Prosthodontics & Occlusion · patient case question
Which material is the most radiolucent?
Patient case: Restoring a broken-down tooth
demo: 45-year-old female
chief: Wants to restore a heavily broken lower molar and to improve the appearance of her upper front teeth.
history: Nothing relevant medically. She has had a crown placed on tooth 12 elsewhere.
meds: None.
findings: Tooth 30 has minimal remaining coronal structure with 0.5 mm of sound dentin above the crown margin circumferentially. An impression and a working cast from the first attempt show voids at the margin and a torn finish line. The crown on tooth 12 is markedly brighter than the adjacent very yellow natural teeth.
Show answer and explanation
Correct answer: A. Polymethyl methacrylate
- A. Correct. Polymethyl methacrylate, the acrylic of denture bases and provisional restorations, is composed of low atomic number elements and is essentially radiolucent. This is clinically important because an aspirated or swallowed acrylic fragment may not be visible on a radiograph.
- B. Amalgam is highly radiopaque because of its silver, tin and mercury content.
- C. Gold alloy is among the most radiopaque of dental materials.
- D. Zirconia is markedly radiopaque, appearing similar to or denser than metal on radiographs.
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