Dental Materials and Biomaterials Flashcards
7 cards from real AGD 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 Materials and Biomaterials flashcards as text
Which resin monomer is most commonly used as the base in contemporary dental adhesive systems due to its bifunctional nature?
Answer: Bis-GMA
Bis-GMA (bisphenol A-glycidyl methacrylate) is the most widely used base monomer, providing high strength and stiffness via its rigid aromatic backbone.
A dentist uses a 10-MDP-based adhesive. What is the primary benefit of 10-MDP over earlier phosphate ester monomers?
Answer: Strong ionic bond to hydroxyapatite calcium that resists hydrolysis
10-MDP forms stable calcium salt bonds with hydroxyapatite that are highly resistant to hydrolytic degradation, improving long-term bond durability.
Bulk-fill composites are formulated to allow curing depths of 4–5 mm primarily through which modification?
Answer: Higher photoinitiator concentration and modified translucency
Bulk-fill composites use optimized photoinitiator systems and increased translucency so the curing light penetrates deeper, achieving adequate conversion at 4–5 mm.
The elastic modulus of a restorative material is most important when matching it to:
Answer: The stiffness of the surrounding tooth structure to distribute stress
Matching the elastic modulus of a restorative to surrounding tooth structure prevents stress concentration at the interface under load.
Which impression material is contraindicated in a patient with a severe latex allergy even when using non-latex gloves?
Answer: Polysulfide rubber base
Polysulfide (rubber base) impression materials contain latex-related compounds and should be avoided in latex-allergic patients regardless of glove choice.
In a CAD/CAM milled zirconia crown, what post-milling procedure is essential to achieve final hardness and translucency?
Answer: High-temperature sintering
Pre-sintered zirconia is soft and machinable; high-temperature sintering (~1500°C) densifies the material, achieving full hardness and desired translucency.
Which property of bioactive glass (Bioglass) makes it suitable for use in bone and dentin regeneration procedures?
Answer: Formation of a hydroxyapatite layer that bonds to hard tissue
Bioactive glass reacts with physiologic fluids to form a hydroxyapatite surface layer that chemically bonds to bone and dentin, enabling true tissue integration.