Amalgam and Composite Restorations 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 Amalgam and Composite Restorations flashcards as text
Zinc-containing amalgam alloys should NOT be contaminated with moisture during condensation because this causes:
Answer: Delayed expansion and post-operative pain
Moisture contamination of zinc-containing amalgam causes a secondary (delayed) expansion due to hydrogen gas production, which can cause pain and restoration failure.
When finishing a composite restoration, the sequence of instruments should generally proceed from:
Answer: Coarser to finer abrasives
Finishing proceeds from coarser instruments (carbide finishing burs, coarse discs) to progressively finer polishing instruments to achieve a smooth surface.
Which finding after amalgam placement indicates the presence of an amalgam overhang?
Answer: Floss tears or catches on the gingival margin
Floss that tears or catches at the gingival margin indicates an amalgam overhang that must be removed to prevent periodontal disease.
A Class V composite restoration on the facial surface of tooth #9 requires etching of:
Answer: Both enamel and dentin (total-etch technique)
Total-etch technique involves etching both enamel and dentin to maximize bond strength, especially at cervical margins where enamel may be minimal.
The 'C-factor' (configuration factor) in composite restorations refers to:
Answer: The ratio of bonded to unbonded surfaces affecting shrinkage stress
A high C-factor (more bonded walls than free surfaces) increases polymerization shrinkage stress, which can debond the restoration or fracture enamel.
To prevent galvanic shock after placing a new amalgam, the clinician should check for:
Answer: Adjacent or opposing gold restorations in contact
Dissimilar metals (amalgam and gold) in contact create a galvanic cell producing an electric current that causes sharp, transient pain (galvanic shock).
When light-curing composite resin, the curing tip should be held:
Answer: As close as possible to the composite surface without touching
Maximum irradiance and depth of cure are achieved when the curing tip is as close as possible (1–2mm) to the composite surface without direct contact.