牙科金属与牙体硬组织对磨的相关磨耗性能研究

Wear properties of dental alloy materials against tooth hard tissues

目的将常用的牙科合金材料与人牙体硬组织进行对磨,对牙本质和牙釉质产生的磨耗量进行比较。方法以4种牙科合金(软质钴铬合金、金合金55.6%、钴铬合金和钛合金)作为对磨样本,人离体牙的牙釉质和牙本质作为磨耗样本,采用配对分组的方法进行磨耗实验,定量检测磨耗样本的磨耗量(磨痕深度)并进行统计学分析;利用立体显微镜观察实验样本和对磨样本的磨痕形貌。结果与软质钴铬合金、金合金55.6%、钴铬合金和钛合金分别进行对磨时,牙釉质样本的磨痕深度分别为(54.37±6.91)、(24.77±4.49)、(127.74±16.25)和(57.79±7.39)μm,牙本质样本的磨痕深度分别为(167.76±18.23)、(44.32±9.21)、(171.39±20.79)和(86.04±11.49)μm。统计学分析结果显示:与金合金55.6%对磨时牙体组织产生的磨耗量显著小于与软质钴铬合金对磨,与钛合金对磨时牙体组织产生的磨耗量显著小于与钴铬合金对磨,差异均有统计学意义(P<0.000 1)。结论在常用固定修复材料中,金合金55.6%对牙体硬组织的磨耗轻于软质钴铬合金;在常用支架材料中,钛合金对牙体硬组织的磨耗轻于钴铬合金。

Objective To wear common dental alloy materials against tooth hard tissues, and compare the vertical substance loss of enamel and dentin. Methods Four dental alloy materials （ soft Co-Cr alloy, gold alloy 55.6%, Co-Cr alloy and titanium alloy） were selected, and were worn against human in vitro enamel and dentin specimens with paired grouping procedures. The vertical substance loss of enamel and dentin was quantified as wear depth, and was statistically analysed. The worn surface areas were observed by stereo microscope. Results The values of wear depth of enamel specimens against soft Co-Cr alloy, gold alloy 55.6%, Co-Cr alloy and titanium alloy were （54.37 ± 6.91） μm, （24.77 ± 4.49） μm, （ 127.74 ± 16.25） μm and （57.79 ± 7.39）μm respectively, and those of dentin specimens were （ 167.76 ± 18.23） μm, （44.32 ± 9.21） μm, （ 171.39 ± 20.79）μm and （86.04 ± 11.49）μm respectively. Statistical analysis revealed that the vertical substance loss of tooth tissues in wear against gold alloy 55.6% was significantly less than that in wear against soft Co-Cr alloy （ P 〈 0. 000 1 ）, and the vertical substance loss of tooth tissues in wear against titanium alloy was significantly less than that in wear against Co-Cr alloy （ P 〈 0. 000 1 ）. Conclusion In common fixed dental prostheses materials, gold alloy 55.6% wears less than soft Co-Cr alloy against tooth hard tissues. In common movable dental prostheses materials, titanium alloy wears less than Co-Cr alloy against tooth hard tissues.