Dental Materials 11th Edition Powers Test Bank Chapter 01: Introduction to Restorative Dental Materials Powers: Dental Materials, 11th Edition MULTIPLE CHOICE 1. What causes caries? a. Food debris b. Materia alba c. Acidic foodstuff d. Bacterial plaque e. Salivary glycoproteins ANS: D
A B
C
D E
Feedback Food debris does not have the structural organization of bacterial plaque biofilm. Materia alba does not have the structural organization of bacterial plaque biofilm. Acidic foodstuff lowers pH and may demineralize teeth but does not directly cause decay. Caries is caused by biofilm; also known as bacterial plaque. Salivary glycoproteins form the acquired enamel pellicle to which bacteria adhere.
DIF: Knowledge REF: p. 1 OBJ: 2 TOP: CDA, GC, V, A,1b. Patient Education and Oral Health Management MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 2. Caries is most likely to occur on which of the following tooth surfaces? a. Buccal b. Lingual c. Occlusal d. Interproximal e. C and D are both correct. ANS: E
A
B
C D
Feedback Buccal surfaces are also susceptible to caries; however, there is less surface area left unchecked. Lingual surfaces are also susceptible to caries; however, there is less surface area left unchecked. Caries is most likely to occur in pits and fissures on the occlusal surface and on interproximal tooth surfaces where plaque accumulates unchecked. Caries is most likely to occur in pits and fissures on the occlusal surface and on interproximal tooth surfaces where plaque accumulates unchecked.
E
Caries is most likely to occur in pits and fissures on the occlusal surface and on interproximal tooth surfaces where plaque accumulates unchecked.
DIF: Knowledge REF: p. 1 OBJ: 2 TOP: CDA, GC, III, B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam, c. composites MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 3. Which of the following is an intracoronal restoration? a. Ceramic–alloy crown on tooth number 21 b. Ceramic veneer on tooth number 8 c. Ceramic onlay on tooth number 30 d. Ceramic inlay on tooth number 14 ANS: D
A B C
D
Feedback The alternate choices are all extracoronal restorations used to repair the external. The alternate choices are all extracoronal restorations used to repair the external. The alternate choices are all extracoronal restorations used to repair the external. A ceramic inlay on tooth number 14 is an example of an intracoronal restoration, meaning that the restoration is being used to repair damage restricted to the internal parts of a tooth. Materials such as amalgam and composite resin are used in addition to ceramic or cast metal.
DIF: Knowledge REF: p. 4 OBJ: 3 TOP: CDA, GC, III, B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam, c. composites MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 4. What is the process called where decay is removed from the tooth in order for a restoration to
be placed? a. Cavity preparation b. Convenience form c. Margination d. Extension ANS: A
A
B C D
Feedback The process is referred to as cavity preparation. Cavity preparation is used to remove diseased or damaged tissue and provide a space accessible for restoration and one that can stably retain the restoration. Convenience form is a term describing the nature of the cavity preparation. Extension is a term describing the nature of the cavity preparation. Margination is the procedure for finishing the margins of a restoration.
DIF: Knowledge
REF: p. 4
OBJ: 2
TOP: CDA, GC, III.B.1. Describe how to prepare, mix, deliver, and store restorative materials MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 5. Which of the following is an example of an intracoronal (direct) restoration? a. Laboratory-cured composite b. Dental amalgam c. Ceramic veneer d. Cast crown ANS: B
A
B
C D
Feedback Laboratory-cured composite is a restoration that is constructed away from the patient in the dental laboratory. Dental amalgam is an example of a direct restoration. All of the other restorations are prepared away from the tooth and then cemented or bonded to the tooth using a procedure that is independent of the manufacturer of the restoration. Ceramic veneer is a restoration that is constructed away from the patient in the dental laboratory. Cast crown is a restoration that is constructed away from the patient in the dental laboratory.
DIF: Knowledge REF: p. 4 OBJ: 3 TOP: CDA, GC, III.B.1. Describe how to prepare, mix, deliver, and store restorative materials MSC: NBDHE, 6.0 ProvidinTgESS upTpB orA tivNeKTS reE atL mL enEt R Se.rvCicOeM s, 6.5 General 6. Which of the following is an example of an extracoronal restoration? Choose all that apply. a. Ceramic inlay b. Ceramic–alloy crown c. Porcelain jacket crown d. A, B, and C e. A and C ANS: D
A
B
C
D
E
Feedback All three restorations involve lab procedures and are examples of indirect restorations. All three restorations involve lab procedures and are examples of indirect restorations. All three restorations involve lab procedures and are examples of indirect restorations. All three restorations involve lab procedures and are examples of indirect restorations. All three restorations involve lab procedures and are examples of indirect restorations.
DIF: Knowledge REF: p. 5 OBJ: 3 TOP: CDA, GC, III.B.1. Describe how to prepare, mix, deliver, and store restorative materials MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 7. Which of the following is an example of an extracoronal restoration? a. Disto-occlusal ceramic inlay on tooth number 29 b. Buccal Cl. V composite resin on tooth number 31 c. Mesio-occlusal gold onlay on tooth number 15 d. Mesio-occlusal amalgam on tooth number 13 ANS: C
A
B C
D
Feedback This is an example of intracoronal restoration because it fits within the internal borders of the anatomical crown. This is an example of intracoronal restoration because it fits within the internal borders of the anatomical crown. An onlay involves an inlay with extension to cover or protect a cusp. Thus a mesio-occlusal gold onlay on tooth number 15 is an example of an extracoronal restoration. This is an example of intracoronal restoration because it fits within the internal borders of the anatomical crown.
DIF: Knowledge REF: p. 5 OBJ: 3 TOP: CDA, GC, III.B.1. Describe how to prepare, mix, deliver, and store restorative materials MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General
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8. Which material is used to fill the root canal once all of the pulpal tissue has been removed? a. Silver point b. Paper points c. Dental cement d. Moisture-resistant sealer ANS: D
A B C
D
Feedback Silver master points are no longer used to fill canals. Paper points are used to dry the canal after irrigation. Dental cements may be used to seal the access opening but are not suited to fill the canals. The space created when the pulpal tissues are removed must be replaced with sealers that prevent ingress of bacteria that comes with moisture.
