**Core Concept**
The treatment of a fresh furcation perforation in periodontal surgery involves the repair of the perforation site to prevent further bone loss and promote healing. The material used for this purpose should be biocompatible, non-toxic, and capable of facilitating the healing process.

**Why the Correct Answer is Right**
For a fresh furcation perforation of 2 mm, the material of choice is a resorbable collagen matrix (e.g., CollaCote or PerioGlas). These matrices provide a scaffold for tissue ingrowth, promoting the healing of the perforation site. They are resorbed by the body over time, allowing the newly formed tissue to replace them. This approach helps to minimize the risk of further bone loss and promotes a successful outcome.

**Why Each Wrong Option is Incorrect**
* **Option A:** A non-resorbable material like titanium or a non-resorbable membrane would not be suitable for a fresh furcation perforation. These materials can cause chronic inflammation and may lead to further bone loss.
* **Option B:** A bioactive glass or ceramic would not be the material of choice for a fresh furcation perforation. While these materials have some biocompatibility, they may not provide the necessary scaffold for tissue ingrowth.
* **Option C:** A xenograft or allograft material may not be the best choice for a fresh furcation perforation. While these materials can provide a scaffold for tissue ingrowth, they may not be as effective as a resorbable collagen matrix in promoting healing.

**Clinical Pearl / High-Yield Fact**
When treating a fresh furcation perforation, it is essential to choose a material that promotes healing and minimizes the risk of further bone loss. A resorbable collagen matrix is an excellent choice for this purpose, as it provides a scaffold for tissue ingrowth and is resorbed by the body over time.

**Correct Answer:** B.