Gypsum
This material is used for study models, often white in color, and requires the greatest amount of water resulting in a weak model
What is Dental Plaster (Plaster of Paris)?
These materials require the use of a water-cooled tray, undergo physical and thermal reactions, and are composed of 85% water and 13% agar
What are reversible hydrocolloids?
This material undergoes 2 reactions; produces hydrogen as a by-product; has great tear strength and elastic recovery; is tasteless, odorless, but very expensive; used for crown& bridge impressions and bite registration
What is Polyvinyl Siloxane/Vinyl Polysiloxane (PVS/VPS)?
Dental waxes are categorized in these three categories
What are Processing, Impression, and Pattern waxes?
The setting of a material may be prevented or slowed by these factors
Food, saliva, blood, disinfectants, and moisture contaminants; use of cold water
This material is used for custom trays, retainers, and dentures; is typically yellow in color; and is exposed to higher temperatures to produce a uniform, durable model
What is Dental Stone?
These materials undergo chemical reactions, are supplied in both fast set and regular set, and may be used with a variety of impression trays
What are irreversible hydrocolloids (alginate)?
This material produces ethyl-alcohol as a by-product; used for crown& bridge and copper band impressions, bite registration, and full/partial dentures impressions; is non-toxic but direct contact with the catalyst should be avoided
What is Silicone?
This type of wax is soft, pliable, and tacky; supplied in rope form; and used to extend impression trays
What is Utility Wax?
The setting of a material may be accelerated by these factors
Excess water, hot/warm water, overspatulation
This material is used for final restorations and wax pattern dies; may be pink, yellow, green, tan or blue; requires the least amount of water and is presoaked before being heated resulting in a very packable, dense model
What is High Strength Stone (Densite)?
These three baths are used to prepare a reversible hydrocolloid for use
This material is hydrophilic (imbibition risk); very strong (difficult to remove); stains; has good flow, elastic recovery, and wettability; does not require surfactants; used for crown& bridge impressions, fixed implants, and open embrasures
What is Polyether?
This type of wax is supplied in pre-formed horseshoe shapes with thin aluminum foil sheets between layers, used for obtaining a patient's occlusion
What is Bite Registration wax?
These factors can caused air bubbles and water voids in both impression materials and stone
Incorrect spatulation/mixing, presence of debris/moisture, movement during setting processes, incorrect vibration/pouring techniques, errors during seating/loading processes
Gypsum is most compatible with these impression taking materials
What is water-based hydrocolloids (alginate)?
Shrinkage of a model due to water loss is termed this
What is syneresis?
This material is hydrophobic (requires a dry field); the oldest, least used& most expensive; low wettability, accuracy& flow; great stability and strength (difficult to remove); has odor and taste; must be hand-mixed; used for crown& bridge and full denture impressions
What is Polysulfide?
The process of burning a wax model in order to pour a molten-alloy to fill and take the shape of the initial wax pattern is termed this
What is the Lost Wax Technique?
These factors may contribute to the tearing/breaking of impression materials and stone
Rocking motion upon removal, improper mixing, compromised strength due to improper water-powder ratios
These reactions occur when gypsum powder is mixed with water to form calcium sulfate dihydrate
What are chemical and exothermic reactions?
Swelling of a model due to water gain/absorption is termed this
What is imbibition?
These materials are used for final impressions, undergo 3 stages (Initial Set, Final Set & Final Cure), are NOT water-based, supplied in 3 forms (Light, Regular & Heavy bodied), and may be mixed using a special mixing unit
What are Elastomeric/Rubber Base impression materials?
This type of wax is made from paraffin and beeswax and used to create patterns for indirect restorations
What is Inlay wax?
These steps can be taken to help a patient with a sensitive gag reflex
Communicate and practice, use fast set material and wax borders, distract the patient, encourage breathing through nose and leaning forward, provide them with a bowl/napkin