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Stack #175461
Arturos Dental Materials
Question | Answer |
---|---|
What are Dental Cements used for? (6 things) | Luting(Cementing),Liner, Base, and Temporary. |
For Luting, what should be done? | Tooth should be roughened for better attachment.Follow the manufacturer instructions. |
Name some characteristics of Luting agents? | Biocompatible, Relatively insoluble, Attach by micro mechanical retention., |
How do Luting agents protect the pulp? | Against thermal sensitivity, chemical irritation, prevents galvanic shock, Used in deep preparations, |
What is the advantage of ZOE? | Maybe used for a temporary due to its sedative effect. |
What are the disadvantages of ZOE? | Not strong enough to seat crowns, Not used as a Base, and because it's oil based, it should never be used on composites! |
What is a cavity sealant? | It is a varnish with chloroform which evaporates. It serves as a barrier. You can't use composite resin on a cavity sealant (no retention). |
What is Calcium Hydroxide (CaOH) used for? | It is used as the liner of choice for pulp protection. (0.5- 1.0 mm) It contains silicilatic acid. |
What is the base of choice for restorations? | Either Zinc Phosphate or Glass Ionomer due to their strength. |
What is an indirect pulp cap? | It is so deep in preparation you can see a pink hue (pulp just under). |
What is a direct pulp cap? | Preparation is in the pulp (red). You should cover it with CaOH, then base, then filling material. This situation may later call for a root canal. |
What does CaOH stimulate? | Secondary Dentin formation. |
How is Zinc Phosphate mixed? | It is mixed on a glass slab. It also produces a lot of heat. |
What causes tooth sensitivity? | The movement of water in and out of dentinotubules. |
What dentrifices such as sensodyne (toothpastes that help with sensitivity)do? | They usually contain Potassium Nitrate which deionizes those sensitive areas. These are only temporary. |
What should you never use a varnish on? | Never use a varnish on composite resin because it is oil based! |
What is an amalgam? | A metal alloy with one element being mercury. |
What does a dental amalgam contain? | Silver, tin, copper, zinc, and mercury. |
With what do we mix amalgams? | A triturator or an amalgamator. |
Where can an amalgam restoration be used? | On virtually any tooth. Class I, II, III, V, (possibly IV). |
Which composition do we use, Low Copper or High Copper? | We use High copper because it contains less mercury. |
What are the three cuts for amalgams? | Lathe cut, spherical, and admix cut. |
What is lathe cut? | irregular, requires 4-6 Ibs. of pressure to condense. |
What is spherical cut? | It is a harder product that is easier to compress (2-3 Ibs. of pressure). Low copper composition. |
What is admix cut? | It is a combination of lathe cut and spherical cut. |
What keeps an amalgam restoration in the tooth? | Mechanical retention. It depends on the tooth for support. No adhesion or cohesion. |
What is a wedge used for? | To prevent overhangs and to avoid open contacts. |
Name Liner properties? | Varnishes (Copal)are mixed with acetone. CaOH is used for direct and indirect pulp-capping. They are used to seal dental tubules. (Glooma is an example) |
Where can a composite resin be used in the mouth? | Anywhere. Class I, II, III, IV, V, VI. |
What are the disadvantages of Composite resins? | They have inadequate marginal structural integrity, polymerize shrinkage (leakage), do not stand heavy occlusal wear, very difficult to place. |
What are the advantages of Composite resins? | Esthetics, more conservative preparation(not so much cutting of tooth), less leakage when done right. |
What are composite resins composed of? | Silica or Quartz or Glass, or combination of the three. |
What type of instruments are used with composite resins? | Gold or plastic intruments. |
What are the steps for placing a composite resin restoration? | 1.Clean tooth (Peridex)2.Acid etch(35-37%)Phosphoric acid 15-30 sec.3.Rinse etch.4.Dry tooth.5.Primer (monomer that allows penetration, removes water)It fills irregularities and seals tubules.6.Adhesive (liquid). light cure (cohesion)7.Composite-light cur |
What are the two main reasons for a composite failing? | Moisture contamination and Incomplete Light curing. |
What does the smear layer(pelicle) consist of? | saliva, burr, debris, proteins |
Why are glass ionomers good as restorations? | They have good strength, and they absorb and release fluoride. Good for class V. |
Why aren't glass ionomers recommended as restorations? | They are monochromatic so they are not esthetically used on anterior teeth. |
What is the physical breaking off of enamel due to occlusion called? | abfraction |
What is the chemical wearing away of enamel called? | erosion |
What are glass ionomers good for? | liners, bases, pulp cap, core buildups,luting agents, class V restorations, adhere to all tooth structures, and they take and release fluoride. |
What is effective in removing the smear layer? | Peridex, peroxide, pure pumice,and phosphoric acid. Never use prophy paste (it is oil based) |