Midterm Exam Review Flashcards
A(n) ______ reaction is the effect of an electrical shock that results when two metals come into contact.
Galvanic
A type of dental restorative material that is nonmetallic, is resistant to heat and corrosion, and resembles clay is _______.
ceramic
For a material to become hardended or set, it is said to be ___________.
cured
To bond or attach two items together is to _______________.
adhere
_______ is a soft, silvery white metaillic chemical element that resembles platinum.
Palladium
____ is a term used to bring a tooth or teeth back to their natural appearance.
Restorative
An object within the amalgam capsule used for pounding or pulverizing is a _____.
pestle
____ is a solid white, translucent ceramic material made by firing pure clay and then glazing it.
Porcelain
An artistically pleasing and attractive apperance is said to be _____.
esthetic
_____ is a soft, yellow, corrision-resistant metal used in the making of indirect restorations.
Gold
The property of a liquid that prevents it from flowing easily is the ______.
viscosity
____ is a mixture of alloys triturated with mecury to produce a restorative material.
Amalgam
______ refers to how a dental material hardens or sets by means of a chemical reaction.
auto-cure
A(n) _________ is a microscopic area where moisture and contaminants can enter.
microleakage
A(n) _______ is a combination of two or more metals.
Alloy
______ is the means of preparing a tooth surface for retaining or holding something in place.
retention
Something that is round is said to be ____________.
spherical
_____ is the distortion or change produced by stress.
Strain
An internal resistance to an externally applied force is referred to as ______.
stress
_____ is an inorganic material that adds strength and other characteristics to composite resins.
filler
What type of reaction does a dental material undergo when distortion occurs?
A dental material undergoes stress when distortion occurs.
What happens to a dental material when it is exposed to hot & cold?
A dental material undergoes contraction and expansion when it is exposed to hot & cold.
What is a source of galvanic action?
Saliva (salt conducting electrical currents) and two metals (acting as a battery) are source of galvanic action.
What are the four properties that must be considered in the application of a dental material?
Flow, adhesion, retention, and curing
How does an auto-cured material harden or set up?
An auto-cured material hardens, or sets up, through a chemical reaction of the materials being mixed together.
What metals make up the alloy powder in amalgam?
Contains silver, tin, coppper and zinc
Would dental amalgam be placed in anterior or posterior teeth?
Dental amalgam would be placed in posterior teeth. Composite resins are used in anterior teeth due to esthetics
What does copper provide to an amalgam restoration?
Copper provides strength and corrosion resistance to amalgam
Where do you dispose of amalgam scraps?
Amalgam scraps are placed in a wide-mouthed, air-tight container marked “noncontact amalgam waste for recycling.” When the container is full, it is sent to a recycler.
How is the amalgam triturated?
Amalgam is triturated in an amalgamator.
Which filler type of composite resin is recommended because of its versatility?
Hybrid resin is recommended for its versatility
When composite resins are light-cured, what factors might contribute to the need for a longer curing time for the material?
Depth of restoration and color might contribute to the need for a longer curing time.
What item is used to determine the color of composite for a procedure?
a shade guide is used to determine the color of composite
What is the final step in finishing a composite resin?
The final step is the use of a polishing paste
What are some of the most common uses of glass ionomer materials?
Commonly used as restorative materials, liners, bonding agents, and permanent cements.
What does the abbreviation IRM stand for?
IRM stands for intermediate restorative material
How could IRM be utilized in a pediatric practice?
IRM can be utilized in a pediatric practice to restore primary teeth that are about to be replaced by permanent teeth.
What material would you use to prepare for provisional coverage?
Acrylic resin or composite resin would be used to prepare for provisional coverage.
How many drops of monomer per tooth are recommended when acrylic resin is mixed for a provisional restoration?
the recommended amount is 10 drops of monomer per tooth
What are the three noble metals used in dentistry?
Gold, palladium, platinum
What type of restoration is made in the dental laboratory?
Indirect restorations are made in the dental laboratory
What type of reaction does a dental material undergo when a person is chewing?
Compressive stress
What happens to a dental material when it is exposed to extreme temperatures of hot and then cold?
Contraction & expansion
Which is an example of how galvanic action can occur?
Salt within saliva
touching of two metals
How does an auto-cured material harden or set?
by chemical reaction
the correct makeup of the allow powder in amalgam.
silver, tin, copper & zinc
Why would dental amalgam not be placed in anterior teeth?
