Class I and Class V Restoration Fundamentals: Flashcards
In clinic the first step of placing an occlusal restoration is:
Step 1- place liner and/or base if needed (deep caries)
When is the placement of a base needed?
Deep caries
What materials serve as a liner and/or base in occlusal restorations?
- calcium hydroxide
- glass ionomer
Give an example of calcium hydroxide:
Dycal (calcium hydroxide liner)
Give an example of a glass ionomer
vitrebond (resin modified glass ionomer liner/base)
Calcium hydroxide (example dycal) is a 2 paste system, that dispenses from separates tubes and is mixed. It function to:
stimulate reparative dentin formation
Glass ionomer (example vitrebond) is a 2 paste system, dispenses from a clicker, and is mixed. It requires ___ and functions to ___.
light cure; release fluoride over time
Where and how should a line and/or base be placed?
- Place in deeper areas only, keeping away from margins
- Placed with dycal instrument (tiny ball shaped)
Calcium hydroxide liners brand names: (2)
Life; Dycal
Describe the placement of a calcium hydroxide liner (life or dycal)
- mix with spatula end of decal instrument
- use dycal instrument to place over area nearest to pulp
- Often cover with RMGI (resin modified glass ionomer)
VItrebond is the brand name for a:
Resin modified glass ionomer liner/base
Describe the placement of Vitrebond:
- mix with spatula end of dycal instrument
- use dycal instrument to place over area nearest pulp
- often used to cover calcium hydroxide
- light cure
____ is placed in a thin layer over dentin
___ is placed in a thicker layer on floor of prepared cavity
liner; base
What is the second step in placing an occlusal restoration (after liner/base placement)?
Step 2: seal dentinal tubules
Is sealing the dentinal tubules always necessary on an occlusal restoration?
Not generally necessary- preps especially prone to sensitivity may
Describe situations where preps may be prone to sensitivity:
Very young teeth- large pulp
What product would seal dentinal tubules?
Name them!
desensitizers
- copal resin (Copalite)
- bonding agents
- Gluteraldehyde & (2-hydroxyethyl)methylacryate (HEMA) desensitizer (example GLUMA)
Copal resin is a ___.
desensitizer
What is a specific copal resin? What are the advantages? What are the disadvantages?
- copalite
- advantages: inexpensive, quick to use
- disadvantage: leaves a film thickness (could wash out, causing micro leakage)
Unfilled dentin bond agent is a ___.
desensitizer
What is a specific unfilled dentin bond agent? What are the advantages? What are the disadvantages?
PQ-1, PEAK
- advantage: intermediate in cost
- disadvantage: some require more than one step, involves etching, leaves a film thickness
Research suggests that etching with an acid:
may leave teeth more vulnerable to recurrent caries
Gluma is a:
desensitizer
Advantages of Gluma:
Disadvantages of Gluma:
Advantages: no film thickness, one step to apply
Disadvantage: expensive, caustic to soft tissue & possible pulp
Application of desensitizer copal resin:
wipe cavity walls with cotton pellet soaked in resin then gently air dry
Application of desensitizer dental-bonded resins:
press resin into dentin using brush, gently air dry, light cure
Application of desensitizer Gluma:
Apply to walls for 30 seconds, dry, rinse, dry
Desensitizer that is considered caustic to the gingiva and possible pulp in deep preps:
Gluma
Since Gluma (desensitizer) is caustic to the gingiva and possible pulp in deep preps, you should minimize contact with _____ and the pulp should be protected using a ____ in deep preparations prior to applying
gingiva; liner/base
The current policy at UMKC regarding dentin desensitizers:
We DO NOT teach the standard use of dentin desensitizers under amalgam
Studies suggest that dentin desensitizers make a ___ difference in tooth sensitivity on routine cases
negligible
Studies suggest that dentin desensitizers make a negligible difference in tooth sensitivity on routine cases- the _____ will seal most dental tubules and after a few weeks, the ___ will seal itself with a ____.
smear layer; amalgam; oxide layer
Although not standard procedure, occasional after consult with faculty, one might use Gluma on an especially sensitive tooth, but:
place a liner or base first in deep preps
Steps in placing an amalgam restoration:
- place amalgam
- condense amalgam
- pre-carve burnish
- carve anatomy
- refine restoration
Used to mix amalgam:
triturator
Prior to picking up the amalgam with the ____, it should be placed into a ____
amalgam carrier; amalgam well
What end of the amalgam carrier should be used first?
