AGD Dental Materials and Biomaterials 5

Question 1

Which resin monomer is most commonly used as the base in contemporary dental adhesive systems due to its bifunctional nature?

Accepted Answer

Bis-GMA

Answer

Bis-GMA (bisphenol A-glycidyl methacrylate) is the most widely used base monomer, providing high strength and stiffness via its rigid aromatic backbone.

Question 2

A dentist uses a 10-MDP-based adhesive. What is the primary benefit of 10-MDP over earlier phosphate ester monomers?

Accepted Answer

Strong ionic bond to hydroxyapatite calcium that resists hydrolysis

Answer

10-MDP forms stable calcium salt bonds with hydroxyapatite that are highly resistant to hydrolytic degradation, improving long-term bond durability.

Question 3

Bulk-fill composites are formulated to allow curing depths of 4–5 mm primarily through which modification?

Accepted Answer

Higher photoinitiator concentration and modified translucency

Answer

Bulk-fill composites use optimized photoinitiator systems and increased translucency so the curing light penetrates deeper, achieving adequate conversion at 4–5 mm.

Question 4

The elastic modulus of a restorative material is most important when matching it to:

Accepted Answer

The stiffness of the surrounding tooth structure to distribute stress

Answer

Matching the elastic modulus of a restorative to surrounding tooth structure prevents stress concentration at the interface under load.

Question 5

Which impression material is contraindicated in a patient with a severe latex allergy even when using non-latex gloves?

Accepted Answer

Polysulfide rubber base

Answer

Polysulfide (rubber base) impression materials contain latex-related compounds and should be avoided in latex-allergic patients regardless of glove choice.

(AGD) Academy of General Dentistry Certification Practice Test

(AGD) Academy of General Dentistry Certification Practice Test

AGD Dental Materials and Biomaterials 5