Which one of the following is the major disadvantage of stone dies used for crown fabrication, A. They lack accurate reproduction of surface details B. Their overall dimensions are slightly smaller than the original impression C. The strength of the stone D. The hazard of aspiration of toxic materials during trimming of the dies.

Which one of the following is the major disadvantage of stone dies used for crown fabrication,
A. They lack accurate reproduction of surface details
B. Their overall dimensions are slightly smaller than the original impression
C. The strength of the stone
D. The hazard of aspiration of toxic materials during trimming of the dies.
by

1 Answer

Answer :

A. They lack accurate reproduction of surface details
by

Related questions

A crown casting with a chamfer margin fits the die; but in the mouth the casting is open approximately 0.3mm. A satisfactory fit and accurate physiological close of the gingival area of the crown can BEST be achieved by: A. Hand burnishing B. Mechanical burnishing C. Using finishing burs and points to remove the enamel margins on the tooth D. Making a new impression and remaking the crown E. Relieving the inside of the occlusal surface of the casting to allow for further

Description : A crown casting with a chamfer margin fits the die; but in the mouth the casting is open approximately 0.3mm. A satisfactory fit and accurate physiological close of the gingival area of the crown ... the crown E. Relieving the inside of the occlusal surface of the casting to allow for further

Last Answer : D. Making a new impression and remaking the crown

When should metallic framework not be contaminated during the fabrication of a porcelain fused to metal crown: A. Between bisque stage and glazing stage B. Between preheat and opaque stages C. Between opaque and bisque stages D. Between one opaque and two opaque stages

Description : When should metallic framework not be contaminated during the fabrication of a porcelain fused to metal crown: A. Between bisque stage and glazing stage B. Between preheat and opaque stages C. Between opaque and bisque stages D. Between one opaque and two opaque stages

Last Answer : B. Between preheat and opaque stages

The ideal length of core in the fabrication of crown and core of endodontically treated tooth is, A. 1.5 of crown length B. The length of the crown C. 2/3 tooth/root length D. ½ root length

Description : The ideal length of core in the fabrication of crown and core of endodontically treated tooth is, A. 1.5 of crown length B. The length of the crown C. 2/3 tooth/root length D. ½ root length

Last Answer : C. 2/3 tooth/root length

A cast crown fits on the die but not on the tooth, the discrepancy is about 0.3mm, what would you do: A. Relieve cast from the inside B. Take a new impression and make new crown C. Burnish margins D. Use thick mix of cement

Description : A cast crown fits on the die but not on the tooth, the discrepancy is about 0.3mm, what would you do: A. Relieve cast from the inside B. Take a new impression and make new crown C. Burnish margins D. Use thick mix of cement

Last Answer : B. Take a new impression and make new crown

An impression with elastomer in custom tray has been taken for crown preparation; it will be two days before the impression gets to the laboratory for construction of the crown. Which impression material is preferred? A. Polyether B. Thiokol or meraptan rubber C. Condensation silicone D. Vinyl polysiloxane

Description : An impression with elastomer in custom tray has been taken for crown preparation; it will be two days before the impression gets to the laboratory for construction of the crown. Which impression ... A. Polyether B. Thiokol or meraptan rubber C. Condensation silicone D. Vinyl polysiloxane

Last Answer : D. Vinyl polysiloxane

The disadvantage of heating the impression compound in a water bath is: A. It may become brittle B. It may become grainy C. Lower moles with constituents are leached out D. The plasticity of the compound may be altered E. All of the above

Description : The disadvantage of heating the impression compound in a water bath is: A. It may become brittle B. It may become grainy C. Lower moles with constituents are leached out D. The plasticity of the compound may be altered E. All of the above

Last Answer : D. The plasticity of the compound may be altered

In the construction of a full veneer gold crown, future recession of gingival tissue can be prevented or at least minimised by, A. Extension of the crown 1 mm under the gingival crevice B. Reproduction of normal tooth incline in the gingival one third of the crown C. Slight over contouring of the tooth in the gingival one fifth of the crown D. Slight under contouring of the tooth in the gingival one fifth of the crown

