Prosth (Mental dental) Flashcards
T/F: Compromised endo teeth should not be used as abutment
True
T/F: compromised perio teeth should not be used as abutment
True
What is the ideal crown to root ratio?
1: 2
What is the minimum crown to root ratio that can be used as abutment tooth?
1:1
The PDL surface area of the abutment teeth should equal or be greater than the imaginary PDL surface area of missing teeth
Ante’s law
____ distributes occlusal forces
Splinting
When replacing canines in maxillary teeth, should you use a splint?
SPlint central and lateral to decrease distal forces
For abutment teeth, is convergent or divergent roots better?
Divergent
What is the major problem with cement retained implants?
Excess cement causing peri-implantitis
What is a contraindication for a CD?
Max CD with opposing only mand anteriors
What compound controls the setting rate for alginate?
Trisodium phosphate
What compound adds strength to alginate?
Diomateceous earth
Position in which condyles with thinnest avascular portion of their respective discs in the most anterior-superior position against articular eminences
Independent of teeth
Centric relation
Complete interdigitation of teeth
Independent of condylar position
Maximum Intercuspation (MIP)
Centric Occlusion
Casts are mounted in ____ where is can be maintained (single fixed procedure)
MIP
Casts are mounted in ____ in case of CDs or multiple teeth being resotred or replaced)
CR
Which MMR position is more reliable and reproducible?
CR
___ facebow: orients max cast to skull via external auditory meatus to stabilize the bow (Less precise but more easy to use)
Arbitrary facebow
_____ facebow: placed on the hinge axis of the mandible ( more precise more difficult to use)
Kinematic facebow
____ articular
Does not reproduce full range of mand movement
Distance between hinge and teeth is significantly shorter than in the pt
May result in premature contacts and incorrect ridge and groove direction of restorations
Nonadjustable articulator
_____ semiajustable articulator:
Condyles are a part of the lower member, fossa area. part of the upper member
Arcon semiadjustable articulator
_____ semiadjustable articulator:
Upper and lower members are rigidly attached
Nonarcon semiadjustable articulator
____ articulator:
Pantograph is used to follow patient’s border movements
Fully adjustable articulator
Are casts poured from alginate better mounted with wax records or elastomeric materiasl?
Wax records
Are Casts poured from elastomeric materials more accurately mounted with wax records or elastomeric materials?
Elastomeric materials
What provides clearance on working side during lateral movements?
Canines
What provides clearance on balancing side during lateral movements?
Balancing side condyle
The _____ vestibule goes from buccal frenum to buccal frenum in anterior
Labial vestibule
The _____ vestibule is the vestibule is posterior to buccal frenum
Buccal vestibule
The ____ is the tissue distal to the alveloar ridge and anterior to pterygoid hamulus
Hamular notch
The ______ is the distobuccal area of impression for denture/ denture; recorded in border molding by moving mandible laterally
Coronoid notch
____ connects buccinator and superior pharyngeal constrictor
- take this by opening wide when border molding
Pterygomandibular raphe
What are the two most important maxillary border molding movements?
LAteral movement (coronoid notch) and opening wide (pterygomandibular raphe)
What muscle makes up the labial frenum in mand?
Orbicularis ori
What muscles makes up the buccal frenum in mand?
Orbicularis oris and buccinator
What muscles makes up lingual frenum?
Genioglossus
What muscle determines depth of labial vestibule in mand?
Mentalis
What muscle attachment determines depth of buccal vestibule in mand?
Buccinator
Marks distal extension of edentulous mand ridge
Ideally covered for support and retention since the integrity of the bone in this area is maintained
Retromolar pad
What are the mucles attachements present in retromolar pad?
Buccinator, superior constrictor, ptergomandibular raphe, and temporalis
Refers to the DB area on the impression/denture
Masseter contracts when mouth closes against resistance
Masseteric notch
What is the lingual portion of the slucus between tongue and alveolar ridge of mand that forms s shape?
Alvelolingual sulcus
SHould the flange be shorter or longer in anterior region of alvelolingual sulcus
Shorter
What sturcture is housed in the anterior region of the alvelolingual sulcus that warrants a shorter flange?
Sublingual gland
Which direction does the middle region of alvelolingual sulucs direct the flange of the denture?
Medially
Why is the flange deflected medially in middle portion of alvelo lingual sulcus?
