Restorative Dentistry and Dental Materials Flashcards
6 cards from real INBDE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Restorative Dentistry and Dental Materials flashcards as text
What is the primary purpose of acid etching enamel before bonding?
Answer: Create microporosities for micromechanical retention
Phosphoric acid (30–40%) selectively dissolves enamel hydroxyapatite, creating microporosities that allow resin tags to form and provide micromechanical retention.
The working time of zinc phosphate cement can be extended by:
Answer: Spatulating on a cold, thick glass slab
Cooling the glass slab to 18°C slows the exothermic setting reaction, extending working time; large slab area also dissipates heat.
Which impression material provides the highest dimensional accuracy and detail reproduction?
Answer: Polyvinyl siloxane (PVS/addition silicone)
Polyvinyl siloxane (addition silicone) provides the highest dimensional accuracy, excellent detail reproduction, and good dimensional stability over time.
A cusp that is fully included within the outer cusp ridges of the opposing arch during maximum intercuspation is classified as a:
Answer: Supporting cusp (centric holding cusp)
Supporting (centric holding) cusps — maxillary palatal and mandibular buccal — contact the opposing tooth in centric occlusion, maintaining vertical dimension.
Secondary caries (recurrent caries) occurs most frequently at which location of an existing restoration?
Answer: Proximal gingival margin
The proximal gingival margin is the most common site for recurrent caries due to difficulty in cleaning, plaque accumulation, and microleakage at the cervical margin.
Which crown-to-root ratio is generally considered the minimum acceptable for a tooth to serve as an abutment?
Answer: 1:1
A crown-to-root ratio of 1:1 is generally considered the minimum acceptable for a tooth to be used as a fixed prosthetic abutment, with 2:3 being ideal.