Fixed Q3 Flashcards
The combined width of Connective Tissue and Junctional Epithelial attachment formed adjacent to a tooth and superior to the crestal bone.
Biological Width
From top to bottom: 1mm
1mm
1mm
Gingival sulcus (pocket depth)
Junctional Epithelium
Connective Tissue attachment
T/F
Biological width can vary from pt to pt
True
How do you measure Biological Width?
Sound to Bone
(subtract sulcus depth)
***done under anesthesia
If a crown prep does not follow soft tissue contour what might happen?
Violation of Biological Width by Crown Margin
If a crown margin is placed within the Junctional Epithelium or Connective tissue what has occurred?
Violation of Biological Width
2 Things happen if you violate Biological Width:
Inflammation
Bone Loss
*body will try to re-establish Bio Width
What defines the bone loss in the case of an Iatrogenic violation of Biological Width?
Uncontrolled/unpredictable
Where is unpredictable/uncontrolled bone loss more likely to occur in the case of Bio Width violation?
Thin Alveolar Bone
What plays a major iatrogenic role in the recession of bone around thin areas?
Trauma from restorative procedures
*like BioWidth violation
What are 2 factors inherent in the Pt that affect the outcome of iatrogenic trauma to the BioWidth?
If Gingiva Thick/Fibrotic or Thin/Fragile
Peridontium Scalloped or Flat
What type of gingiva is more prone to recession?
What type is less prone?
Highly scalloped thin
Thick and Fibrous
What factor correlates to the Thickness of the Alveolar Bone?
Gingival Biotype
- thin gingiva = thin alveolar bone
- thick gingiva = thick alveolar bone
What is the simplest way to determine Gingival Biotype?
Metal Perio probe in the Sulcus
*if thin, probe visible through gingiva
T/F
Thin biotype is more likely to recede, and is correlated to a highly scalloped gingiva
True
What are the 2 ways to treat a Violation of BioWidth?
Orthodontic Extrusion
Crown Lengthening
When a tooth is extruded via orthodontics to move the margin out of the the BioWidth, what is often indicated?
New Restoration
What is the advantage to Crown Lengthening procedure as opposed to letting the bone loss resolve on its own?
Healing process of Crown Lengthening very predictable
*may lose more bone than you want if you let it resolve on its own
Crown lengthening is a ____ method
Subtractive
T/F
The re-establishment of health in a crown lengthening is predictable
Not treating BioWidth invasion may lead to unpredictable bone loss
True
True
Average distance from the Bone to the height of the FGG? (not interproximal)
Height from bone to soft tissue Scallop? (interproximal)
3 mm
4.5 mm
Papillary height is established by what 3 things?
Level of bone
Biological width
Form of the Gingival Embrasure
T/F
Changes in the form of an embrasure can impact the height and form of the papilla
True
The tip of the papilla behaves differently than the FGG on what aspect of the tooth?
Facial
The FGG averages 3 mm above the facial alveolar bone, but the tip of the papilla averages _____ above the interproximal bone
4.5 - 5 mm
If the papilla is further away from the alveolar bone on the facial interproximal side but but has the same BioWidth as the rest of the surface, what must be deeper?
Sulcus
*1 - 1.5 mm deeper
If the measurement is ___ to ____ mm, there is a full papilla
3 - 5
Who studied the relationship between the papilla and interproximal contact to the underlying bone to establish papillary height above bone?
Tarnow et al
When the interproximal contacts are _____ mm or less (to the alveolar bone), papilla always fill the space
5 mm
If the interproximal contact point is 6 mm above the alveolar bone, ____ % of the time the papilla fills the space
56%
If the interproximal contact point is 7 mm above the alveolar bone ______% of the time the papilla will fill the space
37%
T/F
On average females have a higher smile line
True
Maxillary incisal edge display at rest does what with age
Mandibular?
Decreases
Increases
What sex has a greater incisal edge display at rest?
Females
What do people notice about midline shift and cant?
Midline shift - no one notices
Cant - everyone notices
T/F
Cant isn’t as important as dental midline
False
How far does a midline shift have to deviate before Orthodontists notice?
Everyone notices a ___mm incisor crown angulation
4 mm
2 mm
Anterior preparations have how much of an incisal reduction?
