Dental Materials Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What type of cement is described as having a fine grain and is used for permanent cementation in crowns and bridges?

Polycarboxylate Cement

Type 1 Cement (correct)

Insulating Cement

Type 2 Cement

Which type of cement is intended to act as an insulating base for deep cavity preparations?

Exothermic Cement

Crown Cement

Type 1 Cement

Type 2 Cement (correct)

What is the recommended mixing time for preparing cement?

5 seconds

30 seconds

1 to 2 minutes (correct)

15 seconds

What mixing method is suggested for achieving the proper consistency of cement?

Mixing in increments Signup and view all the answers

What is the primary purpose of the thin film layer produced when using cement for castings?

To provide a strong bond for assemblies Signup and view all the answers

What is the primary purpose of bite registrations?

To reproduce the occlusal relationship between maxillary and mandibular teeth Signup and view all the answers

Which material is NOT commonly used for impression trays?

Glass Signup and view all the answers

When taking impressions, what is important to prevent during the removal of the tray?

Warpage of the impression material Signup and view all the answers

What is the purpose of using a bite tray?

To maintain centric relation during impression taking Signup and view all the answers

Which type of tray is primarily used for preliminary impressions?

Stock trays Signup and view all the answers

What should be avoided to ensure the integrity of an impression?

Removing the tray too quickly Signup and view all the answers

Which of the following is a potential consequence of breaking an impression during removal?

Need for re-impression due to inaccuracies Signup and view all the answers

Which of these factors is important when placing an impression in the oral cavity?

The tray must hold material closely to the teeth Signup and view all the answers

What type of composite contains both macrofill and microfill particles?

Hybrid composite Signup and view all the answers

Which composite is specifically designed for anterior teeth restorations?

Microfilled composite Signup and view all the answers

What feature is essential in flowable composite materials?

Low viscosity Signup and view all the answers

How is polymerization of resin materials primarily achieved in composites?

By light exposure Signup and view all the answers

What does the term 'flow' specifically relate to concerning composite materials?

Ease of application Signup and view all the answers

What characteristic is true for nanofilled composites?

They can be used in both anterior and posterior restorations. Signup and view all the answers

What is a unique attribute of macrofilled composites?

They lack polishability. Signup and view all the answers

What is the primary purpose of the syringe tip in flowable composites?

To extrude the composite into preparations Signup and view all the answers

What is the purpose of temporary restorative materials?

To maintain and restore function for a limited time Signup and view all the answers

What should be avoided when working with dental materials?

Water contamination and contact with the material Signup and view all the answers

What visual cue indicates that a dental material has begun to set?

A glossy appearance Signup and view all the answers

How is precured paste in dental applications typically prepared?

By being mechanically triturated and dispensed Signup and view all the answers

What can negatively impact the working time of cement in dental procedures?

Water contamination Signup and view all the answers

When should a dental professional protect the matrix during the procedure?

After the material has a glossy appearance Signup and view all the answers

What is one characteristic of pre-measured capsules used in dental procedures?

They are designed for single-use applications Signup and view all the answers

What is a common mistake when identifying the stage of setting for dental materials?

Assuming gloss indicates complete curing Signup and view all the answers

What is the primary concern related to food causing corrosion in dental materials?

Surface discoloration Signup and view all the answers

In the context of dental restorations, what does 'direct restorations' refer to?

Materials that are applied and sculpted within the mouth Signup and view all the answers

What properties are often associated with corrosive materials in the dental context?

Ability to dissolve metals Signup and view all the answers

How are dental models created in the clinical setting?

Through impressions of hard and soft tissues Signup and view all the answers

What does the term 'solubility' refer to in the context of dental materials?

The degree to which a substance can be dissolved in a liquid Signup and view all the answers

What effect does a saline environment have on metals in the dental context?

Promotes corrosion due to electrolytic processes Signup and view all the answers

What is a critical aspect of the adaptation process during direct restorations?

Material should align perfectly with existing tooth structure Signup and view all the answers

What characteristic of 'sand-low solubility' might be significant in dental applications?

It influences the effectiveness of dental adhesive methods Signup and view all the answers

What is the primary purpose of a rim lock in an impression tray?

To hold the impression material in place Signup and view all the answers

How far beyond the third molar should the impression tray extend?

2-3 mm Signup and view all the answers

Which type of impression material offers excellent dimensional stability?

Polysiloxane Signup and view all the answers

What additional material can be added to an impression tray for patients with an unusually high palate?