Description : In the construction of a full veneer gold crown, future recession of gingival tissue can be prevented or at least minimised by, A. Extension of the crown 1 mm under the gingival crevice B. ... of the crown D. Slight under contouring of the tooth in the gingival one fifth of the crown

Last Answer : B. Reproduction of normal tooth incline in the gingival one third of the crown

The polysulfide rubber impression materials are: A. Not sensitive to temperature when curing B. Quite sensitive to temperature when curing C. Less sensitive to temperature than silicone rubber D. The same sensitivity to temperature as silicone rubber E. None of the above

Description : The polysulfide rubber impression materials are: A. Not sensitive to temperature when curing B. Quite sensitive to temperature when curing C. Less sensitive to temperature than silicone rubber D. The same sensitivity to temperature as silicone rubber E. None of the above

Last Answer : B. Quite sensitive to temperature when curing

Dental impression materials are hydrocolloids of: A. The emulsoid type B. The suspension type C. The sol type D. The gel type E. None of the above

Description : Dental impression materials are hydrocolloids of: A. The emulsoid type B. The suspension type C. The sol type D. The gel type E. None of the above

Last Answer : A. The emulsoid type

During mouth preparation for RPD on tooth adjacent to edentulous area. There is dentine exposure: A. Restoration is required B. Proceed with rest seat preparation and fabrication if involved area is not more than 2mm

Description : During mouth preparation for RPD on tooth adjacent to edentulous area. There is dentine exposure: A. Restoration is required B. Proceed with rest seat preparation and fabrication if involved area is not more than 2mm

Last Answer : A. Restoration is required

The major cause of jacket crown breakage is, A. Inclusion of platinum foil B. Use of weak cementum C. Voids of porcelain D. Porcelain is thinner than 1mm

Description : The major cause of jacket crown breakage is, A. Inclusion of platinum foil B. Use of weak cementum C. Voids of porcelain D. Porcelain is thinner than 1mm

Last Answer : D. Porcelain is thinner than 1mm

What is the best way to apply aspiration before injection: A. Short, sharp pressure backwards B. Pressure for 2 to 3 seconds C. Long pressure D. Turning the needle 90° between two aspirations

Description : What is the best way to apply aspiration before injection: A. Short, sharp pressure backwards B. Pressure for 2 to 3 seconds C. Long pressure D. Turning the needle 90° between two aspirations

Last Answer : A. Short, sharp pressure backwards

cyst at the apex of an upper central incisor measuring 1 cm in diameter is visualized in radiograph and confirmed by aspiration biopsy; which method of treatment would you consider?** A. Extraction of the central incisor and retrieving the cyst through the socket B. Exteriorizing the cyst through the buccal bone and mucosa C. Making a mucoperiosteal flap and removing the cyst through an opening made in the alveolar bone, followed by tooth removal. D. Making a mucoperiosteal flap and removing the cyst through an opening made in the alveolar bone, followed by endodontic treatment. E. Routine orthograde endodontic treatment followed by observation.

Description : cyst at the apex of an upper central incisor measuring 1 cm in diameter is visualized in radiograph and confirmed by aspiration biopsy; which method of treatment would you consider?** ... bone, followed by endodontic treatment. E. Routine orthograde endodontic treatment followed by observation.

Last Answer : D. Making a mucoperiosteal flap and removing the cyst through an opening made in the alveolar bone, followed by endodontic treatment.