2 mm
Integrity is what kind of material?
PMMA?
Bis-acryl
Poly methyl methacrylate
PMMA goes through what kind of reaction?
steps?
Polymerization rxn
initiation, propagation, termination
Acrylics can be classified by their activation (initiation), which can be what 3 things?
Heat
Chemical
Light (400-500 wavelength) = camphroquinone
For PEMA (SNAP), what is the Initiator found in the Powder?
What is the Activator found in the Liquid?
Benzoyl Peroxide
Tertiary amine
PEMA =
PMMA =
Which is SNAP?
Poly ethyl methacrylate (SNAP)
Poly methyl methacrylate (Jet)
PEMA vs PMMA - which one heats up more?
What is it called?
PMMA - may traumatize pulp
Jet acrylic
PEMA and PMMA are both chemically activated
True
*by a Tertiary Amine
What is the main advantage to working with PEMA (SNAP) over PMMA (Jet)?
Low curing heat
What is Triad activated by?
What is the Initiator?
Light (400-500 nm)
Camphorquinone
T/F
Triad is activated by heat
False
*Light 400-500 nm
Polyvinyl siloxane can go through a _____ rxn whose byproduct is ______
Condensation
Ethanol
PVS that goes through a condensation rxn (2 types of putty squished together) has what advantage over condensation silicone impression materials?
Less polymerization shrinkage
*highly filled
3 reasons for a beveled shoulder:
bend or burnish metal margin to tooth
minimize marginal discrepancy if crown doesn’t seat completely
Protect chipping (by removing unsupported enamel)
A Heavy Chamfer is also referred to as a ________ and is achieved with the ________ bur
Deep Chamfer
856.025
T/F
Sharp corners are more prone to impression voids
True
For adequate resistance form, how high should Anterior preps be?
Posterior?
3 mm axial wall height
4 mm
Teeth that have greater than ____ height to base ratio will have adequate resistance form
0.4
3 general esthetic considerations to keep in mind for All Ceramic restorations?
Pink framing
Shade
Translucency
When would metal show through a Metal-Ceramic restoration?
If prep too thin (so porcelain too thin)
T/F
A metal to porcelain (ceramic) crown is one of the Least conservative restorations available to the dental profession
True
A metal-porcelain crown will often look like what on the gingival border? (PFM)
What might prevent this?
Gray
New labial designs moving metal margin away from gingiva
3 indications for use of an all Ceramic restoration?
Single crown
High Esthetic demand
Metal allergy
T/F
Metal allergy includes those pts that can’t wear metal jewelry - must ask the pt before Tx planning
True
T/F
An all ceramic is basically an all glass restoration, and most people are high Esthetic demand pts
True
All ceramic restorations - 4 Patient Selection Criteria:
Optimal Esthetics required and ACHIEVABLE
ideal prep
favorable occlusion
compatible opposing dentition
6 important properties of Ceramic Materials:
Translucent
Chemically stable
Fluorescent
Biocompatible
High compression resistance
CTE (coefficient of thermal expansion) similar to natural tooth
Advantages to Ceramic Crowns: Excellent ______
Good peripheral blend of _____
Luting material not _____ in oral fluids
_______ margins
Soft tissue _______
esthetics
shade
soluble
Supra-gingival
compatibility
T/F
PFM is not translucent, whilst all ceramic is
True
With some dark teeth, what can be used to mask the dark dentin?
Zirconia
Ceramics have less irritation/inflammation at the margins compared to metals
True
T/F
All ceramics have enhanced esthetics b/c of no metal and improved light transmission
True
All ceramics are most beneficial for those teeth that have what colored dentin?
If dentin is dark, use what?
Normal
Zirconia
T/F
Facial tooth reduction isn’t as much using all ceramics (supra gingival)
True
T/F
ACC’s can be technique sensitive and there is a time consuming luting procedure
True
T/F
ACC’s can be brittle, fragile to occlusal adjustment, and have a lack of repair ability (if fracture, that’s it)
True
What might cause gingival irritation in an ACC?
Where would you not use an ACC?
rough margins - easy to do
molars - greater potential for fracture (Empress)
Contraindications for ACC’s include compromised teeth, bad habits, occlusal interferences, difficulty isolating, and if the margin is where?
