Dental Materials Foundations And Applications11th Edition by Powers – Test Bank

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INSTANT DOWNLOAD COMPLETE TEST BANK WITH ANSWERS

 

Dental Materials Foundations And Applications11th Edition by Powers – Test Bank

 

Sample  Questions

 

 

Chapter 03: Preventive Dental Materials

Powers: Dental Materials, 11th Edition

 

MULTIPLE CHOICE

 

  1. Which of the following is considered to be a preventive dental material?
a. Pit and fissure sealant
b. Dental amalgam
c. Ceramic veneer
d. Full gold crown

 

 

ANS:  A

 

  Feedback
A Fluoride gels, pit and fissure sealants, and mouth protectors are considered to be preventive dental materials.
B Dental amalgam is considered to be a restorative dental material.
C Porcelain veneers are considered to be a restorative dental material.
D Full gold crowns are considered to be a restorative dental material.

 

 

DIF:    Knowledge     REF:   p.  27             OBJ:   10

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application)

MSC:  NBDHE, 5.0 Using preventive agents, 5.2 Pit and fissure sealants

 

  1. Which type of fluoride treatment is best to use for a patient with dentinal hypersensitivity (has a neutral pH)?
a. Acidulated phosphate fluoride
b. Stannous fluoride
c. Sodium fluoride
d. A and C
e. B and C

 

 

ANS:  C

 

  Feedback
A Acidulated phosphate does not have a neutral pH.
B Stannous fluorides have acidic values of pH.
C Sodium fluoride has a neutral pH.
D A is an incorrect answer. C is a correct answer
E B is an incorrect answer, and C is a correct answer.

 

 

DIF:    Comprehension                              REF:   p.  27             OBJ:   3

TOP:   CDA, GC, V Patient education and oral healthcare management; C Demonstrate the understanding of plaque control techniques, including but not limited to: Explain the effects of all types of fluoride, the advantages of various methods of administration, and the dangers and results of overdosage

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Which type of fluoride will not etch restorations?
a. Acidulated phosphate fluoride
b. Stannous fluoride
c. Sodium fluoride
d. A and B
e. B and C

 

 

ANS:  C

 

  Feedback
A Acidulated phosphate fluorides can etch restorations.
B Stannous fluoride can etch restorations.
C Sodium fluoride will not etch restorations.
D A and B are incorrect answers.
E B is an incorrect answer, and C is a correct answer.

 

 

DIF:    Comprehension                              REF:   p.  28             OBJ:   2

TOP:   CDA, GC, V Patient education and oral healthcare management; C Demonstrate the understanding of plaque control techniques, including but not limited to: Explain the effects of all types of fluoride, the advantages of various methods of administration, and the dangers and results of overdosage

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Which type of fluoride can stain restorations?
a. Sodium fluoride
b. Stannous fluoride
c. Acidulated phosphate fluoride
d. A, B, and C
e. A and C

 

 

ANS:  B

 

  Feedback
A Sodium fluoride does not stain restorations.
B Stannous fluoride can stain restorations.
C Acidulated phosphate fluoride does not stain restorations.
D A is the only correct choice.
E A is the only correct choice.

 

 

DIF:    Comprehension                              REF:   p.  28             OBJ:   2

TOP:   CDA, GC, V Patient education and oral healthcare management; C Demonstrate the understanding of plaque control techniques, including but not limited to: Explain the effects of all types of fluoride, the advantages of various methods of administration, and the dangers and results of overdosage

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. What does thixotropic mean?
a. Viscosity of the material is changeable.
b. Material will adhere to an intraoral surface.
c. Grain size of cast gold is affected by quenching.
d. Setting time of the material is affected by glove powder.

 

 

ANS:  A

 

  Feedback
A Thixotropic means the viscosity of the material is changeable. Examples found in dentistry include one form of topical dental anesthetic. Yogurt is another example of a thixotropic material.
B The material does not have adhesive properties.
C Quenching is the process of rapidly cooling cast gold.
D There is no chemical or setting reaction involved.

 

 

DIF:    Knowledge     REF:   p.  28             OBJ:   1

TOP:   CDA, GC, V Patient education and oral healthcare management; C Demonstrate the understanding of plaque control techniques, including but not limited to: Explain the effects of all types of fluoride, the advantages of various methods of administration, and the dangers and results of overdosage

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Fluoride varnishes are available that contain ________ fluoride.
a. 1% sodium
b. 5% sodium
c. 1% stannous
d. 5% stannous
e. 2.34% acidulated phosphate-fluoride (APF)

 

 

ANS:  B

 

  Feedback
A 1% sodium is related to gel deliveries of acidulated phosphate fluoride.
B Fluoride varnishes are available that contain 5% sodium fluoride.
C Because it stains, 1% stannous is rarely used.
D Because it stains, 5% stannous is rarely used.
E 2.34% APF is related to gel deliveries of acidulated phosphate fluoride.

 

 

DIF:    Knowledge     REF:   p.  28             OBJ:   1

TOP:   CDA, GC, V Patient education and oral healthcare management; C Demonstrate the understanding of plaque control techniques, including but not limited to: Explain the effects of all types of fluoride, the advantages of various methods of administration, and the dangers and results of overdosage

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Which of the following statements is true about 4-minute versus 1-minute application of a fluoride treatment? A 4-minute application is
a. not currently recommended.
b. less effective than a 1-minute application.
c. equally effective as a 1-minute application.
d. more effective than a 1-minute application.

 

 

ANS:  D

 

  Feedback
A A 4-minute application is necessary for full fluoride uptake.
B A 4-minute application is necessary for full fluoride uptake.
C A 4-minute application is necessary for full fluoride uptake.
D A 4-minute application appears to be more effective than a 1-minute application.

 

 

DIF:    Knowledge     REF:   p.  28             OBJ:   3

TOP:   CDA, GC, V Patient education and oral healthcare management; C Demonstrate the understanding of plaque control techniques, including but not limited to: Explain the effects of all types of fluoride, the advantages of various methods of administration, and the dangers and results of overdosage

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Which of the following statements is true of the manipulation of fluoride foams and gels during their application for office fluoride treatment?
a. The troughs of the maxillary and mandibular trays should be completely filled with the gel.
b. The teeth are to be kept as free from saliva as possible before application of the tray.
c. After application of the gel, the patient is instructed not to eat for 4 hours.
d. Rinses are recommended for children under 6 years old.
e. They should be applied prior to dental prophylaxis.

 

 

ANS:  B

 

  Feedback
A A ribbon of gel should be placed in the troughs of the maxillary and mandibular trays.
B The teeth are to be kept as free from saliva as possible before application of the tray during the application of office fluoride treatments.
C After application of the gel, the patient is instructed not to eat for 30 minutes.
D Rinses are not recommended for children under 6 years old.
E They should be applied after rather than before dental prophylaxis.

 

 

DIF:    Analysis         REF:   p.  28             OBJ:   2

TOP:   CDA, GC, V Patient education and oral healthcare management; C Demonstrate the understanding of plaque control techniques, including but not limited to: Explain the effects of all types of fluoride, the advantages of various methods of administration, and the dangers and results of overdosage.

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.3 Methods of administration

 

  1. Application of fluoride is least effective in preventing caries on which of the following surfaces of posterior teeth?
a. Distal
b. Mesial
c. Buccal
d. Lingual
e. Occlusal

 

 

ANS:  E

 

  Feedback
A Distal involves smooth surfaces where fluoride is most effective.
B Mesial involves smooth surfaces where fluoride is most effective.
C Buccal involves smooth surfaces where fluoride is most effective.
D Lingual involves smooth surfaces where fluoride is most effective.
E Application of fluoride is least effective in pits and fissures as a result of the special anatomy of the occlusal surfaces of posterior teeth.

