Hummert T, Barghi N, Berry T
Department of Restorative Dentistry, University of Texas Health Science Center, Dental School, San Antonio.
J Prosthet Dent. 1991 Aug;66(2):177-81. doi: 10.1016/s0022-3913(05)80044-7.
The effect of die spacing and precementation internal adjustments on the compressive strength of a new ceramic foil crown system was examined in vitro. Twenty-four ceramic foil crowns were made for identical stylized master dies made of polycarbonate filled with 30 wt% carbon. One half of the stone working dies were coated with die spacer and the remaining were left untreated. A special foil used for these crowns was adapted to the working dies under 2500 psi loading. A sculpturing device was used to standardize the size and shape of the ceramic foil crowns. Only crowns made on dies coated with die spacer received precementation fitting adjustment. All crowns in the two groups were cemented with zinc phosphate cement and were subjected to compressive force until fracture occurred. Compressive strength data were analyzed and compared. Results showed that the use of die spacer and internal adjustments increased the compressive strength of the new ceramic foil crown.
体外研究了模具间距和粘固前内部调整对一种新型陶瓷箔冠系统抗压强度的影响。针对由填充30 wt%碳的聚碳酸酯制成的相同风格的母模制作了24个陶瓷箔冠。一半的石膏工作模用模具间隔剂涂层，其余的未处理。用于这些冠的特殊箔在2500 psi载荷下适配到工作模上。使用雕刻装置使陶瓷箔冠的尺寸和形状标准化。只有在涂有模具间隔剂的模具上制作的冠进行了粘固前适配调整。两组中的所有冠均用磷酸锌粘固剂粘固，并施加压缩力直至发生断裂。对抗压强度数据进行了分析和比较。结果表明，使用模具间隔剂和内部调整提高了新型陶瓷箔冠的抗压强度。