Sub-gingival
*not possible especially if restoring using resin cement
What are 2 Major problems with ACC’s?
Brittle - a flaw will propagate along crack
Abrasive to opposing tooth
The higher the _____ concentration of an ACC, the more wear there is
Leucite
2 General ways to classify dental ceramics:
Composition
Lab processing
3 Types of ceramics (by composition):
Glass - looks great
Glass infiltrated (particle filled glass) - stronger
Polycrystaline - almost like metal
Glass ceramics are highly esthetic and best at mimicking what?
Optical properties of enamel/dentin
An example of a glass ceramic:
Feldspathic porcelain
Glass infiltrated ceramics (particle-filled glass) have what in them that improves their mechanical properties?
Filler particles
3 examples of the filler material in Glass infiltrated ceramics?
alumina
magnesia-alumina
alumina-zirconia
Polycrystalline materials have increased what?
Reduced what?
and No what?
strength
translucency
glassy components
What is the only way to process Polycrystalline ceramics into shapes?
computer-assisted machining
2 Examples of Polycrystalline ceramics?
Cercon Base
DC-Zirkon
Where are Glassy materials most often used? (weak, translucent)
Particle-filled glass?
Polycrystalline?
Anteriors
Anteriors/posteriors
Posteriors (some anteriors)
3 Glassy materials:
3 Particle filled glasses:
4 Polycrystalline:
feldspathic, VMK95, Initial
In-Ceram, Empress I/II, E max
Lava, Everest, Cercon, Procera
Classification of ceramics according to Laboratory processing (4 ways)
Sintered conventional powder-slurry
Castable/Pressable
Machinable
Infiltrated
What is the traditional method of fabricating an ACC?
Powder condensation
*moist brush, compact, vacuum firing
Ceramics made by what technique are translucent and esthetic, used mostly for veneering layers
Powder condensation
What ceramic is used with an Aluminous Core w/ a platinum matrix heated to drive off dissolved gases and a core porcelain build up?
Conventional Powder-Slurry
Powder-Liquid ceramics have great translucency and can be as thin as _____ mm
0.2 mm
T/F
Dual cures can change colors, so if you want a highly translucent product use a light cure
True
*zirconia = dual cure
When was the Porcelain Jacket Crown developed?
Aluminous Porcelain Jacket Crown?
1800’s
1965 - aluminous oxide strengthened
What is stronger than the Powder Liquid ceramic?
2 examples:
Pressed ceramic
IPS Empress, IPS Empress 2
Y-TZP is an example of what?
Polycrystalline ceramic matl
*YTTRIUM Tetragonal Zirconia Polycrystals
2 All ceramic products that can be used in Press Technology or CAD/CAM technology?
IPS Empress
IPS E max
Leucite can be a filler for what?
Lithium disilicate, alumina spinel, and zirconia can be a filler for what?
High glass content
Low glass content
No glass content (polycrystalline) can be what 2 matls?
alumina
zirconia
What IPS matl is Leucite Glass Ceramic, low flexural strength?
IPS Empress Esthetic
*looks really good - highly translucent
What is the Improvement over IPS Empress Esthetic with increases strength, higher flexural strength, and in monochromatic?
Empress 2 (pressed ceramic)
IPS Empress Esthetic is what matl?
Empress 2 is what matl?
IPS E max?
Leucite glass
disilicate glass
Lithium-disilicate
IPS E max press (Ivoclar Vivadent) was introduced in 05 and uses what type of cement?
Resin cement
IPS E max has better physical properties and improved esthetics
True
What high strength ceramic with a superior marginal fit has 2 fabrication methods and must be bonded?
Pressed
Under or Over etching will do what to bond strength?
Decrease
T/F
HF acid has better bonding properties than phosphoric
True
What creates a bond between the HF etched teeth and an ACC?
Monobond-S
With IPS Empress, when should you adjust occlusion?
After bonding
IPS Empress is very esthetic and translucent and must be ______ to the tooth
However, it is relatively ______ and ______
*use for esthetic restoration
bonded
weak, expensive
Lithium disilicate, titanium, zirconium, alumina, inflitrated Al/Zr, glass ceramics, composite, and castable plastic are used for what?