 

 

DIF:    Knowledge     REF:   p.  28             OBJ:   3

TOP:   CDA, GC, V Patient education and oral healthcare management; C Demonstrate the understanding of plaque control techniques, including but not limited to: Explain the effects of all types of fluoride, the advantages of various methods of administration, and the dangers and results of overdosage

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Which of the following statements is true about pits and fissures?
a. A smooth-based depression on the occlusal surface of a tooth.
b. The result of noncoalescence of dentin during tooth formation.
c. The result of noncoalescence of enamel during tooth formation.
d. May be cleansed by the excursion of food or a toothbrush bristle.

 

 

ANS:  C

 

  Feedback
A Pits and fissures are narrow, deep depressions.
B It may extend as far as the dentoenamel junction.
C The pit and fissure is an enamel fault that is the result of noncoalescence of enamel during tooth formation. The noncoalescence may extend to the dentoenamel junction, or it may be incomplete.
D Pits and fissures may be very narrow, smaller than a single toothbrush bristle.

 

 

DIF:    Comprehension                              REF:   p.  28             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Approximately ____% of dental caries in children 5 to 17 years of age involves pits.
a. 11
b. 24
c. 49
d. 74
e. 84

 

 

ANS:  E

 

  Feedback
A Eleven is a low random distracter.
B Twenty-four is a low random distracter.
C Forty-nine is low random distracter.
D Seventy-four is a low random distracter.
E Approximately 84% of dental caries in children 5 to 17 years of age involve pits.

 

 

DIF:    Knowledge     REF:   p.  29             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Pit and fissure sealants may be used to prevent caries in _____ teeth.
a. deciduous but not permanent
b. permanent but not deciduous
c. both deciduous and permanent
d. neither deciduous nor permanent

 

 

ANS:  C

 

  Feedback
A This option is incorrect based on the answers of both.
B This option is incorrect based on the answers of both.
C Pit and fissure sealants may be used to prevent caries in both deciduous and permanent teeth.
D This option is incorrect based on the answers of both.

 

 

DIF:    Comprehension                              REF:   p.  29             OBJ:   1

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.2 Pit and fissure sealants, 5.2.1 Mechanisms of action

 

  1. A preventive resin restoration involves the use of _____ to restore the teeth.
a. flowable composite
b. hybrid ionomer
c. glass ionomer
d. compomer
e. ceramic

 

 

ANS:  A

 

  Feedback
A A preventive resin restoration involves the use of flowable composite to restore the teeth.
B Hybrid ionomer is a thick material with little to no flow
C Glass ionomer is a thick material with little to no flow.
D Compomer is a thick material with little to no flow.
E Ceramic is used for indirect restorations only.

 

 

DIF:    Knowledge     REF:   p.  29             OBJ:   7

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants.

MSC:  NBDHE, 5.0 Using preventive agents, 5.3 Other preventive agents

 

  1. Which of the following materials is the chemistry of sealants most similar to?
a. Composite restorative material
b. Acidulated phosphate-fluoride
c. Ceramic restorative material
d. Glass ionomer cement

 

 

ANS:  B

 

  Feedback
A APF is a fluoride.
B The chemistry of sealants is similar to composite restorative material. Sealants have fewer filler particles and are more fluid in order to penetrate pits and fissures in addition to the etched areas produced on the enamel.
C Ceramic is an indirect restorative material.
D Glass ionomer is a cement with a fluoride ion.

 

 

DIF:    Knowledge     REF:   p.  29             OBJ:   7

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.2 Pit and fissure sealants, 5.2.1 Mechanisms of action

 

  1. Sealants polymerized by visible light are ______-component systems that _____ require mixing.
a. one; do
b. one; do not
c. two; do
d. two; do not

 

 

ANS:  B

 

  Feedback
A A one-component system does not require mixing.
B Sealants polymerized by visible light are one-component systems that do not require mixing.
C Sealants that self-cure are two-component systems that do require mixing.
D Sealants that self-cure are two-component systems that do require mixing.

 

 

DIF:    Comprehension                              REF:   p.  30             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants.

MSC:  NBDHE, 5.0 Using preventive agents, 5.2 Pit and fissure sealants, 5.2.1 Mechanisms of action

 

  1. What is the purpose of benzoyl peroxide in sealant materials?
a. Monomer
b. Inorganic filler
c. Initiator of a two-component sealant system
d. Initiator of a one-component sealant system
e. Organic amine accelerator of a one-component sealant system

 

 

ANS:  C

 

  Feedback
A Monomer is only present in a one-component system.
B Inorganic material is present in one- and two-component systems.
C Benzoyl peroxide is the initiator of a two-component sealant system.
D Diketone is the initiator in a one-component system.
E Organic amine accelerator is present in one- and two-component systems.

 

 

DIF:    Knowledge     REF:   p.  30             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.2 Pit and fissure sealants, 5.2.1 Mechanisms of action

 

  1. How does acid etching of the enamel surface improve the retention of a sealant?
a. Decreases the surface area
b. Cleans the area to be sealed
c. Improves the wettability of the enamel
d. A, B, and C are all correct.
e. Only B and C are correct.

 

 

ANS:  E

 

  Feedback
A Acid etching increases the surface area.
B B and C are correct.
C B and C are correct.
D Only B and C are correct.
E Acid etching of the enamel surface improves the retention of sealant by cleaning the area to be sealed, improving the wettability of the enamel, increasing the surface area, and forming spaces into which the sealant can penetrate to form tags.

 

 

DIF:    Comprehension                              REF:   p.  30             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.2 Pit and fissure sealants, 5.2.1 Mechanisms of action

 

  1. What did the results of a 5-year clinical study about sealant effectiveness, after a single application of a pit and fissure sealant, indicate?
a. Increased
b. Decreased
c. Remained unchanged
d. Was tied to oral hygiene

 

 

ANS:  B

 

  Feedback
A The clinical study found the effectiveness of a single application of a sealant clearly decreases with time.
B The clinical study found the effectiveness of a single application of a sealant clearly decreases with time.
C The clinical study found the effectiveness of a single application of a sealant clearly decreases with time.
D Caution is warranted in comparison of some of these studies, because materials, techniques, teeth studied, and clinical criteria for judging success or failure vary from study to study.

 

 

DIF:    Comprehension                              REF:   p.  30             OBJ:   3

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.2 Pit and fissure sealants, 5.2.1 Mechanisms of action

 

  1. Current evidence indicates that sealants should not be used on the teeth of which type of patient?
a. Cooperates in maintaining good oral hygiene
b. Has pits and fissures on occlusal surfaces
c. Has been free of caries for several years
d. Has no proximal lesions

 

 

ANS:  C

 

  Feedback
A Sealants also should not be used on the teeth of a patient who does not cooperate in maintaining good oral hygiene.
B Sealants should be used on occlusal surfaces where pits and fissures exist.
C Current evidence indicates that sealants should not be used on the teeth of a patient who has been free of caries for several years.
D Sealants should not be used on teeth with many proximal lesions.

 

 

DIF:    Knowledge     REF:   p.  30             OBJ:   3

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.2 Pit and fissure sealants, 5.2.1 Mechanisms of action

 

  1. Etchants are generally _____ acid.
a. hydrochloric
b. phosphoric
c. salicylic
d. acetic

 

 

ANS:  B

 

  Feedback
A Hydrochloric acid is not used to etch enamel.
B Etchants are generally 37% solutions of phosphoric acid in water.
C Salicylic acid is not used to etch enamel.
D Acetic acid is not used to etch enamel.

 

 

DIF:    Knowledge     REF:   p.  32             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.2 Pit and fissure sealants, 5.2.1 Mechanisms of action

 

  1. Which of the following statements is true regarding placement of a sealant?
a. If an etched tooth becomes contaminated with saliva, the etching and rinsing steps need not be repeated.
b. The self-cured sealant is cured with a light source for at least 20 seconds.
c. Moisture enhances retention of the sealant by the fissure.
d. A small cotton pellet may be used to remove sealant that has failed to polymerize because of exposure to air.
e. If a fluoride treatment is used in conjunction with the pit and fissure sealant, the fluoride treatment is applied before the sealant has polymerized.

