DM 7&8 Bonding Systems/Esthetic Restorative Materials

What are 2 mechanisms of retention?

mechanical retention & chemical adhesion

Which type of retention?

• Physically interlocks the restorative material with the tooth.

• Uses undercuts or projections to lock material into place.

mechanical retention

Which type of retention?

• Attaches restorative material to tooth structure through adhesion.

chemical adhesion/bonding

Attraction within the same material that holds it together

cohesion

Attraction/bonding between dissimilar materials

adhesion

Surface to which the adhesive bonds

adherent

Point where adhesive/restorative material contacts the adherend/tooth

interface

How well an adhesive spreads over a surface

wetting

Measure of a liquid's ability to flow

viscosity

Determines how easily a surface can be wetted

surface energy

What are the different types of bonds?

Primary: Ionic, Covalent, Metallic. Secondary: Van der Waals

• electrons transferred from 1 atom to another

• produces + and - ions that attract

• can be unstable in water (not commonly used)

• using in bonding glass ionomer to tooth structure

Ionic bond

• Sharing of electrons between atoms.

• Strong and stable.

Covalent bond

• Many atoms share their valence electrons.

• Strong and stable.

• Allows metals to conduct heat and electricity.

• Dental metals are held by this bond.

Metallic bond

• Weak physical/interatomic attractions.

• Less stable than primary bonds.

Secondary (Van der Waal) bond

What contact angle is considered good for wettability?

less than 90 degrees

What contact angle is considered bad for wettability?

more than 90 degrees?

These are all _______ traits

• "Water loving"

• Contact angle < 90°

• Strong attraction

• Good wetting

hydrophilic

These are all _______ traits

• "Water hating"

• Contact angle > 90°

• Poor attraction

• Poor wetting

hydrophobic

________ means thick and resistance to flow

high viscosity

________ means thin, watery, and flows easily

low viscosity

restorative material experiences a ________ in viscosity when placed under a load of pressure

decrease

high surface energy will lead to ________ wettability

more

low surface energy will lead to _______ wettability

less

What are the 3 steps to enamel bond?

1. etch 2. resin adhesive 3. composite

When etching you use 37% _________

phosphoric acid

how long should you etch for?

30 seconds

Etching creates a rough surface and ________

enamel tags

Resin adhesive acts as the _______ between composite and enamel.

• want to use Unfilled, low-viscosity resin

glue

After resin adhesive, you apply composite in _____ mm layers

.5 - 2

what should you do after applying a thin layer of composite?

light cure it

A thin layer of fluid and ground tooth components, plaque, bacteria, saliva left on

enamel/dentin and inside dentinal tubules following cavity preparation.

smear layer

The smear layer makes _______ harder to bond to

dentin

dentin is made up of 50% _________

dentin tubules

In Traditional 3 Step dentin bonding, what are the 3 steps?

1. acid etch 2. resin primer 3. resin adhesive

acid etching _____ dentin by removing hydroxyapatite

decalcifies

Acid etching exposes what?

collagen fibrils

Resin primer has _____ viscosity

low

The second step, resin primer prepares surface for ______ by penetrating dentin

adhesion

Resin primer is ________

hydrophilic

The third step, resin adhesive produces the ______ layer consisting of dentin collagen fibrils and resin bonding agents.

hybrid

What is the two-step version of dentin bonding?

1. self-etching primer 2. adhesive

What is the single step version of dentin bonding?

etchant + primer + adhesive all in one

Which type of dentin bonding is considered the “current” method?

1 step

What is in composite?

Organic resin matrix + inorganic filler + silane coupling agent + initiators/accelerators + pigments

What does the silane coupling agent do in composite material?

bonds inorganic and organic materials together

Filler particles have different affects, based on size. What are some of the affects?