CAD/CAM matls
The Alumina CAD/CAM matl is known as what?
Procera
T/F
Procera crowns are digitized and emailed to Sweden or NJ
True
What type of cement is used for Zirconia or Crystalline crowns?
Glassionomer
*no need for translucency
What type of cement is used if you need translucency?
Resin (acid etch then bond)
*more difficult to use
Any substructure =
coping
What is the strongest laminate w/ great esthetics on the market?
(must be bonded - translucent - resin)
Procera Laminate
Procera AllCeram system using glass free high strength ceramic core, used ant/post, CAD/CAM
Densely sintered high-purity Aluminum Oxide
Aluminum Oxide sinters at _____degrees C
___% shrinkage upon sintering
1650
20%
***remember, Aluminum Oxide = Procera
In the Procera system why is the die enlarged?
Compensates for sintering shrinkage
Review: Glass powder liquid
Pressor matls (2):
CAD/CAM =
Empress, Emax
CAD/CAM
What is the strongest matl (but not very esthetic)?
Zirconia system
What type of cement do you use with Zirconia?
Conventional cement
T/F
Removing Zirconia is easy
False
*very strong
How is Zirconia cured?
Dual
*as opposed to light
What product cleans after try-in of pretreated restoration?
What is the universal Restorative Primer? Applied for _____ secs then air dried
Next step?
***then?
Ivoclean
Monobond Plus, 60 seconds
Cement into restoration (dual cure)
***then seat, clean up, and Final Cure 20 secs/side
IPS Empress, when adjust Occlusion?
Zirconia, when adjust Occlusion?
After bonding
Before bonding (high strength means cracks won’t go further)
Glass Ceramics used in Anteriors for forces of ____ N
Alumina used on Premolars for forces of _____ N
Metal ceramics, zirconia, and gold (3M) are used in the Molars for forces of ____ N
150
300
400-800
7 ACC matls from least to highest strength
Feldspathic porcelain
IPS Empress
IPS E max
In-ceram Alumina
In-ceram Zirconia
Alumina (Procera)
Zirconia (Cercon, LAVA)
Incisal reduction for ACC:
The rest:
1.5 mm
1 - 1.2mm axial, 1.0 mm marginal
2 systems to describe color:
Munsell (hue, chroma, value)
CIELAB
Visible light spectrum:
380-750 nm (violet - red)
Northern-exposure sunlight in the middle of the day that is slightly overcast.
Standard daylight
or northern daylight
The reproducing capacity of artificial light to mimic natural daylight is measured by what 3 things?
color temperature
spectral reflectance curves
CRI- color rendering index
The CRI is on a scale of 0-100 and indicates what?
color rendering of artificial light source
compared to standard Northern Daylight
Incandescent lights emit higher concentrations of _____ light waves and has what CRI?
Fluorescent lights emit higher concentrations of _____ waves, has what CRI?
Yellow, low CRI
Blue, 50-80 CRI
T/F
Incandescent and Fluorescent lights are suitable for shad matching
False
What type of artificial light provides the best color matching?
Can these be used alone?
Color corrected fluorescent lamps w/ CRI over 90
Should use multiple sources
What is the phenomenon when objects match color under one light source but not another?
Metamerism
Dental offices should use color corrected lights and others for shade matching
True
What 2 types of lighting are commonly used in the home and office and should be used to match shade (along with color corrected source)?
Incandescent
cool white fluorescent
T/F
Shade match with the dental operating light
False
*only use ambient lighting
T/F
A CRI of around 90 should be used to shade match
True
What 3 factors determine color?
Hue
Chroma
Value
3 primary subtractive colors
Blue
Red
Yellow
What are the primary Additive Colors?
Red
Blue
Green
Hue:
Chroma:
Value:
color (determined by wavelength)
color intensity (saturation)
light from dark (black and white grayscale)
What is the most important factor in color?
Value
Value is measured on a scale from _______
0 - 10
What is a common color matching mistake in metal-ceramic prosth?
Restoration too high in Value
T/F
Objects of different chroma/hue can have the same value
True
CIELAB is better than Munsell and distinguishes color space by what 3 coordinates?