DIF: Knowledge REF: p. 5 OBJ: 4 TOP: CDA, GC, II. B.2. h. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to h. endodontic therapy MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 9. A(n)
is also known as a bridge.
a. b. c. d.
removable partial denture fixed partial denture abutment pontic
ANS: B
A
B
C
D
Feedback A removable partial denture may be removed by the patient and is not known as a bridge. A fixed (cemented) partial denture is commonly known as a bridge. The crown preparation portions of the bridge are called abutments, and the missing tooth replacement is called the pontic. An abutment is an individual component of a fixed partial denture and is not known as a bridge. A pontic is an individual component of a fixed partial denture and is not known as a bridge.
DIF: Knowledge REF: p. 9 OBJ: 5 TOP: CDA, GC, II. B.2. e. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to e. crown and bridge MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 10. A resin-bonded fixed partial denture is sometimes used under which conditions? a. Bridge has only one abutment. b. Abutment teeth have bT eeEnSeT ndBoA doNnKtiS caEllL yL trE eaRte.dC . OM c. Abutment teeth are healthy and free of major restorations. d. The bridge has a long span involving more than four teeth. ANS: C
A
B C
D
Feedback Placement of crowns on the abutment teeth requires substantial sacrifice of tooth structure regardless of the condition of the abutment tooth. Endodontically treated teeth become brittle over time once the blood supply has been removed. The teeth need additional reinforcement. A resin-bonded fixed partial denture may be used when the abutment teeth are healthy and free of major restorations. Case selection is critical, because retention problems may occur with this type of restoration. Long span bridges require a significant amount of retention. A resin-bonded fixed partial, bridge.
DIF: Knowledge REF: p. 10 OBJ: 5 TOP: CDA, GC, II. B.2. h. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to e. crown and bridge preparation/cementation MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 11. The
of a fixed partial denture fills the edentulous space.
a. b. c. d.
pontic obturator abutment connector
ANS: A
A
B C D
Feedback The artificial replacement tooth used to fill the edentulous space of a fixed bridge is called a pontic. An obturator is used to fill tissue defects due to an accident or disease. The crowned teeth are called abutments. A connector joins crowns to pontics.
DIF: Comprehension REF: p. 9 OBJ: 5 TOP: CDA, GC, II. B.2. e. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to e. crown and bridge preparation/cementation MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 12. Dental implants are commonly fabricated from _ a. dental amalgam b. titanium c. gold d. iron
-based metal alloys.
ANS: B
A B
C D
Feedback Dental amalgam is used to fill intracoronal restorations. Dental implants are commonly fabricated from titanium alloys. The surface of the implant may be titanium oxide or may be treated with other materials. Gold is used to fabricate extracoronal restorations. Iron is not a metal used in the oral environment.
DIF: Knowledge REF: p. 11 OBJ: 5 TOP: CDA, GC, II. B.2. m. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to m. implants MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 13. Which of the following types of implants are placed into but not through bone? a. Subperiosteal b. Transosseous c. Endosseous d. Mucosal ANS: C
A
Feedback A subperiosteal implant is placed between the bone and the overlying soft
B C
D
tissue. A transosseous (staple) implant is placed through bone (e.g., the mandible). An endosseous implant is placed into but not through bone. It is usually a single tooth form. A mucosal implant is placed between the bone and overlying soft tissue.
DIF: Knowledge REF: p. 11 OBJ: 5 TOP: CDA, GC, II. B.2. m. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to m. implants MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 14. Which of the following is an advantage of endosseous implant placement when contrasted
with fixed bridgework? Endosseous implants a. leave adjacent teeth unrestored. b. do not require invasive surgery. c. are less costly than fixed partial dentures. d. require floss threaders to clean abutment teeth. ANS: A
A B C D
Feedback Endosseous implants leave adjacent teeth unrestored. Endosseous implants require a surgical procedure. Endosseous implants are relatively costly. Fixed partial dentures require floss threaders to clean abutment teeth.
DIF: Knowledge REF: p. 11 OBJ: 5 TOP: CDA, GC, II. B.2. m. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to m. implants MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 15. Which type of crown is placed on an implant? a. Direct intracoronal b. Direct extracoronal c. Indirect intracoronal d. Indirect extracoronal ANS: D
A B C D
Feedback A direct intracoronal restoration is fabricated in the mouth. Direct extracoronal restorations for implants do not exist. An indirect intracoronal restoration is surrounded by tooth structure. An indirect extracoronal crown is placed on an implant.
DIF: Knowledge REF: p. 10 OBJ: 5 TOP: CDA, GC, II. B.2. m. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to m. implants MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General
16. When would removable partial dentures be indicated? a. Replacement of single missing teeth b. Replacement of multiple missing teeth in multiple locations c. Situations where there is a distal abutment tooth to anchor a fixed bridge d. A and C e. B and C ANS: B
A
B
C
D E
Feedback Fixed partial dentures or single tooth implants are appropriate for replacement of single missing teeth. Removable partial dentures are appropriate for replacement of multiple missing teeth in multiple locations. Removable partial dentures are appropriate for situations in which there is not a distal abutment tooth to anchor a fixed partial denture. A and C are incorrect answers. C is an incorrect answer, but B is a correct answer.
DIF: Comprehension REF: p. 12 OBJ: 5 TOP: CDA, GC, II. B.2. e. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to e. crown and bridge MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 17. The abutment teeth of a removable partial denture are engaged by what method? a. Ceramic–alloy crowns b. All-ceramic crowns c. Pontics d. Clasps ANS: D
A B C D
Feedback Abutment teeth of a removable partial denture may be restored with crowns. Abutment teeth of a removable partial denture may be restored with crowns. Pontics are artificial teeth used with fixed partial dentures to restore edentulous spaces. Abutment teeth of a removable partial denture are engaged by clasps.
DIF: Knowledge REF: p. 12 OBJ: 5 TOP: CDA, GC, II. B.2. V. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to V. removable partials or full dentures MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 18. Which of the following statements is true of removable partial dentures? a. Removable partial dentures use a framework made of acrylic. b. The partial denture framework rests on tissue.
c. The partial denture framework rests on specific abutment teeth. d. The partial denture framework rests on specific pontic teeth. ANS: C
A B C D
Feedback The framework is made of metal. The acrylic portion of a removable partial denture rests on tissue. The framework of a removable partial denture rests on specific abutment teeth. Pontic teeth are associated with fixed rather than removable partial dentures.
