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
