What provides the best retention for occlusal amalgam cavities in premolars?

The best retention for occlusal amalgam cavities in premolars is achieved through the utilization of buccal and lingual undercuts. These undercuts provide additional mechanical retention by enhancing the interlocking of the dental material with the prepared tooth structure. This is particularly beneficial in cases where the cavity design may not allow for sufficient retention purely from the walls of the preparation.

In occlusal cavities, the orientation and position of these undercuts can optimize the engagement of the amalgam, helping to prevent dislodgement caused by occlusal forces during function. Amalgam restorations rely significantly on the physical retention provided by these undercuts, making them a critical factor in ensuring that the restoration remains secure and effective over time.

While options like undercutting walls with an inverted cone bur or the use of retention pins may provide some degree of retention, they do not necessarily offer the same level of efficacy as buccal and lingual undercuts, particularly in the context of the specific requirements of premolar occlusal cavities.