DH104: Dental Materials Quiz 2 & 3

Your patient is claustrophobic and has a strong gag reflex. You need a final impression material with pleasant characteristics. Which material would you not chose?

a. Polyvinyl siloxane

b. Addition silicone

c. Polysulfide

d. Polyether

c. Polysulfide

Extra alginate should be added to the tray for the patient with a deep palatal vault. Solid rim lock impression trays do not require adhesive.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

b. Both statements are false.

A retraction cord should always fit end-to-end when placed in the sulcus.

True or False?

False

The practice you work in is located in Denver. You are sending a final impression to a lab in Seattle to have a gold crown made. Which final impression material would you not choose due to transit time?

a. Condensation silicone

b. Polyether

c. Polyvinyl siloxane (PVS)

d. Both b and c

a. Condensation silicone

What kinds of gloves should be worn when mixing polyvinyl siloxane putty?

a. Latex

b. Nitrile

c. Vinyl

d. None

c. Vinyl

Wax bite registrations are the most dimensionally stable.

True or False?

False

Polyether can stay dimensionally stable for 2 weeks. It is hydrophilic and can absorb disinfecting solutions.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

a. Both statements are true

Digital impressions do not require gingival retraction. The impression process is much easier for patients with digital impressions.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

d. The first statement is false; the second statement is true.

You are selecting a tray for a mandibular alginate impression. The tray should extend to which of the following to ensure inclusion of proper anatomy?

a. The tuberosity

b. The retromolar pad

c. The hamular notch

d. The canine eminence

b. The retromolar pad

Alginate materials are which of the following?

a. Final impression materials

b. Reversible hydrocolloids

c. Irreversible hydrocolloids

d. Inelastic

c. Irreversible hydrocolloids

Which of the following is used as a hemostatic agent?

a. Ferric sulfate

b. Aluminum oxide

c. Tin oxide

d. Silicone carbide

a. Ferric sulfate

Which of the following is an inelastic impression material?

a. Agar

b. Zinc oxide eugenol

c. Alginate

d. Condensation silicone putty

b. Zinc oxide eugenol

Syneresis is the update of fluid by an impression material.

True or False?

False

Polysulfides are still used for complete denture impressions.

True or False?

True

Racemic epinephrine hemostatic agents can cause blood pressure spikes.

True or False?

True

All of the following are pattern waxes except:

a. baseplate.

b. boxing.

c. casting.

d. inlay.

b. boxing.

The product with the least amount of expansion is plaster.

True or False?

False

Inlay waxes can be used directly in the patient's mouth.

True or False?

True

Which portion of a diagnostic cast should be trimmed to a point?

a. Maxillary anterior art portion

b. Mandibular anterior art portion

c. Mandibular canine portion

d. No area should be trimmed to a point.

a. Maxillary anterior art portion

The base of a model should be trimmed to size so that it makes up half of the total depth of the model. Before the casts are trimmed, they should be immersed in water for 5 minutes to allow for easier trimming.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

b. Both statements are false.

Which of the following uses two mixes of gypsum product to make casts?

a. Double pour

b. Single step

c. Boxing method

d. Both b and c

a. Double pour

Which wax comes in orange and red sticks?

a. Inlay

b. Corrective impression

c. Sticky

d. Boxing

c. Sticky

Which processing wax comes in ropes or sheets and comes in white, pink, and red?

a. Utility

b. Boxing

c. Sticky

d. None of the above

a. Utility

Agar and alginate form the best surface detail with gypsum products due to being water based.

True or False?

True

The strength of gypsum products is dependent on the amount of powder. The less water used, the weaker the product.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

b. Both statements are false.

Warmer water can speed up the setting process of gypsum.

True or False?

True

The calcination process determines the type of gypsum product created.

True or False?

True

Which of the following gypsum materials would you use to fabricate a working model?

a. Dental stone (α hemihydrates)

b. β Hemihydrates

c. Densite

d. Dental investment

a. Dental stone (α hemihydrates)

Type IV stone is dental stone used for models requiring higher strength. Impression plaster is rarely used in dentistry today.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

d. The first statement is false; the second statement is true.

It's 4:35 and you have just poured up impressions for bleaching trays, but the office is closing at 5:00. What is the ideal amount of time to allow gypsum to set before separating models from the impression?

a. 15 minutes

b. 30 minutes

c. 60 minutes

d. 24 hours

c. 60 minutes

Initial bond strength is more important than longevity.

True or False?

