Cement Shade Try-In — How Cement Affects Final Shade and When to Use It

No Revelation Here — But Cement is a Powerful Variable

Every lab technician knows that cement is more than just a 'bonding agent'. The problem arises when clinicians don't realize that cement changes the final shade of a restoration by 1-3 shades – sometimes dramatically.

The clinician specifies A1, the laboratory produces A1, the crown comes out A1 – but in the operatory, under an opaquer cement, it looks like A2/A3. The patient is unhappy.

In reality: the cement changed the shade. This is light physics, not a laboratory error.

How Cement Changes Shade — Light Physics

Cement is a fluid — it can be:

• Transparent — allows light to pass through without shade changes
• Opaquer — contains pigments that absorb specific wavelengths

Transparent Cement — Pure Material Shade If you choose A1 for e.max and cement it with transparent cement, the result in the mouth = A1 (plus abutment influence).

Opaquer Cement — 1-3 Shade Change Opaquer cement contains pigments (typically metal oxides — iron, chromium, titanium). These pigments reduce translucency and change the final shade.

Example:

• A1 e.max + transparent cement = A1
• A1 e.max + opaquer cement (e.g., "universal shade") = A2/A3

This is a powerful tool for correction.

When Cement Try-In Makes Sense (and When It Doesn't)

E.max — Translucent, Therefore Cement Works

E.max has 60-70% translucency. Cement passes through the material → shade changes are visible.

Cement try-in makes sense:

• If you are unsure about the shade
• If the patient has specific aesthetic expectations
• If you are working with e.max, where cement has a significant influence

Zirconia — Opaque, Cement Has Less Influence

Zirconia has 0% translucency. Cement does not pass through the material → the influence of cement is smaller.

Clinical Practice — How to Try-In Cement

Try-in Materials: Temporary or Permanent Cement?

Temporary Cement (Temporary Resin):

• Easy to remove
• Allows for multiple try-ins
• Ideal for try-in

Permanent Cement (Permanent Resin):

• Better shade match
• But harder to remove
• Typically used for final cementation

Recommendation: try-in with temporary cement, cement with permanent.