Esthetics
Most amalgams have high copper content. What does copper provide to amalgam restorations?
Strength & Corrosion resistance
Where are amalgam scraps disposed of?
In an airtight container
What is used to triturate capsulated dental materials?
Amalgamator
The term commonly used to refer to dimethacrylate is _____.
BIS-GMA
Which filler type of composite resin has the strongest makeup and is used most commonly for posterior restoratations?
Macrofilled
In light-curing of composite resins, which factor can affect curing time of the material?
Depth or extent of restoration
What is used to determine the color of composite resin material for a procedure?
Shade guide
The final step in finishing a composite resin is ___________.
use of a rubber cup and polishing paste
The acronym IRM stands for…
intermediate restorative material
What temporary restorative material would be selected for a class II cavity preparation?
IRM
Which material would be selected for the fabrication of provisional coverage?
Acrylic resin
The three noble metals used in making indirect restorations are _______.
Gold, palladium and platinum
what type of restoration is always made in a dental laboratory setting ?
indirect restoration
What should a Dental Assistant explain to the patient before the procedure begins?
- The procedure’s location in the mouth
- The type of restorative material being used
- Approximately how long the procedure will be
- What to expect through the procedure
- Post Op Instructions
What are Post Operative Instructions for Amalgam?
Explain how long the anesthetic will last, depending on whether it was infiltration or mental block
The patient should be careful not to bit or chew on the soft tissue in that area
Soft foods for at least 24 hours while the amalgam is setting (3-7 days for full strength)
There may be some sensitivity to hold and cold for a couple days but it should gradually subside
Optional - show the patient where the filling was done in mirror
What materials are required for Amalgam restoration procedures?
disposable brushes or applications
matrix system - tofflemeire, band and wedges
amalgam well
amalgam carrier
amalgam condensers
amalgam carvers - discoid/cleoid, hollenback carver
When do you need Varnish?
When its a NON bonded amalgam restoration
What is the difference between Bonded & Non Bonded Amalgam?
Non-bonded - varnish (copalite) is used to seal the dentinal tubules BEFORE the amalgam is placed (amalgam is held through MECHANICAL retention)
Bonded - a bonding system is used to chemically bond the amalgam into the restoration (amalgam is held in through CHEMICAL rentention)
What does the Bonding System at SAIT include?
Primer (two liquid w/ activator)
Adhesive (two liquids with a catalyst)
What is the concentration of phosphoric acid in Acid Etch?
30-40% phosphoric acid
What is the purpose of Acid Etch?
Opens up the tubules
So Primer flows into the tubues
Bonding resin attaches to the primer - chemical reaction
-Amalgam and bonding resin create a hybrid layer
Order for Amalgam Restorations?
Acid Etch
Primer
Adhesive
What are some precautions for Acid Etch?
-avoid direct contact with patient’s soft tissues
* When removing etch from the tooth always use HVE and water stream to avoid dispersing onto adjacent teeth or tissues
* If contact with tissues occurs thoroughly rinse area with lots of running water
* Eye protection is essential for patient and dental personnel – if eye exposure occurs immediately flush with water and seek medical attention
Which of the following metals are not found in dental amalgam alloy?
Magnesium
Contains
Silver
Tin
Copper
Zinc
The material used as a wetting agent, attracted to the fluid within the dental tubues is __________.
Primer
Acid etch is made up of
30-40% phosphoric acid
The best technique for application of primer to the cavity preparation is:
multiple thin layers
Amalgam bonding products can:
Decrease the effects of amalgam expansion
The instrument used to transfer triturated amalgam to the prepped tooth is:
amalgam carrier
The instrument used to carve fine detail on the occlusal surface of amalgam is:
discoid cleoid
Amalgam must be condensed into the prep prior to the chemical hardening of the bond. True or False?
False
Acid etching gel is effective when:
It is allowed to remain on the prepped tooth for 15 seconds
Is acid etch done before or after the matrix band?
After
When using adper scotch bond the following protocol is correct:
Mix activator/primer, dry. Mix adhesive/catalyst
One disadvantage of amalgam is that it:
Has a tendency to tarnish and corrode over time
What are the 3 instrument grasps used in four handed dentistry?
Pen, Palm and Palm Thumb
What is NOT one of the 11 criteria used when assessing a good restorative material ?