DIF: Knowledge REF: p. 12 OBJ: 5 TOP: CDA, GC, II. B.2. v. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to v. removable partials and full dentures MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 19. What types of teeth are bonded to the framework of removable partial dentures? a. Resin composite b. Ceramic c. Acrylic d. Alloy ANS: B
A B C D
Feedback Ceramic teeth are noTt E usSeT dB foAr N reK mSoE vaLbL leEpR ar.tiC alOdM entures. Acrylic teeth are bonded to the framework of removable partial dentures. Resin composite is used as an esthetic restorative material. Teeth cast in alloy are not used for removable partial dentures.
DIF: Knowledge REF: p. 12 OBJ: 5 TOP: CDA, GC, II. B.2. v. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to v. removable partials or full dentures MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 20. Which of the following is an advantage of removable partial dentures over fixed partial
dentures? a. Removable partial dentures are more esthetic. b. Removable partial dentures are more comfortable. c. With removable partial dentures, it is easier to clean and inspect the remaining teeth. d. Teeth adjacent to the edentulous space can be used to anchor dentures. ANS: C
A
Feedback Fixed partial dentures (fixed bridgework) are more esthetic and more comfortable.
B
C
D
Fixed partial dentures (fixed bridgework) are more esthetic and more comfortable. It is easier to clean and inspect the remaining teeth with removable partial dentures. This is a technique used with fixed partial dentures, not removable partial dentures.
DIF: Knowledge REF: p. 12 OBJ: 5 TOP: CDA, GC, II. B.2. e. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to v. removable partial or full dentures MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 21. Which type of restoration is recommended for an edentulous patient? a. Complete denture b. Fixed partial denture c. Removable partial denture d. Acid-etched resin-bonded bridge ANS: A
A
B
C D
Feedback A complete denture is appropriate for an edentulous patient. The complete denture may be fixed to tissue or to dental implants for retention. A three-unit fixed partial denture is a fixed restoration that is anchored to stable teeth in the same arcThE . STBANKSELLER.COM A removable partial denture is a fixed restoration that is anchored to stable teeth in the same arch. An acid-etched resin-bonded bridge is a fixed restoration that is anchored to stable teeth in the same arch.
DIF: Knowledge REF: p. 12 OBJ: 5 TOP: CDA, GC, II. B.2. v. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to v. removable partials or full dentures MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 22. The phrase fixed bridge is a common term to describe which type of restoration? a. Complete denture b. Fixed partial denture c. Single tooth implant d. Removable partial denture ANS: B
A B C
Feedback A complete denture is a removable denture. Fixed bridge is analogous to fixed partial denture. A single tooth implant is not an example of a multiunit restoration.
D
A removable partial denture is a removable denture.
DIF: Knowledge REF: p. 12 OBJ: 5 TOP: CDA, GC, II. B.2. e. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to e. crown and bridge MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 23. Fluoride gels, rinses, and varnishes are highly effective at treating which dental condition? a. Caries b. Drifting c. Staining d. Gingival recession ANS: A
A B C D
Feedback Fluoride gels, rinses, and varnishes are highly effective at preventing caries. Treating periodontitis and restoring edentulous spaces prevent drifting of teeth. Some forms of fluoride will stain teeth. Using the correct toothbrushing technique and avoiding periodontitis prevent gingival recession.
DIF: Knowledge REF: p. 12 OBJ: 6 TOP: CDA, GC, II. B.2. j. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to j. fluoride application MSC: NBDHE, 5.0 Using Preventive Agents, 5.1.2 Toxicology 24. Acid etching is used to bond pit and fissure sealant material to which tooth tissue? a. Enamel b. Dentin c. Cementum d. Dental pulp ANS: A
A
B C
D
Feedback Pit and fissure sealants are bonded to enamel that is typically etched with phosphoric acid before bonding. Dentin must be restored with a heavier weight material such as composite resin. Cementum must be restored with a heavier weight material such as composite resin. Dental pulp exposure must be treated endodontically.
DIF: Knowledge REF: p. 12 OBJ: 6 TOP: CDA, GC, III.D.2. e. Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to e. pit and fissure sealants MSC: NBDHE, 5.0 Using Preventive Agents, 5.2.2 Techniques for application 25. What is the purpose of mouth protectors?
a. b. c. d.
Trauma Temporomandibular arthritis Orthodontic crowding of teeth Insufficient vertical dimension
ANS: A
A B C D
Feedback Mouth protectors are used to prevent trauma to the oral structures during sports. Temporomandibular arthritis is a disease process. Orthodontic treatment is performed to relieve crowding. Insufficient vertical dimension is corrected using a partial or complete denture.
DIF: Knowledge REF: p. 12 OBJ: 6 TOP: CDA, GC. IV. B. 3. Laboratory materials and procedures MSC: NBDHE, 5.0 Using Preventive Agents, 5.3 Other preventive agents 26. Which tooth surface is most susceptible to caries in older adults? a. Pits and fissures of the occlusal surface b. Cervical smooth surface of all teeth c. Exposed root surfaces of all teeth d. Interproximal areas of all teeth ANS: C
A
B
C D
Feedback Pits and fissures of tT heEoScT clB usAaN l sKuS rfE acLeLaE reRty.pCicOaM lly more vulnerable at the time of eruption. Cervical smooth surfaces of all teeth are susceptible at any age based on oral hygiene habits. While all tooth surfaces can be susceptible to caries, exposed cementum is more vulnerable than enamel for caries formation due to its softer composition. Interproximal areas of all teeth are susceptible at any age based on oral hygiene habits.
