Prosthodontics

Question 1

Alginate (Irreversible Hydrocolloid)

Answer 1

Sodium or potassium salts of alginic acid which react chemically with calcium sulfate to produce insoluble calcium alginate.
• Diatomaceous earth adds strength
• Trisodium phosphate controls the setting rate
• More bulk means less susceptibility to unwanted
dimensional changes
• 2-3 minutes  remove tray
• Within 15 minutes  pour impression
• 30-60 minutes  cast sets

Question 2

Labial Frenum- orbicularis oris
• Buccal Frenum- orbicularis oris, buccinator
• Lingual Frenum- genioglossus
• Labial Vestibule- mentalis
• Buccal Vestibule- buccinator

Question 3

Retromolar pad contains ?

Answer 3

temporalis, buccinator, superior pharyngeal constrictor, and

pterygomandibular raphe

Question 4

Frenectomy:

Labial > buccal > lingual (most to least
common)

Question 5

Combination Syndrome

Answer 5

• Specific pattern of bone resorption in the anterior
edentulous maxilla when it is opposing
mandibular anterior teeth only

Question 6

Christensen’s phenomenon=

Answer 6

refers to the distal space created between the maxillary and mandibular occlusal surfaces when the mandible is protruded, due to downward and forward movement of condyles down their articular eminences

Question 7

Camper’s line= imaginary line from ala of nose to
tragus of ear

• Interpupillary line= imaginary line between pupils
of the eyes

Question 8

• Bennett angle= angle obtained after nonworking
side condyle has moved anteriorly and medially
relative to the sagittal plane

• Bennett shift= lateral movement of mandible
toward the working side during lateral excursions

• Bennett movement= lateral movement of both
condyles toward the working side, basically “TMJ
looseness”

Question 9

Heat-Cured Acrylic
• PMMA= polymer (powder)
• MMA= monomer (liquid)

Answer 9

Liquid
• Methyl methacrylate (MMA)= monomer
• Hydroquinone= inhibitor
• Glycol dimethacrylate= cross-linking agent
• Dimethyl-p-toluidine= activator

Powder
• Polymethyl methacrylate (PMMA)= powder
• Benzoyl peroxide= initiator
• Salts of iron, cadmium, or organic dyes=
pigment

Question 10

Shrinkage always occurs, but more shrinkage if
excessive monomer
• Ideal ratio of monomer to polymer is 1:3
• Porosity is due to underpacking with resin at
time of processing or being heated too rapidly