Where do Maryland bridges often lose retention?

Maryland bridges commonly experience issues with retention primarily at the resin-metal interface. The design of a Maryland bridge involves bonding a pontic (the false tooth) to the adjacent teeth with metal wings on each side, which are often retained by a resin-based adhesive. Over time, factors such as occlusal forces, wear, and moisture can compromise this adhesive bond, leading to retention loss specifically at the resin-metal junction.

The bonding material, which is intended to hold the metal wings securely to the underlying tooth structure, can degrade, especially in areas where there is high stress or poor oral hygiene. This degradation can result in the bridge becoming loose or failing altogether. Therefore, understanding the mechanics of how Maryland bridges are constructed and bonded is crucial for predicting and addressing potential failures.