DIF: Knowledge REF: p. 1 OBJ: 2 TOP: CDA, GC, V. A.1b. Patient Education and Oral Health Management MSC: NBDHE, 3.0 Planning and Managing Dental Hygiene Care, 3.3.2.1 Dental Caries 27. Which areas of the teeth are most susceptible to caries? a. Interproximal b. Occlusal c. Lingual d. All of the above are correct. e. Only A and B are correct. ANS: E
Feedback
A
B
C D E
Interproximal area of the teeth is difficult to keep clean, thus resulting in a higher incidence of caries forming. Occlusal surfaces are susceptible to caries because of poorly coalesced pits and fissures. Lingual surface is smooth and easier to keep clean. Not all options listed are correct. Only A and B are correct.
DIF: Knowledge REF: p. 1 OBJ: 2 TOP: CDA, GC, III.B.1. Describe how to prepare, mix, deliver, and store restorative materials MSC: NBDHE, 3.0 Planning and Managing Dental Hygiene Care, 3.3.2.1 Dental Caries 28. Which of the following tissues is most likely to be affected by periodontal disease caused by
bacterial plaque? a. Periodontal ligament b. Enamel c. Dentin d. Pulp ANS: A
A B
C
D
Feedback Unlike caries, periodontal disease affects the tissues supporting the teeth, including the gingiva, periodontal ligament, cementum, and alveolar bone. Enamel is not a supporting tissue of the teeth and therefore is not affected by periodontal disease. Dentin is not a supporting tissue of the teeth and therefore is not affected by periodontal disease. Pulp is not a supporting tissue of the teeth and therefore is not affected by periodontal disease.
DIF: Knowledge REF: p. 1 OBJ: 2 TOP: CDA, GC, V. A.1b. Patient Education and Oral Health Management MSC: NBDHE, 3.0 Planning and managing dental hygiene care, 3.3.2.1 Dental Caries 29. What is a significant cause of dental caries and periodontal disease in older adults? a. Diet b. Health c. Salivary flow d. Brushing habits ANS: C
A
B
Feedback Poor diet may contribute to caries formation and periodontal disease, but it requires additional factors to produce results. Poor health may contribute to caries formation and periodontal disease, but it requires additional factors to produce results.
C
Many older individuals experience decreased salivary production, which limits the body’s oral immune response and promotes both caries and periodontal disease.
D
Poor brushing habits may contribute to caries formation and periodontal disease but require additional factors to produce results.
DIF: Knowledge REF: p. 3 OBJ: 2 TOP: CDA, GC, V. A.1b. Patient Education and Oral Health Management MSC: NBDHE, 3.0 Planning and managing dental hygiene care, 3.3.2.1 Dental Caries 30. Of the following, which material would not be used for an intracoronal restoration? a. Amalgam b. Porcelain c. Composite resin ANS: B
A B
C
Feedback Cavity preparations may be restored with materials such as amalgam, resin composites, cast alloys, or ceramics, or less often by gold foil. Porcelain is an indirect placement material that is fabricated in the dental laboratory and cemented into place. Cavity preparations may be restored with materials such as amalgam, resin composites, cast alloys, or ceramics, or less often by gold foil.
DIF: Comprehension EF p.R. 4 COM OBJ: 3 TESTBANKSRE L:LE TOP: CDA, GC, III, B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam, c. composites MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials 31. Which of the following would not be considered an extracoronal, or indirect placement,
restoration? a. Amalgam b. Veneer c. Crown d. Onlay ANS: A
A
B C D
Feedback Extracoronal restorations are not conservative preparations and require a material strong enough to cover and support the exterior surfaces of the tooth. Veneers are extracoronal restorations that are fabricated in the dental laboratory. Crowns are extracoronal restorations that are fabricated in the dental laboratory. Onlays are extracoronal restorations that are fabricated in the dental laboratory.
DIF: Knowledge REF: p. 5 OBJ: 3 TOP: CDA, GC, III, B, 1, Describe how to prepare, mix, deliver, and store restorative materials,
including but not limited to a. amalgam, c. composites MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials 32. How would a permanent three-unit bridge be classified? a. Indirect restoration b. Direct restoration c. Intracoronal d. Extracoronal e. Both A and D are correct. ANS: E
A
B C
D
E
Feedback A permanent three-unit bridge is made outside of the mouth; therefore it is an indirect restoration. A direct restoration is placed directly into the tooth at the time of preparation. An intracoronal restoration is placed directly into the tooth either by way of an immediate restorative material or a cemented direct restoration. A permanent three-unit bridge, is comprised of extracoronal restorations soldered together into a single unit. Answers A and D are both correct.
DIF: Comprehension REF: p. 11 OBJ: 5 TOP: CDA, GC, II. B.2. e. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to e. crown and bridge MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials 33. How would a composite resin restoration be classified? a. Direct restoration b. Indirect restoration c. Intracoronal restoration d. Extracoronal restoration e. Both A and C ANS: E
A B C D
E
Feedback A composite resin restoration is placed directly into the mouth. An indirect restoration is fabricated in the dental laboratory. A composite resin restoration is placed intracoronally. An extracoronal restoration covers the outside surfaces of a tooth and is cemented into place. Both A and C are correct.
DIF: Comprehension REF: p. 10 OBJ: 5 TOP: CDA, GC, III.B.1. Describe how to prepare, mix, deliver, and store restorative materials MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials 34. Endosseous dental implants rely on which method to retain them permanently? a. Osseointegration b. Bone graft c. Resin cement d. Pins or posts e. Both A and B ANS: E
A
B
C D
E
Feedback Osseointegration is the process whereby new bone grows in and around the implant to retain it in place. A bone graft might be used prior to the implant being prepared and placed when there is not enough natural bone to retain the implant. Resin cement is not a viable option. Pins and posts are used to retain intraoral and extraoral restorations when not enough tooth structure remains. Both A and B are correct.
DIF: Knowledge REF: p. 12 OBJ: 5 TOP: CDA, GC, III.B.1. Describe how to prepare, mix, deliver, and store restorative materials MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials 35. Of the following, which is not an advantage of finishing and polishing a restoration? a. Minimized stain b. Minimized corrosion c. Minimized recurrent caries d. Minimized plaque retention ANS: D
A B C D
Feedback The statement is an advantage. The statement is an advantage. The statement is an advantage. Restoration also may be polished to minimize plaque retention and corrosion, and other abrasives may be used to finish the edges (margins) of the restoration to help prevent the recurrence of caries, but staining will not be minimized.