 

 

ANS:  D

 

  Feedback
A The area must be re-etched and dried again.
B Self-cured sealant does not require a light to cure.
C Moisture inhibits retention of the sealant.
D If an etched tooth becomes contaminated with saliva, the etching and rinsing steps are repeated.
E If a fluoride treatment is used in conjunction with the pit and fissure sealant, the treatment is applied after the sealant has polymerized.

 

 

DIF:    Analysis         REF:   p.  32             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.2 Pit and fissure sealants, 5.2.2 Techniques for application

 

  1. Surveys report that orofacial injuries most frequently occur in which sport when the athlete is not wearing a mouth protector?
a. Basketball
b. Football
c. Hockey
d. Skiing
e. Golf

 

 

ANS:  A

 

  Feedback
A Orofacial injuries most commonly occur in basketball, baseball, and soccer. Most injuries occur when the athlete does not wear a mouth protector. The Centers for Disease Control and Prevention (CDC) recommends that all players of contact sports use mouth protectors.
B The CDC found that football players do not sustain as many orofacial injuries as other athletes do because of required faceguards and mouth protectors. Most junior colleges and many amateur hockey and football leagues have adopted the rule mandated by the National Football Alliance Rules Committee that all high school athletes be equipped with internal mouth protectors.
C The CDC found that hockey players do not sustain as many orofacial injuries as other athletes do because of required faceguards and mouth protectors. Most junior colleges and many amateur hockey and football leagues have adopted the rule mandated by the National Football Alliance Rules Committee that all high school athletes be equipped with internal mouth protectors.
D Skiers do not sustain as many orofacial injuries as other athletes.
E Golfers do not sustain as many orofacial injuries as other athletes.

 

 

DIF:    Knowledge     REF:   p.  33             OBJ:   14

TOP:   CDA, GC, IV Laboratory materials and procedures, B Demonstrate an understanding of laboratory procedures, including but not limited to 2. fabricate custom occlusal appliances and bleaching trays        MSC:   NBDHE, 5.0 Using preventive agents, 5.3 Other preventive agents

 

  1. Which statement(s) is/are true of custom-made mouth protectors?
a. Athletes prefer the custom-made mouth protector over mouth-formed and stock mouth protectors.
b. Custom-made mouth protectors are less expensive than mouth-formed or stock mouth protectors.
c. Custom-made mouth protectors are less likely to interfere with speech than mouth-formed or stock mouth protectors.
d. A and B are correct.
e. A and C are correct.

 

 

ANS:  D

 

  Feedback
A A and C are correct.
B Mouth protectors are more expensive than mouth-formed or stock mouth protectors.
C A and C are correct.
D A and C are correct.
E Athletes prefer the custom-made mouth protector over mouth-formed and stock mouth protectors; custom-made mouth protectors are more expensive than mouth-formed or stock mouth protectors; and custom-made mouth protectors are less likely to interfere with speech than mouth-formed or stock mouth protectors.

 

 

DIF:    Comprehension                              REF:   p.  33             OBJ:   17

TOP:   CDA, GC, IV Laboratory materials and procedures, B Demonstrate an understanding of laboratory procedures, including but not limited to 2. fabricate custom occlusal appliances and bleaching trays        MSC:   NBDHE, 5.0 Using preventive agents, 5.3 Other preventive agents

 

  1. A mouth protector thickness of _____ mm of material over incisal edges and cusps of teeth is recommended for best protection and acceptable comfort.
a. 0.5
b. 1.0
c. 2.0
d. 4.0
e. 8.0

 

 

ANS:  D

 

  Feedback
A This answer provides insufficient thickness.
B This answer provides insufficient thickness.
C This answer provides insufficient thickness.
D A thickness of 4 mm of material over incisal edges and cusps of teeth is recommended for best protection and acceptable comfort.
E This answer provides excessive thickness.

 

 

DIF:    Application    REF:   p.  35             OBJ:   18

TOP:   CDA, GC, IV Laboratory materials and procedures, B Demonstrate an understanding of laboratory procedures, including but not limited to 2. fabricate custom occlusal appliances and bleaching trays        MSC:   NBDHE, 5.0 Using preventive agents, 5.3 Other preventive agents

 

  1. Which of the following represents the correct sequential order for manipulation of pit and fissure sealants that require etching with phosphoric acid?

 

  1. Cleansing and etching the occlusal surfaces
  2. Drying the occlusal surfaces
  3. Washing the occlusal surfaces
  4. Finishing the occlusal surfaces
  5. Polymerizing
  6. Applying sealant to the pits and fissures
a. 2, 1, 3, 4, 6, 5
b. 1, 2, 4, 3, 5, 6
c. 1, 3, 2, 6, 4, 5
d. 1, 3, 2, 6, 5, 4
e. 3, 1, 2, 6, 4, 5

 

 

ANS:  D

 

  Feedback
A The correct order of sequential steps is cleansing and etching the occlusal surfaces, washing the occlusal surfaces, drying the occlusal surfaces, applying sealant to the pits and fissures, polymerizing, and finishing.
B The correct order of sequential steps is cleansing and etching the occlusal surfaces, washing the occlusal surfaces, drying the occlusal surfaces, applying sealant to the pits and fissures, polymerizing, and finishing.
C The correct order of sequential steps is cleansing and etching the occlusal surfaces, washing the occlusal surfaces, drying the occlusal surfaces, applying sealant to the pits and fissures, polymerizing, and finishing.
D The correct order of sequential steps is cleansing and etching the occlusal surfaces, washing the occlusal surfaces, drying the occlusal surfaces, applying sealant to the pits and fissures, polymerizing, and finishing.
E The correct order of sequential steps is cleansing and etching the occlusal surfaces, washing the occlusal surfaces, drying the occlusal surfaces, applying sealant to the pits and fissures, polymerizing, and finishing.

 

 

DIF:    Analysis         REF:   p.  32             OBJ:   12

TOP:   CDA, GC, IV Laboratory materials and procedures, B Demonstrate an understanding of laboratory procedures, including but not limited to 2. fabricate custom occlusal appliances and bleaching trays        MSC:   NBDHE, 5.0 Using preventive agents, 5.3 Other preventive agents

 

  1. Which composition is used to help prevent caries in the pits and fissures of posterior teeth?
a. Glass ionomers
b. Polymers
c. Acrylic
d. Ceramic

 

 

ANS:  B

 

  Feedback
A Glass ionomers are cements.
B Pit and fissure sealants are polymers applied to the occlusal surfaces of posterior teeth to prevent pit and fissure caries.
C Acrylics are used to make complete dentures, portions of removable partial dentures, temporary crowns, custom impression trays, and denture teeth.
D Ceramics are used in indirect restorations.

 

 

DIF:    Knowledge     REF:   p.  28             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application)

MSC:  NBDHE, 5.0 Using preventive agents, 5.2 Pit and fissure sealants, 5.2.1 Mechanisms of action

 

  1. Neutral sodium fluoride is used for patients with composites, ceramics, and glass ionomers, because it will not _____ esthetic restorations.
a. stain
b. etch
c. marginate
d. remineralize

 

 

ANS:  B

 

  Feedback
A Stannous fluoride stains.
B With neutral sodium fluoride the pH is adjusted to be between 6 and 8. Values of pH in this range should minimize acid etching of restorative materials, such as composites, compomers, resin-modified glass ionomers, glass ionomers, and ceramics, caused by more acidic APF gels.
C The gel is neutral and therefore safe for esthetic restorations.
D Some fluoride varnishes contain ACP remineralization properties.

