REMOVABLE MCQs 2011
It is well established that a greater likelihood of imparting tipping force are transmitted to the abutment when the direct retainer is placed :
Closer to the occlusal or incisal one third of abutment tooth surface
Closer to the middle one third of abutment tooth surface
Closer to the gingival one third of abutment tooth surface
Closer to both the middle and gingival one third of abutment tooth surface
In removable partial denture restoring class 3 kennedy , the abutment teeth are subjected primarily to :
The following type of removable partial denture is not considered as a combined tooth – tissue supported prosthesis :
RPD restoring bilateral free end edentulous areas
RPD restoring unilateral free end edentulous areas
RPD restoring a short span single anterior edentulous area
RPD restoring a long span single anterior edentulous area
4- the non-axial loading of abutments retaining an RPD can be controlled through :
Utilizing abused tissue to support the prosthesis
minimal coverage of soft tissue by the denture base
proper use of direct and indirect retainer .
use of non- rigid major connectors
5- the distal extension RPD present the greatest potential for damaging loads to supporting structure because the:
Leverage induced loading relatively high
Axial induced loading are relatively high
Induced stresses cannot be controlled by enough number of abutments
Prosthesis restores the posterior teeth
6-the most suitable direct retainer for an abutment tooth with questionable periodontal support is :
Vertical projection clap- T or modified clasp -T
Wrought wire clasp
Simple circlet clasp
7-for a clasp assembly to be passive when it is completely seated on abutment tooth ,the reciprocal arm should contact the tooth:
Before the retentive tip passes over the greater bulge of the abutment
After the retentive tip passes over the greater bulge of the abutment
Simultaneously when the retentive tip passes over the greater bulge of the abutment
After the retentive tip passes over the occlusal one third of the abutment
8- It is advised that the retentive clasp arm should be designed in a curved course on the abutment tooth to improve the :
Reciprocity of the clasp
Flexibility of the clasp
Encirclement of the clasp
Stabilization of the clap
9- the preferred material construction of a direct retainer that retains an RPD to questionable abutment is :
Chromium-cobalt based alloy
Gold based alloy
Titanium based alloy
Nickel chromium based alloy
10- it is advised in dista-extention based that the occlusal loads be applied :
In the center of the denture bearing area
At the mesial end of the denture bearing area
At the distal end of the denture bearing area
At both of center and distal of the denture bearing area
11- the primary objective of surveying a partially edentulous castes before RPD construction is to :
Fabricate an RPD with acceptable support ,retention, stability
Fabricate an RPD with suitable path of insertion and removal
Determine the exact location of partial denture components
Determine the number of direct retainers required
12- the selection of suitable path of placement of an RPD during surveying partially edentulous casts is made by use of :
13- the size of undercut gauge used to measure desirable undercut are :
0.01 , 0.02 , 0.03 CM
0.01 , 0.02 , 0.03 INCH
0.01 , 0.02 , 0.03 MM
0.01 , 0.02 , 0.03 METER
14- the area of the the tooth that is above the survey line is called :
Retentive and stabilization area
Supporting and stabilization area
Reciprocal and stabilization area
Supporting and retentive area
15- the retentive undercut must be present on the abutment teeth :
At zero tilt
At the tilt of the selected path of placement
At both zero and tilt of the selected path of placement
Neither of the zero nor the selected path of placement
16- the shoulder formed on lingual surface of the surveying crown is made at the :
Junction of the middle and gingival portion
Junction of the occlusal and middle portion
17- the most acceptable location of retentive clasp arm is at :
Occlusal one third of the tooth
Gingival one third of the tooth
Middle one third of the tooth
Both occlusal and middle one third of the tooth
18- if desirable undercuts are not present on the cast being surveying at the horizontal plane, this can be solved through :
Antero-posterior tilt of the cast
Lateral tilt of the cast
Scrap the tooth on the cast at gingival area
A simple grinding naturally at the gingival portion
19- the preparation of a guiding planes on the lingual of an abutment teeth before RPD fabrication aims primarily at :
Providing enough bracing to the RPD
Guiding the RPD during insertion and removal
Enhancing the esthetics of the RPD
Improving the retention of the RPD
20.The most appropriate path of insertion to be selected with RPD restoring anterior edentulous areas is:
a. The vertical path of placement.
b. The rotational path of placement.
c. The dual path of insertion.
d. Both the vertical and rotational paths of placement.