“Pop off” of a porcelain veneer from the under the lying gold crown is due to:** A. Too thick application of pure gold surface conditioner B. Contamination at the porcelain metal interface C. Under firing the opaque layer D. All of the above

Description : “Pop off” of a porcelain veneer from the under the lying gold crown is due to:** A. Too thick application of pure gold surface conditioner B. Contamination at the porcelain metal interface C. Under firing the opaque layer D. All of the above

Last Answer : B. Contamination at the porcelain metal interface

When you try to seat a crown on a tooth you find a discrepancy of 0.3mm at the margin; you will: A. Reduce inner surface of crown B. Remake a new crown C. Smooth the enamel at the margin D. Hand burnish crown margins

Description : When you try to seat a crown on a tooth you find a discrepancy of 0.3mm at the margin; you will: A. Reduce inner surface of crown B. Remake a new crown C. Smooth the enamel at the margin D. Hand burnish crown margins

Last Answer : B. Remake a new crown

.When correction preparation for re contouring of occlusal surface is to be applied, grinding only of the adjusted surface: A. Should not be felt flat B. Requires a flat crown C. Requires no contact with adjacent teeth D. Should be felt flat

Description : .When correction preparation for re contouring of occlusal surface is to be applied, grinding only of the adjusted surface: A. Should not be felt flat B. Requires a flat crown C. Requires no contact with adjacent teeth D. Should be felt flat

Last Answer : A. Should not be felt flat

When primary molars are prepared for stainless steel crowns, should the depth for reduction of the proximal surface be similar to the depth of the buccal and lingual surfaces? A. Yes; reduction of all wall is similar for best retention B. No, proximal reduction is greater to allow the crown to pass the contact area C. No, the buccal surfaces has the greatest reduction to remove the cervical bulge D. Yes, all undercuts are uniformly removed so that the steel crown can be seated E. No, because of lateral constriction, the lingual surface needs greatest reduction

Description : When primary molars are prepared for stainless steel crowns, should the depth for reduction of the proximal surface be similar to the depth of the buccal and lingual surfaces? A. Yes; reduction ... can be seated E. No, because of lateral constriction, the lingual surface needs greatest reduction

Last Answer : B. No, proximal reduction is greater to allow the crown to pass the contact area

The major disadvantage of self-threaded pins is: A. Friction locked B. Too expensive C. Not all sizes available D. May cause tooth cracking

Description : The major disadvantage of self-threaded pins is: A. Friction locked B. Too expensive C. Not all sizes available D. May cause tooth cracking

Last Answer : D. May cause tooth cracking

Which of the following is a major disadvantage to immediate complete denture therapy: A. Trauma to extraction site FB. Increased the potential of infection C. Impossibility for anterior try in D. Excessive resorption of residual ridge

Description : Which of the following is a major disadvantage to immediate complete denture therapy: A. Trauma to extraction site FB. Increased the potential of infection C. Impossibility for anterior try in D. Excessive resorption of residual ridge

Last Answer : C. Impossibility for anterior try in

Which of the following is a major disadvantage to immediate complete denture therapy, A. Trauma to extraction site B. Increased potential of infection C. Impossibility for anterior try in D. Excessive resorption of residual ridge

Description : Which of the following is a major disadvantage to immediate complete denture therapy, A. Trauma to extraction site B. Increased potential of infection C. Impossibility for anterior try in D. Excessive resorption of residual ridge

Last Answer : C. Impossibility for anterior try in

In the construction of partial dentures the surveyor is not used to, A. Contour the wax as part of the fabrication of the working cast B. Locate the guide planes C. Determine the location of indirect retainers D. Identify any undesirable undercuts

Description : In the construction of partial dentures the surveyor is not used to, A. Contour the wax as part of the fabrication of the working cast B. Locate the guide planes C. Determine the location of indirect retainers D. Identify any undesirable undercuts

Last Answer : A. Contour the wax as part of the fabrication of the working cast

Why would you invest the wax pattern as soon as possible in an indirect inlay fabrication: A. Minimise distortion B. Avoid contraction C. Avoid expansion

Description : Why would you invest the wax pattern as soon as possible in an indirect inlay fabrication: A. Minimise distortion B. Avoid contraction C. Avoid expansion

Last Answer : A. Minimise distortion

A partial denture that seats on the master cast but fails to seat correctly in the mouth is a result of, A. Contraction of the metal framework during casting B. Insufficient expansion of the investment material C. Distortion of impression D. Failure to block out unwanted undercuts

Description : A partial denture that seats on the master cast but fails to seat correctly in the mouth is a result of, A. Contraction of the metal framework during casting B. Insufficient expansion of the investment material C. Distortion of impression D. Failure to block out unwanted undercuts

Last Answer : C. Distortion of impression

The most accurate way to evaluate the effectiveness of root planning is by: A. Inspect the root surface with an instrument for root smoothness B. Use air for visual inspection C. Activate a curette against root surface and listen for a high pitched sound which indicates a smooth, hard surface. D. Evaluate the soft tissue at the end of the appointment for a decrease oedema and bleeding E. Evaluate the soft tissues 10 to 14 days later.