Mylohyoid ridge and muscle contracting medially
What Direction is flange directed in posterior portion of alvelolingual sulcus? Shorter or longer?
Laterally; longer flange
What is the denture distal extension limited by in posterior alvelolingual sulcus area?
Palatoglossus and superior constrictor
Provides support for denture in mand
Lies perpendicular to occlusal forces
Buccinator attaches here
Buccal shelf
What is the most common frenectomy done?
Labial frenectomy
Where is the most common area to see hypermobile ridge?
Anterior maxilla
COmmon when large tuberosities touch RM pads
Can interfere with denture construction by limiting interarch space
Corrected by surgical excision of fibrous tissue and/or bone
Fibrous (pendulous) tuberosity
Multiple papillary projections of palate caused by local irritation, ill-fitting denture, poor oral hygiene, and leaving dentures in all the time
Candidiasis is the main cause
Treat with OHI, leave dentures out at night, soak dentures in 1% bleach and rinse thoroughly, use tissue conditioner, and brush irritated area lightly with soft brush
Papillary hyperplasia
What are the 5 components of combinatiion syndrome?
Specific bone resorption in anterior maxilla
Overgrowth of tuberosities
Papillary hyperplasia
Extrusion of lower anterior teeth
Loss of bone under the partial denture bases
Unknown etiology, bone resorption and repair leading to deformities
Denture not fitting hat not fitting
Paget’s ds
Are horizontal or vertical bone grafts more likely to work for bone augmentation?
Horizontal
The following things are due to ____ VD0
-Excessive display of mand teeth
-Muscles of mastication fatigue
-CLicking of posterior teeth when speaking
Strained appearance of lips
Pt unable to wear dentrues
Discomfort
Excessvie trauma to supporting tissues
Gagging
Excessive VDO
The following things are due to ____ VD0
-Aging appearance of lower third of face bc of thin lips, wrinkles, chin too near the nose, overlapping corners of mouth
Diminished occlusal force
Angular chelitis
Insufficient VDO
_______ refers to distal space created between max and mand occlusal surfaces when the mand is protruded, due to downward and forward movement of condyles down their articular eminences
Christensen’s phenomenon
_____ imaginary line from ala of nose to tragus of ear
Camper’s line
_____ occlusion for CDs refers to simultaneous anterior and bilateral posterior contacts (tripodization) in centric and eccentric movements to maintain seating of dentures
-Don’t want anterior guidance
Balanced occlusion
____ occlusion is where only the palatal cusps of max posterior teeth contact the mand posterior teeth theroeritcally eliminating the destabilizing buccal force vectors
Lingualized occlusion
Angle obtained from nonworking side condyle has moved anteriorly and medially relative to sagittal plane
Bennet angle
Lateral movement of mand toward working side during lateral excursions
Bennet shift
Lateral movement of both condyles toward the working side, basically “TMJ looseness”
Bennet movement
Factors that favor disclusion:
Steep or shallow anterior guidance
Steep anterior guidance
Factors that favor disclusion:
Steep por shallow horizontal condylar inclincation
Steep horizontal condylar inclination
Factors that favor disclusion:
Less or more bennet movement
Less bennet movement (side shift)
Factors that favor disclusion:
Short cusps with shallow inclines or tall cusps with steep inclines
Short with shallow inclines
Factors that favor disclusion:
Less or more curve of spee /wilson
Less curve of spee/ wilson
Factors that favor disclusion:
more of less Parallel occlusal plane to condylar path
Less parallel
Which direction does the inclination of teeth move as you go distally in curve of spee?
More mesial inclination
Which direction does the inclincation of teeth move as you go distally in curve of wilson?
MOre lingual inclination
WHat do fricative sounds tell about CDs?
Incisal edge position on lips
If a pt whistles when using sibiliant sounds, what is the problem?
Narrow arch form
HOw much interincisal space should be present with sibiliant sounds?
1-1.5 mm
Resitance to vertical seating forces
Support
What are the structures in upper arch that provide support?
Palate
Alveolar ridge
What are the structures in lower arch that provide support?
Retromolar pad
Buccal shelf
What part of the denture provides support?
Denture base
Resitatnce to horizontal disloding forces
Stability
What are the portions of the upper and lower arches that provide stability?
Ridge height
Depth of vestivule
What portion of the denture provides stability?
