calcium sulfate dihydrate

*when heated, calcium sulfate hemihydrate*

type I - impression plaster (rare!)

type II - model plaster (white)

type III - dental stone (yellow)***

type IV - high strength, high expansion stone

type I - .45ml/100gm

type III - .30ml/100gm

type IV - .23ml/100gm

increasing the W/P ratio makes the mix weak

decreasing the W/P ratio makes it hard to work with

alloy

silver: 40-70%

tin: 20-30%

copper: 10-30%

zinc: 0-2%

safety

reliabiltiy

consistent mix

ADA no longer recommends hand mixing of mercury

following of instructions

condensation of mix

finish of restoration

avoiding contamination

strength

solubility

viscosity/film thickness

biocompatibility

retention

esthetics

tooth prep

acid etch

application of bonding agent *primer*

adhesive

depends on restoration...

when etching dentin, you etch for 10 seconds then rinse to remove the smear layer. 

in enamel, its etched longer byecause of the lower water content and must be rinsed and dried thoroughly.

dentin should be etched for LESS time and should not be over-dried OR over moistened.

the smear layer is the layer of sludge procuded by enamel from use of the high speed hand piece. 

occludes dentin tubules and you'll need to acid etch for 10 seconds and then rinse to remove the smear layer

1. bonding agents

2. prep of internal surfaces of the resto

anterior and posterior restorations.

class I through class VI

can be used as sealants, core build up, indirect restorations

resin matrix: BIS-GMA & UDMA

filler particles: silica, glass, quartz

coupling agent: silane

macro (1-100), micro (.04) , nano (1-5)

volume is much greated in nano particles 80-85%

amorphous, spherical particles 

'microfillers' .02-.04 microns

related to the size of particles

&

viscosity of resin

macro, .5-3 microns, 75-80% filler

strong and polishable

anterior and posterior

low viscosity

40-70% filler

.07 to 1 microns

DELIVERED BY SYRINGE!

initiators: benzoyl peroxide (base)

activator: tertiary amine (catalyst)

initiator: camphoroquinone

activator: light (470 nm wavelength)

accelerator: tertiary amine

same initiators and activators as light cure and chemical cure

light activation speeds the set, chemical reaction will complete polymerization process

dentures

partials

implants

crowns/bridge work

hydrocolloids

elastomers

polysulfide

silicone rubber

polyether

very accurate

somewhat hydrophilic

dimensional stability is high

permanent deformation is low

short working time/setting time

sensitive to temps and moisture

must not be immersed in water/disinfecting solutions

odor

taste

messy

can't clean out of fabric

initiation

propagation

termination

addition polymerization has 3 stages: initiation, propagation and termination

carbon atoms joined by a double bond

condensation polymerization - silicone impression materials, not widely used, produces by-products of water, hydrogen gas or alcohol

softer, weaker more porous than heat cured resins

leaves residual monomer causing irritation

hard, strong, less porous

less than 1% residual monomer

residual monomer leaches our more quickly

chair side reline

lab reline

OTC reline

tissue conditioners

long term soft liners or short term soft liners

water sorption and thermal expansion

(polymerization is a source)

as water is absorbed, the acrylic will increase slightly in size

expansion may help offset some of polymerization shrinkage

long term - placed chairside or lab

short term - placed chair side (tissue conditioners)

dentures that have become loose overtime

chairside reline

lab reline

crowns & bridges

veneers

endodontics

implants

vitality of the tooth is in question

emergency care

restoration of primary teeth

maintaining position of prepared tooth to adjacenet teeth and opposing teeth

protection of exposed tooth surfaces and margins

protection of gingival tissues

providing function and esthetics

strength

hardness

tissue compatibility

esthetics

handling

metals - stainless steel or aluminum

polycarbonate - versatile, tough plastic

celluloid - clear plastic crown form

acrylic

composite

cement

stainless steel (most durable, used on childs primary teeth, economical)

aluminum - last for several weeks, used on posterior teeth

polycarbonate - used on anteriors and esthetic in color, rigid material, compatibile with acrylic resins

celluloid - clear plastic crown form, easily cut w/ scissors

thermoplastic wax

alginate (easy and less $$)

silicone impression materials

vacuum formed plastic

acrylic - methacrylates, used for years, good esthetics, low cost, easy, bad taste, bad odor, exothermic reaction

composite - low shrinkage, low heat release, good strength, biocompatibile, low wear, expensive, too brittle, self cure, light cure, dual cure

more mineral is leaving the tooth than is entering

occurs in the presence of acid

replacing minerals lost from the tooth surface

requires calcium, phosphorus and fluoride

fluorapatite is formed on tooth surface

consumption of excess fluoride during tooth formation

often from water, over use of ingested fluoride sources

systemic is through water and drops or vitamins

topical includes water, toothpaste, rinses, gels, varnishes or foams

home products: tooth paste, OTC rinse, non-Rx gel or rinse

in-office products: gel, foam, varnish

BIS-GMA, UDMA, filled or unfilled particles

glass ionomer

improper brushing

dietary acid

loss of tooth structure

tooth paste

gels

varnishes

inorganic salt solutions

resin primer

bonding agents

closing the exposed dentinal tubules

some work directly on the pulp by soothing it

tooth sensitivity

gingival irritation

allergy

unrealistic expectations

allergies to ingredients

sensitive teeth

tooth colored restorations on the anteriors

unrealistic expectations

topical

systemic

in-office

in office = 1.23%

Rx home use = 1.1%

OTC = .05%

MFP usually used in tooth paste

prophy paste often contains 1.23% APF

toothpastes - potassium nitrate (active ingredient)

inorganic salt and solutions - potassium nitrate, potassium oxalate, ferric oxalate

resin primers and bonding agents - immediate effects, some require acid etch, duration varies from days to a year

chemical element that readily loses electrons to form a positive ion and forms metallic bonds with other metal atoms

high luster, density, ability to be deformed under stress

high noble: 60%

noble: 25%

base metal: < 25%

casting alloy is used for partial frameworks

wrought metal frameworks used for orthodontic wire, prosthetic clasps, and endodontic files

fabricating a metal restoration by encasing a wax pattern in stone and then vaporizing the wax under high temps to leave an empty space that once occupied by wax

molten metal is then cast into the space and takes the shape of the pattern

low fusing porcelain is used first and is layered into metal substructure or "coping"

porcelain chemically fuses to the surface oxides as the two materials are heated together and a durable bond is formed

THINK OF CHOCOLATE CHIPS!

particles melting together at their borders and fusing together, results in shrinkage by 25-40%

cracks from occlusal loading

bond at metal oxide layer might be inadequate

coefficient of thermal expansion of porcelain and metal need to be compatible 

(porcelain should have less thermal expansion than metal)

slip casting

heat pressing

sintering

computer assisting machining (CAM)

paste: prophy paste/tooth paste

loose powder

bonded

coated

I - softest

II - medium hardness; inlays and crowns

III - hard; inlays, crowns & bridges

IV - extra hard; partial denture framework