Hudis S I, Goldstein G R
J Prosthet Dent. 1986 Jan;55(1):33-8. doi: 10.1016/0022-3913(86)90068-5.
Once the individual components of the Richmond crown were isolated from the post-core-crown complex, each was subjected to scrutiny. Consensus declared that the core portion should resemble the ideal preparation for a vital tooth. Current techniques allow the dentist to create an "ideal" preparation to accommodate clinical conditions such as occlusion and esthetics. Post construction evaluation can be divided into two categories: retention and stress distribution. Research has demonstrated that threaded posts screwed into tapped post holes were the most retentive, followed by cylindrical posts, and the tapered posts were the least retentive. In photoelastic stress distribution studies, cylindrical posts showed the most favorable patterns, with screw posts demonstrating the least desirable configurations. There is no exclusive technique that satisfies all criteria for success. Compromise is common and the method with more advantages and fewer disadvantages is chosen. Stress distribution is of greater importance than retention because a post can be recemented if dislodged from a tooth. However, if the root fractures, the tooth is commonly lost. Cementation of posts has received limited attention. Some posts with vents are commercially available, but there is little evidence that this effectively decreases hydrostatic pressures during cementation. An important consideration is the choice of materials. Traditionally, pulpless teeth were restored with cast gold posts covered with either complete gold crowns or gold crowns with acrylic resin veneers. These materials had a similar modulus of elasticity and coefficient of thermal expansion.(ABSTRACT TRUNCATED AT 250 WORDS)
一旦将里士满牙冠的各个组件从桩核冠复合体中分离出来，便对每个组件进行仔细检查。大家一致认为，桩核部分应类似于对活髓牙的理想预备。当前的技术使牙医能够创建一种“理想”的预备，以适应诸如咬合和美观等临床情况。桩修复后的评估可分为两类：固位和应力分布。研究表明，拧入攻丝桩孔的螺纹桩固位力最强，其次是圆柱桩，而锥形桩的固位力最弱。在光弹性应力分布研究中，圆柱桩显示出最有利的模式，而螺纹桩则显示出最不理想的形态。没有一种独家技术能满足成功的所有标准。妥协很常见，会选择优点更多、缺点更少的方法。应力分布比固位更重要，因为如果桩从牙齿上松动，可以重新粘结。然而，如果牙根折断，牙齿通常就保不住了。桩的粘结受到的关注有限。一些带有通气孔的桩在市场上有售，但几乎没有证据表明这能有效降低粘结过程中的静水压力。一个重要的考虑因素是材料的选择。传统上，无髓牙用铸造金桩修复，外面覆盖全金冠或带有丙烯酸树脂贴面的金冠。这些材料具有相似的弹性模量和热膨胀系数。（摘要截选至250词）