DIF: Comprehension REF: p. 12 OBJ: 6 TOP: CDA, GC, III.D.1. Select and describe how to manipulate the various finishing, polishing and cleaning agents MSC: NBDHE, 5.0 Using preventive agents, 5.1.2 Toxicology
36. Fluoride are commonly used to deliver fluoride to an area prepared for restoration. a. gels b. rinses c. varnishes d. filling materials ANS: C
A
B
C
D
Feedback Fluoride gels are highly effective at preventing caries through topical applications. Fluoride rinses are highly effective at preventing caries through topical applications. Fluoride gels, rinses, and varnishes are highly effective at preventing caries. Fluorides also have been incorporated into direct esthetic filling materials and cements. Fluoride varnishes are highly effective at preventing caries through topical applications.
DIF: Comprehension REF: p. 47 OBJ: 6 TOP: CDA, GC, III.B.1. Describe how to prepare, mix, deliver, and store restorative materials MSC: NBDHE, 5.0 Using preventive agents, 5.1.1 Mechanisms of action SHORT ANSWER 1. Compare and contrast intraTcE orS onTaBl A reN stK orSatEioLnL sE wR ith.C exOtrM acoronal restorations. ANS:
Intracoronal restorations are used to repair damage that is restricted to the internal parts of the tooth. Extracoronal restorations are used if the damage to the tooth is extensive, because they extend beyond the interior of the tooth to cover the cusp tips and other external surfaces. DIF: Analysis REF: pp. 4-5 OBJ: 3 TOP: CDA, GC, II. B.2. e. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to e. crown and bridge preparation/cementation MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 2. Identify an advantage to a patient who wears a partial denture. ANS:
Removable partial dentures are advantageous to the patient from the standpoint of cleaning and inspection of the remaining teeth. DIF: Knowledge REF: p. 12 OBJ: 5 TOP: CDA, GC, II. B.2. e. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to e. crown and bridge preparation/cementation MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General
3. Discuss the role of dental materials in treating trauma-related tooth injuries. ANS:
Restorative materials are used to repair teeth, stabilize them until the supporting tissues heal, or replace them. DIF: Comprehension REF: p. 12 OBJ: 5 TOP: CDA, GC, II. B.2. e. Select and describe how to prepare tray setups and all necessary armamentaria for chairside dentistry and dental emergency procedures, including but not limited to cc. temporary restoration MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.5 General 4. Describe the purpose of mouth protectors. ANS:
Mouth protectors are made of polymers that absorb the energy of facial blows and prevent this energy from affecting the teeth and facial structures. DIF: Comprehension REF: p. 12 OBJ: 6 TOP: CDA, GC, IV. B. 3. Laboratory materials and procedures MSC: NBDHE, 5.0 Using Preventive Agents, 5.3 Other preventive agents
Chapter 02: Properties of Materials Powers: Dental Materials, 11th Edition MULTIPLE CHOICE 1. For which of the following materials do dimensional changes occur during setting as a result
of a chemical reaction? a. Elastomeric impression materials b. Gold restorations c. Wax patterns d. A and C e. B and C ANS: A
A
B C D E
Feedback Dimensional changes occur during setting as a result of a chemical reaction with elastomeric impression materials. Resin composite materials also set as a result of a chemical reaction and undergo shrinkage. Gold restorations undergo dimensional changes from cooling during fabrication. Wax patterns undergo dimensional changes from cooling during fabrication. A and C are incorrect answers. B is an incorrect answer, and C is an incorrect answer.
DIF: Comprehension REF: p. 15 OBJ: 1 TOP: CDA, GC, III. ChairsiTdE eD SeTnB taA lM NaKteSriEalL sL (PE reR pa.raCtiO onM, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 2. How is the percentage of dimensional change measured? a. An original length or volume b. The final length or volume c. The compressive strength d. The tensile strength e. The shear strength ANS: A
A B C D E
Feedback The dimensional change usually is expressed as a percentage of an original length or volume, not the final length or volume. The dimensional change usually is expressed as a percentage of an original length or volume, not the final length or volume. Compressive strength is a measure of stress that may result when force is applied to a material. Tensile strength is a measure of stress that may result when force is applied to a material. Shear strength is a measure of stress that may result when force is applied to a material.
DIF: Knowledge REF: p. 15 OBJ: 1 TOP: CDA, GC, III. Chairside Dental Materials (Preparation, Manipulation and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 3. The volumetric dimensional change is equal to a. two b. three c. four d. six
times the linear dimensional change.
ANS: B
A B
C D
Feedback Two is an incorrect answer. The volumetric dimensional change is equal to three times the linear dimensional change. Volume is described as length times width times depth (or height). Four is an incorrect answer. Six is an incorrect answer.
DIF: Knowledge REF: p. 15 OBJ: 1 TOP: CDA, GC, III. Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials
ER 4. Because the thermal expanT siE onST ofBaArN esK toSraEtiL veLm at. erC iaO lM usually does not match that of the tooth structure, a differential expansion or contraction occurs that may result in leakage of oral fluids between the restoration and tooth. 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
A B C D
Feedback Statement 1 is correct; statement 2 is correct. Statement 1 is correct; statement 2 is correct. Statement 1 is correct; statement 2 is correct. Statement 1 is correct; statement 2 is correct.
DIF: Comprehension REF: p. 15 OBJ: 2 TOP: CDA, GC, III. Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 5. A new addition silicone impression material is tested for linear dimensional change upon
setting. The result of –0.34% indicates that after setting.
took place within 24 hours
a. b. c. d.
linear expansion linear shrinkage thermal expansion thermal shrinkage
ANS: B
A B C D
Feedback Linear thermal expansion is expressed as a coefficient of thermal expansion. The result is a negative number, which indicates shrinkage took place. Thermal expansion is measured by determination of the difference in the length of a specimen at two temperatures. Shrinkage is measured by determination of the difference in the length of a specimen at two temperatures.
DIF: Knowledge REF: p. 15 OBJ: 1 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 6. The thermal coefficient of expansion
and is usually a. is; lower b. is; higher c. is not; lower d. is not; higher
uniform throughout the entire temperature range for liquids than solids.
