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48 Cards in this Set
- Front
- Back
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The are the different types of FPDs?
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1. Fixed-Fixed partial denture (traditional)
2. Fixed-Removable partial denture 3. Cantilever-Fixed partial denture 4. Implant-Supported partial denture 5. Resin-Retained partial denture |
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What type of fixed partial denture are these advantages and disadvantages related to?
ADVANTAGES - No need for parallel preparations -Each retentive design independent -More conservative tooth preparation -Allow minor tooth movement DISADVANTAGES -Limited length of span -More complicated lab procedure -Difficult to make temporary bridge |
Fixed-Removable partial denture
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What is the long-term failure rate of resin-retained fixed partial denture (aka Marilyn Bridge)?
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90% 1 year
74% 4 years 38-50% 10 years |
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Which FPD can result in debonding occur, risking swallowing?
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resin-retained FPD
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___________ bond strength (i.e occlusal loading) >> ______ bond strength of enamel to resin.
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Shear >> Tensile
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Where does clinical failure of bond occur almost exclusively?
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At the alloy-resin interface (fracture doesn't occur in the resin itself, and the resin enamel bond is quite strong)
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What are 3 key things with any FPD?
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Retention
Stability Support |
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In FPDs what are the types of mechanical and chemical bonding?
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Mechanical - Macromechanical & Micromechanical
Chemical - Interfacial bonding & Adhesive |
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What are the consequences of partial edentulism?
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1. Undermined cosmetic appearance
2. Modification of areas of support 3. Loss of masticatory efficiency 4. Tipping and migration of teeth 5. Extrusion of teeth 6. Attrition and depression of teeth 7. Mandibular deviation 8. Loss of vertical dimension 9. TMJ dysfunction 10. Loss of alveolar bone |
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After extracting a tooth what happens with ridge reduction?
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1. 5-7 mm of buccolingual ridge reduction occurs over 6-12 months
2. Apicocoronal height reduction of 2-3.5 mm 3. Greater ridge reduction occurs at multiple adjacent extraction sites compared to single extraction site 4. Molars>Premolars; Mandible>Maxilla |
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How much time is spent with direct occlusal force applied to periodontal tissue in a 24 hr period?
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17.5 minutes
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What should the crown:root ratio be?
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1:2 or better is ideal
2:3 is ok 1:1 is acceptable, beyond this prognosis is questionable |
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T/F
Endo or perio treated teeth should be used as a cantilever abutment |
False
They cannot be used |
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The following methods can be used to properly fabricate a provisional restoration for a prepared tooth EXCEPT:
a) indirect method (i.e. fabrication of provisional extraorally on study cast before teeth are prepped) b) Direct method (i.e. using a matrix and fabricating provisional in the mouth) c) Flipper (fills an edentulous space, not a prepared tooth) d) Pre-fabricated provisional e) A, B f) A, B, D g) All of the above |
c) Flipper (fills an edentulous space, not a prepared tooth)
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T/F
The term pre-fabricated provisional refers to the dentist using the indirect method to create a provisional that is relined over the prepared tooth |
False - indirect is a custom method where the provisional is fabricated on the study cast
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Examples of provisional materials used in clinic belong to each group
a) Poly (methyl methacrylate) [PMMA] b) Poly (ethyl methacrylate) [PEMA] c) Poly (vinylethyl methacrylate) [PVMA] d) Bis-GMA composite e) Uerthane dimethacrylate composite [UDMA] |
Examples of provisional materials used in clinic belong to each group
a) Poly (methyl methacrylate) [PMMA] JET & DURALAY b) Poly (ethyl methacrylate) [PEMA] SNAP c) Poly (vinylethyl methacrylate) [PVMA] TRIM d) Bis-GMA composite INTEGRITY & PROTEMP e) Uerthane dimethacrylate composite [UDMA] TRIAD |
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Which of the following combinations is NOT correct?
a) Duralay = Poly (methyl methacrylate) b) Snap = Poly (ethyl methacrylate) c) Trim = Poly (vinylethyl methacrylate) d) Integrity = Urethane dimethacrylate |
d) Integrity = Urethane dimethacrylate
(It is a Bis GMA composite) |
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Choose the correct statement (s) for a chemically cured provisional restoration material?
a) The greater the size of the monomer molecules, the less the exothermal heat of the reaction on setting b) The greater the size of the monomer molecules, the lower the physical strength of the set mass |
Both statements are true
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Color stability: which statement is true?
a) PMMA materials are better than BIS-GMA composites b) PEMA materials are better than UDMA composite c) Composites are better than PMMA and PEMA d) Composites are equally color stable compared with PMMA or PEMA |
c) Composites are better than PMMA and PEMA
(best for long term provisionals) |
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Provisional margins that impinge on gingival tissue would result in the following?
a) gingival proliferation and/or recession b) Chronic periodontitis c) Gingival inflammation d) Hemorrhage during cementation e) A,C,D f) All of the above |
e) A,C,D
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All of the following contribute to a poorly fabricated provisional Except:
a) Lack of occlusal contact b) provisional is too thin c) Using triad rather than integrity d) Open contacts e) Open margins |
c) Using triad rather than integrity
(can meet all the criteria with any of the materials we've discussed) |
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Provisional restoration is a transitional restoration that provides _______, _________, and ______ before fabrication of the definitive prosthesis.
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Protection, Stability, and Function
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What are the requirements of good provisional restorations?
