Final answer:
Retention pins are used in dentistry during the direct restorative process to provide additional support for dental fillings in large cavities or when the tooth structure is significantly weakened. They are placed into the dentin of a tooth to ensure stability and retention of the filling material.
Step-by-step explanation:
Retention pins are typically used in dentistry as a component of the direct restorative process. They are small, thread-like metal pins that are placed into the dentin of a tooth to provide additional support for a dental filling, particularly when there is not enough tooth structure remaining to hold the filling by natural means. This technique is employed when the cavity is large or the remaining tooth structure is weakened. A pin is placed into a pre-drilled hole in the tooth, and then a dental filling material is applied.
The retention pin ensures stability and retention of the filling material, helping to prevent the filling from becoming loose or falling out. It is particularly useful in situations where traditional bonding techniques may not be sufficient to secure the restoration.