Summitt J B, Rindler E A, Robbins J W, Burgess J O
University of Texas Health Science Center at San Antonio, Dental School, Department of Restorative Dentistry.
Oper Dent. 1994 Mar-Apr;19(2):53-8.
This study measured fracture resistance of complex amalgam restorations when pins or amalgapins were either distributed around the preparation or concentrated in one area of the preparation. The occlusal surfaces of 80 extracted molars were ground flat to 2 mm occlusal to the cementoenamel junction (CEJ). Roots were notched and embedded. Teeth were sized and distributed equally into eight groups (n = 10). Resistance features, four TMS stainless steel Regular pins or four amalgapin channels, were inserted into each molar. Resistance features were either distributed at the four line angles of each molar or clustered at two line angles. Matrices were applied, and amalgam was mechanically condensed into the matrices. Restorations were adjusted to a 4 mm vertical height and flat occlusal surfaces. A load was applied to each restoration at either a 45 degrees or a 90 degrees angle to the long axis of the tooth. Distributed pins provided significantly more resistance than clustered pins in groups tested at 90 degrees. Resistance to fracture in all groups loaded at 45 degrees and in amalgapin groups was not significantly affected by distribution of resistance features. Pins provided significantly more resistance than amalgapins at both angles of testing.
本研究测量了在针或银汞桩钉分布于窝洞周围或集中于窝洞某一区域时，复杂银汞合金修复体的抗折性。将80颗拔除磨牙的咬合面磨平至距牙釉质牙骨质界（CEJ）咬合面2毫米处。对牙根进行刻痕并包埋。将牙齿按大小平均分为八组（n = 10）。在每颗磨牙中插入抗折部件，四个TMS不锈钢常规针或四个银汞桩钉通道。抗折部件要么分布在每颗磨牙的四个线角处，要么聚集在两个线角处。放置基质，将银汞合金机械压实到基质中。将修复体调整至4毫米垂直高度且咬合面平整。以与牙长轴呈45度或90度的角度对每个修复体施加负荷。在90度测试的组中，分布的针比聚集的针提供的抗力显著更大。在45度加载的所有组以及银汞桩钉组中，抗折性不受抗折部件分布的显著影响。在两个测试角度下，针提供的抗力均显著大于银汞桩钉。
