Singh Ipsha, Nair K Chandrasekharan, Shetty Jayakar
KLES's Institute of Dental Sciences, Bengaluru, Karnataka, India.
Vishnu Dental College, Kovvada, Andhra Pradesh, India.
J Indian Prosthodont Soc. 2017 Oct-Dec;17(4):388-394. doi: 10.4103/jips.jips_144_17.
The aim of this study is to evaluate the strain developed in simulated mandibular model before and after the joining of an implant-supported screw-retained prosthesis by different joining techniques, namely, arc welding, laser welding, and soldering.
A specimen simulating a mandibular edentulous ridge was fabricated in heat-cured acrylic resin. 4-mm holes were drilled in the following tooth positions; 36, 33, 43, 46. Implant analogs were placed in the holes. University of California, Los Angeles, abutment was attached to the implant fixture. Eight strain gauges were attached to the acrylic resin model. Six similar models were made. Implant-supported screw-retained fixed prosthesis was fabricated in nickel-chromium alloy. A load of 400 N was applied on the prosthesis using universal testing machine. Resultant strain was measured in each strain gauge. All the prostheses were sectioned at the area between 36 and 33, 33 and 43, and 43 and 46 using 35 micrometer carborundum disc, and strain was measured in each strain gauge after applying a load of 400 N on the prosthesis. Specimens were joined by arc welding, soldering, and laser welding. After joining, a load of 400 N was applied on each prosthesis and the resultant strain was measured in each strain gauge.
Highest mean strain values were recorded before sectioning of the prostheses (889.9 microstrains). Lowest mean strain values were recorded after sectioning the prosthesis and before reuniting it (225.0 microstrains).
Sectioning and reuniting the long-span implant prosthesis was found to be a significant factor in influencing the peri-implant strain.
本研究旨在评估通过不同连接技术（即电弧焊、激光焊和软钎焊）连接种植体支持的螺丝固位修复体前后，模拟下颌模型中产生的应变。
用热固化丙烯酸树脂制作一个模拟下颌无牙颌牙槽嵴的标本。在以下牙位钻4毫米的孔：36、33、43、46。将种植体代型放入孔中。将加利福尼亚大学洛杉矶分校基台连接到种植体固定装置上。八个应变片附着在丙烯酸树脂模型上。制作六个类似的模型。用镍铬合金制作种植体支持的螺丝固位固定修复体。使用万能试验机在修复体上施加400牛的载荷。测量每个应变片中产生的应变。所有修复体均在36和33、33和43以及43和46之间的区域用35微米的碳化硅盘进行切割，在修复体上施加400牛的载荷后，测量每个应变片中的应变。标本通过电弧焊、软钎焊和激光焊进行连接。连接后，在每个修复体上施加400牛的载荷，并测量每个应变片中产生的应变。
在修复体切割前记录到最高平均应变值（889.9微应变）。在修复体切割后且重新连接前记录到最低平均应变值（225.0微应变）。
发现长跨度种植修复体的切割和重新连接是影响种植体周围应变的一个重要因素。
