**Core Concept**
A crevicular incision is a type of surgical incision made in the gingival sulcus, typically used in periodontal surgery. The goal of this incision is to minimize trauma to the gingival tissues and promote healing.

**Why the Correct Answer is Right**
A number 15 blade is the most suitable for crevicular incisions due to its fine, sharp edge and short length, which allows for precise cutting and minimal tissue damage. This type of blade is ideal for making shallow, curved incisions in delicate tissues such as the gingiva. The fine edge of the 15 blade also reduces the risk of tearing the tissue, promoting a smooth, even incision.

**Why Each Wrong Option is Incorrect**
**Option A:** A number 22 blade is too large and coarse for crevicular incisions, making it more suitable for deeper, more extensive surgical cuts.
**Option B:** A number 11 blade is too long and has a more robust edge, making it less suitable for delicate gingival tissue.
**Option C:** A number 3 blade is too large and has a more curved edge, which can cause uneven cuts and tissue damage.

**Clinical Pearl / High-Yield Fact**
When performing crevicular incisions, it's essential to use a fine, sharp blade to minimize tissue trauma and promote healing. This can be remembered by the mnemonic "FINE" (Fine Incision, No Edge, No Trauma, Every time).

**Correct Answer: . 15**