Description : The most accurate way to evaluate the effectiveness of root planning is by: A. Inspect the root surface with an instrument for root smoothness B. Use air for visual inspection C. Activate a ... the appointment for a decrease oedema and bleeding E. Evaluate the soft tissues 10 to 14 days later.

Last Answer : E. Evaluate the soft tissues 10 to 14 days later.

Rough surface/Porosity of porcelain is a result of: A. Lack of compression/ condensation B. Sudden high temperature

Description : Rough surface/Porosity of porcelain is a result of: A. Lack of compression/ condensation B. Sudden high temperature

Last Answer : A. Lack of compression/ condensation

When describing a removable partial denture, the minor connector refers to:** A. Rigid components anterior to the premolar teeth B. Flexible components, in contrast to rigid major connectors C. Smaller connectors which connect denture components to the major connector D. The components of the denture base which provides reciprocation

Description : When describing a removable partial denture, the minor connector refers to:** A. Rigid components anterior to the premolar teeth B. Flexible components, in contrast to rigid major connectors ... components to the major connector D. The components of the denture base which provides reciprocation

Last Answer : C. Smaller connectors which connect denture components to the major connector

Which of the following restoration material’s strength is not effected by pins: A. Amalgam B. Composite resin

Description : Which of the following restoration material’s strength is not effected by pins: A. Amalgam B. Composite resin

Last Answer : B. Composite resin

Which of the following is true regarding preparation of custom tray for elastomeric impression: a. Adhesive is preferred over perforation. b. Perforation provides adequate retention c. Adhesive is applied immediately before procedure d. Perforations are not made in the area over the prepared tooth .

Description : Which of the following is true regarding preparation of custom tray for elastomeric impression: a. Adhesive is preferred over perforation. b. Perforation provides adequate retention c. Adhesive is ... before procedure d. Perforations are not made in the area over the prepared tooth .

Last Answer : a. Adhesive is preferred over perforation.

The removable partial denture requires relining what would be the most appropriate action, A. take a new impression by asking the patient to occlude on it B. Provide equal space (maybe it was thickness) between denture and gingival tissues. C. Make sure the framework and retainers are seated in place before taking impression

Description : The removable partial denture requires relining what would be the most appropriate action, A. take a new impression by asking the patient to occlude on it B. Provide equal space (maybe it was ... gingival tissues. C. Make sure the framework and retainers are seated in place before taking impression

Last Answer : C. Make sure the framework and retainers are seated in place before taking impression

How long should acrylic self-cure special trays been made prior to taking impression: A. 12 hrs B. Immediately after fabricating it C. After been left in water for an hour D. Wait for an hour before pouring

Description : How long should acrylic self-cure special trays been made prior to taking impression: A. 12 hrs B. Immediately after fabricating it C. After been left in water for an hour D. Wait for an hour before pouring

Last Answer : A. 12 hrs

Elastomers are:** A. Hydrophilic B. Hydrophobic C. Water-loving impression material D. Potassium alginates E. None of the above

Description : Elastomers are:** A. Hydrophilic B. Hydrophobic C. Water-loving impression material D. Potassium alginates E. None of the above

Last Answer : B. Hydrophobic

Fusion temperature of impression compound should occur: A. Below mouth temperature B. Above mouth temperature C. As of the skin temperature D. At the room temperature E. None of the above

Description : Fusion temperature of impression compound should occur: A. Below mouth temperature B. Above mouth temperature C. As of the skin temperature D. At the room temperature E. None of the above