Beading wax Signup and view all the answers

What is a characteristic of condensation silicones as impression materials?

They have poor dimensional stability Signup and view all the answers

What does an impression tray need to cover to ensure successful impression taking?

The entire arch of teeth Signup and view all the answers

What is one disadvantage of using polysulfide as an impression material?

Poor dimensional stability Signup and view all the answers

What feature is specifically important for the adaptation of the impression tray?

Extension over the facial surfaces of teeth Signup and view all the answers

Study Notes

Dental Materials and Laboratory Procedures

Mouthwash is used for a pure and clean mouth.

Mechanical Properties

Force: Causes physical changes via energy and strength, creating stress or strain.
Stress: Reaction within the material causing distortion, creating stress and strain.
Strain: Change in product in the result of stress.
Tensile Stress: Pulling and stretching the material.
Compressive Stress: Pushing materials together, such as chewing.
Shear Stress: Breakdown over sliding of two materials.
Ductility: Change shape via pulling force without fracturing.
Malleability: Change shape into thinner sheet or plate via compressive force.

Thermal Properties

Contraction/Expansion: Hot to cold food/drinks cause sudden contraction and expansion in seconds, causing restorative materials to pull away from teeth. This results in microleakage or cracked restorations.
Microleakage: Separation of material from teeth due to temperature changes during hot or cold food/drinks, or through expansion and contraction, allowing fluids, debris and microorganisms to enter between the cavity preparation wall and material.
Percolation: Process of liquid slowly passing through a porous substance.

Application Properties

Flow: Dental material should possess a pliable(soft) consistency to fill the preparation of teeth.
Adhesion: Proper adhesion prevents microleakage and loss of restorations. Force causes unlike materials to adhere to each other, affecting the adhesion process.
Wetting: Ability of a liquid to flow over a surface.
Viscosity: Liquids flow over surfaces; the resistance of a fluid flowing, described in terms of wetting and viscosity.

Retention

Retention: Holding together two things that otherwise wouldn’t adhere to each other.

Curing

Auto-cured: Materials harden through a chemical reaction, often triggered by light exposure in the blue wave spectrum.
Light-cured: Harden only under light.

Electrical Properties

Galvanic/Shock: Two dissimilar metals in the oral cavity with saliva causing electrical conduction can lead to galvanic shock.
Saliva: containing salt acts as a good electrical conductor.

Solubility

Solubility: Substance will dissolve in certain amount of another substance (liquid). For Example Material in oral cavity that dissolves easily will wash away and leave tooth structure exposed

Corrosive Properties

Corrosion: Reaction of metals in contact with temperature, humidity, and saline.

Dental Amalgam

143-54% of mercury equal to 46-57% of alloy powder
Alloy powder is mixed with mercury.
Soft pliable mixture that's placed in the tooth, then condensed, carved and hardened to create a permanent amalgam filling.

Amalgam Composition

Silver
Tin
Copper
Zinc

Amalgam Indications

Small to medium sized cavities in posterior teeth.
Patients with poor oral hygiene.
Foundation of metal-ceramic, cast metal and ceramic restorations.
Severe destruction of tooth structure.

Amalgam Contraindications

Allergy to mercury.
Large restorations when other restorative materials aren't a significant factor for esthetics.

Composite Resin

Properties: Withstand oral cavities. Matches natural tooth color. Easily shaped to tooth anatomy. Bonds directly to teeth.
Indications: restorations for surface defects (hypocalcification, attrition, abrasion, and congenital abnormalities). Closure of diastema.
Composition: Organic resin material (dimethacrylate), Inorganic fillers, Coupling agents, pigments.

Flowable Composite

Properties: Wear resistance from sufficient filler, ability to flow into conservative restorations.
Application: Extrusion into minute cavity preparations.

Acid Etch

Steps: Dry cavity vigorously, apply acid etch to enamel wall, for 15-30 seconds, when prep is contaminated repeat for half the time.
Precautions: Avoid contact with soft tissue; thoroughly rinse if contaminated.

Bonding Procedures

Chemically bonds material to tooth structure (adds micro-mechanical retention)
Light cured, so no mixing.

Protective Shield

Protective shield needed when curing bonding agent.

Precautions

Protective shield when curing bonding agent to protect eye hazard to provider and patient.
Light should be positioned correctly on relevant surface.