 

 

DIF:    Knowledge     REF:   p.  27             OBJ:   1

TOP:   CDA, GC, V Patient education and oral healthcare management; C Demonstrate the understanding of plaque control techniques, including but not limited to: Explain the effects of all types of fluoride, the advantages of various methods of administration, and the dangers and results of overdosage

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Which of the following terms describes a neutral fluoride gel containing thickening agents?
a. Wetting
b. Viscous
c. Flowable
d. Thixotropic

 

 

ANS:  D

 

  Feedback
A Wetting is related to the thickness or thinness of a material and/or surface tension.
B Viscosity is related to the thickness or thinness of a material and/or surface tension.
C Flowable is related to the thickness or thinness of a material and/or surface tension.
D Neutral sodium fluoride foams, gels, and rinses are available. One product is thixotropic and contains sodium fluoride and thickening agents.

 

 

DIF:    Knowledge     REF:   p.  28             OBJ:   2

TOP:   CDA, GC, V Patient education and oral healthcare management; C Demonstrate the understanding of plaque control techniques, including but not limited to: Explain the effects of all types of fluoride, the advantages of various methods of administration, and the dangers and results of overdosage

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Which type of fluoride may be responsible for depositing stains on teeth and restorations?
a. Acidulated phosphate
b. Neutral sodium
c. Stannous
d. Sodium

 

 

ANS:  C

 

  Feedback
A Acidulated phosphate is used as an alternative to stannous fluoride because it does not stain.
B Neutral sodium is used as an alternative to stannous fluoride because it does not stain.
C Stannous fluoride products are effective in providing fluoride but can cause staining of tooth surfaces and restorations.
D Sodium fluoride is used as an alternative to stannous fluoride because it does not stain.

 

 

DIF:    Knowledge     REF:   p.  28             OBJ:   3

TOP:   CDA, GC, V Patient education and oral healthcare management; C Demonstrate the understanding of plaque control techniques, including but not limited to: Explain the effects of all types of fluoride, the advantages of various methods of administration, and the dangers and results of overdosage

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. How should a mouth protector be stored when not in use?
a. In a cool, dry place
b. In water to prevent shrinkage
c. In the case provided by the dentist
d. In a denture cleaner to remove any bacteria present

 

 

ANS:  C

 

  Feedback
A While helpful, storing a mouth protector in a cool, dry place is not necessary.
B A mouth protector should not be stored in water.
C When the mouth protector is delivered, the athlete will be given a case to keep it in.
D Mouth protectors should be rinsed with cool water after use and occasionally cleaned with mild soap and water. Denture cleaners and abrasive dentifrices should not be used.

 

 

DIF:    Knowledge     REF:   p.  38             OBJ:   26

TOP:   CDA, GC, IV Laboratory materials and procedures, B Demonstrate an understanding of laboratory procedures, including but not limited to 2. fabricate custom occlusal appliances and bleaching trays        MSC:   NBDHE, 5.0 Using preventive agents, 5.3 Other preventive agents

 

  1. Which light spectrum is used to polymerize sealant materials?
a. Incandescent
b. Fluorescent
c. Ultraviolet
d. Visible

 

 

ANS:  D

 

  Feedback
A Incandescent light sources may affect the surface setting of resin materials. However, the optimum response comes from the visible light spectrum.
B Fluorescent light sources may affect the surface setting of resin materials. However, the optimum response comes from the visible light spectrum.
C Ultraviolet light sources may affect the surface setting of resin materials. However, the optimum response comes from the visible light spectrum.
D Sealants polymerized by visible light (490 nm wavelength) are one-component systems that require no mixing.

 

 

DIF:    Knowledge     REF:   p.  30             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. It can be difficult to fill a fissure completely with sealant due to _____ trapped in the fissure.
a. air
b. debris
c. moisture
d. all of the above

 

 

ANS:  D

 

  Feedback
A All answers are correct.
B All answers are correct.
C All answers are correct.
D Filling the fissure completely is difficult because air frequently is trapped in the bottom of the fissure, or the accumulation of debris and moisture at the base of the fissure prevents it from being sealed completely.

 

 

DIF:    Knowledge     REF:   p.  30             OBJ:   7

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.2.2 Techniques for application

 

  1. Eighty-five percent of dental caries on posterior teeth of children ages 5 to 17 occur on which surface?
a. Mesial
b. Distal
c. Buccal
d. Lingual
e. Occlusal

 

 

ANS:  E

 

  Feedback
A Mesial are smooth surfaces and are not as susceptible to formation of caries.
B Distal are smooth surfaces and are not as susceptible to formation of caries.
C Buccal are smooth surfaces and are not as susceptible to formation of caries.
D Lingual are smooth surfaces and are not as susceptible to formation of caries.
E The unusual anatomy of the pit and fissure causes such sites to exhibit a high incidence of dental caries. In fact, 84% of dental caries in children 5 to 17 years of age involve pits.

 

 

DIF:    Knowledge     REF:   p.  29             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Teeth should be etched with a _____ phosphoric solution for _____ seconds.
a. 18%; 15
b. 23%; 30
c. 37%; 60
d. 42%; 45

 

 

ANS:  C

 

  Feedback
A Etch material is dispensed at 37% dilution. It takes approximately 60 seconds to obtain an adequate etch.
B Etch material is dispensed at 37% dilution. It takes approximately 60 seconds to obtain an adequate etch.
C Etchants are generally 37% solutions of phosphoric acid in water. The solution is left on the tooth for 60 seconds before the surface is washed with a liberal amount of water for at least 15 seconds.
D Etch material is dispensed at 37% dilution. It takes approximately 60 seconds to obtain an adequate etch.

 

 

DIF:    Knowledge     REF:   p.  32             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. What should the operator do if teeth become contaminated with saliva after they are etched?
a. Re-etch, rinse, and dry.
b. Rinse the area again and dry it.
c. Use the high-velocity suction to dry.
d. Add more cotton rolls for moisture control.

 

 

ANS:  A

 

  Feedback
A If an etched tooth should become contaminated by saliva, the etching and rinsing steps are repeated.
B Contamination by saliva will decrease the ability for the sealant to bond. Therefore the tooth should be re-etched, rinsed, and dried prior to placement.
C Contamination by saliva will decrease the ability for the sealant to bond. Therefore the tooth should be re-etched, rinsed, and dried prior to placement.
D Contamination by saliva will decrease the ability for the sealant to bond. Therefore the tooth should be re-etched, rinsed, and dried prior to placement.

 

 

DIF:    Knowledge     REF:   p.  32             OBJ:   9

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.2.2 Techniques for application

 

  1. As the thickness of mouth protector material increases, the energy forces _____, and the transmitted forces _____.
a. increase; decrease
b. increase; increase
c. decrease; increase
d. decrease; decrease

 

 

ANS:  A

 

  Feedback
A As the thickness of a mouth protector material is increased from 2 to 6 mm, the energy absorption is increased, and the transmitted forces on impact are decreased. Thicker materials, however, are more uncomfortable to wear.
B As the thickness increases, it absorbs blows better and decreases transmitted forces. If the material thickness decreases, blows have an increased impact.
C As the thickness increases, it absorbs blows better and decreases transmitted forces. If the material thickness decreases, blows have an increased impact.
D As the thickness increases, it absorbs blows better and decreases transmitted forces. If the material thickness decreases, blows have an increased impact.

 

 

DIF:    Comprehension                              REF:   p.  35             OBJ:   18

TOP:   CDA, GC, IV Laboratory materials and procedures, B Demonstrate an understanding of laboratory procedures, including but not limited to 2. fabricate custom occlusal appliances and bleaching trays        MSC:   NBDHE, 5.0 Using preventive agents, 5.3 Other preventive agents

 

  1. Of the following, which would not be a sign of mouth-protector deterioration?
a. Tearing
b. Bite-through
c. Discoloration
d. General wear

 

 

ANS:  C

 

  Feedback
A The breakdown of a mouth protector usually results from one of three causes: bite-through, tearing, or a general deterioration that results from chewing the protector.
B The breakdown of a mouth protector usually results from one of three causes: bite-through, tearing, or a general deterioration that results from chewing the protector.
C Mouth-protectors do discolor and stain, but it is not necessarily a sign of deterioration.
D The breakdown of a mouth protector usually results from one of three causes: bite-through, tearing, or a general deterioration that results from chewing the protector.

