Dental Putty Mixing Techniques
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Questions and Answers

What is the recommended mixing time for putty by hand to achieve a streak-free mix?

  • 1 minute
  • 15 seconds
  • 2 minutes
  • 30 seconds (correct)

    • Vinyl gloves can be used when handling putty material.

    True

    Which type of zinc oxide-eugenol (ZOE) impression is suitable for an edentulous mouth?

  • Type II - Soft set (correct)
  • Type I - Hard set
  • Final impression for a dentate mouth
  • Type III - Temporary set

    • What is the maximum setting time for putty at a temperature of 37°C?

    <p>5 minutes</p> Signup and view all the answers

    The __________ should be held firmly until the wash material sets.

    <p>impression area</p> Signup and view all the answers

    Type I ZOE impressions have a setting time of 10 minutes for fast set.

    <p>True</p> Signup and view all the answers

    What is the primary use of ZOE as a relining material?

    <p>To improve the fit of ill-fitting dentures.</p> Signup and view all the answers

    Match the following components with their roles in the putty-wash system:

    <p>Catalyst = Aids in curing the putty Retarder liquid = Extends the working time Putty = Base material for impressions Wash material = Enhances accuracy of impressions</p> Signup and view all the answers

    The catalyst in ZOE impressions helps to speed up the ______.

    <p>setting time</p> Signup and view all the answers

    Match the components of ZOE with their functions:

    <p>Zinc oxide = Base material Oil of cloves = Reactor / Catalyst Hydrogenated rosin = Thermoplasticity Calcium chloride = Accelerator for setting time</p> Signup and view all the answers

    What is the proper proportion for mixing ZOE paste?

    <p>1:1</p> Signup and view all the answers

    Eugenol is used in ZOE impressions to enhance flow properties.

    <p>False</p> Signup and view all the answers

    What is the primary purpose of fillers in hydrocolloids?

    <p>To improve strength, viscosity, and rigidity</p> Signup and view all the answers

    Name a plasticizer used in ZOE impressions.

    <p>Mineral oil or vegetable oil.</p> Signup and view all the answers

    Syringe material for reversible hydrocolloids has a higher strength compared to tray material.

    <p>False</p> Signup and view all the answers

    What is the role of glycerine in reversible hydrocolloids?

    <p>Plasticizer</p> Signup and view all the answers

    The tray material should be tempered to _____ in the third water bath before making impressions.

    <p>43-46 C</p> Signup and view all the answers

    Which temperature is used to convert agar to sol in the hydrocolloid conditioner?

    <p>100 C</p> Signup and view all the answers

    What is the primary characteristic of dimensional stability in impression materials?

    <p>Negligible shrinkage</p> Signup and view all the answers

    What is the recommended manner of withdrawal for taking impressions?

    <p>Single stroke, sudden jerk without side movements</p> Signup and view all the answers

    The tear strength of the tray type material is _____ lb/in².

    <p>4</p> Signup and view all the answers

    Irreversible hydrocolloids can be converted back to a sol once they have gelled.

    <p>False</p> Signup and view all the answers

    Match the material with its property or usage:

    <p>Diatomaceous Earth = Filler for strength Thymol = Anti-microbial agent Glycerine = Plasticizer Benzoates = Preservative</p> Signup and view all the answers

    What is the main ingredient by weight in reversible hydrocolloid materials?

    <p>Water</p> Signup and view all the answers

    Agar is derived from certain types of ______.

    <p>seaweed</p> Signup and view all the answers

    Match the reversible hydrocolloid components with their functions:

    <p>Agar = Basic constituent Borax = Improved strength Potassium sulfate = Ensures proper setting of gypsum Water = Principal ingredient by weight</p> Signup and view all the answers

    What is the gelation temperature of agar?

    <p>43.3°C</p> Signup and view all the answers

    Agar was the first successful elastic impression material used in dentistry.

    <p>True</p> Signup and view all the answers

    What is a common use for reversible hydrocolloids in dentistry?

