Dental Biomaterials Flashcards
7 cards from real ADEX practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Dental Biomaterials flashcards as text
What does the term 'wettability' mean in the context of dental adhesive materials?
Answer: The ability of a liquid material to spread over and contact a surface
Wettability describes how well a liquid spreads across a surface; materials with low contact angles spread readily, promoting intimate contact and adhesion.
Amalgam creep refers to:
Answer: Slow plastic deformation of amalgam under sustained compressive load
Creep in amalgam is time-dependent plastic deformation that occurs under sustained compressive stress, which can lead to overhanging margins and marginal breakdown.
Which component of a dentin bonding system is responsible for penetrating and sealing the dentinal tubules?
Answer: Primer
The primer contains hydrophilic monomers that penetrate the demineralized collagen network and dentinal tubules to create a hybrid layer and resin tags.
A dental material is described as having high 'resilience.' This means the material:
Answer: Can absorb elastic strain energy without permanent deformation
Resilience is the ability of a material to absorb energy elastically (within the proportional limit) and return to its original shape upon removal of the load.
Which characteristic of gypsum products determines their final strength: dental plaster (Type II) vs. die stone (Type IV)?
Answer: Type IV uses alpha-hemihydrate with lower water-to-powder ratio, producing denser crystals
Die stone (Type IV) uses alpha-hemihydrate crystals that are denser and more regular in shape, requiring less water per gram and producing a denser, stronger set material than plaster's beta-hemihydrate.
When a patient bites through a celluloid crown form filled with composite, the purpose of making small vent holes is to:
Answer: Release excess material and prevent air entrapment
Vent holes in crown forms allow air bubbles and excess composite to escape as the patient bites down, reducing voids in the final restoration.
What is the role of an oxygen inhibition layer on the surface of a light-cured composite restoration?
Answer: It is an incompletely polymerized tacky surface layer that can bond subsequent increments or veneers
Oxygen inhibits polymerization at the composite surface, leaving a thin uncured layer that is advantageous for bonding additional increments or veneers chemically.