21.In RPD designing, reciprocation means:
a. Nullifying the effect of pressure on one side of the tooth by the application of pressure, equal in amount but opposite in direction.
b. Nullifying the effect of pressure on one side of the tooth by the application of pressure, less in amount but opposite in direction.
c. Nullifying the effect of pressure on one side of the tooth by the application of pressure, greater in amount but opposite in direction.
d. Nullifying the effect of pressure on one side of the tooth by the application of pressure, equal in amount and in the same direction.
22.The most preferable material construction in distal extension bases is:
a. Entirely made of metal.
b. Entirely made of acrylic resin.
c. A combination of both metal and acrylic resin.
d. entirely made of reinforced acrylic resin.
23.The retentive tip of a cast circumferential cast in a class I Kennedy can engage:
a. A mesio-buccal undercut.
b. A disto-buccal under cut.
c. Both a mesio-buccal and distobuccal undercuts.
d. an undercut at the center of the tooth.
24.The most obvious advantage of using a cast circumferential-type retentive arm is the:
a. Avoidance of problems associated with large tissue undercuts and high frenum attachment.
b. Better retention it provides.
c. Better neutralization of non-axial loadings.
d. Better esthetics it provides.
25.A T-shaped vertical projection clasp is indicated on abutment teeth have:
a. A normal contour and available disto-facial under cuts.
b. A normal contour and available mesio-facial under cuts.
c. An abnormal contour and available disto-facial under cuts.
d. An abnormal contour and available disto-facial under cuts.
26.The most appropriate treatment plan for lone-standing abutment supporting an RPD is to:
a. Clasp the tooth with a flexible clasp.
b. Clasp the tooth with a rigid clasp.
c. Leave the tooth out of clasping.
d. Involve the tooth in a fixed partial denture.
27.The primary objective of using indirect retainers in RPD construction to:
a. Neutralize the rotation that occurs when a dislodging force is placed on bounded end bases.
b. Magnify the rotation that occurs when a dislodging force is placed on distal-extension base.
c. Minimize the rotation that occurs when a dislodging force is placed on distal-extension base.
d. Minimize the vertical forces that occurs when a masticatory forces is placed on distal-extension base.
28.The fulcrum line in RPD restoring class IV Kennedy will run through the:
a. Most posterior abutments.
b. Most anterior abutments.
c. Opposite cuspeds.
d. Opposite to first molars.
29.The most appropriate solution when an RPD has to be supported with short, tapered root of a periodontally compromised first premolar is to:
a. Avoid this tooth from being clasped.
b. Perform a surgical augmentation of bone around this tooth.
c. Extract this tooth.
d. Splint this tooth to a stronger tooth.
30.It is well established that the following assembly provide greater horizontal forces within the supporting structures supporting class:
a. The distal rest in conjunction with cast circumferential retainer.
b. The mesial rest in conjunction with cast circumferential retainer.
c. The distal rest in conjunction with vertical projection retainer.
d. The mesial rest in conjunction with vertical projection retainer.
31.The primary objectives of establishing the occlusal relationship form to:
a. Enhance the deflective occlusal contact.
b. Establish harmonious occlusal contacts in both centric and eccentric excursions.
c. Create stable intercuspal position.
d. Release the maxilla to the mandible in eccentric position.
32.Occlusal equilibration is the modification of occlusal surfaces by:
a. Selective grinding with the intention of altering the cuspal relations.
b. Selective grinding with the intention of neutralizing the occlusal stresses.
c. Cast crowns with the intention of altering the cuspal relations.
d. Either a selective grinding, crown fabrication or even extraction with the intention of neutralizing the occlusal stresses.
33.It is estimated that the centric relation and maximal intercuspal position... Do not coincide in:
a. 50% of population.
b. 90% of population.
c. 10% of population.
d. All of population.
34.The most acceptable articulator for RPD construction is:
a. Plain+line articulation.
b. Semi-adjustable articulators.
c. Fully adjustable articulators.
d. Mean-value articulators
35.Facebow is a caliper like device used to record the relationship of maxillary arch to the:
a. Ala-tragus line.
b. Terminal hinge axis.
c. Interpupillary line.
d. Tragus-canthus line.
36.A direct apposition technique is usually used to articulate casts that have:
a. Sufficient number of teeth to make occlusion.
b. Occlusal wear among teeth.
C. Malposed and drifted teeth.
d. Teeth with multiple edentulous areas in between.