False

In dentin bonding, the attraction of dissimilar molecules is referred to as:

a. adherent.

b. adhesion.

c. cohesion.

d. fission.

b. adhesion.

Dentin should be etched for ______ seconds.

a. 10

b. 20

c. 30

d. 60

a. 10

Which of the following can contribute to microleakage?

a. Saliva

b. Oil from handpieces

c. Blood

d. All of the above

d. All of the above

The resin/dentin layer formed by the application of bonding agent is referred to as the:

a. smear layer.

b. oxygen-inhibited layer.

c. hybrid layer.

d. smooth layer.

c. hybrid layer.

Self-etching bonding products do not require rinsing and drying. Self-etching bonding systems use phosphoric acid to etch the tooth.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

c. The first statement is true; the second statement is false.

A separate silane agent must be applied to ceramic veneers for appropriate bonding.

True or False?

True

The layer of tooth structure debris that must be removed by conditioning or etching to ensure bonding is called the __________ layer.

a. hybrid

b. smear

c. oxygen-inhibited

d. incremental

b. smear

Which is the most common material used to etch teeth in preparation for resin bonding?

a. Phosphoric acid

b. Hydrofluoric acid

c. Carbonic acid

d. Sulphuric acid

a. Phosphoric acid

Orthodontic brackets cannot be bonded with conventional cement. Orthodontic brackets can be bonded directly or indirectly.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

a. Both statements are true.

Primary teeth should be etched for 60 seconds or more.

True or False?

True

It is important to ensure that all moisture is removed after using an etch-and-rinse acid. Etch-and-rinse or total etching involves the etching of enamel and dentin.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

d. The first statement is false; the second statement is true

Bonding agents are high viscosity to create a better bond.

True or False?

False

A separate bonding step is not needed when bonding to enamel. Etching alone on enamel allows the formation of a hybrid layer, creating a very strong bond between the resin material and the enamel.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

c. The first statement is true; the second statement is false.

Endodontic posts must be bonded to the crown of a tooth with dentin bonding resins or resin cements.

True or False?

False?

Fluoride benefits the enamel in what way?

a. By leaving the resulting crystalline structure more resistant to acid

b. By reducing the ability of bacteria to adhere to the hydroxyapatite structure

c. By creating fluorapatite, which has a much lower solubility

d. All of the above

d. All of the above

Chlorhexidine can stain artificial teeth.

True or False?

True

Your patient has some early, incipient caries on the cervical areas of their maxillary molars. Which delivery method would you choose to help remineralize these areas?

a. OTC rinse

b. Varnish

c. Gel in trays

d. Foam in trays

b. Varnish

All of the following can cause demineralization and dentin sensitivity in patients except:

a. bacterial acid.

b. gastric acid.

c. dietary acid.

d. hydrofluoric acid.

d. hydrofluoric acid.

Which teeth are most susceptible to caries and would therefore most benefit from pit and fissure sealants?

a. Maxillary molars

b. Mandibular molars

c. Maxillary premolars

d. Mandibular premolars

b. Mandibular molars

Maxillary molars are the teeth most prone to decay if not sealed.

True or False?

False

Which of the following monomers make up the resin component of sealants?

a. PMMA

b. MMA

c. bis-GMA

d. EMMA

c. bis-GMA

The appearance of mottled teeth due to the excess intake of fluoride is called:

a. erosion.

b. remineralization.

c. fluorosis.

d. caries.

c. fluorosis.

The characteristic of chlorhexidine that makes it most beneficial as an antimicrobial in the prevention of caries is:

a. substantivity.

b. solubility.

c. staining.

d. none of the above.

a. substantivity.

Glass ionomer sealants last longer than resin sealants.

True or False?

False

Fluoride supplements should be used when a patient's water at home is lower than 0.7 ppm.

True or False?

False

Resin infiltration cannot be used on early interproximal lesions. Resin infiltration can make white spot lesions less noticeable.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

d. The first statement is false; the second statement is true.

Fluoride has some antibacterial properties. It is most effective when used alone, as rinses can negate the effect of fluoride.

a. Both statements are true.

b. Both statements are false.

c. The first statement is true; the second statement is false.

d. The first statement is false; the second statement is true.

c. The first statement is true; the second statement is false.

Which of the following is found in remineralization materials?

a. Calcium sodium phosphosilicate

b. Hydroxyapatite

c. Potassium

d. Fluorapatite

a. Calcium sodium phosphosilicate

Bonding agents make sealants more retentive on enamel.

True or False?

True