Neiva G, Yaman P, Dennison J B, Razzoog M E, Lang B R
Department of Cariology, Restorative Sciences, and Endodontics, University of Michigan, Ann Arbor, USA.
J Esthet Dent. 1998;10(2):60-6. doi: 10.1111/j.1708-8240.1998.tb00339.x.
All-ceramic restorations have become an attractive alternative to porcelain-fused-to-metal crowns, but their strength is still an important issue. The purpose of this study was to compare the in vitro fracture resistance of three all-ceramic systems: IPS Empress, In-Ceram, and Procera AllCeram. Thirty dies were replicated from a master die using high filler resin with a modulus of elasticity similar to dentin. Ten cores each of In-Ceram and Procera were fabricated to a thickness of 0.5 mm. The remaining porcelain was applied using a sculpting device to produce a crown with a final thickness of 1.0 mm axially and 2.5 mm occlusally. Ten IPS Empress crowns were mixed to the same dimensions and were pressed by the manufacturer. The internal surfaces of all the crowns were etched and silanated prior to cementation with a resin cement (Panavia 21). The cemented samples were loaded in an Instron machine until fracture. The mean fracture loads were: IPS Empress, 222.45 (+/- 49) kg; In-Ceram, 218.8 (+/- 36) kg; Procera AllCeram, 194.20 (+/- 37) kg. Tukey's test showed no statistically significant differences among the three all-ceramic systems at p < .05.
全瓷修复体已成为烤瓷熔附金属冠的一种有吸引力的替代方案，但其强度仍是一个重要问题。本研究的目的是比较三种全瓷系统（IPS Empress、In-Ceram和Procera AllCeram）的体外抗折强度。使用与牙本质弹性模量相似的高填料树脂从母模复制30个代型。分别制作10个In-Ceram和Procera核，厚度为0.5mm。使用塑形装置施加剩余的瓷料，制作出轴向最终厚度为1.0mm、咬合面最终厚度为2.5mm的冠。将10个IPS Empress冠混合至相同尺寸并由制造商压制。在使用树脂粘结剂（Panavia 21）粘结之前，对所有冠的内表面进行蚀刻和硅烷化处理。将粘结后的样本在Instron机器上加载直至断裂。平均断裂载荷为：IPS Empress，222.45（±49）kg；In-Ceram，218.8（±36）kg；Procera AllCeram，194.20（±37）kg。Tukey检验显示，在p<0.05时，三种全瓷系统之间无统计学显著差异。
