Vryonis P
J Prosthet Dent. 1979 Nov;42(5):592-3. doi: 10.1016/0022-3913(79)90260-9.
The technique described produces a metal-ceramic crown exhibiting excellent esthetic qualities and marginal accuracy superior to that achieved on the cast metal margin. A platinum foil apron or refractory dies are not necessary. A precise shoulder preparation, preferably with two master dies, is required. A chamfer with a bevel, a shoulder with a bevel, or chamfer preparations are not suited to this technique. Quantitative evaluation using a measuring microscope showed that a marginal gap on a crown fabricated on an International Bureau of Standards crown die measured 6 microns at the porcelain shoulder and from 17 to 34 microns on a gold margin of the same crown. On a prepared-tooth, rubber-base compression densite die, the marginal gap on the porcelain shoulder was 10 microns.
所述技术制作出的金属烤瓷冠具有出色的美学质量,其边缘精度优于铸造金属边缘的精度。无需铂箔围模或耐火代型。需要精确的肩台预备,最好使用两个主代型。带斜面的肩台、带斜面的切角或切角预备均不适合该技术。使用测量显微镜进行的定量评估表明,在国际标准局冠代型上制作的冠,其瓷肩台处的边缘间隙为6微米,同一冠的金边缘处为17至34微米。在预备好的牙齿上,采用橡胶基加压致密代型时,瓷肩台处的边缘间隙为10微米。