small
Dispensing only a small amount of amalgam into the preparation allows for:
proper condensation
What should be used to condense amalgam?
hollenback condenser
When condensing the amalgam:
a: tamp into the preparation to fix amalgam in place
b: use the small condenser ___ to pack material _____, at a ____ angle , using a pressing, wiggling motion in a step-wise fashion
nib; firmly into all line angles; 45 degree
Describe how you should fill an amalgam preparation:
overfill preparation to around 1.0 mm beyond margins
After overfilling the amalgam restoration, the next step is the:
pre-carve burnish
What instruments should be used for the pre-carve burnish in an amalgam restoration?
condensor or large ball burnisher
When pre-carve burnishing an amalgam restoration, burnish towards the ____ to eliminate voids and to ____, where it can be carved away, then begin to define the grooves.
towards the margins; bring excess mercury to surface
What instruments should be used to carve the anatomy into the amalgam:
- hollenback carver
What step should the initial defining of grooves occur in (amalgam restoration)
pre-carve burnish step
When using the hollenback carver to carve the anatomy into the amalgam:
- It should be held ____ to the ____
- Use the tip of the carver to ____
- Carve _____ to the margins
- Remove all ____ beyond the margins
- perpendicular to the margins
- recreate groove anatomy
- exactly
- flash
When checking and refining occlusion in amalgam restorations, use the _____ to remove high occlusion marks and incline plane contacts
discoid carver
When checking and refining occlusion in amalgam restorations, try to ____ of fossae (_____ on the teeth)
preserve cusp seats in the bottoms of fossae- long axis forces on teeth)
What instrument should be used to smooth the surface of an amalgam restoration?
beavertail burnisher
Why should you avoid burnishing on amalgam that has began to set?
This could bring excess mercury to surface
What type of finish should the amalgam restoration initially have?
matte finish
Is finishing and polishing amalgam always necessary?
No
When is finishing and polishing amalgam necessary?
needed when something needs to be corrected (occlusion, overhang, anatomy, marginal plaque trap, contour improvement)
Research suggests that well condense, well carved amalgam does not gain longevity from:
the finishing process
If you need to finish/polish an amalgam restoration, you must wait ___ for the amalgam to be completely set up.
24 hrs
Finish bur sequence for amalgam:
- green stone
- white stone
- 12 bladed polishing bur
Finishing burs for amalgam include:
- green stone =
- white stone =
- 12 bladed polishing bur =
- coarse
- medium
- medium- fine
Polishing burs sequence for amalgam:
- brown (pre-polish)
- green (polish)
- green with yellow collar (superpolish)
List the finishing burs (12-bladed flutes)
- flame
- round
- bullet
- small round
- bullet pointed
The finishing burs (12-bladed flutes) are all:
needle point
What is the most important area for finishing an amalgam?
cavosurface margin
What does a composite restoration require that an amalgam restoration does not?
- etch
- bond
- high cure
- incremental placement
- finish/polish
When placing composite resin in an incremental fashion, the increments should be placed at:
2mm or less
While condensing composite, ____ may occur
pullback
Anatomy in an occlusal composite restoration should be placed:
prior to light curing
What instruments should be used to create anatomy in an occlusal composite restoration?
hollenback or optrasculpt
describe polishing points that are used to polish a composite restoration:
latch-type, preimpregnated with polished paste, moisture activated
List the advantages of using a composite restoration:
- prep can be more forgiving
- esthetics
- operator control of set-up tie
- preserve tooth structure
List the disadvantages of using a composite restoration:
- more technique sensitive
- additional steps
- longevity
- strength
- no moisture tolerance
In a Class V restoration, ____ restorations will be more traumatic to gingiva
over contoured
major classes of dental materials:
- metals and alloys
- composites
Metals and alloys include:
- porcelains
- ceramics
- polymers
Polymers include both:
elastomeric and plastics
An impression material is an example of:
elastomeric polymer
Denture bases and sealants are examples of:
plastic polymers
polymer with fillers=
composites
Who regulates dental materials
ADA and FDA
Protect the public from hazardous or ineffective medical materials and devices:
FDA
In 2009, the FDA reclassified amalgam from ___ to ___.
