The choice of ingot depends on:
- The esthetic quality of the prepared tooth.
- If you are doing multiple preparations, do they all appear the same color and value or are there significant differences between the teeth.
- Preparation design: How much space has been created for the restorative material?
- How many shade changes are expected to create the desired outcome?
- What degree of translucency or opacity is acceptable or desired in the final restorations?
These guidelines are generalizations and final decisions are case dependent. Choose a HT (High Translucency) restoration when:
- Little or no masking of the underlying preparation is required. • All preparations in multi-unit cases have the same normal esthetic appearance.
- The preparation design creates a uniform thickness for all the restorations.
- Zero to one shade changes are desired.
- A more translucent restoration is necessary or desired.
Choose a LT (Low Translucency) restoration when:
- Slight to moderate masking of the underlying preparation is required.
- There are slight variations in the appearance of the preparations in multi-unit cases.
- There are varying preparation designs which result in minor variations in the thicknesses of the restorations.
- You have prepared for thin restorations that require several shade changes.
- A more opacified restoration is acceptable or desired.
Choose another restorative option when:
- Significant masking of the underling prepared tooth structure is required, such as in cases with severe discoloration or metal post and cores.
- There are significant differences in the esthetic appearance of the prepared teeth in multi-unit cases.
- There are varying preparation designs in multi-unit cases that result in significant variations in restoration thickness.
- Three or more shade changes are desired.
- The expected esthetic outcome mimics natural tooth transparency, which can only be achieved by layering ceramic.
These guidelines should help in making clinical or technical decisions concerning HT or LT monolithic restorations.