Denture flange
Resistance to vertical dislodging forces
Retention
Attraction of unlike molecules
Adhesion
Clinging of like molecues
Cohesion
Does thick and ropy saliva or thin watery saliva cause better retention?
Thin watery
Combo of adhesion and cohesion forces that maintain film integrity
Water molecules are more attracted to each other than to surrounding air
Surface tension
Disloding and sore spots are caused by _____ of dentrue
Overextension
What is the best indicator for success of denture?
Ridge (square is better)
What is methyl methacrylate in liquid for denture?
Monomer
What is hydroquinone in liquid for denture?
inhibitor
What is glycol dimethacrylate in liquid for denture?
Cross-linking agent
What is Di-methyl-p-toluidine in liquid for denture?
Activator
What is polymethyl methacrylate in powder for denture?
Polymer (powder)
What is benzoyl peroxide in powder for denture?
Initiator
What is slats of iron, cadmium, or organic dyes in powder for denture?
Pigment
Does more polymerization shrinkage occur in case of excess monomer or polymer?
Excess monomer
What is the proper ratio of monomer to polymer?
1:3
What can occur in denture processing if resin is underpacked or heated too quickly?
Porosity
WHICH kennedy class does not ever have any. modifications?
Class 4
What is the maor fucntion of a major connector?
Rigidity
Exclusive to max major connector
Scribing 0.5 mm rounded groove in cast at borders of major connector
Add strength and maintain tissue contact to prevent food impaction
Beading
How deep does lingual vestibule need to be for lingual bar?
> or equal 7 mm
What portion of RPD provides support?
Rest
What 2 part of the direct retainer provides stability?
Recirporcal clasps and minor connector
What part of the direct retainer provides retention?
Retentive clasp
HOw many degrees should the clasp portion encircle the tooth?
At least 180 degrees
___ clasp is a suprabulge clasp used when the undercut is adjacent to bounded edentuous space
Ring clasp
What class lever system does an RPI create ideally in distal extension cases?
Class 2 lever
_____ is used in RPDs for periodontally compromised and endo treated teeth to put less force on them
Wrought wire
What are the 3 principles of tooth prep?
Biologic
Mechanical
Esthetic
Where is the thinnest gingiva located in the mouth?
Lingual of molars and facial of premolars
____ form: those featrues that prevent removal of crown by apical, horizontal, or oblique forces (occlusal forces)
Resistance form
What feature of tooth prep does the operator have the most control?
Taper
What is the minimum height in incisors?
3mm
What is the minimum height of molars?
4 mm
What is the minimum height to base ratio for tooth preps?
0.4
Is height or width more important for tooth prep?
Height
Resistance or retention form?
What do buccal grooves placed in short crown preps help?
Retention
Resistance or retention form?
What do proximal grooves help?
Resistance form
What is the minimum connector height for PFM connectors?
3mm
Absorption of water
Imbition
Loss of water
Syneresis
_____ impression material
-Water byproduct
Moisture tolerant (hydrophobic and syneresis)
-30-45 mintues to pour
Polysulfide rubber
What is the polysulfide impression material by product?
Water byproduct
What is the Condensation silicone impression material byproduct?
Alcohol
Very stable but easily influenced by water and humidity
-Hydrophilic and humidity
-Very stiff and easy to break teeth on cast
60 minutes to pout
POlyether
Which impression material undergoes imbitiion? swells with water
POlyether
Which impression material undergoes syneresis (water loss)?
Polysulfide
Alcohol byproduct, which causes shrinnkage of the impression when evaporated
30 mins to pout
Condesation silicone
No byproducts
Best fine detail, elastic recovery, dimensional stability
Inhibited by sulfur in latex gloves and rubber dam
Addition silicone (PVS)
Which impression material is inhibited by rubber dam and latex gloves?
Addition silicone (PVS)
MIned as calcium-sulfate dihydrate
Manufactured with heat to get rid of some water to become calcium-sulfate hemihydrate
Gypsum
Type _____ gypsum
IMpression plaster
Low expansion
For mounting casts in articulator
Sets quickly no time for expansion
Type 1 gypsum
Type _____ gypsum
MOdel plaster
Used to make mouth guards and essix retainers
Type 2 gypsum
Type _____ gypsum
Dental stone
Removable prostheses and diagnostic casts
Type 3 gypsum
Type _____ gypsum
Dental stone High strength low expansion
-largely regarded as best stone
Best abrasion resistance
Least gauging water
Least amount of expansion
Used for fabrication of dies
Type 4 gypsum
Type _____ gypsum
Dental stone High strenth and expansion
Used for fabrication of dies
Type 5 gypsum
Which gypsum material is strongest?