ANS: D
A B C D
Feedback The thermal coefficient of expansion for a solid generally increases at some point as the temperature is increased. The thermal coefficient of expansion for a solid generally increases at some point as the temperature is increased. The thermal coefficient of expansion for a solid generally increases at some point as the temperature is increased. The thermal coefficient of expansion is not uniform throughout the entire temperature range and is usually higher for liquids than solids.
DIF: Comprehension REF: p. 16 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 7. Which of the following restorative materials has a linear thermal coefficient of expansion that
is lower than that of human teeth? a. Ceramics b. Composites c. Dental amalgam d. Unfilled acrylics and sealants
ANS: A
A B C D
Feedback Ceramics have a linear thermal coefficient of expansion of 14. Teeth have a linear thermal coefficient of expansion of 15. The linear thermal coefficient of expansion of composites is 68. The linear thermal coefficient of expansion of dental amalgam is 28. The linear thermal coefficient of expansion of unfilled acrylics and sealants is 100.
DIF: Knowledge REF: p. 16 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 8. Which of the following dental restorative materials has a linear coefficient of thermal
expansion closest to teeth? a. Unfilled acrylics and sealants b. Glass ionomer base c. Dental amalgam d. Composites e. Gold alloys ANS: A
A B C D E
Feedback Unfilled acrylics and T seEalSanTtB s ha eS aE linLeL arEcR oe.fC ficOiM ent of thermal expansion of ANvK 70-100. Glass ionomer base has a linear coefficient of thermal expansion of 10-11. Dental amalgam has a linear coefficient of thermal expansion of 22-28. Composites have a linear coefficient of thermal expansion of 25-68. Gold alloys have a linear coefficient of thermal expansion that is closest to teeth.
DIF: Knowledge REF: p. 16 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 9. What occurs as the result of a discrepancy between the linear thermal coefficient of expansion
between teeth and the restorative material if there is no bonding? a. Stress b. Strain c. Percolation d. Yield strength e. Elastic modulus ANS: D
A
Feedback If the restoration is bonded, then stress occurs at the interface of the tooth and
B C
D E
restoration. Strain occurs as result of the change in length or deformation by unit. Percolation occurs as the result of a discrepancy between the linear thermal coefficient of expansion between teeth and the restorative material. It is thought to be undesirable due to possible irritation to the dental pulp and recurrent decay. Yield strength is affected by stress at some arbitrary value. Elastic modulus equals the ratio of stress to strain.
DIF: Knowledge REF: p. 20 OBJ: 6 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 10. Percolation is thought to decrease with time following insertion of which of the following
dental restorative materials? a. Filled resin composite b. Unfilled acrylic resin c. Dental amalgam d. Cast gold e. Ceramic ANS: D
A
B
C D
E
Feedback Filled resin composite is restoration that is either bonded or cemented into place. Percolation related to these restorations would place stress at the interface, which over time would lead T toEfS aiT luBreAoNfKthSeEbL onLdE . R.COM Unfilled acrylic resin is restoration that is either bonded or cemented into place. Percolation related to these restorations would place stress at the interface, which over time would lead to failure of the bond. Percolation is thought to decrease with time with dental amalgam, presumably as a result of the space being filled with corrosion products from the amalgam. Cast gold is restoration that is either bonded or cemented into place. Percolation related to these restorations would place stress at the interface, which over time would lead to failure of the bond. Ceramic is restoration that is either bonded or cemented into place. Percolation related to these restorations would place stress at the interface, which over time would lead to failure of the bond.
DIF: Knowledge REF: p. 16 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 11. What is used as a measurement of heat transfer? a. Linear coefficient of thermal expansion b. Thermal conductivity c. Galvanism d. Absorption e. Adsorption
ANS: B
A B C D E
Feedback Linear coefficient of thermal expansion is determined by the length of a specimen at two temperatures. Thermal conductivity is used as a measure of heat transferred. Galvanism is the generation of an electric current a patient can feel. Absorption refers to uptake of liquid. Adsorption refers to concentration of molecules at the surface of a solid or liquid.
DIF: Knowledge REF: p. 16 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 12. Which of the following dental restorative materials has the greatest thermal conductivity? a. Resin composites b. Unfilled acrylics c. Dental amalgam d. Gold alloys e. Ceramic ANS: D
A B C D E
Feedback OpMarable to tooth structure. Resin composites havT eE thSerTmBaA l cNoK nS duEcL tivLitEieRs .coCm Unfilled acrylics have lower thermal conductivity than enamel. The thermal conductivity of dental amalgam is substantially lower than gold. Gold alloys have the greatest thermal conductivity. Ceramic has thermal conductivity comparable to tooth structure.
DIF: Knowledge REF: p. 16 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 13. Which of the following dental materials has a thermal conductivity that is most similar to
tooth structure? a. Composites b. Gold alloys c. Dental amalgam d. Zinc phosphate cement e. Zinc oxide–eugenol cement ANS: B
A B
Feedback Composites have thermal conductivity most similar to tooth structure. Gold alloys have thermal conductivity higher than tooth structure.
C D E
Dental amalgam has some thermal conductivity but not at a level similar to tooth structure. Zinc phosphate cement is a poor conductor of temperature and is used for insulating bases. Zinc oxide–eugenol cement is a poor conductor of temperature and is used for insulating bases.
DIF: Knowledge REF: p. 16 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 14. Why are cavity varnishes and liners ineffective as thermal insulators? a. Used in thin layers b. High thermal conductivity c. Low coefficient of thermal expansion d. High coefficient of thermal expansion ANS: A
A B C D
Feedback Cavity varnishes and liners have low thermal conductivities but are used in layers so thin that they are ineffective as thermal insulators. Varnishes and liners have low thermal conductivity. Low coefficient of thermal expansion is a measurement of how much a material expands. High coefficient of thT erE mSaT l eBxA paNnK siS onEiL sL aE mR ea.sC urOem M ent of how much a material expands.
