What design of tooth preparation is recommended to prevent dislodging of restoration?

The cylindrical design of tooth preparation is recommended to prevent dislodgment of restorations because it provides a more uniform and stable foundation for the restoration to adhere to the tooth structure. This preparation design creates a tighter fit and better retention, which reduces the chances of the restoration becoming loose over time.

Cylindrical preparations typically involve preparing the tooth with parallel walls, which helps maintain the position of the restoration, making it less susceptible to lateral forces that could easily dislodge other designs. Furthermore, the shape allows for optimal cementation techniques, ensuring that the restoration remains firmly attached.

In contrast, other designs, such as chamfers or shoulders, may not provide the same level of resistance to dislodgment due to their geometric properties, which can sometimes lead to less effective retention mechanisms.