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1. Pulpal protection
2. Positional stability 3. Correct occlusal function 4. Easy to claim 5. Good marginal adaptation 6. Strength 7. Good retention 8. Good esthetics |
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What could be wrong with the provisional if you get lack of gingival stimulation, plaque retention, cheek biting, difficult access for cleaning which may all result in gingival recession, sensitivity, bleeding and/or swelling?
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Over contouring restoration
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What could be wrong with the provisional if you get food impaction or traumatic ulcers?
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Undercontouring restoration
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What could be wrong with the provisional if you get supraeruption - interferences during eccentric movements, especially protrusive?
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No occlusal contact
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What could be wrong with the provisional if you get breakage of the provisional, exposing dentinal tubules resulting in sensitivity and/or vulnerability to bacteria?
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Material too thin
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Is an interocclusal record always required when replacing crowns?
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No. If you can align models reliably in MICP there is no need for interocclusal record.i.e. replacing a single crown when the patient has a full compliment of teeth
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When you trim your occlusal record, why do you only have supporting cusp tips?
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Because the record is more accurate than alginate produced models; if not trimmed, will end up with a high crown because models will not seat together fully.
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What are some potential problems associated with triple trays?
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1. No occlusal stops
2. Patient does not close properly (not in MICP) 3. Patient closes down on frame, causing potential frame flexing and impression distortion 4. Impression distortions can occur if impression material with high flexibility utilized with an open gauze tray therefore, use trays with rigid frames 5. Contacting Soft Tissue 6. Limited lateral excursions |
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When should you use centric relation?
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1. Non-physiologic occlusion (ie only hitting on one tooth)
2. Pathology related to occlusion 3. No Posterior Support 4. Posterior Collapse 5. Orthodontics 6. Disengagement of one or more posterior quadrants 7. VDO change 8. Complete/Partial dentures |
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A crown casting with a chamfer margin fits the die. In the mouth, the casting is open approximately 0.3mm. A satisfactory fit and an accurate physiologic contour of the gingival area of the crown can best be achieved by:
a) hand burnishing b) mechanical burnishing c) using finishing burs and points to remove the enamel margins on the tooth d) taking a new impression and remaking the crown e) relieving the inside of the occlusal surface of the casting to allow for further seating. |
d) taking a new impression and remaking the crown
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What are the different recording materials used for CR?
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1. Hard Waxes
2. Zinc oxide eugenol (mousse-like material, much more stable than wax) 3. Vinyl polysiloxane |
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What are the advantages of ZOE used as recording material?
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1. Negligible shrinkage
2. preserved indefinitely 3. almost no resistance to closing the mandible, allowing for better accuracy 4. More stable than wax [Disadvantages: stinging or burning sensation caused by the eugenol on tissue, Also Difficult to Clean Up] |
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What are the advantages and disadvantages of VPS?
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1. Stability (just as accurate 1 week later)
2. Least amount of distortion Disadvantages: high cost, inherent hydrophobic nature (surfactant is added to render the surface of the impression hydrophillic, needs a dry field) |
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Why is it important that interocclusal records are trimmed through the buccal cusp tips?
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To enable easy verification that both casts are properly positioned in the record and stable
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What does a lucia jig do?
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Lucia Jig provides a contacting surface for the lower central incisors, which is 90 deg to the arc of mandibular closure. This eliminates the potential for a distal vector force
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What type of pontic looks most like a tooth?
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Saddle pontic
contacts the ridge and extends both on the facial and lingual sides. IMPOSSIBLE TO CLEAN AND SHOULD NEVER BE USED |
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What type of pontic:
-no contact with the edentulous ridge -used in nonappearance zones -very easy to keep clean |
Sanitary (hygienic) pontic
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What are the three layers of porcelain covering the coping of a PFM?
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1. Opaque porcelain- conceals the metal underneath, initiates the development of the shade, and plays and important role in the development of the bond between the ceramic and the metal
2. Dentin or body porcelain- makes up the bulk of the restoration providing most of the color or shade 3. Enamel or incisal porcelain- imparts translucency to the restoration |
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What is the difference between noble and high noble metals?
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High noble is >60% noble metal, with at least 40% GOLD
Noble is at least 25% noble metal content |
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What is a metal that possesses a high intrinsic commercial value based on supply and demand, i.e. Be, In, Ga
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Precious alloys
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What is a metal that is half precious and half non precious, no alloys meet this specific definition, description valueless?
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Semi-precious alloys
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What noble metal has the following properties: Corrosion and tarnish resistance, workability, burnishability?
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GOLD
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What noble metal has the following properties: Increase strength, melting range, hardness, corrosion resistance?
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Platinum
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What noble metal has the following properties: Increase strength, increases melting range, hardness, corrosion and tarnish resistance, increased sag resistance, affinity to carbon?
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PALLADIUM
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What are the four important features when designing metal coping?
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1. Thickness of metal underlying and adjoining the porcelain
2. Placement of occlusal and proximal contacts 3. Extensions of the area to be veneered for porcelain 4. Design of facial margin |
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A crown casting with a chamfer margin fits the die. In the mouth, the casting is open approximately 0.3mm. A satisfactory fit and an accurate physiologic contour of the gingival area of the crown can best be achieved by:
a) hand burnishing b) mechanical burnishing c) using finishing burs and points to remove the enamel margins on the tooth d) taking a new impression and remaking the crown e) relieving the inside of the occlusal surface of the casting to allow for further seating. |
d) taking a new impression and remaking the crown
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