Class I & 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 for an occlusal restoration?
- Calcium hydroxide
- Glass ionomer
Give an example of calcium hydroxide:
Dycal (liner)
Give an example of a glass ionomer:
Vitrebond (Resin-modified glass ionomer - liner/base)
Calcium hydroxide (example Dycal) is a two paste system that dispenses from separate tubes and is mixed, it functions to:
Stimulate reparative dentin formation
Glass ionomer (example Vitrebond) is a two paste system, dispenses from clicker, and is mixed. It requires ____ and functions to ____
Light cure; release fluoride over time
Where & how should a liner and/or base be placed?
Place in deeper areas only, keeping away from margins; placed with Dycal instrument (tiny ball-shaped)
What are two brand names of calcium hydroxide liners:
Life or Dycal
Describe the placement of a calcium hydroxide line (Life or Dycal):
- Mix with spatula, end of dycal instrument
- Use dycal instrument to place over area nearest pulp
- Often cover with RMGI (Resin modified glass ionomer)
Vitrebond is the brand name for a:
Resin-modified glass ionomer liner/base
Describe 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 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, following liner/base placement:
Step 2) seal dentinal tubules
Is sealing the dentinal tubules always necessary on an occlusal restoration? Explain:
Not generally necessary- most do not require it unless it is a prep that is especially prone to sensitivity
Describe situations in which preps may be prone to sensitivity:
Very young teeth, large pulp
What product would seal dentinal tubules?
Name them
Desensitizers
1. Copal resin (Copalite)
2. Bonding agents
3. Gluteraldehyde & (2-hydroxyethyl)methylacrylate (HEMA) desensitizer (Gluma)
Copal resin is a:
Densensitizer
What is a specific copal resin?
What are the advantages:
What are the disadvantages:
Copalite
Advantages: inexpensive, quick to use
Disadvantages: Leaves a film thickness (could wash out, causing microleakage)
Unfilled dentin bond agent is a:
Desensitizer
What is a specific unfilled dentin bond agent?
PQ-1, Peak
Advantages: Intermediate in cost
Disadvantages: some require more than one step, invovles etching, leaves a film thickness
Research suggests that ethcing with an acid:
May leave teeth more vulnerable to recurrent caries
Gluma is a:
Densensitizer
Advantages of Gluma:
Disadvantages of Gluma:
Advantages: No film thickness, one step to apply
Disadvantages: Expensive, caustic to soft tissues & possibly pulp in deep preps
Application of desensitizer copal resin:
Wipe cavity 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 gingiva & possibly pulp in deep preps:
Gluma
Because gluma (desensitizer) is caustic to gingiva & possibly pulp in deep preps, you should minimize contact with _____ & the pulp protected using a _____ in deep preparations, prior to applying
Gingivae; 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
Negligable
Studies suggest that dentin desensitizers make a negligiable difference in tooth sensitivity on routine cases. The _____ will seal most dentinal tubules & after a few weeks, the _____ will seal itself with a _____
Smear layer; amalgam; oxide layer
Although not a standard procedure, occasionally after a consult with faculty, one might use gluma on an especially sensitive tooth, but:
Place a liner or base first in deep preparations
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 end
Dispensing only a small amount of amalgam into the preparation allows for:
proper condensation
What should be used to condense the amalgam:
Hollenback condensor
When condensing 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 degrees
Describe how you should fill an amalgam preparation:
Overfill preparation to around 1.0mm beyond margins
After overfilling the amalgam restoration, the next step is the:
Pre-carbe burnish
What instruments should be used for the pre-carve burnish of an amalgam restoration:
Condenser or large ball burnisher
When pre-carve burnishing an amalgam restoration you should burnish towards the _____ to eliminate voids and to ____ where it can be carved away before beginning to define the grooves
margins; bring excess mercury to the surface
What instruments should be used to carve the anatomy into the amalgam?
Hollenback carver
What step should the initial defining of groove occur in (amalgam restoration)
The 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; margins
- Recreate groove anatomy
- Exactly to the margins
- Flash
When checking an refining occlusion in amalgam restoration, use the _______ to remove high occlusal marks and inclined 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 the teeth)
What instrument should be used to smooth the surface of an amalgam restoration?
Beavertail burnisher
Why should you avoid burnishing on amalgam that is beginning to set>
This could bring excess mercury to surface
What type of finish should the amalgam restoration initially have?
Matte finish
Is finishing & 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 condensed, well carved amalgam does not gain longevity from:
The finishing process
If you need to finish/polish an amalgam restoration, you must:
Wait 24 hours
Finishing 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 bur 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
What does a composite restoration require that an amalgam restoration does not?
