Al Rifaiy M Q
Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia.
Niger J Clin Pract. 2017 Dec;20(12):1610-1617. doi: 10.4103/1119-3077.196083.
To investigate and compare the degree of vertical marginal discrepancy of four provisional crown materials by digital microscope.
A total of 100 provisional crowns were fabricated on standardized resin dies by direct technique of provisional fabrication, using four different provisional materials (n = 25): Provisionals Fabricated by Systemp® c and b II, ivoclar vivadent, Schaan, Liechtenstein (group A); ProtempTM Plus, 3M ESPE, Neuss, Germany (group B); Success CD, PROMEDICA, Neumunster, Germany (group C); and Trim® Plus, Bosworth Company, Illinois, USA (group D). The provisional crowns were finished, tried, and locked with a customized device under 15N of vertical axial force. The vertical marginal discrepancy between the crown margin and the resin die was measured in micrometers using digital microscope (KH-7700, Hirox-USA, Inc., NJ, USA) at mid of buccal, lingual, mesial, and distal margin areas by a trained technician.
The mean values obtained for each group were as follows: group A = 129.10 ± 41.64, group B = 123.36 ± 40.94, group C = 89.67 ± 25.34, and group D = 107.24 ± 38.32. Assessment by post hoc Tukey's test at 5% significance level showed a statistically significant difference (P < 0.05) between group C and group D with the other groups. Results of one-way ANOVA showed a statistically nonsignificant difference (P > 0.05) between the means of the four areas of measurement for each group.
Marginal discrepancy of the group C (Success CD) was the lowest among the provisionals tested. The mean vertical marginal gap values for the materials tested were found to be with in the clinically acceptable range (<130 μm).
通过数字显微镜研究并比较四种临时冠材料的垂直边缘差异程度。
采用临时制作的直接技术，在标准化树脂代型上制作100个临时冠，使用四种不同的临时材料（n = 25）：由Systemp® c和b II制作的临时冠，义获嘉伟瓦登特公司，沙恩，列支敦士登（A组）；ProtempTM Plus，3M ESPE公司，诺伊斯，德国（B组）；Success CD，普瑞美迪卡公司，新明斯特，德国（C组）；以及Trim® Plus，博斯沃思公司，伊利诺伊州，美国（D组）。临时冠完成后，使用定制装置在15N垂直轴向力下试戴并固定。由一名经过培训的技术人员使用数字显微镜（KH - 7700，美国浩视公司，新泽西州，美国）在颊侧、舌侧、近中及远中边缘区域的中点，以微米为单位测量冠边缘与树脂代型之间的垂直边缘差异。
每组获得的平均值如下：A组 = 129.10 ± 41.64，B组 = 123.36 ± 40.94，C组 = 89.67 ± 25.34，D组 = 107.24 ± 38.32。在5%显著性水平下通过事后Tukey检验评估显示，C组与D组和其他组之间存在统计学显著差异（P < 0.05）。单因素方差分析结果显示，每组四个测量区域的平均值之间无统计学显著差异（P > 0.05）。
在测试的临时冠中，C组（Success CD）的边缘差异最小。测试材料的平均垂直边缘间隙值在临床可接受范围内（<130μm）。