 

 

DIF:    Knowledge     REF:   p.  35             OBJ:   21

TOP:   CDA, GC, IV Laboratory materials and procedures, B Demonstrate an understanding of laboratory procedures, including but not limited to 2. fabricate custom occlusal appliances and bleaching trays        MSC:   NBDHE, 5.0 Using preventive agents, 5.3 Other preventive agents

 

  1. What is the purpose of etching enamel prior to placing a sealant?
a. Improve wetting
b. Cleaning the enamel surface
c. Makes the surface smooth and uniform.
d. A and B are correct

 

 

ANS:  D

 

  Feedback
A Etching enamel improves the wetting of the enamel surface.
B Etching cleans the enamel surface and removes debris that could prevent bonding.
C Etching the enamel forms spaces for the sealant material to penetrate and form retentive tags.
D A and B are correct answers.

 

 

DIF:    Knowledge     REF:   p.  30             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants.

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.2.2 Techniques for application

 

  1. How many seconds should the light-activated sealant material be polymerized with the curing wand?
a. 10
b. 15
c. 20
d. 25

 

 

ANS:  C

 

  Feedback
A 10 seconds is inadequate for a complete cure of the material.
B 15 seconds is inadequate for a complete cure of the material.
C The visible light wand should remain activated for 20 seconds in order to provide an adequate cure of the material.
D Over-curing of the material is not necessary.

 

 

DIF:    Knowledge     REF:   p.  30             OBJ:   7

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.2.2 Techniques for application

 

  1. What is the optimum mixing time for a two-step, self-curing, sealant material?
a. 5 to 10 seconds
b. 10 to 15 seconds
c. 15 to 20 seconds
d. 20 to 25 seconds

 

 

ANS:  C

 

  Feedback
A Mixing the two components for 10 to 15 seconds will not insure a homogeneous mixture.
B The optimum mixing time for a two-step sealant material is 10 to 15 seconds.
C Mixing a two-step sealant for more than 15 seconds will reduce the operator’s working time.
D Mixing a two-step sealant for more than 15 seconds will reduce the operator’s working time.

 

 

DIF:    Knowledge     REF:   p.  30             OBJ:   7

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

SHORT ANSWER

 

  1. Identify four criteria for not using a pit and fissure sealant.

 

ANS:

Current evidence indicates that sealants should not be used on the teeth of a patient who does not cooperate in maintaining good oral hygiene, on occlusal surfaces where pits and fissures do not exist, on teeth that have been free of caries for several years, and on teeth with many proximal lesions.

 

DIF:    Application    REF:   p.  32             OBJ:   11

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.1.1 Mechanisms of action

 

  1. Discuss the significance of placing a pit and fissure sealant over existing caries.

 

ANS:

One concern is what happens to dental caries that are purposely or inadvertently left beneath sealed pits and fissures. Several studies have reported that the number of cultivable microorganisms from carious dentin left in situ in sealed pits and fissures for up to 5 years was considerably less than before sealant was applied. Sealing a suspected carious pit and fissure appears to be a reasonable clinical service if appropriate clinical observation is maintained.

 

DIF:    Comprehension                              REF:   p.  32             OBJ:   12

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) 2. Describe how to prepare, mix, deliver, and store other dental materials, including but not limited to e. pit and fissure sealants

MSC:  NBDHE, 5.0 Using preventive agents, 5.1 Fluoride: systemic and topical, 5.2.2 Techniques for application

 

  1. List the steps for cleaning a mouth protector after each use.

 

ANS:

After each use, the following steps should be performed:

  1. Rinse your mouth protector under cold tap water.
  2. Occasionally clean your mouth protector in a solution of soap and cool water.
  3. Do not scrub your mouth protector with an abrasive dentifrice.
  4. Do not use alcohol solutions or denture cleansers to clean your mouth protector.
  5. Store your mouth protector in the container provided.

 

DIF:    Knowledge     REF:   p.  38             OBJ:   26

TOP:   CDA, GC, IV Laboratory materials and procedures, B Demonstrate an understanding of laboratory procedures, including but not limited to 2. fabricate custom occlusal appliances and bleaching trays        MSC:   NBDHE, 5.0 Using preventive agents, 5.3 Other preventive agents

 

  1. Compare and contrast the three types of mouth protectors available for athletes to use.

 

ANS:

There are three types of mouth protectors available to the student athlete. They are stock, self-bite, and custom made. Stock trays can be purchased in the sporting goods section of most stores and are disliked by athletes because it is difficult to talk, and the stock mouth protector does not fit well. Self-bite, also known as boil and bite, fit marginally better, but athletes often complain of gagging and a foul taste. Custom-made mouth protectors provide the athlete with optimum coverage and ease of speech. They are also tasteless.

 

DIF:    Analysis         REF:   p.  33             OBJ:   17

TOP:   CDA, GC, IV Laboratory materials and procedures, B Demonstrate an understanding of laboratory procedures, including but not limited to 2. fabricate custom occlusal appliances and bleaching trays        MSC:   NBDHE, 5.0 Using preventive agents, 5.3 Other preventive agents

 

Chapter 05: Dental Amalgam

Powers: Dental Materials, 11th Edition

 

MULTIPLE CHOICE

 

  1. Which component of dental amalgam exists as a liquid in the capsule before trituration?
a. Tin
b. Silver
c. Copper
d. Mercury

 

 

ANS:  D

 

  Feedback
A Tin metals are solid powders.
B Silver metals are solid powders.
C Copper metals are solid powders.
D Mercury is the sole liquid in the capsule.

 

 

DIF:    Knowledge     REF:   p.  59             OBJ:   3

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. A freshly mixed mass of amalgam has a puttylike consistency for _____ minutes.
a. 1 to 2
b. 4 to 5
c. 9 to 10
d. 15

 

 

ANS:  A

 

  Feedback
A A freshly mixed mass of amalgam has a puttylike consistency for 1 to 2 minutes. The amalgam must be manipulated into the cavity preparation during this time. The amalgam progresses to a carvable consistency for an additional 2 to 4 minutes.
B This time is beyond the reaction limits, and carving after that point could result in fracture.
C This time is beyond the reaction limits, and carving after that point could result in fracture.
D This time is beyond the reaction limits, and carving after that point could result in fracture.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   1

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following is not an advantage of dental amalgam when contrasted with direct resin composite?
a. Longevity
b. Superior esthetics
c. Marginal integrity in subgingival areas
d. Ease of placement in diverse clinical situations

 

 

ANS:  B

 

  Feedback
A Longevity decreases when using an esthetic material.
B Alternate restorative materials such as direct composite suffer from clinical problems such as expense, shorter longevity, and technique sensitivity. However, amalgams are not considered esthetic materials.
C Marginal integrity decreases when using an esthetic material.
D Ease of placement decreases when using an esthetic material.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   4

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. High-copper amalgam has about _____ wt % copper.
a. 3
b. 5 to 10
c. 13 to 30
d. 30 to 40
e. 40 to 50

 

 

ANS:  C

 

  Feedback
A Low-copper amalgams have a copper content less than 13 wt % and are rarely used today.
B Low-copper amalgams have a copper content less than 13 wt % and are rarely used today.
C High-copper amalgam has about 13 to 30 wt % copper.
D This percentage is far beyond the set parameters for copper content in amalgam.
E This percentage is far beyond the set parameters for copper content in amalgam.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. High-copper amalgams have __________________ than low-copper amalgams.
a. more corrosion
b. higher strength
c. better longevity
d. A and C are correct.
e. B and C are correct.

 

 

ANS:  E

 

  Feedback
A High-copper amalgams have higher strength, less corrosion, and better longevity than low-copper amalgams.
B B and C are correct.
C B and C are correct.
D High-copper amalgams have higher strength, less corrosion, and better longevity than low-copper amalgams.
E B and C are correct.

