Binon P P
Department of Restorative Dentistry, School of Dentistry, University of California at San Francisco, USA.
Int J Prosthodont. 1996 Mar-Apr;9(2):149-60.
A series of 10 incrementally larger, machined ASTM Grade 23 titanium non-segmented (UCLA type) abutments was loaded off axis with 133 N and cycled at 1150 vertical strokes per minute and 28 counterclockwise rotations per minute to determine screw joint stability. Abutment internal hexagonals ranged from 0.1065 to 0.1110 inches. External hexagonal mean flat-to-flat width was 2.684 mm. Rotational misfit between international and external hexagonals ranged from 1.94 degrees for the smallest abutment to 14.87 degrees for the largest. Screw joint failure ranged from 134,000 to 9.3 million cycles. The tightest matrix/patrix hexagonal screw joint failed at a mean of 6.7 million cycles. This study indicated that there was a direct correlation between hexagonal misfit and screw joint loosening. A rotational misfit of under 2 degrees provided the most stable and predictable screw joint.
一系列10个尺寸逐渐增大的、经过加工的ASTM 23级非分段（加州大学洛杉矶分校类型）钛基台，以133 N的偏轴载荷加载，并以每分钟1150次垂直冲程和每分钟28次逆时针旋转进行循环，以确定螺钉连接的稳定性。基台内部六边形尺寸范围为0.1065至0.1110英寸。外部六边形的平均平面到平面宽度为2.684毫米。内部和外部六边形之间的旋转不匹配范围从最小基台的1.94度到最大基台的14.87度。螺钉连接失效范围为134,000至930万次循环。最紧密的基体/基体六边形螺钉连接平均在670万次循环时失效。这项研究表明，六边形不匹配与螺钉连接松动之间存在直接关联。小于2度的旋转不匹配提供了最稳定和可预测的螺钉连接。
