Dental Materials

lab should be located where?

separate space

non-patient care area

what is the lab used for?

pour preliminary impressions

trim & finish diagnostic models

prepare custom trays

polish provisionals, partial/full dentures & indirect restorations

what kind of dental offices have a lab?

most do

specialty labs might be more extensively set up such as orthodontics, pediatrics, and prosthodontics

sets the guidelines to follow (federal regulated agency)?

OSHA

laboratory rules (OSHA)?

no eating, drinking, or smoking

wear PPE

need eye protection

hair pulled back

report all accidents to dentist immediately

follow manufacturer’s instruction for equipment

turn off all equipment before leaving

clean work area before/after procedures

heat source fueled by alcohol or gas; ethyl alcohol 90% or higher?

alcohol burner

use of alcohol burner?

heat wax

machine used to trim stone or plaster models?

model trimmer

small electric appliance used to construct custom trays for bleaching mouth guards, surgical templates, and positioners for orthodontics?

vacuum former

used to remove air from the mix of plaster or stone and to aid in the flow of material when diagnostic models are poured?

dental lab vibrator

a low-speed handpiece used in the lab for many tasks (trimming custom trays, adjusting dentures, polishing temporary & indirect restorations)?

laboratory handpiece

handheld unit that sprays at a high rate of speed, creating an etching or pitting on a surface area of metals, porcelain, or acrylic; sprays sand at a high speed could cause abrasion on skin?

sand blaster

mechanical device used to hold mx and md dental models in a position to aid in the reproduction of the md in relation to the mx?

articulator

determines the positional relationship of the maxillary arch to the TMJ?

face bow

used to trim and polish custom trays, temp coverage, dentures, and indirect restorations?

dental lathe

double-ended instrument used in waxing a pattern or when working with wax for a partial or full denture; use it to place plaster/stone in impressions when pouring up models (most used)?

wax spatula

more of a paddle or beavertail shaped spatula, used to mix alginate?

alginate spatula

used to mix gypsum products (plaster/stone/die stone); straight, less flexible?

laboratory mixing spatula

knife used to separate and smooth or remove excess gypsum products when set?

laboratory knife

used for mixing of alginate or gypsum products?

rubber bowl

used to measure the powder/gypsum products for mixing accuracy?

gram scale

used to cure (set) various materials used in lab?

dental lab curing unit

holds dental models that are being prepared to send to the lab; we could use this to soak models before trimming as well?

lab pan

used to mix (triturate) amalgam or other materials; usually chairside while placing a silver amalgam filling?

amalgamator

“grand old man of dentistry”?

Dr. G. V. Black

set specifications for dental materials/new dental materials?

ADA

ADA sets specifications for what properties?

mechanical

physical

chemical

if a product meets the specifications?

seal of certification

for products proven to be safe and effective, but no standards have been established?

seal of acceptance

ensures safety and efficacy of dental materials?

FDA

summaries that provide information about the potential hazards of a product as well as required safety measures?

SDS - safety data sheets

average weight of mechanical properties in mouth?

170 lbs

a push or pull which produces a stress or strain?

force

internal resistance to resist the external force that cause distortion?

stress

a change in an object that causes deformation of a material because of stress?

strain

types of stress or strain?

tensile

compressive

shear

material is pulled and stretched (tug of war)?

tensile

two forces directed toward each other (biting/chewing)?

compressive

two forces parallel to each other sliding in opposite directions (cutting paper)?

shear

stretched by pulling or tensile forces (stress) without losing strength of breaking (metal to be made into thin wire)?

ductility

compressive force (stress) is its ability to withstand rolling or hammering (thin sheet or plate)?

malleability

the rate in which heat flows through a material?

thermal conductivity

why is it important for selecting restorative material (2 reasons)?

contraction & expansion happens during temperature change

protect pulp from thermal changes

temperature change can cause dental materials to pull away from the tooth which results in?

microleakage

when microscopic separation (microleakage) allows fluids, debris, and microorganisms to enter between the restoration and the wall of the cavity preparation?

percolations

mechanical properties of dental materials?

force

stress

strain

hardness

electrical property of dental materials?

galvanic action/shock

action or shock in the oral cavity when two different or dissimilar metals and saliva are present?

galvanic action/shock

saliva contains ____ making it a good electrical conductor?

salt

corrosive properties of dental materials?

corrosion

tarnish

the reactions that occurs within a metal when it is exposed to factors such as temperature, humidity, and saline; causing roughness or pitting in metal?

corrosion

when the metal in the mouth starts to discolor?

tarnish

an indication of strength and wearability?

hardness

the degree in which a substance will dissolve in a given amount of another substance?

solubility

application properties for dental materials?

flow

adhesion

retention

dental material must have a certain amount of flow to fill the preparation of the tooth?

flow

allow ______ to take place between two different properties such as dental material and tooth structure?

adhesion

liquid adhesive with the ability to flow over a hard or solid surface; this can affect the adhesion process?

wetting

water has a ____ wetting ability because it flows easily?

high

part of liquid that doesn’t flow easy; can affect adhesion process; maple syrup does not flow easy and is not affected by wetting surface?

viscosity

the ability to hold tow things firmly together when they are not adhered to each other naturally is called?

mechanical bonding/retention

example of mechanical bonding/retention?

amalgam prep

how the tooth is prepared placing grooves or undercuts to hold material?

retention

to harden a material using light?

cure/curing

self-cures due to chemical reaction caused by two different materials being mixed together; causes chemical bonding/retention?

auto cure

ability to remove decay or disease and “restore” to proper function of the tooth?

restorative

recreating a tooth or teeth with an artistically pleasing appearance?

esthetic

silver material made with alloy, a powder, and liquid?

amalgam

resin matrix, filler, a coupling agent, and tooth colored pigment; hardened by curing light?

composite resin

adhere chemically to teeth and release fluoride as it cures?

glass ionomer

used to restore a patients tooth for a short time?

temporary restorative materials

used to restores esthetic; made from peroxide base; used to remove stain?

tooth whitening products (bleaching)

indirect restoration, has the ability to resist tarnish and etching; full gold is too soft and needs other metals added to it?

gold alloy

compound of metallic and nonmetallic elements like dishes; it is made with a clay like material with a glaze that has metallic components for strength?

ceramic castings

type of ceramic; can be fused with metal; chose for color match, esthetic, strength, good insulator, low coefficient of thermal expansion?

porcelain

dominant color?

hue

lightness of a color?

value

intensity of the color?

chroma

amount of light entering the tooth?

translucency

measurement of dimensional change per unit based on each degree change of temperature?

low coefficient