Last Answer : B. Above mouth temperature

After making an impression to reline an RPD the dentist notes that the indirect retainers are not resting on the tooth. To avoid this, what process should have undertaken initially: A. Ask patient to bite firmly while impression is setting B. Hold the metal base frame against the abutment tooth while setting C. Fabricate new denture D. Add impression material and close the gap

Description : After making an impression to reline an RPD the dentist notes that the indirect retainers are not resting on the tooth. To avoid this, what process should have undertaken initially: A. Ask ... abutment tooth while setting C. Fabricate new denture D. Add impression material and close the gap

Last Answer : B. Hold the metal base frame against the abutment tooth while setting

Which impression material should NOT be kept in water within on hour: (in another paper it was: 30 mins before pouring) A. Polyether B. Condensation silicone C. Polyvinyl silicone

Description : Which impression material should NOT be kept in water within on hour: (in another paper it was: 30  mins before pouring)  A. Polyether  B. Condensation silicone  C. Polyvinyl silicone 

Last Answer : A. Polyether 

.Which of the following is true regarding preparation of custom tray for elastomeric impression: A. Adhesive is preferred over perforation B. Perforation provides adequate retention C. Adhesive is applied immediately before procedure D. Perforations are not made in the area over the prepared tooth

Description : .Which of the following is true regarding preparation of custom tray for elastomeric impression: A. Adhesive is preferred over perforation B. Perforation provides adequate retention C. Adhesive is ... immediately before procedure D. Perforations are not made in the area over the prepared tooth

Last Answer : A. Adhesive is preferred over perforation

To minimize the load on a free-end saddle partial denture: (distal extension saddle) A. Use teeth with narrow Buccal-Lingual dimension B. Use mucco-compressive impression

Description : To minimize the load on a free-end saddle partial denture: (distal extension saddle) A. Use teeth with narrow Buccal-Lingual dimension B. Use mucco-compressive impression

Last Answer : B. Use mucco-compressive impression

.Oil or water on impression for treatment casts causes: A. An increase of the quality B. No alteration C. A decrease of the quality D. Bubbles on the cast

Description : .Oil or water on impression for treatment casts causes: A. An increase of the quality B. No alteration C. A decrease of the quality D. Bubbles on the cast

Last Answer : C. A decrease of the quality

Plasticisers are added to synthetic plastics to (A) Impart flexibility (B) Improve workability during fabrication(C) Develop new improved properties not present in the original resin(D) All (A), (B) and (C)

Description : Plasticisers are added to synthetic plastics to (A) Impart flexibility (B) Improve workability during fabrication (C) Develop new improved properties not present in the original resin (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Plasticisers are added to synthetic plastics to (A) Impart flexibility (B) Improve workability during fabrication (C) Develop new improved properties not present in the original resins (D) All (A), (B) and (C)

Description : Plasticisers are added to synthetic plastics to (A) Impart flexibility (B) Improve workability during fabrication (C) Develop new improved properties not present in the original resins (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

The major DISADVANTAGE of a mail survey versus a telephone or personal interview survey is 1. having to offer incentives 2. the low response rate 3. the elimination of interview bias 4. the lack of open-ended questions 5. cos

Description : The major DISADVANTAGE of a mail survey versus a telephone or personal interview survey is 1. having to offer incentives 2. the low response rate 3. the elimination of interview bias 4. the lack of open-ended questions 5. cos

Last Answer : the low response rate

The major DISADVANTAGE of a mail survey versus a telephone or personal interview survey is: A)having to offer incentives B)the low response rate C)the elimination of interview bias D)the lack of open-ended questions E)the cost

Description : The major DISADVANTAGE of a mail survey versus a telephone or personal interview survey is: A)having to offer incentives B)the low response rate C)the elimination of interview bias D)the lack of open-ended questions E)the cost

Last Answer : B)the low response rate

A vital tooth has a crown cemented to a pin-retained amalgam core; where does a failure occur: A. Between crown and cement B. Between core and cement C. In the crown and the root D. In the core and the margin preparation