From class I to class II
FDA lowest risk class=
FDA highest risk class=
class 1
class 3
performance of all dental materials depends on their:
anatomic structure
anatomic structure determines:
mechanical and physical properties
Types of interatomic bonds:
primary and secondary
Ionic, covalent, and metallic bonds are all:
primary interatomic bonds
Hydrogen bonds and Van Der Waals forces are both:
secondary interatomic bonds
Electrostatic attraction of positive and negative charges describes:
ionic bonds
involves electron transfer between ions:
ionic bonds
List the properties of ionic bonds:
- non-directional
- strong
- no free electrons
- good thermal & electrical insulator
Ceramics and gypsums are examples of materials displaying:
ionic bonds
When two atoms share an electron:
covalent bond
List the properties of covalent bonds:
- directional
- low electrical and thermal conductivity
- water-insoluble
Water, glass, polymers, and composite are all examples of materials that display:
covalent bonds
Cluster of positive metal ions surrounded by a gas of electrons:
metallic bonds
List the properties of metallic bonds:
- non-directional
- high electrical and thermal conductivity
Amalgams and gold allows are examples of materials that display:
metallic bonds
Classifications of material properties:
- biological
- surface
- physical
- mechanical
The biological response to a material when in contact with the human body:
Biological
The unique properties of a material associated with its surface:
surface
Depends on the type of atoms and the bonding present in the material, size of shape have NO affect
Physical
Physical properties are depending on:
type of atoms
Reaction of a material to the application of an external force, size and shape of specimen AFFECT properties:
mechanical
A type of property that is structure sensitive:
mechanical
A type of property that is structure insensitive:
physical
Gingivitis is an example of what type of property?
biological
Optic (color, gloss), Thermal (conductive) are examples of what type of property?
physical
Denture retention and adhesive bonding are examples of what type of property?
surface
Applied force refers to:
load
When load (force) is applied to material, ____ develops in response
stress
= load per unit area
stress
strength of material =
stress at fracture
Type of strength measured is dependent on the type of:
force applied
List the following types of forces/stress:
- pushing
- pulling
- sliding
- twisting
- bending
- compressive
- tensile
- shear
- torsion
- flexure
Label this photo from top to bottom:
- compression
- tension
- shear
- torsion
- flexure
highest strength measure for most materials:
compressive strength
Measure of stress necessary to fracture a material by 2 opposing forces directed toward each other:
compressive strength
____ pushes atoms and structure closer:
compression
Compression usually requires _____ loads to cause failure
higher loads
pulling force:
tensile strength
What is usually the lowest strength for most materials?
tensile
measure of the stress necessary to fracture a material by 2 opposing forces directed away from each other
tensile strength
____ pulls the atoms and structure apart
tension
Failure of this type of strength occurs at lower loads:
tensile strength
sliding force:
shear strength
Typically, an intermediate strength between compressive and tensile:
shear strength
Stress necessary to rupture a material by 2 opposing parallel forces directed toward each other but not in the same plane
shear strength
Describe a clinical situation with shear force/ shear strength:
implant-bone interface
Twisting force:
torsion strength
What motion is used on a wrench to place dental implants:
torque
What type of strength is not relevant to direct or indirect dental restorations?
torsion
Bending force:
flexural strength
measure of stress to cause failure in bending:
flexural strength
What type of test is used to determine flexural strength?
3-point bend test
The three-point bend test takes into account:
- compressive load
- combination of compressive and tensile stress
_____ strength is relevant in numerous clinical situations
flexural stress/strength
Type of strength vital to occlusal load:
flexural strength
Flexural strength is vital to occlusal load on both:
- direct restorations
- indirect/removable
Protrusive movement is an example of dental stress on _____ teeth.
anterior teeth
flexure load on incisors=
protrusive movement
chewing = ____ load
compressive
Posterior occlusion is an example of:
compressive load
posterior occlusion occurs at:
marginal ridge contact areas & fossa
equation for occlusal stress:
occlusal stress= occlusal load / occlusal contact area
Allows for distribution of occlusal load across maximum area resulting in minimized stress:
tripodized occlusal contracts
Premature contact resulting in:
decreased area
With a premature contact, the patients occlusal force _____, but the occlusal stress is ____.
