Dental Materials Quiz

<p>Palladium (C)</p> Signup and view all the answers

<p>Excellent resistance to corrosion (D)</p> Signup and view all the answers

<p>Permanent deformation over time due to stress (D)</p> Signup and view all the answers

<p>Copper (C)</p> Signup and view all the answers

<p>It should be avoided due to slow elimination from the body (B)</p> Signup and view all the answers

<p>Temperature and water to powder ratio (A)</p> Signup and view all the answers

<p>Evaporation of moisture (B)</p> Signup and view all the answers

<p>Decreased tear strength (D)</p> Signup and view all the answers

<p>Higher strain rates result in higher values of modulus (B)</p> Signup and view all the answers

<p>To enhance hardness and white color. (C)</p> Signup and view all the answers

<p>Controls the working time (C)</p> Signup and view all the answers

<p>Contain more than 60% noble metal and 40% gold. (D)</p> Signup and view all the answers

<p>It results in permanent deformation (D)</p> Signup and view all the answers

<p>Brittleness (A)</p> Signup and view all the answers

<p>Limited surface detail (D)</p> Signup and view all the answers

<p>The veneer remains in tension and may fracture (D)</p> Signup and view all the answers

<p>It allows for a range between liquidus and solidus temperatures. (C)</p> Signup and view all the answers

<p>Using a smooth restoration surface (D)</p> Signup and view all the answers

<p>High modulus of elasticity. (A)</p> Signup and view all the answers

<p>Shortens both times (D)</p> Signup and view all the answers

<p>Porcelain fused to metal (PFM) crown (A)</p> Signup and view all the answers

<p>Minor amounts of noble metals and complex compositions. (B)</p> Signup and view all the answers

<p>They exhibit questionable biocompatibility. (C)</p> Signup and view all the answers

<p>Coefficient of thermal expansion (CTE) (B)</p> Signup and view all the answers

<p>It can increase hardness. (B)</p> Signup and view all the answers

<p>They have minimal adverse effects on biological tissue (C)</p> Signup and view all the answers

<p>The maximum stress that can be applied without permanent deformation. (B)</p> Signup and view all the answers

<p>Roughening the surface interface (A)</p> Signup and view all the answers

<p>The bond may fail due to tension (A)</p> Signup and view all the answers

<p>cp-Ti contains 99% titanium, while Ti-6Al-4V contains 90% titanium, 6% aluminum, and 4% vanadium. (D)</p> Signup and view all the answers

<p>The amount of oxygen present in the alloy. (A)</p> Signup and view all the answers

<p>A spontaneously formed oxide layer. (D)</p> Signup and view all the answers

<p>High strength resin bases. (D)</p> Signup and view all the answers

<p>Cements for restorative materials. (B)</p> Signup and view all the answers

<p>High strength resin bases. (D)</p> Signup and view all the answers

<p>Superior biocompatibility and mechanical properties. (C)</p> Signup and view all the answers

<p>It inhibits low-charge transfer and prevents corrosion. (A)</p> Signup and view all the answers

<p>Animal-based, plant-based, and mineral-based (A)</p> Signup and view all the answers

<p>They transition to a liquid state with decreased viscosity (B)</p> Signup and view all the answers

<p>Waxes exhibit shear-thinning behavior under force (A)</p> Signup and view all the answers

<p>Stress remaining from manipulation during various processes (A)</p> Signup and view all the answers

<p>They should exhibit little or no flow (C)</p> Signup and view all the answers

<p>They may exhibit time-dependent deformation (D)</p> Signup and view all the answers

<p>It has a small contact angle promoting good wettability (D)</p> Signup and view all the answers

<p>Change in shape under applied force (D)</p> Signup and view all the answers

The amount of copper in an amalgam affects its properties. High copper amalgams are stronger, resist corrosion better, and don't expand as much as low copper amalgams.

The shape of silver alloy particles in amalgam affects its properties. Spherical particles give higher compressive strength, while irregular particles provide more interlocking strength and higher surface area.

During the setting of amalgam, there is a contraction phase followed by an expansion phase.

Creep is the slow deformation (bending) of amalgam under constant stress over time.

Amalgam is a brittle material, and the risk for fracture is higher in the early restorations.

Noble metals like gold, palladium, and platinum are highly resistant to corrosion in the oral environment.

Base metals like silver and copper have a higher tendency to corrode in the oral environment compared with noble metals.

Mercury is toxic and should be handled carefully. Amalgam generates little mercury vapor, but minimizing its usage is preferred.

Categorization of alloys based on gold and noble metal content.

Alloy with more than 40% gold and more than 60% noble metals.

