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49 Cards in this Set
- Front
- Back
Why is there "dentin sensitivity " ?
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Toxic products and stains from restorations.
Bacteria from the oral cavity. |
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Define "Liners"
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aqueous or volatile organic suspensions or solutions
Their solvents evaporate quickly, leaving behind a film residue. |
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What's the thickness of liners ?
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thin films usually not exceeding a thickness of 0.5 mm.
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What are the classification of liners ?
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1. Solution liners or Varnishes
2. Suspension liners |
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What's the other name for solution liners ?
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Varnishes
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Talk about Solution liners or varnishes
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are solutions of natural gums (e.g. copal) or synthetic resins (e.g. nitrated cellulose) dissolved in organic solvents (such as chloroform, acetone or ether).
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Describe the mechinesm of action in which the varnishe help reduce pulp sensitivity
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When solvent evaporates it leaves behind a semi permeable membrane which can protect the dental pulp from toxic products of restorative materials as well as from microleakage of newly placed amalgam
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How do you apply the varnish ?
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Place a cotton pellet in the varnish, then swab the cleaned cavity. Air dry and reapply varnish. Air dry again to see a shiny hard surface which is ready to receive the gold or amalgam restoration
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Talk about the other type which is suspension liners
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These liners contain suspensions such as calcium hydroxide and or zinc oxide in a synthetic resin.
They are applied to provide a barrier against irritating compounds of most restorative materials. |
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Give an examples to suspension liners
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E.G. are Pulpdent, Dycal and Life
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Talk about Dycal
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DYCAL® Radiopaque Calcium Hydroxide Composition is a rigid, self-setting material useful in pulp-capping, and as a protective base/liner under dental filling materials.
Shown to protect the pulp and promote the formation of secondary dentin Easy to place, with ability to flow where needed while it stays in place when necessary It is alkaline and has antibacterial activity It neutralizes the acid from restorative materials |
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Talk about the disadvantages of dycal
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Low tensile strength
Exhibit plastic deformation Undergo hydrolytic breakdown and dissolve under acidic conditions. Bacteria may decompose it. Hence it may disappear under restorations when there is microleakage. |
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What are the systems avalbile for the dycal liner ?
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Single -paste system dycal
viable light cured dycal --> It utilizes the polymerization of dimethacrylate by means of light. |
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Define base and catalyst
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Base - main or supporting ingredient in material.
Catalyst - substance that initiates a chemical reaction |
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What does the base provide ?
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May be placed in thick layers on the pulpal floors of deep cavities to provide thermal, chemical and electrical insulation for the dental pulp.
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what does the bases serves ?
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It servers a protective, therapeutic or structural function.
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Explain why Zinc Phosphate is irrtiant to the pulp ?
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- A pH of 1.6 is found after 2 minutes of mixing
- pH below 4 within the first hour - pH 6 – 7 after 24 hours. |
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what are the uses and charctrastics of Zinc Phosphate ?
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Cementing agent for crowns and FPDs.
Temporary restorations. Insulating base. Produces heat when mixed. |
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What are the disadvantages of Zinc Phosphate ?
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It is soluble in oral fluids
It has no antibacterial properties It is very soluble in organic acids |
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Zinc Phosphate
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Phosophate
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Pheonlate
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Zinc Oxide Eugeonl Cement
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Talk about Zinc oxide eugoenl cement
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Zinc oxide powder + eugenol
It provides good marginal seal It has antibacterial effects It has anodyne (tranquilizer) effect |
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List the disadvantages for Zinc oxide eugeonal cement
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Low compressive strength
Too long setting time It stains the composite restoration |
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What's "Fortified cement " ?
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Fortified cement is marketed by adding silica, alumina or resin to the powder or by
adding Orthoethoxybenzoic acid (EBA) to the liquid. |
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Talk about "Reinforced Zinc oxide eugenoal cements "
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contains natural or synthetic resin to increase the compressive strength.
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Give an example of a reincorced zinc oxide eugeonal cements
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IRM
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Talk about IRM
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Temporary restoration up to 1 year
Base or a temporary cement |
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Can we use IRM under compiste ?