DIF: Knowledge REF: p. 16 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 15. Which of the following is an electrical property of interest in the mouth? a. Coefficient of thermal expansion b. Elastic modulus c. Percolation d. Galvanism e. Ductility ANS: D
A B C D
Feedback Coefficient of thermal expansion measures how much a material expands. Elastic modulus is equal to the ratio of stress to strain in the liner portion of the stress-strain curve. Percolation occurs as the result of a discrepancy between the linear thermal coefficient of expansion between teeth and the restorative material. Galvanism is an electrical property. Galvanism results from the presence of
E
dissimilar metals in the mouth. Metals placed in an electrolyte have various inherent tendencies to go into solution. Ductility is the percent of elongation.
DIF: Knowledge REF: p. 17 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 16. Given a schematic sketch of two opposing teeth, one with a temporary aluminum alloy crown
and the other with a gold crown, which one would be the electrolyte? a. Saliva b. Gold crown c. Difference in electrical potential d. Temporary aluminum alloy crown ANS: A
A B C D
Feedback The saliva functions as the electrolyte. Gold crown does not go into solution. The difference in electrical potential in this case would be 2.69 volts. The patient experiences pain and a metallic taste. Temporary aluminum alloy crown has a tendency to go into solution.
DIF: Knowledge REF: p. 17 OBJ: 2 TOP: CDA, GC, III ChairsiT deEDSeT ntB alAMNaK teS riaElsL(L PrE epRa. raC tioOnM , Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 17. What refers to the uptake of liquid by a bulk solid? a. Absorption b. Adsorption c. Hydrophilic d. Hydrophobic ANS: A
A B C D
Feedback Absorption refers to the uptake of liquid by a bulk solid. Adsorption indicates concentration of molecules at the surface of a solid or liquid. Hydrophilic surface is readily wetted if the solution is water. Hydrophobic surface is resistant to wetting if the solution is water.
DIF: Knowledge REF: p. 17 OBJ: 3 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials
18. Which of the following terms indicates concentration of molecules at the surface of a solid or
liquid? a. Corrosion b. Adsorption c. Absorption d. Hydrophilic ANS: B
A B C D
Feedback Corrosion is the dissolution of metals in the mouth. Adsorption indicates concentration of molecules at the surface of a solid or liquid. Absorption is the uptake of liquid by a bulk solid. Hydrophilic surface is readily wetted if the solution is water.
DIF: Knowledge REF: p. 17 OBJ: 3 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 19. With regard to wettability and water, what does a low contact angle indicate? a. The material is hydrophilic. b. The material is hydrophobic. c. The contact angle is greater than 90°. d. Both A and C are correct. e. Both B and C are correT ctE. STBANKSELLER.COM ANS: A
A B C D E
Feedback A low contact angle indicates the material is hydrophilic. If the contact angle is greater than 90°, poor wetting occurs. The material is considered hydrophobic if the liquid is water. A is correct, and C is incorrect. B and C are incorrect.
DIF: Comprehension REF: p. 18 OBJ: 4 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 20. Which of the following choices encourage good wetting? a. Low-energy solid b. High-energy solid c. High-energy liquid d. A and C are correct. e. B and C are correct. ANS: A
A B C D E
Feedback Liquids bead up on low-energy solids. High-energy solids and low-energy liquids encourage good wetting. High-energy liquids can be made more wettable by adding a wetting agent. A is correct, and C is incorrect. B and C are incorrect.
DIF: Comprehension REF: p. 18 OBJ: 4 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 21. On which teeth are the greatest biting forces located? a. Molars b. Canines c. Incisors d. Premolars ANS: A
A B C D
Feedback The greatest biting forces are on molars. Canines’ maximum biting forces decrease from the molar to the incisor region. Premolars’ maximum biting forces decrease from the molar to the incisor region. Incisors’ maximum biting forces decrease from the molar to the incisor region.
DIF: Knowledge REF: TpE . S1T 8 BANKS OE BL J:LE 5 R.COM TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 22. Patients with dentures can apply about a. 10 b. 19 c. 50 d. 90 e. 150
% of the force of those with normal dentition.
ANS: B
A B C D E
Feedback Patients with dentures can apply about 19% of the force of those with normal dentition. Patients with dentures can apply about 19% of the force of those with normal dentition. Patients with dentures can apply about 19% of the force of those with normal dentition. Patients with dentures can apply about 19% of the force of those with normal dentition. Patients with dentures can apply about 19% of the force of those with normal
dentition. DIF: Knowledge REF: p. 18 OBJ: 5 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 23. What is the ratio of the force to the area called? a. Stress b. Strain c. Tensile strength d. Elastic modulus ANS: A
A B C D
Feedback The ratio of the force to the area is called stress. Strain changes in length per unit of a material produced by stress. Tensile strength results when a material fractures from tensile stress. Elastic modulus is equal to the ratio of the stress to the strain.
DIF: Knowledge REF: p. 18 OBJ: 5 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 24. For a given force, the
stress. a. smaller; smaller b. smaller; larger c. larger; larger d. A and C e. B and C
e area over which it is applied, the TEStThB ANKSELLER.COM
the value of the
ANS: B
A B C D E
Feedback The smaller the area over which force is applied, the larger the value of stress. The smaller the area over which force is applied, the larger the value of stress. The smaller the area over which force is applied, the larger the value of stress. The smaller the area over which force is applied, the larger the value of stress. The smaller the area over which force is applied, the larger the value of stress.
DIF: Comprehension REF: p. 18 OBJ: 5 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 25. Which of the following statements is true of the proportional limit? a. Below the proportional limit a material is plastic, and above the proportional limit
it is elastic.
b. Below the proportional limit a material is elastic, and above the proportional limit
it is plastic. c. A material is elastic both below and above the proportional limit. d. A material is plastic both below and above the proportional limit. ANS: B
A B C D
Feedback A restoration can be classified as a clinical failure if deformation occurs beyond set limits. Below the proportional limit a material is elastic, and above the proportional limit it is plastic. A restoration can be classified as a clinical failure if deformation occurs beyond set limits. A restoration can be classified as a clinical failure if deformation occurs beyond set limits.