High thermal and electrical conductivity
What are the four processes that the dental team can take to make dentistry less difficult?
Rearrangement, elimination, combination, and simplification
Who is at the greatest risk from dental amalgam in the dental office?
Dental Assistant
What is the correct order when passing instruments for a bonded amalgam procedure
ball burnisher, articulating paper, discocleiod, hollenback
After an amalgam procedure, what gets wiped down with with disinfectant wipes?
everything in the operatory
How is amalgam properly disposed of?
in a sealed air tight container
Which of the following is added to dental amalgam alloy powder to increase strength?
Silver
What is NOT one of the prinicples of 4 handed dentistry?
Suction efficiently
DOES INCLUDE:
operate in a seated postion
organize everything in the practice/your operatory
simplify all tasks as much as possible
When is a ball burnisher used in an amalgam restoration?
After the amalgam has been condensed
How long does it take for an amalgam restoration to achieve its initial strength?
24 hours
(total strength is 3-7 days)
When checking a patients occlusion initially you instruct them to:
Bite lightly (to avoid any trauma if filling is too high)
Next can bite and slide side to side
What is the purpose of the Hollenback carver?
interproximal carving (it is not needed if no interproximal surface)
What is not a type of stress or strain that can be placed upon a restoration?
Expansive
Does have…
Shear
Compression
When is Primer applied in an amalgam restoration?
Primer is applied after the tooth has been etched
How is Primer retained in an amalgam restoration?
retained with mechanical retention
flows into defects and tags created by the etchant
How is Primer cured in an amalgam restoration?
Can be light cured, self cured, or dual cured
What will happen if you dont immediately recap Primer containers?
It will evaporate
When is adhesive applied in an amalgam restoration?
Adhesive is applied on the primer layer
Is adhesive used for a bonded or non bonded amalgam restoration?
BONDED
Non bonded uses varnish only
How will Adhesive bond in an amagam restoration?
Resin will chemically bond to the bonding agent
How is adhesive bond cured?
Bond is light-cured
What is placed after the adhesive in the amalgam restoration?
Amalgam is placed directly over top
Why do you think an activator and catalyst are added to our primer and adhesive?
During an amalgam procedure, a curing light is not typically used. Therefore, an activator and catalyst must be added into the primer and adhesive to create the chemical reaction requried to make the materials set.
Do you over fill or under fill an amalgam restoration?
The restoration is always overfilled then the excess is removed with carving instruments
Is amalgam condensing done in large or small increments?
small increments
The longer the time between the trituration and condensation, the weaker the amalgam restoration will be. True or False?
TRUE - 5 mins of time can decrease the strength by up to 40%
What are Burnishers used for in Amalgam Restorations?
Burnishers have no sharp edges and are ideal for smoothing dental amalgam
How is the type of burnisher chosen for an amalgam restoration?
Design of burnisher is based on
size, location of restoration, DDS preference
When is the surface of amalgam burnished?
Typically the surface of the amalgam is burnished prior to removal of the matrix system
What is the purpose of carvers for an amalgam restoration?
After condensing, amalgam carvers are passed to the DDS to create anatomy in the restoration
It is important that the patient’s bite is even in order to:
- avoid fracturing the restoration
-avoid injuring/traumatizing opposing teeth
-ensure optimum chewing
-avoid potential TMJ injury/trauma
How is Occlusion checked?
- Dry the patient’s teeth with gauze 2X2
- Ask the patient to bite in centric occlusion (natural bite) on the carbon paper
- Adjustments are made
- Patient is asked to slide their jaw side to side (lateral) and front to back
- Adjustments are made
- To adjust use a slow speed and round bur
- Repeat steps if necessary
What is a benefit of polishing an amalgam restoration?
Final polishing can reduce surface roughness and make the amalgam more resistant to corrosion
When can polishing of amalgam be performed?
It cannot be performed until atleast 24 hours after initial placement
What to avoid when polishing amalgams?
Avoid generating excess heat, as heat can release mercury vapors from the restoration
What type of bur is used for amalgam polishing?
Slow speed greenie/brownie points are typically used
What is required for a non-bonded amalgam restoration?
Hand cutting instruments are required (uses mechanical retention)
Copalite varnish is used
What is required for a bonded amalgam restoration?
Etch and Bonding agent Used (Primer & adhesive)
Hand cutting instruments are NOT required (uses chemical retention)
Varnish is NOT used
Biting forces are approx _______ pounds of pressure on a single material.
