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Impression Materials and Techniques Flashcards

7 cards from real EFDA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Impression Materials and Techniques flashcards as text

  1. A heavy-body PVS material placed in the impression tray is also called:

    Answer: Putty or tray material

    Heavy-body or putty PVS fills the tray and provides bulk support while light-body (wash) material captures fine detail.

  2. Which factor most significantly shortens the working time of alginate?

    Answer: Using warm water during mixing

    Warm water accelerates the chemical setting reaction of alginate, reducing working time; cold water retards it.

  3. What is the purpose of the 'two-step putty-wash' PVS technique?

    Answer: To allow putty to set first, creating a rigid tray, then a thin wash captures fine detail

    The set putty acts as a rigid custom tray, and the subsequent thin wash flows to capture precise marginal detail without distortion from tray flex.

  4. Which impression material contains eugenol and is contraindicated in patients with eugenol sensitivity?

    Answer: Zinc oxide eugenol (ZOE) paste

    ZOE impression paste contains eugenol (oil of cloves) and can cause allergic reactions or tissue irritation in sensitive patients.

  5. An impression that records only the occlusal surfaces and interproximal contacts without capturing soft tissue is called a:

    Answer: Bite registration

    A bite registration records the spatial relationship of opposing teeth in occlusion and is not intended to capture tissue or tooth detail for a restoration.

  6. Why is a custom tray with uniform spacer thickness preferred over a stock tray for final impressions?

    Answer: It ensures a uniform layer of impression material, reducing distortion and improving accuracy

    Uniform material thickness distributes seating pressure evenly and reduces the risk of areas where tray contact displaces material and distorts the impression.

  7. What characteristic of polyether impression material makes it well-suited for use in a moist or slightly wet field?

    Answer: It is hydrophilic and can set accurately in the presence of moisture

    Polyether's hydrophilic nature allows it to wet tooth surfaces effectively even when saliva or moisture is present, capturing detail accurately.