Which preparation design is best known for providing a stronger resistance to dislodgment?

The shoulder preparation design is popularly recognized for its potential to provide a stronger resistance to dislodgment in prosthetic dentistry. This design features a flat surface that is perpendicular to the long axis of the tooth, creating a distinct margin. This flat margin allows for better adaptation and seating of the restorative material, whether it’s a crown or a bridge, leading to improved retention.

Shoulder preparations are particularly advantageous because they provide a greater surface area for cement adhesion, enhancing the overall stability of the restoration. This is vital in ensuring that the prosthetic remains securely in place, resisting both vertical and lateral forces that can lead to dislodgment. The definitive margin created by the shoulder design also reduces the risk of food trapping and bacterial accumulation, contributing to healthier outcomes in long-term tooth preservation.

In contrast, other designs such as a heavy chamfer or cylindrical preparations might not provide the same level of retention due to their more rounded or shallow angles, which can limit the contact area for cement and make the restoration more susceptible to dislodgment. Similarly, converging preparations may inherently lack the sharp, well-defined margin that a shoulder provides, leading to a less stable restoration. Thus, the shoulder design stands out as the optimal choice for maximizing resistance to dislod