Ghadhanfari Husain A, Khajah Hasan M, Monaco Edward A, Kim Hyeongil
Specialist, Fixed Prosthodontics, Al-Amiri Dental Center, Kuwait City, Kuwait.
Consultant, Fixed Prosthodontics, Al-Amiri Dental Center, Kuwait City, Kuwait.
J Prosthet Dent. 2014 Oct;112(4):994-1000. doi: 10.1016/j.prosdent.2014.02.015. Epub 2014 May 17.
The tensile strength obtained by conventional postceramic application soldering and laser postceramic welding may require more energy than microwave postceramic soldering, which could provide similar tensile strength values.
The purpose of the study was to compare the tensile strength obtained by microwave postceramic soldering, conventional postceramic soldering, and laser postceramic welding.
A gold-palladium metal ceramic alloy and gold-based solder were used in this study. Twenty-seven wax specimens were cast in gold-palladium noble metal and divided into 4 groups: laser welding with a specific postfiller noble metal, microwave soldering with a postceramic solder, conventional soldering with the same postceramic solder used in the microwave soldering group, and a nonsectioned control group. All the specimens were heat treated to simulate a normal porcelain sintering sequence. An Instron Universal Testing Machine was used to measure the tensile strength for the 4 groups. The means were analyzed statistically with 1-way ANOVA. The surface and fracture sites of the specimens were subjectively evaluated for fracture type and porosities by using a scanning electron microscope.
The mean (standard deviation) ultimate tensile strength values were as follows: nonsectioned control 818 ±30 MPa, microwave 516 ±34 MPa, conventional 454 ±37 MPa, and laser weld 191 ±39 MPa. A 1-way ANOVA showed a significant difference in ultimate tensile strength among the groups (F3,23=334.5; P<.001). Follow-up multiple comparisons showed a significant difference among all the groups. Microwave soldering resulted in a higher tensile strength for gold and palladium noble metals than either conventional soldering or laser welding.
Conventional soldering resulted in a higher tensile strength than laser welding. Under the experimental conditions described, either microwave or conventional postceramic soldering would appear to satisfy clinical requirements related to tensile strength.
通过传统的陶瓷修复体应用焊接和激光陶瓷修复体焊接获得的拉伸强度可能比微波陶瓷修复体焊接需要更多能量，而微波陶瓷修复体焊接可以提供相似的拉伸强度值。
本研究的目的是比较微波陶瓷修复体焊接、传统陶瓷修复体焊接和激光陶瓷修复体焊接所获得的拉伸强度。
本研究使用了一种金钯金属陶瓷合金和金基焊料。将27个蜡型铸造成金钯贵金属，并分为4组：使用特定的焊后填充贵金属进行激光焊接、使用陶瓷修复体焊料进行微波焊接、使用与微波焊接组相同的陶瓷修复体焊料进行传统焊接以及一个未切割的对照组。所有标本都经过热处理以模拟正常的瓷烧结过程。使用英斯特朗万能试验机测量4组的拉伸强度。使用单因素方差分析对平均值进行统计学分析。通过扫描电子显微镜对标本的表面和断裂部位进行主观评估，以确定断裂类型和孔隙率。
平均（标准差）极限拉伸强度值如下：未切割对照组818±30MPa，微波组516±34MPa，传统组454±37MPa，激光焊接组191±39MPa。单因素方差分析显示各组之间的极限拉伸强度存在显著差异（F3,23 = 334.5；P <.001）。后续的多重比较显示所有组之间存在显著差异。微波焊接对于金和钯贵金属产生的拉伸强度高于传统焊接或激光焊接。
传统焊接产生的拉伸强度高于激光焊接。在所描述的实验条件下,微波或传统的陶瓷修复体焊接似乎都能满足与拉伸强度相关的临床要求。