 

 

DIF:    Comprehension                              REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which component of earlier low-copper amalgam caused a significant, unacceptable expansion of amalgam when it was contaminated with moisture during placement?
a. Mercury
b. Copper
c. Silver
d. Zinc
e. Tin

 

 

ANS:  E

 

  Feedback
A Mercury elements are used in today’s dental amalgam.
B Copper elements are used in today’s dental amalgam.
C Silver elements are used in today’s dental amalgam.
D Zinc causes a significant, long-term, and clinically unacceptable expansion of the amalgam when it is contaminated with moisture during placement. Such immediate expansion may fracture teeth.
E Tin elements are used in today’s dental amalgam.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. An admixed dental amalgam contains _______________ shaped alloy powder particles.
a. only irregularly
b. only spherically
c. neither irregularly shaped nor spherically
d. a mixture of irregularly shaped and spherically

 

 

ANS:  D

 

  Feedback
A Irregularly shaped alloy particles are used in conjunction with spherical particles.
B Spherically shaped particles require more mercury and will set faster.
C Irregularly shaped alloy particles are used in conjunction with spherical particles.
D An admixed dental amalgam alloy contains a mixture of irregularly shaped and spherical silver alloy powder particles.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following statements is true of admixed amalgam in contrast with spherical amalgam? Admixed amalgams
a. contain only irregularly shaped particles, not spherically shaped particles.
b. require more condensation force than spherical amalgams.
c. require less mercury than spherical amalgams.
d. set somewhat faster than spherical amalgams.

 

 

ANS:  B

 

  Feedback
A Admixed amalgams are a combination of irregular and spherical particles.
B Admixed amalgams require more condensation force than spherical amalgams. This property is considered an advantage to obtain good proximal contacts.
C Admixed amalgams require more mercury.
D Spherical amalgams set somewhat faster than admixed amalgams.

 

 

DIF:    Analysis         REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following elements is a liquid at room temperature?
a. Beryllium
b. Mercury
c. Gallium
d. Sodium
e. Lead

 

 

ANS:  B

 

  Feedback
A Beryllium is a solid.
B Mercury is the only metallic element in the periodic table that is a liquid at room temperature.
C Gallium melts at slightly above room temperature.
D Sodium is a solid.
E Lead is a solid.

 

 

DIF:    Knowledge     REF:   p.  59             OBJ:   3

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following delivery methods for silver amalgam exposes the staff to the least amount of mercury?
a. Mercury added to alloy particles and mixed with a mortar and pestle
b. Silver alloy powder and mercury sealed into a disposable hard plastic capsule
c. Powder compressed into tablets and mixed with mercury in a reusable mixing capsule
d. None of the above

 

 

ANS:  B

 

  Feedback
A A premeasured capsule is the recommended method of dispensing amalgam.
B The precapsulated method provides the proper ratio of alloy powder to mercury, limits exposure to mercury of the dental staff, and keeps the mercury clean.
C A premeasured capsule is the recommended method of dispensing amalgam.
D A premeasured capsule is the recommended method of dispensing amalgam.

 

 

DIF:    Knowledge     REF:   p.  59             OBJ:   3

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Elimination of which compound in the gamma-2 phase of amalgam setting increases clinical longevity in today’s high-copper amalgam restorations?
a. Silver–tin
b. Copper–tin
c. Mercury–tin
d. Silver–copper

 

 

ANS:  B

 

  Feedback
A Silver–tin is not a component of the gamma-2 phase.
B Elimination the mercury–tin compound during the gamma-2 phase increases the clinical longevity in today’s high-copper amalgam restorations.
C Copper–tin is not a component of the gamma-2 phase.
D Silver–copper is not a component of the gamma-2 phase.

 

 

DIF:    Comprehension                              REF:   p.  61             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. In the set mass of amalgam, original silver alloy particles comprise over ____% of the volume.
a. 10
b. 25
c. 50
d. 75
e. 90

 

 

ANS:  C

 

  Feedback
A Ten is too low to be useful.
B Twenty-five is too low to be useful.
C In the set mass of amalgam, original silver alloy particles comprise over 50% of the volume of the material. The set volume is significant to the strength and corrosion resistance of the product.
D Seventy-five is too high.
E Ninety is too high.

 

 

DIF:    Knowledge     REF:   p.  59             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. ________ mercury vapor is released from dental amalgam per day, as a result of chewing.
a. 1 to 2 µg
b. 2 to 4 wt %
c. 50%
d. No

 

 

ANS:  A

 

  Feedback
A In practice, minute amounts of mercury vapor (approximately 1 to 2 µg per day) are released as a result of chewing.
B This is the weight of copper content.
C This is the weight of silver by volume.
D Small amounts of mercury vapor are released while chewing.

 

 

DIF:    Knowledge     REF:   p.  60             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which phase is absent in a high-copper amalgam?
a. g
b. g1
c. h
d. g2

 

 

ANS:  D

 

  Feedback
A This phase remains in a high-copper amalgam setting.
B This phase remains in a high-copper amalgam setting.
C This phase remains in a high-copper amalgam setting.
D Gamma-2 (g2) is absent in a high-copper amalgam.

 

 

DIF:    Knowledge     REF:   p.  65             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. In its reacted state, little mercury is released from an amalgam. Little free mercury is available to be released from a set amalgam.
a. Statement 1 is correct; statement 2 is correct.
b. Statement 1 is correct; statement 2 is incorrect.
c. Statement 1 is incorrect; statement 2 is correct.
d. Statement 1 is incorrect; statement 2 is incorrect.

 

 

ANS:  A

 

  Feedback
A Both statements are correct.
B Both statements are correct.
C Both statements are correct.
D Both statements are correct.

 

 

DIF:    Comprehension                              REF:   p.  60             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. What would insufficient strength in a dental amalgam lead to?
a. Tarnish
b. Fracture
c. Expansion
d. Condensation

 

 

ANS:  B

 

  Feedback
A Tarnish is a surface reaction.
B Insufficient strength may lead to bulk fracture or marginal fracture requiring replacement.
C Some expansion and contraction is expected during the setting phases.
D Condensation relates to placement.

 

 

DIF:    Knowledge     REF:   p.  61             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following statement(s) is(are) true of the property of creep for amalgam restorations?
a. High-copper amalgams have values of creep far above old low-copper amalgams.
b. It is associated with the breakdown of marginal integrity.
c. The ANSI/ADA requires that creep be less than 3%.
d. A, B, and C are true.
e. B and C are true.

 

 

ANS:  E

 

  Feedback
A High-copper amalgams have values of creep far below old low-copper amalgams and the ANSI/ADA limits.
B Creep is associated with the breakdown or marginal integrity, and the ANSI/ADA requires that creep be less than 3%.
C Creep is associated with the breakdown or marginal integrity, and the ANSI/ADA requires that creep be less than 3%.
D A and C are correct answers.
E A and C are correct answers.

 

 

DIF:    Knowledge     REF:   p.  64             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. What is tarnish?
a. A surface phenomenon
b. Equivalent to corrosion
c. A destructive process that eventually leads to failure of the restoration
d. The result of chemical reactions that penetrate into the body of the amalgam

 

 

ANS:  A

 

  Feedback
A Tarnish is a surface phenomenon.
B Corrosion and tarnish are both prominent reactions of dental amalgam.
C Corrosion is the result of chemical reactions that penetrate into the body of the material and eventually lead to failure of the restoration.
D Corrosion is the result of chemical reactions that penetrate into the body of the material and eventually lead to failure of the restoration.

 

 

DIF:    Knowledge     REF:   p.  65             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. What is the correct order for the manipulation of amalgam?
a. Carving, condensation, mixing, and finishing
b. Condensation, finishing, mixing, and carving
c. Mixing, condensation, carving, and finishing
d. Mixing, finishing, condensation, and carving

 

 

ANS:  C

 

  Feedback
A These tasks are out of order and not viable.
B These tasks are out of order and not viable.
C The correct order for manipulation of amalgam is mixing, condensation, carving, and finishing.
D These tasks are out of order and not viable.