stays the same; increased
The DEFORMATION that occurs in a material when force is applied to the material:
strain
Equation for strain:
strain = change in strength (deformation) / unit original strength
____ and ___ are interrelated, if you have one, you will have the other:
stress and strain
An example of a stress strain curve would be:
someone on a diving board
temporary distortion of a material by applied force:
elastic strain
In elastic strain, strain is:
BELOW elastic limit
In elastic strain, once force is removed:
material revert to original form
Example of elastic strain:
rubber band
PERMANENT distortion of a material:
plastic strain
in plastic strain, strain is:
beyond elastic limit
In plastic strain: ____ portion of strain is recovered, while ____ portion of strain is NOT recovered
elastic; plastic
In plastic strain, once the force is removed:
shape remains changes
Example of plastic strain:
bending a paper clip
Amalgam is placed in a ____ state, and carved before it hardens
plastic
Amalgam alloy composition:
Elements that make it up and their percents:
- Ag- 70%
- Sn-16%
- Cu- 13%
Zn-1%
What principal function do the following elements of amalgam contribute to:
- silver:
- tin:
- copper:
- zinc:
- strength
- expansion
- strength
- deoxidizer
Amalgam is an allow of ______, and is mixed with ___ to form an alloy that can be packed into a dental restoration.
silver, copper, tin, and zinc; mercury
Amalgam in capsule = _____. It is mixed with ___ in ___.
powder; liquid mercury; triturator
Lower copper amalgam, similar to G.V. Black’s original formula:
conventional amalgam
Amalgam that contains 9-30% copper, superior form, what we use in U.S.
High copper amalgam
The presence of copper in high copper amalgam nearly ____, resulting in ___.
nearly eliminates the gamma-2 phase; stronger restoration
The presence of ____ in a high copper amalgam nearly eliminates the gamma-2 phase
copper (9-30%)
Phases of amalgam setting include:
- gamma
- gamma-1
- gamma-2
Describe the gamma phase of amalgam setting:
tin and silver react with mercury, forms silver-mercury (gamma-1) and tin-mercury (gamma-2)
The gamma phase of amalgam setting can be described as:
strong-corrosion resistant
Describe gamma-1 phase of amalgam setting:
silver- mercury, weaker and susceptible to corrosion
Describe the gamma-2 phase of amalgam setting:
tin-mercury, weakest, most susceptible to corrosion
Adding copper to amalgam setting creates:
Copper-tin phase (eta), eliminates tin-mercury gamma-2 pahse
The following equation describes:
gamma+ mercury –> gamma + gamma-1 + gamma-2
low copper amalgam
The following equation describes:
gamma+ copper + mercury –> gamma + gamma-1 + CuSn
high copper amalgam
List the shape of amalgam particles:
- lathe
- admixed
- spherical
- outdated- particles formed by cutting block of allow with a lathe
- results in large, irregular particles
Lathe
- lathe type particles mixed with small spheres
- requires more condensation force
- most commonly used type of amalgam
- low early strength (1 hr)
admixed
- spherical shape
- higher early strength, and higher 24hr strength
- may be more difficult to achieve inter proximal contact
- requires less condensation force
spherical
Which type of amalgam particles have have low early strength?
admixed
All the types of amalgam particles have:
similar clinical success, different handling properties
What are the variables to amalgam manipulation (4)?
- mercury-alloy ratio
- trituration
- condensation
- carving and finishing
When considering the mercury to allow ratio:
Less mercury to final restoration is:
superior
Most critical variable in amalgam restoration:
condensation
Most common error made by dentists in amalgam manipulation:
undercondensation
Why should we not remove amalgam due to mercury concerns?
- unwarranted loss of tooth structure
- unnecessary expense
- limited longevity when replaced
Amalgam has ____ compressive strength and ___ tensile strength
high compressive; low tensile
amalgam is ___ in small bulk
brittle
am requires ___ of material to avoid breaking
minimal thickness (1.5-2.0 mm)
Why can the isthmus be 1.0mm minimal thickness when the floor must be (1.5-2.0) thickness in an amalgam restoration?
Because chewing forces are not directed at isthmus width
Amalgam is sensitive to:
moisture contamination during placement
when ____ reacts with ____ in the amalgam, it causes an eventual expansion of the allow out of the prep
water with zinc
Can amalgam corrode?
yes
disadvantages of amalgam: (6)
- poor esthetics
- need for good mercury hygiene
- removal of more tooth structure (for adequate bulk)
- no bonding
- thermal conductor (leads to sensitivity)
- may ditch at margins after time
Advantages of amalgam: (6)
- more forgiving for moisture control
- high wear resistance & compressive strength
- less timely/lower cost
- long-lasting
- regenerates seal
- less prone to recurrent decay
Indications for amalgam: (8)
- moderate to large class 1 and 2 restorations
- heavy occlusal wear
- high caries rates
- difficult isolation
- gingival margins on root
- class V restorations on non-esthetic zones
- temporary restorations on teeth with questionable prognosis
- buildups on crowns for extensively damaged teeth
