dent 1200 materials i lesson 3 alginate impression material

Download DENT 1200 Materials I Lesson 3 Alginate Impression Material

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  • Slide 1
  • DENT 1200 Materials I Lesson 3 Alginate Impression Material
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  • Introduction Alginates are salts of alginic acid (crystalline compounds that are typically water soluble and are extracted from seaweed). When alginate is mixed with water, it has the ability to set or gel. Dental alginates are called irreversible hydrocolloids (have the ability to change from a liquid state (sol) to a semisolid state (gel) but do not have the ability to change from a semisolid to a liquid state). The material is supplied as a powder. Alginate is used for making impressions for study models, primary impressions of edentulous mouths and impressions in areas in which partial dentures are to be fabricated.
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  • 1. Main Ingredients Potassium Alginate (seaweed, active ingredient) 15% Calcium Sulfate ( cause the chemical reaction) 16% Trisodium phosphate (inhibit) 1% Diatomaceous earth ( filler) 60% Zinc Oxide ( filler & set time) 4% Potassium Titanium Fluoride 3% ( makes compatable with gypsum)
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  • 2. Measure, mix and load tray 1 scoop of fluffed alginate for 1 ring of water Quadrant tray- 1 increments Maxillary- 3 increments Mandibular- 2 increments
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  • 2. Measure, MIX and Load tray Add water first Sift in powder and wet with spatula Hold bowl in palm of left hand and rotate while stroping spatula against the side of the bowl
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  • ALGINATOR There is a mechanical device called an alginator, in which the bowl spins.
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  • 2. Measure, mix and LOAD tray Maxillary 1 increment, load posterior to anterior Mandibular material into left flange, into right flange, load from the lingual Trays should extend into the muccobuccal fold but not inpinge on any Frenum.
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  • Frenum Tissue that attaches Be careful of the maxillary labial frenum, so the tray does not extend onto it.
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  • 3. Dimensional Changes Pour up ASAP Syneresis- drying out, shrink, harden Pour asap or wrap in a moist paper towel. Imbibition- take in fluids and swell Do not immerse in fluid
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  • 4. Taking a functional impression of each arch Try in trays for size and modify peripheral area with utility wax if needed. ALWAYS take MANDIBULAR 1 st. Load tray and smooth with a wet finger. Smear some alginate over occlusals to prevent peduncles. Stand in front of patient, center over teeth and seat. Stabilize with a finger on each flange. Remove in a quick snap, protecting the teeth of the opposing arch.
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  • Wax and Mandibular
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  • 4. Functional Maxillary Load tray and smooth with wet finger. Smear alginate over occlusals Seat from BEHIND the patient. Seat posterior to anterior. Stabilize with finger on palate area. Remove with quick snap protecting opposing arch
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  • Maxillary
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  • 5. Model Trim Pour up and separate Use a model trimmer Check Lab sheet for the Steps
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