National Dental Assisting Examining Board (NDAEB) Practice Exam

To prevent air bubbles when using light body material for a final impression, the material should be:

1. Mixed carefully

2. Extruded with the tip in the material

3. Poured slowly

4. Vibrated before use

The correct answer is: Extruded with the tip in the material

Using light body material for a final impression requires specific techniques to ensure the optimal quality of the impression and to avoid issues like air bubbles, which can compromise the accuracy. The correct approach involves extruding the material with the tip submerged in the material itself. By doing this, the material flows smoothly and evenly, minimizing the introduction of air as the light body material is dispensed. When the tip is placed into the material, it allows the material to push out without creating a pathway for air bubbles to enter. This technique helps maintain the integrity of the impression material and ensures that it captures the details accurately without the distortion that air bubbles can cause. Additional methods like mixing carefully or vibrating before use also have their benefits in reducing bubbles but do not specifically address the air bubble issue during the dispensing process as directly as ensuring the tip is positioned correctly during extrusion. Pouring slowly does not effectively control the flow and may still allow for air entrainment. Thus, the optimal technique for preventing air bubbles is to extrude the light body material with the tip inserted into the material, which directly reduces the likelihood of air being trapped within the impression.