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32 Cards in this Set
- Front
- Back
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dental materials
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the study and science of the development , properties, manipulation, care, evolution and evaluation of materials used in the treatment and prevention of dental disease
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why study dental materials
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understand properties & effects
safety- handling, disposal, patient safety maintenance- cleaning,polishing instrumentation delivery- behavior of material patient education |
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the concept of using materials for restoration, replacement, or beautification was introduces as long ago as
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600 BC
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Romans
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known to use gold to restore teeth
materials include gold shells, fixed bridges & partial and full dentures |
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mind 18th century
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casts were constructed from wax impressions
teeth replacements using hippopotamus ivory bases with human& animal teeth retention accomplished by hinging the top and bottom together with spring like device |
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France
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French dentist forced porcelain from prosthetic teeth
in 1800 silver shavings from coins were mixed with mercury to form a paste (in 1846 amalgam was banished due to mercury poisoning) |
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G.V. Black developed
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the 1st viable amalgam formula in 1895
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American Dental Association
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ADA seal of approval
professional products review, test products est in 1859 |
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Food & Drug Administration
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Medical Device Amendment
Dental Materials are considered devices by FDA |
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International Agencies
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International Dental Federation
International Standards Organization |
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Dr William Taggart
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demonstrated a casting method for inlays in 1907
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Dr. Fredrick McKay
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credited with noting flourosis in 1901
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England in 1874
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first mention of the use of flouride for prevention of caries
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strain
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distortion or deformation
produced by stress amount of change that the force has produced change in length/original length measured as % |
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Mechanical Retention
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uses undercuts in the preparation
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Chemical Retention
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uses adhesion or bonding
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viscosity
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ability of a material to flow
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effects of moisture
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most materials react adversely to moisture
breakdown of most dental materials is brought about by moisture, acid and stress materials needed to last a long time must withstand this hostile environment |
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exothermic reaction
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heat given off during a reaction
may cause sensitivity or pulpal damage |
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thermal insulators
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something that prevents heat from passing through
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biomechanics
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function of the material is dependent on the properties of that material and on what the material is expected to do
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moisture and acid levels
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saliva
normal PH 6.2-7.0 |
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retention
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mechanical or chemical through adhesion or a combo of the two
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solubility
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dissolves in fluid
low solubility for materials gold & porcelain retained in oral env. (insoluable) materials that are tooth colored are more soluble, they dont last long |
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fatigue failure
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microscopic flaws occur until the material fails
results in fracture |
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flexural stress
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combination, tension & compression
seen as binding |
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metals
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suffer effects of moisture and acidity
(except noble metals) many corrode because of their continued contact with acid environments tarnish=discolor due to oxidation dental amalgam is highly susceptible to both corrosion and tarnish |
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biocompatibility
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materials must not adversely affect living tissue
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water sorption
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materials may enlarge slightly because they absorb moisture
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stress
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internal force that resists applied force
mastication is a form of stress load/area pounds per sq inch |
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galvanism
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-transmission of electrical current between two dissimilar metals in a moist and acidic environment
-creates a metallic taste |
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galvanic shock
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current can stimulate the pulp
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