• Wear resistance

• Polishability

• Strength

Traits of ______ filler

• harder to wear down

• more filler can be packed into resin

• makes stronger composites

larger

Traits of ____ filler

• polishes/wears smoothly

• hard to load large volumes into resin

• makes weaker composites

smaller

What are the different types of composites?

microfilled, macrofilled, hybrid, nanocomposite

• 10–100 μm

• Average 40 μm

• Quartz/glass

• 50–60% filler volume

macrofilled

• Average filler size 0.04 μm

• Pre-polymerized resin particles

• 30–55% filler volume

microfilled

• Combination of large + small particles.

hybrid

• 1,000× smaller than regular fillers.

• Made from molecular-size zirconia and silica.

• High polishability, compressive strength, and flexural strength; low wear and fluoride

release.

nanocomposites

What are different types of polymerization?

self cure, visible light cure, dual cure

What type of polymerization?

• Paste/paste.

• Benzoyl peroxide initiator + tertiary amine activator.

self-cure

What type of polymerization?

• Eye protection required.

• Includes LED and other light sources.

visible-light cure

What type of polymerization?

• Can polymerize chemically or with curing light.

• Light speeds polymerization?

dual-cure

Term for dominant color in composites

hue

What are examples of hues in teeth?

yellow, brown, and gray

Term for intensity in color of composite

chroma

What are different examples of chroma?

rich or pale

Term for light transmission/reflection of composite (how light/dark)

value

To be able to see through

transparent

Not able to see through

opaque

What are types of special composites?

flowable composite

condensable/packable composite

core buildup composite

What is flowable composite?

diluted microfilled composite

Major disadvantages of flowable composite are:

more shrinkage, lower strength, and greater wear.

What is condensable composite?

Has more filler

• high strength

• low shrinkage

• packable like amalgam

• used in class I, II and VI areas

Core buildup composite is used to build up a badly broken-down tooth before a _______. Can be self-cure, light-cure, or dual cure

dual-cure.

crown

Glass ionomers bond to __________

the tooth itself

What do glass ionomers release?

fluoride

Glass ionomers can release fluoride. Can they absorb it?

yes

Should glass ionomers be used in stress-bearing areas?

no

Glass ionomers wear ______ than composite

faster

glass ionomers are moisture-sensitive for the first _____ ______

24 hours

Glass ionomers are especially used for:

root caries (class V) and noncarious class V abrasion

A compomer is ___ % glass ionomer and ____% resin

80, 20

In resin-reinforced gass ionomers (compomers), adding resin does what?

increases compressive/tensile strength and moisture resistance.

Adding resin to Glass Ionomer, making it compomer, makes the material:

stronger, more polishable, more wear resistant, less soluble

Most common phosphoric acid is ___%

37

Enamel etching time is roughly ____ _____

30 sec

Hydrophilic contact angle is _____

< 90

Hydrophobic contact angle is _______

> 90

Smear layer thickness is ____

2 μm

When building up composite, you should add it in increments that are _______ thick

0.5 - 2 mm

macrofilled composite has particles that are _________ big

10 - 100 μm

Microfilled composite has particles that are _____ big

~0.04 μm

Flowable filler content has what percentage of filler in it?

< 45%

Compomer is made up of ____% glass ionomer and _____% resin

80% GI & 20% resin

Are these things good or bad for bonding?

overly wet surface, overly dry dentin

bad

Are these things good or bad for bonding?

saliva and blood contamination, recent witening/fluoride

bad

Are these things good or bad for bonding?

inadequate resin saturation, inadequate curing

bad

Are these things good or bad for bonding?

handpiece oil, eugenol, and certain astringents

bad

What kind of bond is used in Glass Ionomer to tooth structure?

ionic bond

For wetting, a low angle is ______

good

For wetting, a high angle is _____

bad

Matrix + Filler + Silane

Composite

Bonds + Fluoride, but Weak/Wears

Glass Ionomer

pours/spreads well → less filler → weaker + more shrinkage

Flowable Composite