Pierpont W F, Gray S E, Hermesch C B, Hilton T J
Wilford Hall Medical Center, Department of General Dentistry, Lackland AFB, TX 78236-5551, USA.
Oper Dent. 1994 Nov-Dec;19(6):211-6.
This study compared the compressive force required to fracture amalgam over nine base materials: a calcium hydroxide product (Dycal); two autocured glass ionomers (GlasIonomer Base Cement and Ketac-Bond); three light-cured glass ionomers (Photac-Bond, Variglass VLC, and Vitrebond); two light-cured resins (Timeline and VLC Dycal); and a zinc phosphate cement (Fleck's Zinc Cement). For the control group, 10 aluminum dies (25 mm x 12 mm x 10 mm) were milled with 3.0 mm x 3.0 mm slots, which were filled with hand-condensed Tytin amalgam with no underlying base. For experimental groups, 10 aluminum dies of equal dimension were milled with 3.5 mm x 3.0 mm slots. Following manufacturer's instructions, the nine base materials were successively placed in these 10 dies using a depth-limiting device made of light-transmitting clear acrylic to ensure a 0.5 mm thickness, and Tytin amalgam was again condensed over each base such that the depth of the amalgam equalled that in the control. All test specimens were stored in 100% humidity for 48 hours then fractured in compression on an Instron machine. Mean force, in Newtons (S D in parentheses), required to fracture the specimens was:
1934(210), Zinc Cement: 1874(147), GlasIonomer Base Cement: 1839(174), Ketac-Bond: 1723(225), Vitrebond: 1485(155), Photac-Bond: 1422(294), Advanced Formula II Dycal: 1296(237), VLC Dycal: 1035(116), Variglass: 909(294) and Timeline: 906(275). ANOVA and Student-Newman-Keuls statistical analysis (alpha = 0.05) indicated that the autocuring glass ionomers, GlasIonomer Base Cement and Ketac-Bond, and a zinc phosphate cement, Zinc Cement, provided significantly more fracture resistance for amalgam than the other bases tested and were not statistically different from a no-base control.
本研究比较了在九种垫底材料上折断银汞合金所需的压缩力：一种氢氧化钙产品（Dycal）；两种自凝玻璃离子水门汀（玻璃离子垫底粘固剂和Ketac-Bond）；三种光固化玻璃离子水门汀（Photac-Bond、Variglass VLC和Vitrebond）；两种光固化树脂（Timeline和VLC Dycal）；以及一种磷酸锌水门汀（Fleck氏磷酸锌水门汀）。对于对照组，将10个铝制模具（25mm×12mm×10mm）铣出3.0mm×3.0mm的槽，槽内填充手工压实的Tytin银汞合金，下面没有垫底材料。对于实验组，将10个尺寸相同的铝制模具铣出3.5mm×3.0mm的槽。按照制造商的说明，使用由透光透明丙烯酸制成的深度限制装置，将九种垫底材料依次放入这10个模具中，以确保厚度为0.5mm，然后在每种垫底材料上再次压实Tytin银汞合金，使银汞合金的深度与对照组相同。所有测试标本在100%湿度下储存48小时，然后在Instron机器上进行压缩折断试验。折断标本所需的平均力，以牛顿为单位（括号内为标准差）为：
1934（210），磷酸锌水门汀：1874（147），玻璃离子垫底粘固剂：1839（174），Ketac-Bond：1723（225），Vitrebond：1485（155），Photac-Bond：1422（294），高级配方II Dycal：1296（237），VLC Dycal：1035（116），Variglass：909（294），Timeline：906（275）。方差分析和Student-Newman-Keuls统计分析（α = 0.05）表明，自凝玻璃离子水门汀玻璃离子垫底粘固剂和Ketac-Bond以及磷酸锌水门汀Fleck氏磷酸锌水门汀为银汞合金提供的抗折断能力明显高于其他测试的垫底材料，并且与无垫底对照组在统计学上无差异。
