Which implant is not placed into the bone?

• A. Zygomatic
• B. Subperiosteal
• C. Endosteal
• D. Transosteal

Answer: (B)

The key idea is where the implant sits relative to bone. A subperiosteal implant rests on top of the bone, just beneath the periosteum, and does not penetrate into the bone tissue. It’s shaped to sit over the bone surface and is supported by the periosteum and surrounding soft tissues rather than by bone integration.

In contrast, the other implant types are inserted into bone. Endosteal implants are the common root‑form implants placed inside the jawbone itself. Transosteal implants pass through the mandible, anchoring to the opposite cortical plate. Zygomatic implants are anchored in the zygomatic bone, extending into the maxillary region, and again involve bone engagement. Thus, subperiosteal is the one not placed into bone.