Quinn G D, Giuseppetti A A, Hoffman K H
Paffenbarger Research Center, American Dental Association Foundation, Stop 854-6, NIST, Gaithersburg, MD 29899, USA.
Paffenbarger Research Center, American Dental Association Foundation, Stop 854-6, NIST, Gaithersburg, MD 29899, USA.
Dent Mater. 2014 May;30(5):545-53. doi: 10.1016/j.dental.2014.02.011. Epub 2014 Mar 25.
The applicability of the edge chipping method to denture tooth materials was assessed. These are softer materials than those usually tested by edge chipping. The edge chipping fracture resistances of polymethylmethacrylate (PMMA) based and two filled resin composite denture tooth materials were compared.
An edge chipping machine was used to chip rectangular blocks and flattened anterior denture teeth. Force versus edge distance data were collected over a broad range of forces and distances. Between 20 and 65 chips were made per condition depending upon the material, the scatter, and the indenter type. Different indenter types were used including Rockwell C, sharp conical 120(o), Knoop, and Vickers. The edge toughness, Te, was evaluated for different indenter types.
The edge chipping data collected on the blocks matched the data collected from flattened teeth. High scatter, particularly at large distances and loads, meant that many tests (up to 64) were necessary to compare the denture tooth materials and to ascertain the appropriate data trends. A linear force-distance trend analysis was adequate for comparing these materials. A power law trend might be more appropriate, but the large scatter obscured the definitive determination of the precise trend. Different indenters produce different linear trends, with the ranking of: sharp conical 120(o), Rockwell C, and Knoop, from lowest to highest edge toughness. Vickers indenter data were extremely scattered and a sensible trend could not be obtained. Edge toughness was inversely correlated to hardness.
Edge chipping data collected either from simple laboratory scale test blocks or from actual denture teeth may be used to evaluate denture materials. The edge chipping method's applicability has been extended to another class of restorative materials.
评估边缘崩裂法对义齿牙齿材料的适用性。这些材料比通常用边缘崩裂法测试的材料更软。比较了基于聚甲基丙烯酸甲酯（PMMA）的材料和两种填充树脂复合义齿牙齿材料的边缘崩裂抗断裂性。
使用边缘崩裂机对矩形块和扁平的前牙义齿进行崩裂。在广泛的力和距离范围内收集力与边缘距离的数据。根据材料、离散程度和压头类型，每种情况制作20至65个崩裂样本。使用了不同类型的压头，包括洛氏C、尖锐圆锥形120°、努氏和维氏压头。针对不同的压头类型评估边缘韧性Te。
在块体上收集的边缘崩裂数据与从扁平牙齿上收集的数据相匹配。高离散性，特别是在大距离和大载荷下，意味着需要进行许多测试（多达64次）来比较义齿牙齿材料并确定合适的数据趋势。线性力-距离趋势分析足以比较这些材料。幂律趋势可能更合适，但大的离散性掩盖了对精确趋势的明确确定。不同的压头产生不同的线性趋势，边缘韧性从低到高的排序为：尖锐圆锥形120°、洛氏C和努氏。维氏压头的数据极其分散，无法获得合理的趋势。边缘韧性与硬度呈负相关。
从简单的实验室规模测试块体或实际义齿牙齿收集的边缘崩裂数据可用于评估义齿材料。边缘崩裂法的适用性已扩展到另一类修复材料。
