What type of tray is used for alginate impressions?

The correct answer is the type of tray that is perforated and rim locked, which is ideal for taking alginate impressions. Perforated trays have small holes that allow the alginate material to flow through and make contact with the underlying teeth and tissues, ensuring an accurate impression. The rim-lock feature provides a secure fit and aids in holding the impression material in place while it sets, minimizing the risk of distortion.

In dental practice, it’s essential to achieve a precise impression because this will be used for various purposes such as creating study models or custom trays. The unique design of perforated trays facilitates better adhesion of the alginate material, ensuring that the impression captures all necessary details of the oral cavity.

The other options do not provide the same level of effectiveness for alginate impressions. Solid and flat trays may not hold the impression material securely or allow for good detail capture. Flexible and soft trays may collapse under pressure, leading to inaccuracies. Lined and rigid trays might not have the necessary features for optimal retention and could compromise the integrity of the impression.