    <p>Making impressions of dentulous and edentulous mouths</p> Signup and view all the answers

    What is the main advantage of the syringe technique in impression taking?

    <p>Provides a detailed impression with no bubbles</p> Signup and view all the answers

    The tear strength of RIM is less than that of hydrocolloids.

    <p>False</p> Signup and view all the answers

    How should an impression be removed from a patient's mouth?

    <p>With a steady force in a single stroke.</p> Signup and view all the answers

    Polysulfide RIM has a dimensional contraction of _____ during the first 24 hours.

    <p>0.3-0.4%</p> Signup and view all the answers

    Match the following types of RIM with their respective dimensional stability:

    <p>Polysulfide RIM = 0.3-0.4% shrinkage Condensation silicone = 0.6% shrinkage Addition silicone = 0.1% shrinkage Polyether RIM = 0.2-0.4% shrinkage</p> Signup and view all the answers

    Which of the following factors can control the setting time of RIM?

    <p>Temperature of the mixing slab</p> Signup and view all the answers

    The use of oleic acid in the mixture will accelerate curing.

    <p>False</p> Signup and view all the answers

    What is the recommended action after removing an impression from the patient's mouth?

    <p>Rinse with cold water, disinfect, and blow dry.</p> Signup and view all the answers

    Study Notes

    ZOE (Zinc Oxide-Eugenol) Impressions

    • Used as a thin layer in trays for wash impressions; thermoset and rigid, ineffective for undercuts.
    • Composed of a two-paste system:
      • Base paste (white)
      • Catalyst paste (brown/amber).
    • Applications include final impressions for edentulous mouths, denture relining, centric jaw registration, cementing, and temporary filling.
    • Types classified by setting properties:
      • Type I: Hard set (3-6 min initial setting time, 10 min final setting time).
      • Type II: Soft set (3-6 min initial, 15 min final).
    • Key Components of Base Paste:
      • Finely divided zinc oxide with minimal water and inert oil for plasticity.
      • Hydrogenated rosin enhances thermoplasticity.
    • Catalyst contains oil of cloves (eugenol substitute) for reduced irritation, polymerized rosin for smoothness, and various accelerators to adjust setting times.

    Hydrocolloid Impression Materials

    • Elastic materials that deform when removed, regaining original shape for accurate impressions.
    • Hydrocolloids transition between sol (liquid) and gel (solid) states based on temperature.
    • Two types:
      • Reversible hydrocolloids (change back to sol).
      • Irreversible hydrocolloids (permanent gel).
    • Agar is the primary component in reversible hydrocolloids, derived from seaweed.
    • Requires specific manipulation techniques, including single and double impression methods.

    Manipulation Techniques

    • For reversible hydrocolloids, agar is heated and cooled in controlled water baths for optimal sol/gel transformation.
    • Double Impression Technique: A weaker syringe material is used first, followed by a stronger tray material.
    • Accurate removal requires a sudden motion to prevent deformation.

    Properties of Reversible Hydrocolloids

    • Compressive strength varies, with tray materials offering maximum strength.
    • Must be kept at ideal temperatures to maintain fluidity and prevent burns to oral tissues.
    • Final impressions should not be submerged in water or exposed to direct sunlight.

    Polyether and Polysulfide RIM (Rubber Impression Materials)

    • Polyether materials require steady removal forces to maintain impression integrity.
    • Setting time influenced by temperature; increasing temperature shortens time, while lowering it extends time.
    • Polysulfide and silicone materials exhibit superior elasticity, strength, and dimensional stability compared to hydrocolloids.

    Key Properties of RIM

    • Excellent elasticity, allowing minimal permanent deformation under strain.
    • High tear strength in comparison to hydrocolloids: polysulfide RIM offers the best performance.
    • Low shrinkage percentages indicate superior dimensional stability during curing.

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    Description

    This quiz explores the procedures involved in mixing dental putty with a catalyst for impression making. Understand the importance of proper mixing techniques and the role of moisture during the process. Test your knowledge on the steps required for achieving optimal results in dental impressions.

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