Wilson P R
School of Dental Science, University of Melbourne.
Aust Dent J. 1993 Apr;38(2):97-101. doi: 10.1111/j.1834-7819.1993.tb05469.x.
Venting of full crown restorations is an effective aid to seating during cementation. Vent hole repair complicates placement procedures and potentially disturbs the coronal integrity of the restoration. Cervical deformation of crowns during cementation was measured with circumferential strain gauges. Crowns were able to be vented occlusally, and two silicone fluids of widely differing viscosities were used. Venting significantly decreased the time to seat for both viscosities. It also decreased deformation of crowns cemented with low viscosity fluid, but increased deformation during cementation with high viscosity fluid. The values of deformation were nearing clinical significance for ceramic systems. Increased axial wall separation gave a similar decrease in seating times, but with no increase in deformation. The advisability of venting is questioned when high viscosity cements are used, and methods of increasing axial wall separation are recommended.
全冠修复体的排气是粘结过程中就位的有效辅助手段。排气孔修复会使就位程序复杂化，并可能破坏修复体的冠部完整性。使用周向应变片测量粘结过程中牙冠的颈部变形。牙冠能够在咬合面排气，并使用了两种粘度差异很大的硅酮流体。排气显著缩短了两种粘度流体的就位时间。它还减少了用低粘度流体粘结的牙冠的变形，但在用高粘度流体粘结过程中增加了变形。对于陶瓷系统，变形值接近临床意义。增加轴向壁间隙会使就位时间有类似的减少，但不会增加变形。当使用高粘度粘结剂时，排气的可取性受到质疑，建议采用增加轴向壁间隙的方法。