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NO
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talk about EBA cements
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EBA (ethoxybenzoic acid) cements: contains alumina and polymeric reinforcing agent
Stailine is a commercial example. |
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List the two forms for Glass inomer cements
والله اعلم هدول الـ RMGI |
Powder = finely ground calcium aluminosilicate glass
Liquid = polyacrylic-itaconic acid or other poly-carboxylate acid copolymers |
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Talk about the "early glass inomer cements "
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Poor esthetics --> due to rough surface
Prolonged setting reaction Poor wear resistance Handling difficulties |
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What are the modifctions done to glass inomer cements that made them what they are today ?
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Refined formulation --> addition of tartaric acid + more reactive acids
Improved packaging Silver added to make radiopaque Addition of resin |
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List the advantages of glass inomer cements ( the one we use nowadays )
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Inherent (chemical) adhesion to tooth structure
Fluoride release Coefficient of thermal expansion (CTE) similar to tooth structure Biocompatible It has high compressive strength It is able to leach fluoride It has good marginal seal. Why? |
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List the uses and charactrsitics of GIC
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Cementing crowns and FPDs.
Temporary filling. Base material. resist recurrent decay |
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List the Disadvantages of GIC
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Sensitive to moisture and desiccation
Low fracture toughness Low flexure strength Low wear resistance Relatively poor esthetics |
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List the idictions for GIC
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Direct restorative :
Class 5 Root caries Pediatric dentistry resin-modified version Tunnel preparations Atraumatic restorative treatment (ART) |
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List the " Basic glass inomner " types
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Conventional GI :
traditional acid-base reaction Resin-modified (RMGI) : acid-base reaction light and/or chemical cure |
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Why did they create RMGI ?
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1) Attempt to comine benifets of :
1)GIC --> a) f release b) adhesion 2) compiste resin --> a) strength b)astehtics 2) Attempt to reduce : 1) GIC --> a) hydration senestivity b)deleayed set c)poor early strength 2)compiste --> a) polymarazation shrinkage b)microleakage c)recurrent carries |
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Arrange the following materials from the weakest to the strongest : RMCI , GIC , COMPORES , COMPISTES
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GIC < RMGI < Compores < Compsites
compiste is the strongest |
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Arrange the following materials from the most polishible to the least polishible : RMCI , GIC , COMPORES , COMPISTES
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GIC < RMGI < Compores < Compsites
compsite is the most polishible |
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Arrange the following materials from the least fluoride release to the highest flouride release : RMCI , GIC , COMPORES , COMPISTES
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Compsite < composres < RMGI < GIC
GIC is the most F releasing cement |
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Define Pascal
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It is a measure of force per unit area, defined as one newton per square metre
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Describe what we are the approprite steps we do when we're having a cavtiy that's exteinding 0.5 mm in dentine
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Coat the cavity with two layers of resin varnish using brush
No insulating cement base is required. DON’T deepen a cavity by removing dentine in order to place an insulating base. |
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As the previous question , but what will happen if the cavity penetrated more ?
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Place modified zinc oxide eugenol or GIC over the pulpal floor or axial wall.
Apply varnish before zinc phosphate but after GIC |
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What are the advantages of doing these steps listed in the previous two quesitons ?
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Reduce the amount of required amalgam for cavity filling
Insulator Reduce microleakage Substitute dentin |
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Describe what we are the approprite steps we do when we're having a cavtiy that's very deep ( only 0.5 mm left before entring the pulp )
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line with calcium hydroxide cement
Place cement base GIC apply varnish Place filling |
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Talk about Vitrebond
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Is resin modified glass ionomer RMGI
3M ESPE Vitrebond is light-cure glass ionomer liner/base. It is recommend for use as a liner or base under composite, amalgam, metal and ceramic restorations. Vitrebond Liner/Base is not indicated for direct pulp capping. If a pulp exposure occurs, cover the exposure with a calcium hydroxide material. Place the Vitrebond liner/base over the calcium hydroxide and surrounding dentin to seal and protect the exposure. |
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talk about compiste resin resotrations
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If the cavity is deep, line it with calcium hydroxide or Vitrebond
Shallow cavities: no need for lining or use dentine bonding agent instead Recurrent caries: use light activated glass ionomer cement. |
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DONT FORGET THAT I DIDN'T WRITE slide 45
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go check it you lazy
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