DIF: Knowledge REF: p. 20 OBJ: 6 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 26. Which of the following statements is true of the tensile and compressive strengths of a
material? a. They may be significantly different. b. Brittle materials are stronger in tension than in compression. c. Brittle materials have sT mEaS ll T diB ffA erNenKcSesEiL nLteEnR si. leCaO ndMcompressive strength. d. A, B, and C are true. e. A and C are true. ANS: A
A B C D E
Feedback The tensile and compressive strength of a material may be significantly different. Brittle materials such as human enamel, amalgam, and composites have large differences and are stronger in compression than in tension. Brittle materials such as human enamel, amalgam, and composites have large differences and are stronger in compression than in tension. Brittle materials such as human enamel, amalgam, and composites have large differences and are stronger in compression than in tension. Brittle materials such as human enamel, amalgam, and composites have large differences and are stronger in compression than in tension.
DIF: Comprehension REF: p. 20 OBJ: 6 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 27. “Measures the energy required to fracture a material” is the definition of which term? a. Ductility
b. Resilience c. Toughness d. Malleability ANS: C
A B C D
Feedback Ductility is the percent of elongation. Resilience is the energy required to deform a material. The energy required to fracture a material is a measure of its toughness. Malleability is the percent of compression.
DIF: Analysis REF: p. 21 OBJ: 7 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 28. Which of the following statements is true of the measure of Knoop hardness? a. It is obtained by measurement of the short diagonal of an indentation from a
diamond indenter. b. Enamel has a lower Knoop hardness value than dentin and cementum. c. Hardness is directly related to yield strength and wear resistance. d. The larger the indentation, the smaller the value. ANS: D
A B C D
Feedback In general, no direct rT elE atS ioTnsBhA ipNeKxS isE tsLbL etE wR ee.nChO arMdness and yield strength and wear resistance. Enamel has a higher Knoop hardness value than dentin and cementum. In general, no direct relationship exists between hardness and yield strength and wear resistance. The larger the indentation of the measurement of the long diagonal from a diamond indenter, the smaller the Knoop hardness value.
DIF: Analysis REF: p. 21 OBJ: 8 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 29. Analysis of the strain–time curve indicates that the
the time and the force applied to the impression material, the lower the permanent strain and the more accurate the impression. a. shorter; less b. longer; less c. shorter; more d. longer; more ANS: A
Feedback
A B C D
The shorter the time and the less force applied to the impression material, the lower the permanent strain and the more accurate the impression. Longer time will result in more force to the material. Shorter time will result in less force to the material. Longer time will result in more force to the material and compromise the accuracy of the impression.
DIF: Analysis REF: p. 22 OBJ: 9 TOP: CDA, GC, V. A.1b. Patient Education and Oral Health Management MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 30. Dimensional change may occur during setting as a result of which factor? a. Volumetric change b. Chemical reaction c. Cooling d. All of the above e. B and C are correct. ANS: E
A B C D E
Feedback Volumetric change is more difficult to measure. B and C are correct answers. B and C are correct answers. B and C are correct answers. Dimensional changesTmEaS yT ocBcA urNdKuS riE ngLsLeE ttiR ng.C asOaMresult of a chemical reaction, such as with elastomeric impression materials or resin composite restorative materials, or from the cooling of wax patterns or gold restorations during fabrication.
DIF: Comprehension REF: p. 15 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 31. Expansion and contraction rates between dental materials and tooth structure caused by
temperature change vary. Gaps at the margins allow fluids to enter the space. What is this known as? a. Coefficient of thermal expansion b. Thermal conductivity c. Dimensional change d. Percolation ANS: D
A B
Feedback Coefficient of thermal expansion is expressed as the linear difference of a specimen at two temperatures. Thermal conductivity is used to measure heat transference.
C D
Dimensional change is expressed as a percent of the original length. Small gaps result at the junction between the two materials. Oral fluids can penetrate this space. When the temperature returns to normal, this fluid is forced out of the space. This phenomenon is called percolation.
DIF: Knowledge REF: p. 16 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 32. Of the following materials, which has the closest coefficient of expansion to tooth structure? a. Ceramic b. Amalgam c. Filled polymers d. Composite resins ANS: A
A B C D
Feedback Ceramic is the closest, being one half to one third, and gold alloys being approximately the same as for human teeth. Values for amalgam and composites are about two to five times those of human teeth. Values for unfilled polymers, however, are five to seven times those of teeth. Values for amalgam and composites are about two to five times those of human teeth.
DIF: Knowledge REF: p. 16 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 33. Which of the following materials has the highest rating related to thermal conductivity? a. Glass ionomer b. Gold alloy c. Enamel d. Dentin ANS: B
A B C D
Feedback Glass ionomer cement bases closely replace lost tooth structure with respect to thermal conductivity. Human enamel and dentin are poor thermal conductors compared with gold alloys and dental amalgam, although amalgam is substantially lower than gold. Human enamel and dentin are poor thermal conductors. Human enamel and dentin are poor thermal conductors.
DIF: Knowledge REF: p. 16 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application)
MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 34. What causes corrosion? a. Contact of two dissimilar metals in the mouth b. Poor oral hygiene around restorations c. Acidic food and drink d. A and C are correct. ANS: D
A B C D
Feedback A and C are correct. Poor oral hygiene around restorations may result in recurrent caries formation. Corrosion also may result from chemical attack of metals by components in food or saliva. Corrosion also can result from this same condition when adjacent restorations are of dissimilar metals. Corrosion may also be a factor due to chemical attacks for food and saliva in the mouth.
DIF: Knowledge REF: p. 17 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 35. Which term refers to the cause of a metallic taste in the mouth? a. Corrosion b. Galvanism c. Percolation d. Contamination ANS: B
A B
C
D
Feedback Corrosion is a result of the same condition. As a result of the galvanic action, material goes into solution, and roughness and pitting occur. When the two restorations touch, current flows because the potential difference is 2.69 volts, and the patient experiences pain and frequently complains of a metallic taste. Small gaps result at the junction between the two materials. Oral fluids can penetrate this space. When the temperature returns to normal, this fluid is forced out of the space. This phenomenon is called percolation. Corrosion may occur if a gold alloy is contaminated with a metal such as iron during handling in the dental laboratory.
DIF: Knowledge REF: p. 17 OBJ: 2 TOP: CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) MSC: NBDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and Manipulation of Materials 36. What is a material called if a liquid presents a contact angle of wettability greater than 90°?