Manipulation of Gypsum Products Quiz & Flashcards

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Questions and Answers

What is the primary component of gypsum products?

Sodium chloride

Silica

Calcium sulfate dihydrate

Calcium sulfate hemihydrate (correct)

What is the purpose of retarders in gypsum products?

To speed up the setting reaction

To slow down the setting reaction (correct)

To improve strength and durability

To reduce thermal conductivity

What is the approximate compressive strength of gypsum products?

2000 psi (correct)

1000-1500 psi

500-600 psi

100-200 psi

How can gypsum products be manipulated to achieve the desired form?

By all of the above methods Signup and view all the answers

What is one of the clinical applications of gypsum products in dentistry?

Making impressions and molds Signup and view all the answers

What is a characteristic of the setting reaction of gypsum products?

It is an exothermic reaction Signup and view all the answers

What is the primary role of calcium sulfate hemihydrate in gypsum products?

To undergo hydration to form gypsum during the setting reaction Signup and view all the answers

What occurs during the initial setting stage of gypsum products?

Rapid hydration and formation of a gel-like matrix Signup and view all the answers

What is a benefit of gypsum products' low thermal conductivity?

Good insulation properties Signup and view all the answers

What is the purpose of vibration or spatulation during the manipulation of gypsum products?

To remove air bubbles and improve consistency Signup and view all the answers

What type of dental application uses gypsum products for diagnosis and treatment planning?

Study models Signup and view all the answers

What is a characteristic of the final setting stage of gypsum products?

Complete hydration and maximum strength achieved Signup and view all the answers

What is the purpose of pigments in gypsum products?

To color the final product to mimic natural teeth Signup and view all the answers

What is a benefit of using gypsum products in dental restorations?

Low cost and easy to manipulate Signup and view all the answers

What is the role of silica in gypsum products?

To provide a filler to improve strength Signup and view all the answers

What is a common use of gypsum products in dentistry?

Dental models and casts for restorative dentistry and orthodontics Signup and view all the answers

Study Notes

Setting Reactions

Gypsum products undergo a hydration reaction when mixed with water, resulting in the formation of gypsum crystals.
The setting reaction involves the reaction of calcium sulfate hemihydrate (CaSO4·0.5H2O) with water to form dihydrate (CaSO4·2H2O).
The reaction is exothermic, releasing heat as it sets.

Composition

Gypsum products typically consist of:
- Calcium sulfate hemihydrate (CaSO4·0.5H2O) as the primary component.
- Water.
- Additives such as:
  - Retarders (e.g., potassium sulfate) to slow down the setting reaction.
  - Accelerators (e.g., sodium chloride) to speed up the setting reaction.
  - Fillers (e.g., silica) to improve strength and durability.

Properties

Gypsum products exhibit:
- High compressive strength (up to 2000 psi).
- Low tensile strength (around 100-200 psi).
- High density (around 2-3 g/cm³).
- Low thermal conductivity.
- Good dimensional stability.

Manipulation

Gypsum products can be manipulated by:
- Mixing with water to achieve the desired consistency.
- Vibration or tapping to remove air bubbles.
- Carving or shaping to achieve the desired form.
- Investment materials can be added to improve strength and durability.

Clinical Applications

Gypsum products are commonly used in dentistry for:
- Making impressions and molds for dental restorations.
- Creating dental models and casts.
- Fabricating dental appliances, such as dentures and orthodontic devices.
- Manufacturing dental implants and surgical guides.

Setting Reactions

Gypsum products undergo hydration reaction when mixed with water, forming gypsum crystals.
The reaction involves calcium sulfate hemihydrate reacting with water to form dihydrate, releasing heat as it sets.

Composition

Gypsum products primarily consist of calcium sulfate hemihydrate (CaSO4·0.5H2O) and water.
Additives can be included, such as:
- Retarders (e.g., potassium sulfate) to slow down the setting reaction.
- Accelerators (e.g., sodium chloride) to speed up the setting reaction.
- Fillers (e.g., silica) to improve strength and durability.

Properties

Gypsum products exhibit high compressive strength (up to 2000 psi).
They have low tensile strength (around 100-200 psi).
They have high density (around 2-3 g/cm³).
They have low thermal conductivity.
They exhibit good dimensional stability.

Manipulation

Gypsum products can be manipulated by mixing with water to achieve desired consistency.
Air bubbles can be removed through vibration or tapping.
Gypsum products can be carved or shaped to achieve desired form.
Investment materials can be added to improve strength and durability.

Clinical Applications

Gypsum products are commonly used in dentistry for making impressions and molds for dental restorations.
They are used for creating dental models and casts.
They are used for fabricating dental appliances, such as dentures and orthodontic devices.
They are used for manufacturing dental implants and surgical guides.

Composition of Gypsum Products

Composed of calcium sulfate dihydrate (CaSO4·2H2O), water, retarders, accelerators, coloring agents, and fillers
Retarders (e.g., sodium citrate) slow down the setting reaction
Accelerators (e.g., potassium sulfate) speed up the setting reaction
Coloring agents (e.g., pigments) and fillers (e.g., silica) are added for specific purposes

Setting Reactions of Gypsum

Involves the hydration of calcium sulfate hemihydrate to form gypsum
Exothermic reaction, releasing heat as it sets
Divided into three stages: initial setting (minutes 1-10), intermediate setting (minutes 10-30), and final setting (after 30 minutes)

Properties of Gypsum Products

Exhibits high compressive strength (up to 10,000 psi)
Exhibits moderate tensile strength (up to 500 psi)
Has low thermal conductivity, making it a good insulator
Low cost and easy to manipulate
Can be colored and shaped to mimic natural teeth
Used as a model material for dental restorations

Manipulation of Gypsum Products

Can be mixed with water to create a workable consistency
Vibration or spatulation can be used to remove air bubbles and improve consistency
Can be carved or shaped to create the desired form
Investment materials can be used to create a mold around the gypsum model

Clinical Applications of Gypsum Products

Used in various dental applications, including dental models and casts for restorative dentistry and orthodontics
Used for impressions and molds for dental restorations
Used for temporary restorations (e.g., temporary crowns)
Used for study models for diagnosis and treatment planning
Used for educational models for dental education and training