Application of the gold alloy with age-hardning ability at 37ﾟC to resin-bonded fixed partial denture

1)牙列缺失区域复制铸件的制作使用金属模具制作了一个与去年生产的牙列缺失区域相同的复制铸件，并将取出的人牙嵌入其中。上颌采用带缺失区域的复制模，下颌骨采用夹板复制模；在基台上形成了原始的和保留型的固位设计。2)树脂粘接固定义齿的制备及与基牙的粘接采用直接打蜡的方法在基牙上制备树脂粘接固定义齿。基于对自然牙列恢复的设想，将瓷与金属熔接在一起，用瓷与金属熔接所使用的合金制作桥状金属框架。这个桥架和金合金保持器是用与去年相同的焊接方法连接的。将完成的树脂粘接固定局部义齿和夹板涂上更多的铝粘接底漆，用粘接树脂将其粘接在基牙上。将得到的夹具放置在37°C和l00%湿度的烤箱中进行3天的时效硬化。3)粘接耐久性试验将树脂粘接固定局部义齿的中心部分在10 kg的重复载荷下承受2万次循环后，利用万能试验装置对固定局部义齿的牙膜施加剥离力，测量基牙的最大剥离强度。保留型覆盖部分咬合面和后固定部分义齿显示出最大的负荷阻力。相比之下，原始类型的前固定局部义齿在重复负荷后，固位强度明显减弱。总之，室温时效硬化金合金在树脂粘接固定局部义齿中的应用几乎可以满足所有预期的病例。少

1) Fabrication of a replicated cast of dentition with a missing areaA metal die was used to fabricate a replicated cast with the same missing area as the one produced last year, and extracted human teeth were embedded in it. The replicated cast with the missing area was fabricated for the maxilla, while a splint replicated cast was fabricated for the mandible ; original and retentive type retainer designs were formed on the abutments.2) Fabrication of a resin-bonded fixed partial denture and bonding to the abutmentsDirect waxing was used to fabricate the resin-bonded fixed partial denture on the abutments. Based on the assumption that recovery of the natural dentition would be accomplished by means of porcelain fused to metal, the pontic metal framework was fabricated from the alloy used for the porcelain fused to metal. This pontic and the gold alloy retainer were joined using the same soldering method as last year. Following sandblasting of the surfaces to be bonded with alumina, met … More al bonding primer was applied to the completed resin-bonded fixed partial denture and splint, and they were bonded to the abutments with an adhesive resin. The resulting fixture was placed in an oven at 37ﾟC and l00% humidity for three days for age-hardening.3) Bonding durability testAfter subjecting the central portion of the pontic of the resin-bonded fixed partial denture to 20,000 cycles of a repeating load of 10 kg, a universal testing device was used to apply peel out force to the embrasure of the fixed partial denture and maximum peel out strength from the abutments was measured. Maximum resistance to load was shown by the retentive type covering a portion of the occlusal surface and by the posterior fixed partial denture. In contrast, the original type anterior fixed partial denture was found to exhibit a major weakening in retentive strength following the repeating load. In conclusion, application of the room temperature age-hardening gold alloy to resin-bonded fixed partial denture was found to be possible for virtually all anticipated cases. Less