother than those that did not receive surface treatment, but this fact did not influence the results.
Commercially pure titanium cast posts and cores cemented with zinc phosphate and resin cements demonstrated similar mean tensile retentive values. Retentive values were also similar to mean values recorded for cast gold-alloy posts and cores cemented with zinc phosphate cement and resin cements.
关于用于固定桩的各种水门汀固位强度的体外研究报告了相互矛盾的结果。
本研究的目的是比较用磷酸锌或树脂水门汀粘结的商业纯钛和III型铸造金合金桩核的拉伸强度。
选取42颗拔除的人犬齿进行根管治疗。使用Largo扩孔钻（深度10mm，直径1.7mm）完成根管预备。制作桩核的丙烯酸树脂模型，并在商业纯钛和III型金合金中铸造标本（n = 7）。14个钛铸造桩核在酸蚀刻前后分别用Kroll酸溶液进行表面处理并进行扫描电子显微镜（SEM）检查。将各组（n = 7）用磷酸锌水门汀或树脂水门汀（Panavia F）粘结。在万能试验机上以0.5mm/min的十字头速度测量拉伸强度。结果（Kgf）通过双向方差分析进行统计学分析（α = 0.05）。
双向方差分析表明，测试组之间没有显著差异。磷酸锌和Panavia F水门汀的固位均值在统计学上相似。粘结强度不受合金、粘结材料或蚀刻处理的影响。SEM分析表明，蚀刻后的表面比未进行表面处理的表面更光滑，但这一事实并未影响结果。
用磷酸锌和树脂水门汀粘结的商业纯钛铸造桩核显示出相似的平均拉伸固位值。固位值也与用磷酸锌水门汀和树脂水门汀粘结的铸造金合金桩核的均值相似。
