Final Flashcards
What is acrylic?
colorless pungent acid
What is resin?
natural or synthetic that form plastic materials after polymerization
Benefits of using polymethylmethacrylate (PMMA)
- excellent esthetic properties
- adequate strength
- low water absorption
- low solubility
- non-toxic/low allergenicity
- easily repaired
- reproduces detail accurately
- simple molding & processing technique
What is the best resin for dentures?
PMMA
What are the 5 ingredients of PMMA?
- liquid monomer - methyl methacrylate
- powdered polymer - polymethyl methacrylate
- plasticizer - dibutyl phthalate
- initiator - benzoyl peroxide
- pigments
What are the 3 parts of the PMMA liquid?
- mehtyl methacrylate
- glycol dimehtacrylate (cross linking)
- hydroquinone (inhibitor for incr shelf life
What are the three acrylic resin types?
- Heat cure
- Chemical cure
- Light cure
Write out the 12 step denture process
- Oral Exam, Tx Plan, prelim impressions
- Make custom trays on prelim casts
- Border molding and 2ndary impressions
- Master casts, record bases and occlusion wax rim (place post palatal seal on master casts, cut notches on wax rim for CR record)
- maxillo-mand relations, teeth selection (facebow transfer)
- arrange max & mand ant teeth
- anterior trial placement
- arrange max and mand post teeth
- trial placement in wax and pt approval (make new interocclusal/CR record and check on articulator)
- process dentures, lab remount
- clinical remount, occlusal corrections, insertion
- post insertion recalls
What is OVD?
distance between two points while in occlusion
What is IOD?
space between teeth when in physiologic rest position
What is RVD?
distance between two points when in phys rest position. OVD + IOD = RVD
What position is preferred because it is repeatable?
CR
Without _______________ the teeth will look fake.
buccal corridor
Do teeth touch when swallowing? When speaking?
Swallowing: yes
Speaking: no
Should the mandibular incisors be visible behind the lower lip?
slightly
How much of the maxillary incisors should show below the upper lip?
1-2 mm
How high up the rm pad should the occlusal plane be?
2/3
Maxillary post teeth should parallel what plane?
ala-tragus line (camper’s plane)
What is over open?
when teeth occlude too early (mandible and maxilla are still “open”) OVD too large
What is over closed?
when teeth occlude too late, speaking space is >3mm (maxilla and mandible are too closed)
What causes internal porosity?
When temp inside flask gets above 100 C. (monomer melts at 100.8)
Main diff between heat activated and autopolymerizing resins?
Method of activation of the initiator benzoyl peroxide
Why is heat activated better than autopolym resin?
- greater degree of polymerization
- better color stability
4 uses for tissue conditioners?
- prevent or treat chronic denture soreness
- stabilize temporary record bases
- stabilize immediate dentures during healing
- Final impression material for functional impressions
Main disadvantage of metal base dentures?
difficult to reline
What is the purpose of relining?
produce a better fitting intaglio surface without affecting the OVD
What are 4 reasons for tissue changes?
- stresses of daily function
- change sin general health status
- hereditary factors
- defects in dentures
What is a static impression? (closed mouth technique)
- pt occludes at OVD
- functional movements made with tongue
- removed moments later
- polysulfide, PVS, polyether, etc
When is the posterior palatal seal placed?
BEFORE PROCESSING
What is combination syndrome?
maxillary complete denture is opposed by mandibular anterior natural teeth
- maxillary anterior tissue is mobile or hyperplasia
- inflammatory palatal hyperplasia (IPH)
- maxillary tuberosities enlarged
- mandibular posterior bone resorption
- mandibular anterior teeth supraerupted
When do you need to “reduce, restore, or remove”?
When leveling the occlusal plane with combination syndrome
Main advantages of overdentures?
- support
- stability
- proprioception
- psychological benefit
Know the many disadvantages of overdentures.
Look them up
What factors lead to abutment tooth loss in overdenture pts?
- after 5-6 years 10% of abutments lost
- perio disease, caries, endo complications
- motivation for hygienic care - mechanical brushes
- Fl2 gel for daily application