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Download EFDA Chapter 4 Hottel Bases And Liners | Questions With 100% Correct Answers | Guaranteed and more Exams Dentistry in PDF only on Docsity!
What are the 9 reasons to use bases and liners? - Correct Answer 1. caries 2.tramatic occl. 3. effect of cutting bus 4. desiccation 5. condensation pressure 6. chemical irritation 7. temperature changes 8. dimensional changes 9. lack of marginal seal Basic function of a sealer? - Correct Answer 1. seal off dentin tubules/ prevent chemical irritation 2. reduces leakage around restoration 3. Do not offer thermal protection Cavity varnish - Correct Answer a thin layer placed on the floor and walls of the preparation to seal the tubules and minimize micro-leakage on amalgam fillings. What is a reinforcer? - Correct Answer used to protect the pulp from pressures during condensing Types of Reinforcers - Correct Answer any material used in a thick layer between floor of prep and restorative material. Insulators - Correct Answer protect pulp from thermal irritation types of insulators - Correct Answer 1.zinc oxide eugenol 2. zinc phosphate cement 3. zinc polyacrylic cements Zinc oxide eugenol - Correct Answer Temporary cement - sedates the pulp oil of cloves base and reinforcer eugenol interferes with the setting of resins Zinc phosphate cement - Correct Answer insulator and reinforcer main ingredient is phosphoric acid can irritate the pulp from exothermic reaction can go under amal fillings to reduce gray appearance Minimal depth restoration - Correct Answer 0.5mm to 1.5mm no stimulator or base needed second type of cavity preparation - Correct Answer --1mm into the dentin but more than 0.5mm away from the pulp --calcium hydroxide is needed, thickness no more than .5mm --excess hydroxide should be removed and not more than 1.0 mm from the cavosurface margin Near pulpal exposure - Correct Answer very deep cavity preps close to pulp -pulp may be seen through dentin -calcium hydroxide needed to stimulate secondary dentin formation -insulator/reinforcer needed to protect pulp from thermal, chemical and physical pressure Pulpal exposure - Correct Answer -may need endodontic tx -*all blood has to clot before calcium hydroxide placement* -glass ionomer or zinc eugenol can be used as temporary criteria for cavity varnish - Correct Answer 1.apply to dentin, walls and cavosurface margin 2.no pooling or thick ridges 3. place calcium hydroxide and bases before brushing on varnish criteria for calcium hydroxide placement - Correct Answer thickness between 0.25-0.5( any more and it may fail) located in deepest portion of prep doesnt touch cavosurface doesnt fill retention areas Glass lonomer - Correct Answer Bonds to dentin, enamel, cementum and stainless steel releases FL bonds chemically to dentin and enamel not mixed on a cool glass slab advantages of glass ionomer - Correct Answer releases FL bondibility to tooth structure some resistance to abrasion dissadvantage of glass ionomer - Correct Answer technique sensitive susceptible to water contamination - temp cement for inlay/only Extracoronal restoration - Correct Answer external surface of the tooth and may extend over the cusp tips intracoronal - Correct Answer within the crown of the tooth. ( no cups ) Absorption - Correct Answer taking up fluids ( water on sponge) Adsorption - Correct Answer liquid on the surface ( water on a vaseline sponge) wettability - Correct Answer At which the liquid beads Elastic Modulus - Correct Answer stiffness of a material Proprtional limit - Correct Answer the stress that the material no longer functions What can zinc oxide eugenol be used for? - Correct Answer temporary cement temporary restoration base under an amalgam What can zinc phosphate cement be used for? - Correct Answer to protect pulp esthetic reasons help with gray appearance from amalgams 
