Dental Materials: Properties, Composites, Glass Ionomers, and Ceramics

What type of bond occurs when two atoms share electrons in their outer shell?

Covalent bond

An example of what type of bond is hydrogen bonding?

Hydrogen bond

What state of matter has both shape and volume?

Solid

Why are waxes considered amorphous solids?

They soften gradually when heated

What are two of the hardest materials relating to dentistry?

Enamel and porcelain

One desirable property of dental materials is:

Biocompatibility

The higher the __________, the greater a liquid's ability to resist flow.

Viscosity

__________ dental materials are used for treatment of disease.

Therapeutic

Give an example of a direct restorative material.

Composite resin or amalgam filling

__________ and __________ affect the mixing of dental materials.

Temperature and humidity

__________ time is the time permitted to manipulate the material in the mouth.

Working time

Dual-set materials utilize __________ and __________ setting reactions.

Chemical and light

The __________ set occurs before the __________ set.

Initial; final

A material that resists breaking under stress and recovers when stress is removed is:

Elasticity

__________ is not a primary bond.

Hydrogen

The stability of a solid is evaluated by:

Solubility and dimensional stability

The maximum amount of stress a material can take before breaking is called:

Ultimate strength

Metals that withstand dimensional change without breaking are described as having:

Ductility

__________ resin is an example of a direct-placement esthetic material.

Composite resin

__________ adhere particles to the resin matrix.

Coupling agents

Filler particles make composites stronger and more __________ resistant.

Wear

Polymerization occurs when __________ molecular-weight resin molecules (monomers) join to form __________ molecular-weight molecules (polymers).

Low; high

A __________ amine is used in chemical-cure composite resin.

Tertiary

The maximum incremental depth of composite resin is:

2 mm

__________ composite resins contain nanometer-sized fillers.

Nanohybrids

__________ composite resins are more fluid and adapt easily.

Flowable

Bulk-fill composite resins permit increments of __________ mm or more.

4 mm

Polymerization shrinkage is reduced by adding __________ modifiers.

Special

Greater filler content = __________ CTE; greater resin content = __________ CTE.

Lower; higher

Darker shades take longer to cure because they absorb more __________.

Light

Each additional increment bonds by __________ bonding.

Chemical

Compomers differ from glass ionomers because they release __________ fluoride.

Less

Hybrid ionomers differ from glass ionomers because they are:

Stronger, more esthetic, more polishable

Glass ionomer sealants have __________ fluoride content.

Higher

Glass ionomer cements are supplied as __________ and __________.

Powder and liquid

Glass ionomers can be used for __________ restorations.

Class V

Tooth preparation for glass ionomer requires __________ conditioning.

Minimal

__________ is used for atraumatic restorative treatment (ART).

Glass ionomer

Type __________ glass ionomer is used for liners and bases.

Type III

Glass ionomer for root caries bonds to:

Dentin (the root)

The technique combining glass ionomer with another material is called:

Lamination or sandwich technique

Nano-ionomers provide superior __________ match.

Color

Finishing glass ionomer requires a protective __________.

Varnish

Bioactive dental materials promote:

Remineralization

Giomers contain pre-reacted __________ glass fillers.

Fluoroaluminosilicate

Porcelain-fused-to-metal (PFM) crowns combine __________ and __________.

Metal and porcelain

Metals in PFM crowns form an __________ layer when heated.

Oxide

CAD/CAM restorations are completed in __________ visit.

One

The first layer of porcelain applied to metal is:

Opaque

Porcelain fracture on a PFM crown is often caused by:

Stress and poor design

Glass-based ceramic crowns look lifelike because of:

Translucency

All-ceramic restorations can be used for:

Inlays, crowns, and veneers

Lithium disilicate and zirconium offer greater __________ strength.

Flexural

The lost wax technique is used to cast gold crowns and for __________ ceramic restorations.

Pressed

CAD/CAM machining uses __________ technology.

Digital scanning

The weakest ceramic material is:

Feldspathic porcelain

Porcelain is prepared for delivery using:

Lath

Silane is added to the __________ surface to enhance bonding.

Porcelain

One disadvantage of ceramic restorations is:

Brittle

Shade selection should occur under __________ lighting.

Natural

When selecting ceramic restorations, __________, __________, and __________ should be considered.

Shade, texture, and luster

Shade matching should be done __________ the tooth.

Adjacent to

The shade tab should be placed __________ the tooth.

Next to

The safest polishing material for ceramic is:

Diamond paste

Medium-fusing porcelain has a temperature range of:

900-1000°C

Veneer tooth reduction requires __________ mm facial reduction.

0.5 mm

Fusing porcelain particles to metal is called:

Sintering

Staining porcelain to mimic natural teeth is called:

Characterization

CAD/CAM crowns use an optical scanner for:

Digital impressions

Too much opaqueness in porcelain veneers is a disadvantage because it reduces:

Translucency

Porcelain with a lifelike appearance is called:

Opalescent

Shade mapping identifies __________ and __________.

Shade distribution and translucency

Shade mapping also locates __________ spots and __________ areas.

White spots and opaque areas

CAD/CAM commonly uses __________ ceramic material.

Lithium disilicate