Introduction to Dental Material Science

Vocabulary flashcards covering key concepts from the lecture on dental material science.

Dental Material Science

The study focusing on the physical, chemical, and mechanical properties of materials used in dentistry.

Dimensional Stability

The ability of a material to maintain its shape and size after placement.

• Relevance: Materials should neither expand nor contract excessively, as this can cause restoration failure.

• Example: Dental composites must maintain shape to ensure a proper fit as shrinkage can lead to marginal gaps, increasing risk of secondary caries.

Density

The mass per unit volume of a material, affecting weight, comfort, and durability of restorations.

• Relevance: Affects the weight, comfort, and durability of restorations.

• Example: Titanium is preferred over gold for implants due to its lower density, reducing strain on the jawbone.

Optical Properties

How a material interacts with light, influencing aesthetics and shade matching in restorations.

• Relevance: Essential for shade matching in restorations to ensure a natural appearance.

• Example: Porcelain crowns are layered to mimic the translucency and colour variations of natural enamel.

Thermal Expansion

The tendency of a material to expand when heated and contract when cooled.

• Relevance: Dental materials should have thermal expansion rates similar to tooth structure to prevent stress and fractures.

• Example: Porcelain-fused-to-metal (PFM) crowns must be designed with compatible expansion rates to prevent cracking.

Specific Heat Capacity

The amount of energy required to change a material's temperature.

• Relevance: Affects material response to oral temperature changes.

• Example: Metal restorations may conduct heat quickly, causing sensitivity in patients.

Latent Heat of Fusion

Energy required for a material to change state.

• Relevance: Important in processing materials such as waxes and alloys.

• Example: Dental waxes used in casting have a lower latent heat than alloys, allowing easier manipulation.

Bonding and Adhesion

The ability of a material to adhere to another substance, essential for restorative materials.

• Relevance: Essential for restorative materials to ensure retention and prevent microleakage.

• Example: Composite resins rely on adhesive bonding to tooth enamel and dentin.

Wetting and Surface Tension

Wetting is the ability of a liquid to spread across a surface, influenced by surface tension.

• Relevance: Affects the ability of dental materials to flow and adapt.

• Example: Impression materials should have low surface tension to capture fine details accurately.

Chemical Stability

The ability of a material to resist chemical changes in the oral environment.

• Relevance: Ensures longevity and prevents degradation due to saliva, acids, and bacteria.

• Example: Porcelain may develop microscopic porosities over time, leading to slight darkening, mimicking the natural aging of teeth.

Toxicity and Biocompatibility

A material’s ability to integrate with human tissue without causing harm.

• Relevance: Ensures patient safety and minimizes adverse reactions.

• Example: Titanium implants demonstrate excellent biocompatibility, promoting osseointegration.

Elasticity

The ability of a material to return to its original shape after deformation.

• Relevance: Essential for materials under repeated stress.

• Example: Orthodontic wires must be elastic to exert continuous force on teeth.

Ductility

The ability of a material to be stretched into a wire without breaking.

Malleability

The ability of a material to be compressed into thin sheets without fracturing.

• Relevance: Important for shaping materials without compromising strength.

• Example: Gold is highly malleable, making it ideal for gold foil restorations.

Hardness

Resistance to surface deformation of a material.

• Relevance: Ensures resistance to wear and fracture.

Toughness

The ability of a material to absorb energy without fracturing.

• Example: Enamel is highly hard and tough, making it durable against mastication forces.

Tensile Strength

Resistance to pulling forces.

• Relevance: Critical for restorative materials enduring different stresses in the oral cavity. (applicable for tensile, compressive and yield)

Compressive Strength

Resistance to squeezing forces.

• Example: Amalgam has high compressive strength, making it ideal for posterior restorations.

Fracture Toughness

The ability of a material to resist crack propagation.

• Relevance: Prevents premature failure of restorations.

Example: Zirconia crowns exhibit high fracture toughness, making them durable

Rigidity (Stiffness)

The resistance of a material to deformation.

• Relevance: Important for restorations that must maintain their shape under stress.

• Example: Crowns require high rigidity to prevent deformation during chewing, whereas orthodontic wires need flexibility.

Viscosity

Resistance of a fluid to flow.

• Relevance: Determines how materials are applied and manipulated.

• Example: High-viscosity composite resins allow controlled placement without excessive flow.

Cost and Practicality

Factors affecting the cost of dental materials, including treatment individuality and regulatory requirements.

• Example: The high cost of gold restorations limits its widespread use despite its excellent properties.