130-170 pounds - dental material must have the same strength
What is Tensile stress and strain?
Pulls and stretches a material. (ex wires used in ortho)
What is Comprehensive stress and strain?
2 forces directed toward each other (ex. chewing)
What is sheer stress and strain?
2 forces of material parallel to each other sliding in opposite directions (bruxism or grinding of the teeth)
What is the normal PH of the mouth?
7.0
What are the ideal ductility & malleability characteristics of a restorative material?
allows material to be shaped and stretched without fracturing
What is the ideal thermal conductivity of a of a restorative material?
must have low thermal conductivity (ability of the material to transmit heat) - materials are placed in layers over the pulp to protect it from thermal changes
What is the ideal thermal expansion characteristcs of a restorative material
the tooth structure and dental materials must have similar contraction and expansion rates to protect the pulp from thermal changes
What happens if the restorative material has a different thermal expansion from the tooth?
The dental material can pull away from the tooth creating microleakages
What is a Galvanic reaction?
When 2 different metals contact eachother
What is the ideal hardness of a restorative material
permanent restoration must be hard enough to resist indentation, scratching or abrasion
Characteristics that can affect adhesion are:
wetting
viscosity
surface characteristcs
film thickness
For adhesion to occur and be permanent the cement must have a think film thickness of _______ microns or less to join the tooth and restoraiton.
25 microns
the thinner the film thickness the stronger the adhesive junction
What is a type 1 restorative material?
cements or luting agents (perm or temp).
used as an adhesive for indirect restorations, adhesive for provisional restorations or ortho appliances
What is a type 2 restorative material?
materials include amalgam, composite or glass ionomer. Maybe permanent restorations or IRM and dental sealant
What is a type III restorative material?
lines, bases and bonding agents that are placed into the cavity preparation
What are some advantages of a glass ionomer restoration?
-biocompatible with the oral environment
-can be used for many different purposes
-adheres to the tooth chemically
-limited tooth prep required
-releases fluoride after final setting
What Class of Caries is Glass Ionomer used for?
Class V and root surfaces - releases fluoride to prvent recurrent decay
What is metal reinforced glass ionomer?
blend of spherical silver-tin alloy with glass ionomer, which produces a strong, abrasion-restistant material
What is the mixing time of glass ionomer?
20-25 seconds
What is percolation?
Percolation is when dental material contracts/expands due to temperature changes. It causes the material to pull away from the tooth which - bacteria and oral fluids can pass through this microscopic space (microleakage)
What is the most predominant metal in amalgam?
Silver
What % of amalgam is mercury?
43-54%
What % of amalgam is alloy?
46-57%
What does silver provide to amalgam filling?
Strength
What does Tin provide to amalgam filling?
Workability and strength
What does copper provide to amalgam filling?
Strength and corrosion resistance
What does Zinc provide to amalgam filling?
Suppress oxidation
What is the Eames Technique?
Amalgam alloy powder is mixed with mercury in a 1:1 ratio (1 portion mercury to 1 portion alloy)
3 Types of High Copper Alloys?
Spherical (round particles)
Irregular (rough, lathe-cut particles)
Admixed (both)
Can Amalgam withstand occlusal forces?
Strength of amalgam is not adequate to withstand occlusal forces alone; so the preparation is designed so that surrounding tooth structure sustains the forces to the amalgam
What does the container for scrap amalgam contain?
Xray fixer, glycerin, or mineral oil
Amalgam Capsules are supplied in 3 sizes:
1 spill - for class I conservative restorations
2 spill - Class II conservative restorations
3 Spill - multi surface restoration
What is trituration time for 1 spill amalgam capsule?
7 seconds
What is the trituration time for a 2 spill amalgam capsule?
9 seconds
What is the purpose of varnish in a non-bonded amalgam restoration?
Varnish is used to seal the dentinal tubules BEFORE the amalgam is placed
What does Acid Etch do?
opens up the tubules for bonded amalgam restorations
What does Primer do (for amalgam)?
flows into the dentinal tubules
What does adhesive do (for amalgam)?
Attaches to the primer - by chemical reaction
After 5 minutes, What % has the strength of amalgam decreased?
40%
When is amalgam burnished?
Typically the surface of amalgam is burnised prior to the removal of the matrix system