 

 

DIF:    Analysis         REF:   p.  66             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. How will under-triturated amalgam appear?
a. Dull
b. Soupy
c. Crumbly
d. A and C
e. B and C

 

 

ANS:  D

 

  Feedback
A Under-triturated amalgam is dull and crumbly.
B Over-triturated amalgam is wet or soupy.
C A and C are correct answers.
D A and C are correct answers.
E A and C are correct answers.

 

 

DIF:    Knowledge     REF:   p.  66             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Why are ultrasonic condensers discouraged for condensation of amalgam?
a. Increase the evaporation of mercury from the setting amalgam
b. Provide insufficient condensation force
c. Apply excessive condensation forces
d. Traumatize the dental pulp

 

 

ANS:  A

 

  Feedback
A Ultrasonic condensers are discouraged because they increase the evaporation of mercury from the setting amalgam.
B Ultrasonic condensers are discouraged because they increase the evaporation of mercury from the setting amalgam.
C Ultrasonic condensers are discouraged because they increase the evaporation of mercury from the setting amalgam.
D Ultrasonic condensers are discouraged because they increase the evaporation of mercury from the setting amalgam.

 

 

DIF:    Knowledge     REF:   p.  67             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following is the most likely route of entry for mercury into the patient and dental personnel during the manipulation of amalgam?
a. Absorption in the gut
b. Contact through skin
c. The lungs as a vapor
d. Intraoral absorption

 

 

ANS:  C

 

  Feedback
A Gut absorption is a route for exposure, but it is less common when good mercury hygiene is used.
B Skin may be a route for exposure, but it is less common when good mercury hygiene is used.
C The most likely route of entry of mercury into the patient and dental personnel is through the lungs as a vapor.
D Intraoral absorption is a route for exposure, but it is less common when good mercury hygiene is used.

 

 

DIF:    Knowledge     REF:   p.  69             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. How should amalgam scrap be handled?
a. Flushed down the drain with ample water
b. Stored in a sealed container in the refrigerator
c. Disposed of in the trash with other daily refuse
d. Stored in a sealed container containing x-ray developer
e. Stored in a sealed container containing x-ray fixer or another reducing agent

 

 

ANS:  E

 

  Feedback
A The office should have a comprehensive plan for mercury hygiene, including an amalgam separator to limit mercury efflux into the water waste. Scrap amalgam in the trash may end up in landfills and contaminate groundwater.
B The office should have a comprehensive plan for mercury hygiene, including an amalgam separator to limit mercury efflux into the water waste. Scrap amalgam in the trash may end up in landfills and contaminate groundwater.
C The office should have a comprehensive plan for mercury hygiene, including an amalgam separator to limit mercury efflux into the water waste. Scrap amalgam in the trash may end up in landfills and contaminate groundwater.
D Amalgam scrap should be stored in a sealed container containing x-ray fixer or another reducing agent.
E The office should have a comprehensive plan for mercury hygiene, including an amalgam separator to limit mercury efflux into the water waste. Scrap amalgam in the trash may end up in landfills and contaminate groundwater.

 

 

DIF:    Application    REF:   p.  69             OBJ:   9

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. The maximum permittable mercury vapor level established by OSHA is _____ mg/m per 40-hour week.
a. 0.05
b. 0.5
c. 5
d. 50

 

 

ANS:  A

 

  Feedback
A The maximum permittable mercury vapor level established by OSHA is 0.05 mg/m per 40-hour week.
B That limit is well above established OSHA guidelines.
C That limit is well above established OSHA guidelines.
D That limit is well above established OSHA guidelines.

 

 

DIF:    Knowledge     REF:   p.  69             OBJ:   9

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. When should high-volume evacuation be used with dental amalgam?
a. Placing
b. Polishing
c. Removing
d. Doing all of the above

 

 

ANS:  D

 

  Feedback
A The use of high-volume evacuation during placement, polishing, and removal of amalgam restorations reduces the exposure of the patient and the dental team to mercury vapor.
B The use of high-volume evacuation during placement, polishing, and removal of amalgam restorations reduces the exposure of the patient and the dental team to mercury vapor.
C The use of high-volume evacuation during placement, polishing, and removal of amalgam restorations reduces the exposure of the patient and the dental team to mercury vapor.
D The use of high-volume evacuation during placement, polishing, and removal of amalgam restorations reduces the exposure of the patient and the dental team to mercury vapor.

 

 

DIF:    Comprehension                              REF:   p.  69             OBJ:   9

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following statements is correct regarding today’s dental amalgam?
a. It is high in zinc.
b. It is low in copper.
c. It has high longevity.
d. It has placement issues.

 

 

ANS:  C

 

  Feedback
A Today’s amalgams are low in zinc or zinc free.
B Today’s amalgams are high in copper.
C Amalgam is a viable clinical choice where longevity, ease of placement, and clinical performance are paramount, especially when clinical conditions are challenging.
D Today’s amalgams work well in difficult placement challenges.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   1

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. At 1 day after placement, amalgam’s tensile strength most closely resembles which human structure?
a. Bone
b. Dentin
c. Enamel
d. Cementum

 

 

ANS:  B

 

  Feedback
A The strengths of bone and cementum are similar.
B The tensile strength of amalgam at 1 day is approximately the same as human dentin.
C Enamel is harder than dentin.
D The strengths of bone and cementum are similar.

 

 

DIF:    Knowledge     REF:   p.  61             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. On average, how much copper is in today’s dental alloy?
a. 4%
b. 10%
c. 20%
d. 50%

 

 

ANS:  C

 

  Feedback
A This is lower than the average amount used in today’s dental alloy.
B This is lower than the average amount used in today’s dental alloy.
C Historically, the silver alloy used in dental amalgams had low (2 to 4 wt %) amounts of copper. These alloys were combined with mercury to form low-copper amalgam. However, the development of silver alloys with higher (13% to 30%, generally about 20%) copper has replaced low-copper alloys, because high-copper alloys produce amalgams with higher strength, less corrosion, less creep, and better longevity at the margins.
D This is an excessive amount of copper and would not be considered.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following is incorrect regarding admixed alloy?
a. It makes better proximal contacts.
b. It is a mixture of particles.
c. It is easy to condense.
d. It is easier to carve.

 

 

ANS:  B

 

  Feedback
A This is a correct statement.
B If a mixture of particles is used, the alloy is referred to as an admixed alloy. Amalgams containing irregular particles with or without spherical particles added require greater packing or condensation forces during placement than amalgams with spherical particles alone. Most practitioners feel that amalgams containing irregular particles produce better proximal contacts and are easier to carve.
C This is a correct statement.
D This is a correct statement.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following is incorrect regarding spherical alloy?
a. It is easy to condense.
b. It sets faster than admixed amalgam.
c. It requires more mercury than admixed amalgam.
d. It makes better proximal contacts than admixed amalgam.

 

 

ANS:  A

 

  Feedback
A Spherical amalgams require less mercury and set somewhat faster than admixed amalgams. Practitioners generally select either a spherical or admixed amalgam, depending on the clinical situation. The importance of proper manipulation of each type cannot be overemphasized. For example, if a condensation force that is appropriate for a spherical amalgam is applied to an admixed amalgam, the restoration will likely contain voids and lack adequate proximal contacts.
B This is a correct statement.
C This is a correct statement.
D This is a correct statement.

 

 

DIF:    Comprehension                              REF:   p.  59             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Mercury is liquid at room temperature. It is one of two liquid metallic elements on the periodic table.
a. Statement 1 is correct; statement 2 is correct.
b. Statement 1 is correct; statement 2 is incorrect.
c. Statement 1 is incorrect; statement 2 is incorrect.
d. Statement 1 is incorrect; statement 2 is correct.

