Mantovani A V, Stephano C B, Roselino R F, Roselino R B, Campos G M
Departamento de Materiais Denários e Prótese, Universidade de São Paulo.
Rev Odontol Univ Sao Paulo. 1990 Jan-Mar;4(1):31-7.
A stainless steel master die simulating a dental preparation for crown was used to make 3 gold castings from wax patterns obtained in 3 different ways: a) directly from the naked master die; b) from the same master die with a copper coping 30 microns thick; and c) with a similar copper coping, but 40 microns thick. The discrepancies of fit of the 3 master gold crowns were evaluated in 99 stones dies (33 for each casting) obtained from 11 different elastomeric impression materials (3 replicae of each). The results showed that: 1) stone dies with no coping presented a medium discrepancy of 284 microns, inadequate for clinical use; 2) the 30 microns and 40 microns copings presented medium discrepancies of 18 and 9 microns respectively, both suitable for clinical use. Thus, the use of copings tend to equalize the cervical discrepancy of fit of gold crowns, whatever be the elastomeric impression material used.
使用一个模拟牙冠牙体预备的不锈钢母模，从通过三种不同方式获得的蜡型制作3个金铸件：a）直接从裸母模；b）从带有30微米厚铜代型的同一母模；c）带有类似的铜代型，但厚度为40微米。在从11种不同弹性印模材料（每种3个复制品）获得的99个石膏代型（每个铸件33个）中评估这3个金冠母模的适合性差异。结果表明：1）没有代型的石膏代型呈现出284微米的中等差异，不适合临床使用；2）30微米和40微米的代型分别呈现出18微米和9微米的中等差异，两者均适合临床使用。因此，无论使用何种弹性印模材料，使用代型都倾向于使金冠的颈部适合性差异均等化。
