A 37 year old female patient complains of discoloration with her upper front teeth. Intra-oral examination reveals Intrinsic staining with maxillary incisors. Dentist prepares teeth to receive direct composite veeners. Which of the following instrument material cannot be used in this case ?

**Core Concept**
Intrinsic tooth discoloration involves stains or chromogens within the tooth structure, affecting the enamel or dentin. Direct composite veneers are a conservative treatment option to address esthetic concerns. The choice of instrument material is crucial to prevent any adverse reactions or discoloration.

**Why the Correct Answer is Right**
The correct answer is a burs made of **Ceramic**. Ceramic burs are not recommended for preparing teeth for direct composite veneers because they can leave scratches or micro-fractures in the enamel, which can lead to a poor bond between the composite and the tooth. Ceramic burs also tend to produce a lot of heat, which can damage the tooth structure.

**Why Each Wrong Option is Incorrect**
* **Option A:** Carbide burs are a common choice for preparing teeth for composite veneers. They are durable and can be used to remove enamel and dentin efficiently.
* **Option B:** Diamond burs are also suitable for preparing teeth for composite veneers. They are gentle on the enamel and can be used to create a smooth surface.
* **Option D:** Steel burs are not typically used for preparing teeth for composite veneers, but they are not the correct answer either. The correct answer is ceramic burs.

**Clinical Pearl / High-Yield Fact**
When preparing teeth for direct composite veneers, it's essential to use instruments that will not damage the tooth structure or compromise the bond between the composite and the tooth. The choice of bur material should be based on the specific needs of the case and the clinical expertise of the dentist.

**Correct Answer:** C. Ceramic.

✓ Correct Answer: A. Stainless steel