GC DANB Exam Study Material

Straight fissure plain cut bur

• #55-60

• used for initial entry and shaping internal walls

Which EXT forcep would be found on a tray setup for tooth #25?

forcep #151

Q.I.D

take four times a day

CaOH is only placed on what?

dentin

When working with a right handed dentist what is the 12-2 area known as?

static zone

In an emergency where should you check the pulse on a conscious patient?

radial artery (wrist)

What is a cavity varnish used for?

used to seal the dentinal tubules of cavity preps

Inscription

medication prescribed

Contraindication to coronal polishing

• hypersensitive teeth

Class III Mobility

• tooth can be moved in a buccolingual direction

• depressible in socket

Biologic Pulpal Stimuli

bacteria

Lidocaine 2% with epinephrine 1:100,000

Red cartridge

Lidocaine 2% with epinephrine 1:50,000

Green cartridge

Lidocaine 2% plain

Light blue cartridge

Mepivacaine 2% with levonordefrin 1:20,000

Brown cartridge

Mepivacaine 3% plain

Tan cartridge

Priolocaine 4% with epinephrine 1:200,000

Yellow/gold cartridge

Prilocaine 4% plain

Black cartridge

Bupivicaine 0.5% with epinephrine 1:200,000

dark blue/royal blue cartridge

Articaine 4% with epinephrine 1:100,000

• Gold cartridge

• also known as septocaine

Articaine 4% with epinephrine 1:200,000

Silver cartridge

Adhesion

the ability of dissimilar materials to stick tot\gether, either chemically or physically

Elasticity

the capacity to undergo distortion and return to the original conformation, such as rubber bands within their elastic limit

Flow

gradual continual shape change under force, such as compression-associated amalgam changes

Hardness

relative ability to resist scratching or denting

Solubility

capacity to dissolve in fluid (extremely soluble materials are undesirable if in contact with saliva)

Viscosity

thickness or facility of a liquid to flow

Wettability

the capacity of a liquid to flow over and sink into another

Corrosiveness

the ability to react with food or saliva causing pitting, coarseness or tarnishing, with metal-containing materials

Galvanism

electric shock caused by reaction between dissimilar metals and carried by saliva

Dental Materials pH acidity scale

0-14

• low numbers indicate acidic

• 7 neutral

• high numbers indicate alkalinity

Thermal Properties of Dental Materials

• thermal conductivity

• thermal expansion

Thermal conductivity

facility to convey heat

Thermal expansion

rate of expansion and contraction when exposed to temperature variations

• can cause dimensional change

Dimensional Change can result in?

• microleakage

• tooth sensitivity

• caries

Two ways retention is achieved..

• chemical

• mechanical

Mechanical Retention

• slanting cavity walls inward

• abrading the tooth surface with etchant

• furrowing cavity walls

Chemical Retention

• chemical reaction between dental material and tooth surface

• often used for insertion of gold inlays/crowns that must be indirectly retained through the use of cements/bonding agents

Irreversible Hydrocolloid Impression materials

alginate

Alginate

• irreversible hydrocolloid

• used to make impressions for diagnostic casts and study models, opposite models for prosthetics, temp. restorations, bleach trays, custom trays, mouth guards

Main ingredients in Hydrocolloids

• marine derived potassium alginate (soluble in water, forming thick liquid/sol)

• calcium sulfate (soldification/a gel occurs)

• trisodium phosphate (slows down setting time

• fillers like diatomaceous earth or zinc oxide (strength)

• potassium titanium fluoride

Advantages of Alginate

• cheap

• easy

• comfortable to use

• sets quickly

• little equipment needed

• elastic properties make it ideal for impressions where there are recessed areas

• both tissue and teeth imprints can be taken

Alginate Disadvantages

• some inaccuracy possible due to changes in water content

• heat, dryness, or contact with air can result in syneresis/shrinkage of material

• water gain (imbibition) or enlargement of the measurements of the impression

• tissue areas being imprinted may be distorted because of thickness of material

What impression material is more accurate than alginate?

e;astomer

How impression tray should fit..

• room for 2mm of hydrocolloid

• several mm posterior to molar area

(can be extended using wax strips/beading)

Alginate mixing time

30-45 seconds (fast set)

60 seconds (regular set)

How to load alginate tray..

• start with lingual sides

Alginate Ratios

• Mandibular- 2:2

• Maxillary- 3:3

Accurate Algniate impression characteristics

• centered over central incisors

• include all areas

• illustrate well-defined anatomic detail of both teeth and tissues

• should encompass vestibule area

• have good peripheal marginal roll

Impression plaster ratio for alginate

50ml water to 100g powder

Reversible Hydrocolloid Impression Material

• agar-agar

• chemical reaction

• quite accurate, useful for final impressions and other things requiring detail

Elastomeric Impression Materials

• more flexible than other types

• less prone to tearing and distortion upon removal

• relatively impervious to temperature changes

What are the three general types of Elastomerics

• polysulfide

• silicone

• polyether

How are elastomerics prepared?

by mixing a catalyst/accelerator and a base material (polymerization)

Polysulfide Impressions

• elastomeric

• 6 minute setting time

Silicone Impressions

• elastomeric

• putty

• 3 minutes setting time

Polyether Impressions

• pastes

• 30 second mixing time

Disadvantages of Elastomerics

• polysulfide: smell, stains, 10 minute setting time

• silicone: expensive

Dental Waxes

• pattern wax

• temporary processing wax

• impression/bite registration wax

• undercut wax

Pattern Wax

• two hard waxes

• inlay and baseplate

Inlay Wax

• pattern wax

• dark sticks

• melted and placed on a die to create a pattern for a restoration or heated to vaporization using lost wax technique

Baseplate Wax

• pattern wax

• comes in sheets

• heated and used for denture bases

Temporary Processing Waxes

• soft boxing wax

• sticky wax

• utility wax

Soft Boxing Wax

• Temporary Processing Waxes

• encloses impressions to keep gypsum in place

Sticky Wax

• Temporary Processing Waxes

• adheres to many surfaces when melted for temporary repairs

Utility Wax

• Temporary Processing Waxes

• has adhesive and malleable properties at room temp. making it ideal for relieving patient discomfort (e.g. orthodontics)

Impression or Bite Registration Wax

• incorporate copper or aluminum particles

Undercut Wax

placed in undercuts before making impressions

List Permanent Cements

• zinc phosphate

• polycarboxylate

• glass ionomer

• reinforced zinc oxide eugenol

• resin cement

• resin reinforced glass ionomer

• compomers

Cements used for orthodontic bands and brackets

• zinc phosphate

• polycarboxylate

• glass ionomer

• resin cementTyp

Type I GI Cement

• used for orthodontics

Type II GI Cement

• modified resin

• used for restorations

Type III GI Cement

• dual cured hybrid for luting

Type IV GI Cement

• tri-cured glass

• opaque structures

• releases less fluoride

Type VI GI Cement

• any metal reinforced admixture containing GIs

• used with silver/amalgam restorations for crown/core buildups

Type I Gypsum

impression plaster

• 60ml:100g

Type II Gypsum

model/lab plaster for casts/models

• 50ml:100g

Type III Gypsum

lab stone

• 30ml:100g

Type IV Gypsum

die stone for strong or dyed models

• 24ml:100g

Type V Gypsum

high-strength, high-expansion die stone

• 18-22ml:100g

Orthodontic Stone

combination of type II lab plaster and type III lab stone