Type 5
Which gypsum is weakest
Type 1
Which gypsum has most porosity?
Type 1
Which gypsum has least porosity?
Type 5
The following are ___ metals
Gold
Platinum
Palladium
Noble metals
____ metal can cause greening of porcelain
Silver
Type ___ gold
Softer
98-99% gold
Used for class 5 restorations
Type 1 gold
Type ___ gold
77% gold
Inlays
Type 2 gold
Type ___ gold
72% gold
Crowns
Type 3 gold
Type ___ gold
69% gold
RPD castings
Type 4 gold
Which type of gold is strongest and has least amount of gold within?
Type 4 gold
ABility to resist fracture to compression
Compressive strength
Ability to resist fracture during pullling
Tensile strength
Abiliity to resist fracture during bending
Flexural strength
Ability to resist propagation of a crack
Zirconia has the best
Fracture toughness
Measure of stiffness or rigidity
Stress divided by strain
Sustain deformation without permanent change in size or shape
Modulus of Elasticity/Elastic Modulus
Fractures easily without substantial dimensional change
High modulus of elasticity
Ex: Porcelain
Brittle
Deforms easily under tensile strength
-Does not break easily but doesn’t spring back to normal shape
Wires are prime example
Low modulus of elasticity
Ductile
Deforms easily under compressive stress
GOld is prime example
Malleability
Ability to be burnished
Contact stress locally exceeds the yield strength of the material
Gold is a good example
Percentage elongation
Measures the fractional change in size per degree in temp (material shrinks or expands with temp changes)
Coefficient of thermal expansion
A higher CTE means more or less likely to change?
More likely to change
Rank the CTe of the following mateirals from highest to lowest
Tooth
Ceramic
MEtal
COmposite
Composite
Metal
Tooth
Ceramic
C o(metol) T E(cEramic)
Do you want high or low elastic modulus?
HIgh elastic modulus
Are noble metals more or less resistant to corrosion?
MOre corrosion resistant
Is PMMA used for direct or indirect provisional crown method?
Indirect (exothermic)
Is bisacryl used for direct or indirect provisional crown method?
Direct
_____ in provisional cements that inhibits polymerization of resin
Eugenol
HOw much reduction is done in gingival third for porcelain veneer?
0.3 mm
HOw much reduction is done in facial third for procelain veneer?
0.5 mm
Do you want to get into dentin for porcelain veneers?
LIke to stay in enamel
What is the main problem with Maryland bridge?
Debonding
Color family
Hue
Saturation or intensity of color
Chroma
LIghtness or darkness
Value
Which portion of shade isithe most important?
Value
Color appears different under different lighting
Metamerism
Light effect of a translucent material appearing blue in reflected light and red-orange in transmittetd light
Opalescence
What is the first thing to do when getting a crown back?
Check shade/esthetics
Dental cement
Phosphoric acid irritates pulp
Mix on chilled glass slab due to exothermic rxn
One of oldest cements
Zinc phosphate
Dental cement
Chelation to calcium
Minimal pulp irritation
Zinc polycarboxylate
Dental cements
Adheres to enamel and dentin
Releases fluoride
Glass ionomer
Dental cements
Higher strength and lower solubility than GI
Not to used with all ceramic crowns due to expansion from water absorption
-one of best cements on market
RMGI
Dental cements
Most compressive strength
Bonds to dentin
Light cure, chem cure, or dual cure
Resin
Is light cure cement or dual cure m ore color stable for veneers?
LIght cure
Is an impression a negative or positive reproduction of the teeth?
Negative
Is a cast/die a negative or positive reproduction of the teeth?
Positive
Gypsum-bonded investments are used to make ___ crowns
Gold: G
Phosphate-bonded investments are used to make ___ crowns
PFM: P
Silica-bonded investments are used to make ___ crowns
BaSe metal: S
What causes shrinkage porosity of metal in lab processing?
Sprue being too thin
What causes back-pressure porosity of metal in lab processing?
Sprue being too short