Alloy with more than 25% noble metal (can be without gold).

Alloy with less than 25% noble metals (can be without gold).

Casting alloys don't melt at a single temperature. Instead, they have a melting range.

Temperature where all the alloy begins to melt (upper range).

Temperature where all the alloy solidifies (lower range).

Measure of how easily an alloy can be indented or polished.

A type of titanium with 99% titanium content. Its strength varies depending on the oxygen content, with grade 1 having the lowest and grade 4 having the highest.

An alloy composed of 90% titanium, 6% aluminum, and 4% vanadium. It has excellent corrosion resistance and is widely used as an implant biomaterial due to its biocompatibility, mechanical strength, and ability to integrate with bone.

Titanium's biocompatibility is due to the spontaneous formation of a self-healing oxide layer when it is exposed to air or body fluids. This oxide layer inhibits corrosion, prevents low-charge transfer, and makes it biocompatible.

Luting agents used to bond permanent and temporary tooth structures. They come in water-based (glass ionomer), oil-based (ZOE), and resin-based (RMGI) varieties.

Used to support restorative materials. They are categorized by strength, where high strength is more suitable as a foundation and low strength is better for liners.

Liners or bases placed within the cavity preparation. They provide protection and support for the tooth's pulp. High strength materials like glass ionomer, RMGI, and zinc phosphate are suitable for this purpose.

Bases are generally stronger than cements. They provide mechanical support and thermal protection for the restoration, especially important for metal restorations due to their high thermal conductivity.

Dental cements have different types with distinct applications and compositions. They are crucial for various procedures in dentistry and their understanding is necessary for optimal treatment.

The time it takes for the chemical reaction in alginate to be complete and the material to solidify.

The time you have to mix and work with the alginate before it starts to set.

Higher temperatures shorten both the setting time and working time of alginate.

Changing the water/powder ratio affects both the setting time and strength of alginate. A thinner mix sets slower and is weaker.

The ability of alginate to return to its original shape after being compressed or stretched.

The amount of change in shape that remains after the compression force is removed from an alginate impression.

The mechanical response of a material (like alginate) depends on how quickly it is loaded or deformed.

The slow deformation of a material under constant stress over time.

As the hardness of a material increases, the amount of contact it has with alginate decreases. This is because harder materials are less likely to deform and mold to the alginate.

Materials tend to be harder when dry compared to when they are wet. Water can soften materials by allowing their molecules to move more freely.

Good wetting between the alginate and gypsum is essential for accurate reproduction of detail in dental casts. This allows the gypsum to flow into the contours of the alginate impression.

Waxes like agar have a small contact angle, indicating good wettability and detail reproduction, while addition silicone (non-water based) and gypsum have limited reproduction due to poor wettability.

Waxes do not melt at a single temperature due to their varying composition. Instead, they have a melting range, meaning they transition from solid to liquid over a specific temperature interval.

Flow is the ability of wax to change shape under force. Dental waxes should exhibit considerable flow at the time of preparing the wax pattern for easy manipulation. However, they should have minimal flow at room temperature for stability.

Residual stress is stress present in wax as a result of manipulation like heating, cooling, or bending. These stresses are released over time as the wax warms up and its molecules move more freely.

The flow of wax is influenced by temperature, time, and the applied force. Higher temperatures, longer times, and greater forces generally lead to increased flow.

A ceramic forming technique where a liquid slip (a suspension of ceramic powder in water) is poured into a plaster mold. As the plaster absorbs water from the slip, a layer of ceramic solid forms on the inside of the mold, creating the desired shape.

A process where powder particles are heated to a high temperature, causing them to bond together and form a solid mass. The heat facilitates diffusion between particles, leading to densification and strengthening of the material.

A measure of how much a material expands or contracts in size per unit length when heated or cooled by one degree Celsius.

When two materials with different CTE values are bonded together, heating or cooling can lead to strain differences, potentially causing the bond to break. The material with a higher CTE will expand more, putting stress on the bond.

Ceramics that are safe and compatible with biological tissue. They minimally trigger adverse reactions in the body, allowing for integration with bone and tissues.

Ceramics are used in dental restorations in various forms. Porcelain fused to metal (PFM) crowns use a metal framework covered with porcelain, while all-ceramic crowns are entirely made of ceramic.

The bond between ceramic and metal in PFM crowns is achieved through chemical reactions and mechanical interlocking. The oxide layer on the metal surface chemically bonds with the ceramic, while roughening the surface further enhances the bond strength.

Failure can occur if the oxide layer on the metal is inadequate, or if there's a significant difference in thermal expansion between the ceramic and metal, causing stress during heating or cooling.