L
a
b
In CIELAB, L =
a =
b =
lightness
red-purple/blue-green axis
yellow/purple-blue axis
L, a, and b correspond to Munsell’s Hue and Chroma
False
What in the eye interprets brightness?
What interprets color?
Rods (no color)
cones (only active under high lighting conditions)
Rods are used for _____ vision
Cones are used for ______ vision
Scotopic
Photopic
Rods have highest concentration where?
Cones?
peripheral retina
central retina
*remember, rods for brightness, cones for color
Because color vision decreases rapidly, what should you look at between shade matching to restore color vision?
Pale blue or Gray surface
When should the color be matched during an appointment?
Beginning
*tooth still hydrated - take off lipstick, try to have neutral background colors
What is the best background to use for color matching?
N7 - N9 gray
*high value pastels also recommended
The portion of the ceiling not occupied by lighting should be what value?
Large vertical surfaces?
9 or more
8 or more
*also, avoid high gloss
Color blindness affects what % males?
Females?
8%
0.5%
3 types of color blindness:
Achromatism - no hue
Dichromatism - 2 primary hues
Anomalous Trichromatism - all 3 hues, but retinal cones affect one primary pigment
How long should you wait after bleaching to match color for a crown?
10 days
3 types of commercial shade guides:
Vita classic
Vitapan 3D master
Extended Range Shade Guides
What does A3 mean in the Vita Classic shade guide?
A - red-yellow
3 - chroma
Vita Classic shade guide colors A:
B
C
D
red-yellow
yellow
grey
red-yellow-gray
Vita Classic shade guide sequence for shade match (4 steps):
Hue (A, B, C, D)
Chroma
Value
Final check, revision
How is value best determined?
squinting @ arms length
*increases rod sensitivity
Would it be better to err on high value or low?
High
*low can’t be stained up in value
Trying to increase value through staining will increase what?
Decrease what?
opacity
light transmission
What shade guide starts with the Value?
Vitapan 3D master
4 steps with Vitapan 3D master?
Value
Chroma
Hue
Final check/revision
T/F
Extended range shade guides will cover bleached, dentin, and custom shades
True
What 2 materials, when preparing for an ACC, would need a Stump Guide?
(match dentin)
Feldspathic porcelain
IPS Empress
T/F
Stains increase surface reflections and prevent light from being transmitted through porcelain
True
When a tooth is divided into 3 regions w/ 9 segments:
Shad mapping
3 types of color measuring instruments:
Spectrophotometers
Spectroradiometers
Colorimeters
A standardized image capture environment for shade matching using a full spectrum 7 band LED light
Crystaleye
What is the default sequence at ASDOH for preparation of the tooth for a crown?
build up first
preparation
A crown prep followed by a build up has what disadvantage?
temporize is difficult if non-restorable
Amalgam, composite, and Glassionomer can all be used to build up a crown
True
What is the dual cure composite material for crown build up?
Paracore
Tooth in tooth relationship
MIP - max. Intercuspal position
CR (centric relation) definition:
Condyles in most Anterior/Superior
90% of people in MIP…
Are not in CR
MIP = CR
10%
MIP:
CR:
Centric Occlusion:
Max intercuspal position
Centric Relation (condylar)
Where the teeth touch first
When would you restore the arch so MIP = CR
Teeth ground down
Endentulous
Full arch/mouth rehab
If MIP and CR differ, there is a ______ to _______ slide
Centric Occlusion (where teeth meet first)
MIP
If MIP and CR differ greatly, the resulting CO to MIP slide can result in what?
Parafunction
The complete intercuspation of opposing teeth INDEPENDENT of condylar position
MIP
*he writes it as ‘maximum intercuspation position’
Centric Relation is independent of what?
MIP and tooth contact
The maxillomandibular relationship, condyles most Anterior and Superior, articulating with the thinnest avascular portion of the disk
Centric Relation
In Centric Relation, the condyles articulate with what?
They are in what position against the articular eminence?
Thinnest avascular portion of disc
most Anterior and Superior position
T/F
Centric Relation depends on tooth contact
False
What type of movement is allowed when in Centric Relation?
