The Morrison Root Screw for manual extraction of posterior molars is a type of dental implant used in specific extraction and replacement procedures, particularly when extracting posterior molar teeth and preparing the site for implants. This root screw typically has a size of 3mm, designed to be used in the posterior regions of the mouth where molars are located.

Key features:

1. Size: The screw is typically 3mm in diameter, which is suitable for posterior molars where there's often more bone density and space.
2. Manual Extraction: The design of the root screw allows for manual extraction, making it easier for the dentist to remove damaged or decayed molars without requiring a more invasive approach.
3. Material: Made from biocompatible materials, these screws are designed to integrate well with the bone tissue once placed.
4. Application: The root screw is used for extractions of posterior molars, followed by the placement of a dental implant in the same area to restore function and aesthetics.

This type of screw is often used in conjunction with a surgical kit that includes tools for precise placement and extraction. It is specifically suited for molars, where extraction may require special attention due to the tooth's size and root structure.