Final answer:
In order to avoid air bubbles in a final dental impression, the light body material must be applied carefully and continuously onto the prepared teeth, using proper techniques to ensure an accurate impression.
Step-by-step explanation:
To avoid air bubbles in a final impression, the light body material should be applied in a thin, continuous manner directly onto the prepared teeth and adjacent tissues just before seating the heavier body tray material. It's essential to carefully express the light body around the details of the preparations using a syringe or a similar applicator and to maintain a steady hand pressure to prevent the incorporation of air bubbles. In dentistry, taking clear and accurate impressions is vital for the creation of prosthetics and ensuring a proper fit and function.