Description : A vital tooth has a crown cemented to a pin-retained amalgam core; where does a failure occur: A. Between crown and cement B. Between core and cement C. In the crown and the root D. In the core and the margin preparation

Last Answer : B. Between core and cement

The OPTIMUM crown to root ratio for abutment tooth is:** A. 2:3 B. 1:1

Description : The OPTIMUM crown to root ratio for abutment tooth is:** A. 2:3 B. 1:1

Last Answer : A. 2:3

The cervical finish line of a full veneer crown preparation should be placed: A. Just supragingival whenever is possible B. According to the depth of gingival crevice C. Subgingival to reduce ability of recurrent caries D. At the junction of tooth and amalgam core

Description : The cervical finish line of a full veneer crown preparation should be placed: A. Just supragingival whenever is possible B. According to the depth of gingival crevice C. Subgingival to reduce ability of recurrent caries D. At the junction of tooth and amalgam core

Last Answer : A. Just supragingival whenever is possible

A 8 years-old patient has 3 first premolars erupted and a swelling on the ridge of the un-erupted premolar. X ray shows a fully developed crown and ¾ roots development with no other pathology. What is your management: A. Remove the dentigerous cyst B. Soft tissues recision to allow eruption C. Soft tissues recision accompanied with orthodontic appliance to help with eruption

Description : A 8 years-old patient has 3 first premolars erupted and a swelling on the ridge of the un-erupted premolar. X ray shows a fully developed crown and ¾ roots development with no ... recision to allow eruption C. Soft tissues recision accompanied with orthodontic appliance to help with eruption

Last Answer : C. Soft tissues recision accompanied with orthodontic appliance to help with eruption

In regard to apically displaced flap, what is TRUE: A. Does not preserve attached gingivae B. Does not lengthen crown of tooth C. Is a pocket elimination procedure D. A & C

Description : In regard to apically displaced flap, what is TRUE: A. Does not preserve attached gingivae B. Does not lengthen crown of tooth C. Is a pocket elimination procedure D. A & C

Last Answer : C. Is a pocket elimination procedure

Odontogenic cysts develop from the following structures except: A. Reduced enamel epithelium of tooth crown B. Dental lamina dura C. Epithelium trapped after sutures D. ertwig’s root sheath

Description : Odontogenic cysts develop from the following structures except: A. Reduced enamel epithelium of tooth crown B. Dental lamina dura C. Epithelium trapped after sutures D. ertwig’s root sheath

Last Answer : C. Epithelium trapped after sutures

What is the ideal length for a post in post-core in an endodontically treated tooth: A. 2/3 of the tooth length B. ½ of the tooth length C. 1.5 times that of the crown D. Same as the anticipated crown

Description : What is the ideal length for a post in post-core in an endodontically treated tooth: A. 2/3 of the tooth length B. ½ of the tooth length C. 1.5 times that of the crown D. Same as the anticipated crown

Last Answer : A. 2/3 of the tooth length

A labially displaced anterior tooth is restored with a gold core porcelain jacket crown so that it is in line with the arch; the crown will appears: A. Short B. Long C. Narrow D. Wide

Description : A labially displaced anterior tooth is restored with a gold core porcelain jacket crown so that it is in line with the arch; the crown will appears: A. Short B. Long C. Narrow D. Wide

Last Answer : C. Narrow

In bridge work, which of the followings terms is NOT CORRECT: A. A retainer could be a crown to which a bridge is attached to B. A connector connects a pontic to a retainer or two retainers to each other C. The saddle is the area of the edentulous ridge over which the pontic will lie and comes in contact with pontic D. A pontic is an artificial tooth as part of a bridge

Description : In bridge work, which of the followings terms is NOT CORRECT: A. A retainer could be a crown to which a bridge is attached to B. A connector connects a pontic to a retainer or two retainers to each ... lie and comes in contact with pontic D. A pontic is an artificial tooth as part of a bridge

Last Answer : C. The saddle is the area of the edentulous ridge over which the pontic will lie and comes in contact with pontic