What is applied to a tray that is not perforated to ensure the impression material holds in place?

The application of adhesive to a non-perforated tray is essential because it creates a strong bond between the impression material and the tray. This ensures that the impression material remains securely in place during the impression-taking process, allowing for an accurate reproduction of the oral structures.

In non-perforated trays, there are no holes to mechanically retain the impression material, which makes it vital to use an adhesive that can enhance adherence and prevent any movement that could distort the impression. The adhesive acts as a sticky interface, providing the necessary support for the impression material to stay attached to the tray while also ensuring that it captures details accurately.

Other substances such as water, dental wax, and gauze are not typically used for this purpose. Water may be used in different contexts, but it does not create adhesion. Dental wax can be helpful for other applications in dentistry but does not serve the same purpose as adhesive in this scenario. Gauze is also unrelated to tray adhesion. Thus, utilizing adhesive is the most effective method to maintain the integrity of the impression and achieve reliable results.