Advantages (Composite Resin)

Bonds further support to tooth structure, preventing damage.
Matches natural tooth color. Fixes mishaped, chipped or discolored teeth in one procedure (6-12 years). Reduced sensitivity.
Reduced need for extensive tooth structure removal compared to amalgam.

Precautions (Composite Resin)

Ensuring proper use of protective shield.
Ensuring correct dispensing of material before exposure to light. For large restorations, increments should be cured before next application.

Micro-mechanical Retention

Bonding agents use microscopic interlocking with enamel porosities, tubules, and other structures.

Macro-mechanical retention

Undercuts in dentin to retain non-bonded amalgams and self or auto cure compounds.

Application of Composite versus Amalgam

Composite resin cavity prep designed for micro-mechanical retention.

Glass Ionomer (GIC)

Versatile dental material.
Excellent biocompatibility with oral environment. Adaptable for various uses.
Used for permanent restorations (liners, bonding agents, and cements) for primary (children) teeth and minor restorations of adults.
Not suitable for high-stress areas.

Types of GIC

For cementing metal restorations and direct-bonded orthodontic brackets.
Restoring areas near gingiva.
Used as liners and dentin bonding agents.
Reinforced GIC, using silver and tin, for high-stress situations.

Supply of GIC

Powder and liquid
Pre-mixed paste tubes and mechanically triturated capsules that dispense through dispenser.

Precautions (GIC)

Avoid exposure to water.

Temporary Restorative Materials

Maintain, restore and function to keep patient comfortable for a limited time.

Temporary Restorative Materials Applications

Tooth Whitening Materials

Bleaching. Cost-effective method of tooth restoration using peroxide-based ingredients.

Indications (Tooth Whitening)

Removal of staining.
Peroxide breaks down and oxygen enters enamel and dentin removing discoloration.

Indirect Restorative Materials

Restorations created outside the mouth by dental technicians. Restorative materials are placed after preparing the tooth and taking an impression.

Indirect Restorative Materials Types

Castings.
Noble metal alloys.
Base metals.
Ceramic castings.

Dentinal Liners and Bases

Insulating the pulp tissue to protect from sensitivity caused by procedures.
Protect tooth from thermal shock.

Dental Cements

Permanent, intermediate, temporary restorations.
Luting for indirect and orthodontic procedures.
Thermal insulator of metallic restorations.
Periodontal packs with zoe sedation.

Affecting Cements

Mixing time
Humidity
Powder to liquid ratio
Temperature

Luting Agents

Permanent temporary
Zinc phosphate, polycarboxylate, and glass ionomer (GIC)

Zinc Oxide Eugenol

Types (1 (ZOE, IRM, temporal bond): for temporary cementation (putty); lacks strength and long-term durability, and Type II (Relyx): has reinforcing agents; for permanent restorations of cast restorations or appliances)

Zinc Phosphate

Types 1 (fine grain) for permanent cementation (e.g., inlays, crowns, onlays, bridges, and thin film layer for castings); and 2 (medium grain) as insulating base for cavities
Properties - viscosity, strength, bonding to enamel.

Zinc Polycarboxylate

Properties - viscosity, strength, bonding to enamel (useful for temporary applications)
Powder and liquid for use in crowns and orthopedic bands and restorations.

Guidelines for Mixing Dental Cements

Powder towards one end of glass or paper pad; liquid on opposite end.
Use explorer, mouth mirror, and spoon excavator for cement removal. Clean instruments right away.

Articulator

Replicates the movement of the TMJ (temporomandibular joint)

Sandblaster

A device that blasts sand and air to polish dental castings.

Dental Lathe

Used for trimming dental castings and appliances

Model Trimmer

A device for trimming study models.

Heat Source

Used to heat waxes.

Impression Trays

Metal, plastic, polystyrene.

Sizes

Quadrant (half of arch)
Section (anterior)
Full arch (covers full arch)

Custom Trays

Designed to fit specific patient needs, often for patients with high palates.

Block Out Material

Soft, light-cured dental material to protect undercuts of soft tissue procedures. It is placed on the cast to make space for impression materials.

Seperating Medium

Liquid used to separate casts and impression materials for proper set.

Hydrocolloid Impression Materials

Includes Alginate or Reversible hydrocolloid for preliminary impressions.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge about various types of dental cement used in crowns, bridges, and cavity preparations. This quiz covers mixing times, methods, and the purpose of cement in dental procedures. Perfect for dental students and professionals looking to refresh their skills.