- Etch
- Bond
- Light cure
- Incremental placement
- Finish/polish
When placing composite resin in an incremental fashion, the increments should placed at:
2mm or less
While condensing composite _____ may occur
Pull-back
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 to polish a composite:
Latch-type, pre-impregnated with polishing paste, use water to activate
List the advantages of composite restorations:
- Prep can be more forgiving
- Esthetics
- Operator control of set-up time
- 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
Overcontured
Major classes of dental materials:
- Metals & alloys
- Composites
Metals & alloys include:
- Porcelains
- Ceramics
- Polymers
Polymers include both:
Elastomeric & plastics
An impression material is an example of:
An elastomeric polymer
Denture bases & sealants are examples of:
Plastic polymers
Polymers with fillers:
Composites
Who regulates dental materials:
ADA & FDA
Protect the public from hazardous or ineffective medical materials and devices:
FDA
In 2009 the FDA reclassified amalgam from ____ to ____
Class I to Class II
FDA lowest risk class:
FDA highest risk class:
Class I
Class II
Performance of all dental materials depends on their:
Anatomic structure
Anatomic structure determines:
Mechanical & physical properties
Types of interatomic bonds:
- Primary
- Secondary
Ionic, covalent, & metallic bonds are all:
Primary interatomic bonds
Hydrogen bonds & Van der Waals forces are both:
Secondary interatomic bonds
Electrostatic attraction of positive & negative charges describes:
Ionic bonds
Involves electron transfer between ions:
Ionic bonds
List the properties of an ionic bond:
- Non-directional
- Strong
- No free electrons
- Good thermal & electrical insulator
Ceramics & Gypsums are examples of materials displaying _____ bonds
Ionic
When two atoms share an electron they form a:
Covalent bond
List the properties of covalent bonds:
- Directional
- Low electrical & thermal conductivity
- Water insoluble
Water, glass, polymers & composite are all example of materials that display:
Covalent bonds
Cluster of positive metal ions surrounded by a gas of electrons describes:
Metallic bonds
List the properties of metallic bonds:
- Non-directional
- High electrical & thermal conductivity
Amalgam & gold alloys are examples of materials that display:
Metallic bonds
List the classifications of material properties: (4)
- 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 or shape have NO AFFECT:
Physical
Physical properties are dependent 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 force/stress:
- Pushing
- Pulling
- Sliding
- Twisting
- Bending
- Compressive
- Tensile
- Shear
- Torsion
- Flexure
List the types of forces/stress depicted in the image from top to bottom:
- Compression
- Tension
- Shear
- Torsion
- Flexure
Highest strength measure for most materials:
Compressive strength
Measure of stress necessary to fracture material by two opposing forces directed toward eachother:
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 two opposing forces directed away from eachother:
Tensile strength
_____ pulls the atoms & 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 & tensile:
Shear strength
Stress necessary to rupture a material by two opposing parallel forces directed toward eachother but not in the same plane:
Shear strength
Describe a clinical situation with shear force/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 strength
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 3-point bend test takes into account:
- Compressive load
- Combination of compressive & 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
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 & fossae
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 contacts
Premature contact results in:
Decreased area
With a premature contact the patient’s occlusal force _____ but the occlusal stress is ____
stays the same; increased
The DEFORMATION that occurs in a material when forces is applied to the material:
Strain
Equation for strain:
Strain= (change in strength) / (unit original strength)
____ & ____ are interrelated, if you have one you have the other
Stress & strain
Example of stress & strain curve:
Someone on a diving board
Temporary distortion of a material by an applied force:
elastic strain
In elastic strain, strain is:
Below the elastic limit
In this type of strain, once force is removed:
Materials revert to original form
Example of elastic strain:
Rubber band
Permanent distortion of any material:
Plastic strain
In plastic strain, strain is:
Beyond the elastic limit
In plastic strain:
____ portion of strain is recovered while ____ portion of strain is NOT recovered
Elastic; plastic
In this type of strain, when force is removed, shape remains unchanged:
Plastic strain
Example of plastic strain:
Bending a paper clip
Amalgam is placed in a _____ state and carved before it hardens:
Plastic state
Amalgam alloy composition:
Elements that make it up and their percents:
- Ag- 70%
- Sn- 16%
- Cu- 13%
- Zn- 1%
What principle properties do the following elements of amalgam contribute:
- Silver
- Tin
- Copper
- Zinc
- Strength
- Expansion
- Strength
- Deoxidizer
Amalgam is an alloy of _____ , ____, ____& ____
& is mixed with _____ to form an alloy that can be packed into a dental preparation
Silver, copper, tin & zinc
Mercury
Amalgam in capsule= ______. It is mixed with _____ in _____
Powder; liquid mercury; triturator
Low copper amalgam similar to G.V. Black’s original formula:
Conventional amalgam
Amalgam that contains 9-30% copper, superior form & what we use in the 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 & 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 & 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), eliminated tin-mercury gamma-2 phase
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 alloy 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 hour)
Admixed
-Spherical shape
-higher early strength (1 hour) & higher 24-hour strength
-may be more difficult to achieve interproximal contact
-requires less condensation force
Spherical
Which type of amalgam particles has a low early strength?
Admixed
Between all the types of amalgam particles they have:
Similar clinical success but different handling properties
What are the variables to amalgam manipulation (4)
- Mercury to alloy ratio
- Trituration
- Condensation
- Carving & finishing
When considering the mercury to alloy ratio:
Less mercury in final restoration is:
Superior
Most critical variable in amalgam restoration:
Condensation
Most common error made by dentist in amalgam manipulation:
Under condensation
Why not remove amalgam due to mercury concerns?
- Unwarranted loss of tooth structure
- Unneccesary expense
- Limited longevity when replaced (new restoration)
Amalgam has ____ compressive strength & _____ tensile strength
Compressive; tensile
Amalgam is ____ in small bulk
Brittle
Amalgam requires _____ of material to avoid breaking:
Minimal thickness (1.5-2.0mm)
Why can the isthmus be 1.0 mm minimal thickness of amalgam when the floor must be 1.5-2.0mm?
Because chewing forces are not directed at isthmus width
Amalgam is sensitive to _____ during placement
Moisture contamination
When ____ reacts with _____ in amalgam it causes an eventual expansion of the alloy out of the preparation
water; zinc
Can amalgam corrode?
Yes
Disadvantages of amalgam include: (6)
- Poor esthetics
- Need for good mercury hygiene
- Remove more tooth structure
4 . No bonding - Thermal conductor (leads to sensitivity)
- May ditch at margins after time
Advantages of amalgam include (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 I & II restorations
- Heavy occlusal wear
- High caries rate
- Difficult isolation
- Gingival margins on root
- Class V restorations in non-esthetic zones
- Temporary restorations on teeth with questionable prognosis
- Buildups on crowns for extensively damaged teeth