Question that where stated in class to be test on final
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| Lecture 1 Metals |
🗑
|
||||
| Are all electropositives metals | Yes, they are cations and usually loose electrons and become ionized
🗑
|
||||
| What are the different names of the melting point | Fusion temperature, solidification temperature, freezing temperature
🗑
|
||||
| In regards to re-crystallization, what crystal made up of | clusters formed grains and grains form crystals
🗑
|
||||
| Do smaller or larger grains give better strength and ductility | smaller grains
🗑
|
||||
| What metal is used to make dental implants | Pure titanium
🗑
|
||||
| Do pure metals have a melting point or melting range | Melting point
🗑
|
||||
| Do solid solution alloys have a melting point or range | Melting range
🗑
|
||||
| Melting range have an upper and lower limit what are they | Upper limit is liquidus (higher temp) and lower limit is solidus (lower temp)
🗑
|
||||
| How does melting temp affect the coeff of therm expansion CTE | The higher melting temp the lower CTE
🗑
|
||||
| What are wrought metals | Are cast metals that have deformed plastically by work hardening or strain hardening
🗑
|
||||
| Are solid solution alloys represented by a mechanical or chemical formula | Chemical
🗑
|
||||
| What the two main characteristics of intermetallic compounds | Hard and brittle
🗑
|
||||
| What are examples of intermetallic compounds that are useful as cutting tools | Ag3Sn (gamma) in amalgams, Fe3C (iron carbide) in steel, WC (tungsten carbide) burs
🗑
|
||||
| Do alloys or pure metals form stronger end products | Alloys, since they have greater interatomic bonds between each element, within the alloy
🗑
|
||||
| What are two factors that affect annealing | Time and temperature
🗑
|
||||
| Lecture 2 Dental Amalgam |
🗑
|
||||
| What are the advantages of amalgam | Low cost, easy to work with, function and long term performance
🗑
|
||||
| In amalgam what happens when you increase copper | You decrease silver
🗑
|
||||
| Do all amalgams harden the same way | No
🗑
|
||||
| How can you increase copper content in high copper amalgam alloys >12% | Ex use admix alloy, which is a mixture of 2-3 different alloys of different composition (low copper and high copper) and shape(lathe and spherical)
🗑
|
||||
| Does spherical alloys require more or less Hg than lathecutr or admixed why | Less because spherical has less surface area
🗑
|
||||
| The amount of mercury changes how strong/weak the amalgam can be, The more the weaker, so how do you avoid a weak amalgam | Variation in Hg content by differences in shape, size, composition and heat treatment of various products
🗑
|
||||
| Do higher amount of copper in an alloy require more or less mercury | More copper the more mercury needed, and more mercury is released
🗑
|
||||
| What is the setting rxn for high copper amalgams | Initial 1 Ag + Hg -> AgHG (gamma1); 2 Sn + Hg -> SnHg (gamma2); 3 Cu + Hg -> CuHg (gamma3) Later 4 SnHg+ CuHg -> CuSn (n prime – eta prime) + Hg
What is the reaction product of amalgamation called
🗑
|
||||
| How do you keep the matrix low | Reduce mercury
🗑
|
||||
| How the amount of matrix affect strength | The less matrix the stronger the amalgam
🗑
|
||||
| What are two properties that are very important in amalgams | Strength and corrosion
🗑
|
||||
| What combination of elements is the strongest/ hardest | AgSn
🗑
|
||||
| What combination is the most corrosion resistant | AgSn
🗑
|
||||
| What combination is the most prone to tarnish | AgCu
🗑
|
||||
| Which one sets faster and exhibit higher early strength 1spherical 2 admixed 3conventional | Spherical
🗑
|
||||
| What is the range for setting expansion at 24 hours and contractions for dental amalgams | +20 and -15 u/cm (+0,2 and – 0,15%)
🗑
|
||||
| Does spherical contract or expan when setting | Contract
🗑
|
||||
| Does admix contract or expand | Expand
🗑
|
||||
| Is there a relationship between creep and marginal fracture; is creep a predictor of marginal fracture | No
🗑
|
||||
| What products of dental amalgam cause corrosion | Oxides, hydroxides, and oxychlorides of Sn, Zn, and Cu
🗑
|
||||
| When condensing, what requires less pressure spherical or lathe cut | Spherical, because of shape have less resistance to condensing
🗑
|
||||
| How does zinc affect surface life of restorations | It improves the longevity of amalgam, They increase surface life of amalgams by protecting the margins, and improve the corrosion resistance
🗑
|
||||
| What is wrong with using indium in amalgams | It causes it to become more prone to tarnish
🗑
|
||||
| Lecture 3 Casting Alloys |
🗑
|
||||
| Is Hg in dental amalgam harmful to px | NO
🗑
|
||||
| Is Hg in dental amalgam a concern to the environment | Yes
🗑
|
||||
| What is stainless steel composed of | Carbon,iron, chromium, iron
🗑
|
||||
| What can you add to steel to make it resistant to rusting | Add chrome
🗑
|
||||
| What is the fineness of 18k 75% carat gold | 750fine he said to just know that you can multiply percent by 10(but if no percent given use full formula,divide carat by 24 multiply by 1000)18/24=0,75 so 0,75x1000= 750fine equation:divide whatever carats of gold given by 24,then multiply by 1000.
🗑
|
||||
| What is the fineness of 24k 100% carat gold | 1000 fine (he said to just know that you can multiply percent by 10)(but if he doesent give percent here is the full formula24/24=1 so 1 x 1000= 1000 fine
🗑
|
||||
| What is the carat gold of 583 fine gold | (he said to just know that you can multiply percent by 10)(but if he doesent give percent here is the full formulaReverse equation, and you get 583/1000= 0,583 so 0,583 x 24 = 14k carat gold (equation is fineness divided by 1000, then multiple by 24)
🗑
|
||||
| What is the maximum amount of corroded ions that can be released in the body | 100ugm/cm^2 will cause toxicity and allergy
🗑
|
||||
| What types of alloys are in gold based alloy secondary, primary, or tertiary | Tertiary, exAuAgCu w/ small amounts of other metals
🗑
|
||||
| What purpose does copper serve in gold based alloys | It is the main hardening element, however all elements contribute to solid solution hardening
🗑
|
||||
| What does Pt and Pd does in gold based alloys | Raise melting temp, and reduce tarnish and corrosion
🗑
|
||||
| What happens to strength if you lower the Au gold conent | The stronger it becomes, and lower the corrosion resistance
🗑
|
||||
| What is the most common type of gold based alloy | Type III
🗑
|
||||
| Lecture 4 Porcelain fused to metal |
🗑
|
||||
| Why is there an intentional slight mismatch of CTE between alloy and porcelain | To keep porcelain in compression
🗑
|
||||
| What is the most important part of bonding in PFM crowns | Chemical bonding (base metal oxidize to provide chemical bond)
🗑
|
||||
| Can you create mechanical bonding by grinding the metal surface and make it rough | No
🗑
|
||||
| Lecture 5 RPD |
🗑
|
||||
| What is the best method for polishing RPD | Electropolishing
🗑
|
||||
| True or False-Adjusting the retentive cast clasps of RPDs to the level of px comfort should be left to the discretion of the patient without any warning of consequences is ok | False
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
shamd1
Popular Dentistry sets