How many threads does the external hex implant have?

• A. Round threads
• B. Square threads
• C. Hexagonal threads
• D. Triangular threads

Answer: (B)

The correct answer is based on the design of the external hex implant system, which features threads that are square in cross-section. This threading design serves multiple purposes in implantology. Square threads increase the surface area for better bone-to-implant contact, which helps to enhance stability and larger torque resistance during the insertion of the implant. Additionally, the square thread profile allows for improved locking capabilities with the abutment, contributing to the stability of the restoration.

In the context of implant systems, each type of thread design has its specific applications and benefits. Round threads, for instance, might optimize ease of insertion but may not offer the same level of engagement with the surrounding bone. Hexagonal threads would not provide sufficient surface area for stability relative to the intended design outcomes of external hex implants. Triangular threads, while they may help in specific applications, are generally not utilized in external hex implants as they do not adequately provide the needed mechanical retention during healing.

Understanding these thread types and their implications helps in selecting the right implant system for a given clinical situation.