Rotational
*any translation will get you out of CR
CR, aka…
Terminal hinge axis
Measured between the incisal edges, how far can CR rotate before translation occurs?
20-25 mm
After 20-25 mm of CR rotation (measured incisally), what ligament tightens?
What direction do the condyles translate?
TemporoMandibular Ligament
Anterior and Inferior
The occlusion of opposing teeth when the mandible is in Centric Relation:
Centric Occlusion
Centric Occlusion is normally found where?
Posterior teeth
A slide from CR to MIP is present in ____% of the population.
Average distance of slide:
90%
1 - 1.25 mm
If the occlusion is stable, prosthetics are mounted in relation to what?
MIP
*existing occlusal scheme - most fall into this category
If you want to perform an occlusal equilibration how should you mount the case?
Centric Relation
A theory is that Interferences between what creates neuromuscular disharmony, resulting in parafunctional activity?
CO and MIP
Unrestricted movement between CO and MIP is considered ideal when?
If there’s no change in Vertical Dimension
T/F
The majority of cases can be restored to the pt’s MIP
True
What are 2 common reasons to mount a case in CR?
No MIP - endendulous, full arch prep
CR to MIP slide interference
Prep paramaters in CEREC are determined by what?
2 things
Material properties
Manufacturing process
CEREC prep minimum shoulder thickness:
min. axial wall:
min. thickness under fissure:
min. thickness under cusp (ant/post):
- 0 mm
- 5 mm
- 5 - 2.0 mm
- 5 (anterior) 2.0 (posterior)
3 aspects important to evaluate when acquiring an image:
distinct separation from adjacent teeth
all margins clearly visible
even amount of shadowing on adjacent teeth
What are 2 ways to fix CEREC crowns to teeth?
each has 2 names
Cementation (luting)
Bonding (resin)
What are the pros/cons to Luting a CEREC crown?
cementation
Cleans easily, no anesthesia, fast
Doesn’t increase restoration strength, dependent on surface area, can’t use w/ all matls
Pros/Cons of Bonding (resin):
Strong w/ enamel, strengthens matl, good esthetics, don’t need retention features in prep
Isolation needed, not predictable, needs anesthesia, difficult clean up, technique/time
When placing a crown clean the tooth with what?
Next 5 steps:
*last step allowed to react for how long?
Proxyt fluoride-free paste
try on
Etch (5% hydrofluoric acid)
rinse
dry
Monobond Plus *60 secs
For Luting (cementation) use what conditioner?
Rins with water then dry (what is important here?)
Coat inside restoration, seat - what’s the working time?
Remove excess cement w/ scaler when?
Finishing can be started how long after seating?
GC Fuji Plus conditioner
don’t dessicate
2 min 15 secs
rubbery
4 min 30 secs
What Resin Cement Bonding do we use?
Maxcem Elite
Maxcem Elite - should do what after seating?
light cure 2-3 secs to achieve gel state
After light curing Maxcem Elite for 2-3 secs to achieve gel state and after excess cement has been cleaned off, light cure all surfaces for how long?
For metal based/opaque restorations, let set for how long after seating
10 seconds
4 minutes
What duplicates the anterior guidance of a patient?
*thereby reproducing excursive movements
Custom Incisal Guide Table
When would a custom incisal guide table be indicated?
When pt’s existing anterior guidance is acceptable
If the pt’s existing anterior guidance is UNacceptable, what 5 steps should be taken?
Diagnostic wax up
Provisional restorations (adjust intraorally)
Impression
Cast
Mount on Articulator
When does a Custom Incisal Guide Table need to be used?
If one/more guiding teeth are prepared
*and want to preserve guidance
What matl is used for a Custom Incisal Guide Table?
Setting time?
DuraLay - chemically activated PMMA
5 minutes
A retention groove effectively does what?
Increases H/B ratio
T/F
A CEREC prep should have smooth flowing transitions and a sharp cavo surface
True
How will CEREC mill if there is a sharp jump in the margin?
Under mill - won’t seat
T/F
High noble metals are more Castable
True
Term for how tight a crown fits onto a preparation:
less rotational movement
Adaptation
What 2 types of crowns have a better adaptation than a Milled Crown?
Pressed
Casted