 

 

ANS:  B

 

  Feedback
A Statement 1 is correct, and statement 2 is incorrect.
B Mercury is a dense metal (density = 13.5 g/mL) and the only metallic element in the periodic table that is a liquid at room temperature.
C Statement 1 is correct, and statement 2 is incorrect.
D Statement 1 is correct, and statement 2 is incorrect.

 

 

DIF:    Comprehension                              REF:   p.  59             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following is a correct assessment regarding mercury vapor in amalgam?
a. Higher release may occur during the setting reaction.
b. Higher release may occur during removal of old amalgams.
c. Higher release may occur if the amalgam is heated above 80° C.
d. All of the above are correct statements.

 

 

ANS:  D

 

  Feedback
A A, B, and C are all correct statements.
B A, B, and C are all correct statements.
C A, B, and C are all correct statements.
D Higher release may occur during the setting reaction, during removal of old amalgams, or if the amalgam is heated above 80° C.

 

 

DIF:    Comprehension                              REF:   p.  60             OBJ:   7

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. The sum of ________________________ determines the overall dimensional change of an amalgam restoration.
a. compressive strength plus condensation
b. contraction and expansion during setting
c. compressive strength plus tensile strength
d. the amount of tarnish and corrosion produced

 

 

ANS:  B

 

  Feedback
A The strength of an amalgam must withstand oral forces. Insufficient strength may lead to bulk fracture or marginal fracture requiring replacement.
B Although it is somewhat confusing, expansion and contraction occur simultaneously during the setting reaction of amalgam. The dissolution of the alloy particles into the liquid mercury generally leads to contraction, whereas the formation of matrix products causes expansion. The overall dimensional change is therefore the sum of these two processes.
C When amalgam restorations are subjected to occlusal forces in service, both compressive and tensile stresses result in an amalgam restoration.
D Tarnish is a surface reaction, and corrosion eventually causes the restoration to fail.

 

 

DIF:    Knowledge     REF:   p.  63             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. How will the mixture appear if amalgam is over-triturated?
a. Puttylike consistency
b. Dry, crumbly mix
c. Wet, soupy mix
d. Hard ball

 

 

ANS:  C

 

  Feedback
A A is the result of proper trituration of the material.
B B is the result of under-triturating the material.
C Over-triturated amalgam is soupy and adheres to the inside of the capsule. It will have poorer strength and creep and may have poorer corrosion properties, all caused by over-formation of the matrix products.
D Hard ball is the result of allowing the material to stand too long unused.

 

 

DIF:    Knowledge     REF:   p.  66             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following are characteristics of under-triturated amalgam?
a. Will appear dry and crumbly
b. Does not condense well
c. Is shiny in appearance
d. A and B are correct.

 

 

ANS:  D

 

  Feedback
A Under-triturated amalgam is dry and crumble in appearance.
B Under-triturated amalgam is more difficult to condense.
C Under-triturated amalgam has a dull, crumbly appearance.
D A and B are correct.

 

 

DIF:    Knowledge     REF:   p.  66             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Amalgam should be placed in the cavity preparation by _____________ increments.
a. large to small
b. consistent size
c. small to large

 

 

ANS:  C

 

  Feedback
A Large increments placed initially may leave voids in the mass.
B Amalgam should be placed in small increments first to ensure proper condensation.
C The assistant selects the end of the instrument appropriate for the clinical needs as directed by the operator; generally, smaller increments are used initially, graduating to larger increments.

 

 

DIF:    Knowledge     REF:   p.  67             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. What is the purpose of over-packing the preparation with amalgam?
a. Adequate contour
b. Correct occlusion
c. Closed margins
d. All of the above

 

 

ANS:  D

 

  Feedback
A A, B, and C are all correct answers.
B A, B, and C are all correct answers.
C A, B, and C are all correct answers.
D The cavity preparation is always over-packed with amalgam and carved back to final contours. Over-packing allows the practitioner to control the final shape and occlusion of the restoration more closely than would be possible otherwise.

 

 

DIF:    Knowledge     REF:   p.  67             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Why is it important to use water when polishing an amalgam restoration?
a. Assures integrity of the enamel
b. Produces a high glossy finish
c. So the tooth won’t overheat
d. Insures smooth margins

 

 

ANS:  C

 

  Feedback
A Enamel integrity is compromised by using highly abrasive materials.
B A glossy finish is achieved by using abrasive polishes.
C Polishing always should be done wet (with water), because dry polishing may overheat the amalgam and tooth. Overheating may damage the pulp of the tooth and the amalgam surface by driving mercury from the amalgam.
D Margins are smoothed using abrasive stones or finishing burs to marginate the restoration.

 

 

DIF:    Knowledge     REF:   p.  68             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which of the following is a component of good mercury hygiene?
a. Using a squeeze cloth to remove excess mercury
b. Using premixed, sealed capsules
c. Handling it only with gloves on
d. Polishing using a dry technique

 

 

ANS:  B

 

  Feedback
A Premeasured capsules eliminate the need to remove excess mercury.
B The use of precapsulated amalgam limits handling of liquid mercury and reduces the possibility of a spill of liquid mercury in the office.
C Mixed amalgam should never be touched, even with gloved hands.
D Polishing should be done in a wet environment to reduce mercury vapor.

 

 

DIF:    Knowledge     REF:   p.  69             OBJ:   7

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Which component added to silver alloy causes amalgam to expand if contaminated by saliva?
a. Mercury
b. Copper
c. Zinc
d. Tin

 

 

ANS:  C

 

  Feedback
A Mercury does not cause the material to expand.
B Copper does not cause the material to expand.
C Historically, amalgams that contained zinc expanded sufficiently to fracture the tooth if they were contaminated with moisture during placement. The expansion occurred slowly over months after placement; restorations sometimes appeared to bulge out of the cavity preparation. Zinc is no longer used in silver alloy.
D Tin does not cause the material to expand.

 

 

DIF:    Knowledge     REF:   p.  64             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Of the following, which is an advantage of using spherical amalgam particles?
a. Uses less mercury
b. Easier to condense
c. Sets slower for additional working time
d. Produces a better interproximal contact

 

 

ANS:  A

 

  Feedback
A Spherical alloy requires less mercury.
B Irregular alloy is easier to condense.
C Spherical alloy sets faster.
D Spherical alloy provides a better interproximal contact.

 

 

DIF:    Comprehension                              REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

SHORT ANSWER

 

  1. Compare and contrast corrosion and tarnish.

 

ANS:

Tarnish is a surface phenomenon that can result in a discolored restoration (Table 5-2). With tarnish, the chemical reaction between the amalgam and the oral cavity is restricted to the amalgam surface. Corrosion results from chemical reactions that penetrate into the body of the amalgam (Table 5-2). Although tarnish may be undesirable esthetically, it will not often cause a restoration to fail. Corrosion, on the other hand, eventually leads to failure of the restoration. Tarnish and corrosion occur more on amalgams with rough surfaces. Thus, a well-polished amalgam limits these problems.

 

DIF:    Knowledge     REF:   p.  65             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Identify the three types of mercury and explain how each is acquired.

 

ANS:

Mercury occurs in three forms: elemental (Hg0), inorganic (Hg2+), and organic. Each of these forms has different dynamics of entry into and excretion from the body. Furthermore, we are exposed to the different forms from different sources. For example, the most common source of organic forms is fish. In general, the organic forms are the most toxic because they are most efficiently distributed to long-term storage sites in the nerve and fat tissues. Exposure to inorganic mercury is less critical because it is poorly absorbed.

 

DIF:    Knowledge     REF:   p.  69             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

  1. Compare and contrast expansion and contraction of a newly mixed amalgam.

 

ANS:

Ideally, a freshly mixed amalgam would neither expand nor contract as it sets after it is condensed into a cavity preparation. Expansion may result in post-placement sensitivity or even protrusion from the cavity, whereas contraction would leave gaps between the restoration and the tooth prone to leakage and recurrent decay.

 

DIF:    Knowledge     REF:   p.  63             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials