DA Chapter 47 Recall Questions

What is the most common wax spatula size used in the laboratory?

#7 wax spatula

What is the water-to-powder (g/ml) ratio of plaster?

100g to 45-50 ml water

How long should you wait before you separate the model from the impression?

45-60 minutes

Of the three types of custom trays discussed, which technique uses a more hazardous material in the fabrication of the tray?

acrylic resin tray materials

What are the two parts of a dental model?

anatomic portion - created from the alginate impression art portion - base of the cast

Where would the dental laboratory be located in a dental office?

away from the patient treatment area

What type of wax could be used to form a wall around a preliminary impression when pouring it up?

boxing wax

What area on the maxillary and mandibular model is trimmed differently?

buccel surfaces

What is the most common wax used to create a pattern for an indirect restoration?

casting wax

What is the purpose of a spacer?

create room in the try for the impression material

What are the three forms of gypsum?

dental plaster, dental stone, high-strength stone

What piece of equipment does the dentist use to determine centric relation on a diagnostic model?

face bow

How are undercuts corrected on a model when a custom tray is prepared?

filled with wax or other molding material

What dental materials are used to make dental models?

gypsum

What type of wax would you use to obtain a patient's bite impression?

impression waxes

What is an example of a contaminated item in the dental laboratory?

items brought into the laboratory from the treatment room area

Which of the two models (maxillary or mandibular) of you begin measuring and trimming first?

maxillary

What piece of equipment is used to grind away plaster or stone?

model trimmer

In which two forms is acrylic resin supplied?

monomer and polymer

What specialty practices might have a more extensive laboratory setup?

pediatric dentistry, orthodontics, and fixed and removable prosthodontics

When pouring an impression, where in the maxillary impression do you begin to place the gypsum material?

posterior

When mixing gypsum materials, do you add the "powder to the water" or the "water to the powder"?

powder to water

In what are gypsum materials mixed?

rubber mixing bowl

What is another term for a dental model?

study cast

Which type of material is used for a vacuum-formed custom tray?

thermoplastic resin

To extend an impression tray, what type of wax would you use?

utility wax

Which type of custom tray is made for a vital bleaching procedure?

vacuum-formed thermoplastic resin

What should be placed between the two models when one is trimming them together?

wax bite