June 2009 | Dental Lab Products
Bench mastery: pizzi on fixed

Space and color management

Difficult cases demand special color and space considerations.

by Peter Pizzi, CDT, MDT

When we have ideal space for our restorative materials, it becomes almost easy to maintain a predictable outcome. One advantage of porcelain-fused-to-metal is we can usually use the metal to control the difference in tooth position or height (Figs. A, B). But in some scenarios, challenges arise.

Fabricating different types of restorations next to each other such as a porcelain-fused-to-metal crown next to an all-ceramic veneer, can be challenging. The premise in this scenario is to have the metal, opaque, and dentin finish in the same position and with the same appearance in terms of value and chroma as the prepared veneer.

However, when fabricating an all-ceramic restoration, we must rely more on our material knowledge for maintaining proper value and depth. A great example of this is creating a porcelain jacket adjacent to a veneer, especially when the coloration of the existing preparations are not the same.

As in the previous scenario, the goal becomes to control the space with the use of ceramic materials (Figs. C-F). Filling a space requires the use of more opacious materials, then gradually layering more translucent materials over them until we can achieve the same base value and chroma in the ceramic as in the adjacent prepared veneer. With ideal or even usable color in the stump shades, the amount of tooth reduction can be reduced and more enamel/translucent materials applied, which will aid in the esthetic outcome (Fig. G).

• Case in pictures
  (refer to slideshow for figures)

With inadequate color or staining of the stump, more reduction will be necessary and the use of opacious materials is a must. For us to idealize the ceramic esthetic outcome, we will always need to have at least 0.5 mm of enamel/translucent materials (Fig. H). This rule applies to all types of ceramic related restorations. How we support the enamel/translucent layer depends on the desired effect and value being created (Figs. I-M).

• Case in pictures (refer to slideshow for figures)

A key here is to remember that dentin works best in 0.6- to 0.8-mm layers. Anything more or less will change its coloration and value and can have a drastic effect on the outcome of the restoration. So a simple approach is to think of each restoration as a veneer, know the amount of translucency needed, and support that with the proper opacious and dentin materials (Figs. N-V). 

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