37.Recording jaw relation ships in partially edentulous cases using a. Technique requires a:
a. Wax occlusion rims with a plaster and pumice content.
b. Compound occlusion rims with a plaster and pumice content.
c. Wax occlusion rims with a purple inlay wax content.
d. Compound occlusion rims with a purple inlay wax content.
38.When recording jaw relation ships in mandibular free-end edentulous areas, the occlusion rim should be adjusted so that it is:
a. 1mm lower than anterior abutment and about 2/3 of the height of the retro molar pad.
b. 5mm lower than anterior abutment and about 1/3 of the height of the retro molar pad.
c. 1mm lower than anterior abutment and about 1/3 of the height of the retro molar pad.
d. 5 mm lower than anterior abutment and about 2/3 of the height of the retro molar pad.
39.The most accurate recording media used in registration of jaw relationships among partially edentulous cases is:
a. Dental waxes.
b. Modeling compounds.
d. Heavy body type silicon.
40.An anatomic tooth is a tooth:
a. With prominent cusps, grooves, and inclined planes.
b. That has been curved to stimulate natural teeth.
c. with faint cusps, grooves and inclined planes.
d. Without cusps, grooves or inclined plane.
41.Which one of the following is used to make final impression for partially edentulous area:
a. Closely fit custom tray and zinc oxide eugenol impression material.
b. Spaced custom tray and regular body rubber base.
c. Closely fit custom tray and impression wax.
d. Spaced custom tray and alginate impression materials
Final impression for partially edentulous arches is done to:
After mouth preparations
Before preliminary surveying
After final surveying
During recording jaw relation
Open interdental spaces between remaining natural teeth are blocked-out with soft wax:
During mouth preparations.
Before final impression making.
To prevent dimensional change of primary impression.
Main advantage of R.P.D over fixed bridge in replacing bilateral lost teeth is:
Cross arch stabilization.
Comfort of the patient.
The material used in making a transitional R.P.D should be radio-opaque if patient has:
The commonly used impression material for diagnostic casts for R.P.D is:
First step in altering the abutment contour for clasp retention in the R.P.D is:
Placement of guiding planes after contouring the proximal surfaces.
Placement of occlusal rests after reducing the occlusal surfaces.
Planning for placement of clasps after reducing the proximal surfaces.
Abutment tooth is not contoured unless it is short.
Preferred shape of occlusal rest seat on the natural posterior teeth in distal extension bases is:
Definite box shaped.
A good clasp design for a distal extension R.P.D is better provided by:
Using stress breakers on the abutment tooth.
Long abutment teeth with healthy alveolar bone support.
Short abutment teeth with healthy alveolar bone support.
The function of the occlusal rest seats is to:
Stimulate natural occlusal contour.
Resist vertical forces of occlusion.
Stabilize removable partial denture.
Determines path of removal.
One of the most important functions of the clasp in R.P.D is to:
Hold the abutments.
Distribute the stresses.
Prevent tissue-ward movement of the denture.
Give flexibility to the denture.
The most effective means of minimizing the applied load on the abutment holding lower distal extension R.P.D is by:
Splinting more number of teeth.
Use of stress breakers.
Maintaining proper denture base tissue contact.
Using semi-anatomic teeth.
Among disadvantages of Parkinson's disease includes:
Dryness of the mouth.
Bullae formation in the oral cavity with gradual extension to the skin.
Difficult insertion and removal of R.P.D.
Fracture and aspiration of the prosthesis.
Abused or irritated tissues should be treated before making primary impression because:
Tissue contour may change according to tissue healing.
Improvement of the patient's may occur.
It regains the health of the periodontium.
It prevents supra-eruption of the teeth opposing the edentulous spaces.
Malaligned teeth produce the following changes in treatment such as:
Difficulty in determining a unique path of insertion.
Good oral hygiene.
Adequate access to the proximal surfaces of crowded teeth.
Weaken the strong tooth.
Saving a mutilated posterior tooth can aid to:
Prevent the formation of distal extension bases.
Prevent malalignment of teeth.
Prevent lateral stabilization of RPD.s.
Prevent the increase of tooth mobility.
Proprioceptive reflex factors resulting from occlusal interferences effects:
Rest vertical dimension.
Centric relation record.
Diagnostic casts provide:
Valuable information about the space the RPD may occupy.
Ideal screening for any pathological condition.
Analysis of the patient's attitude.
Quality of the soft tissue covering the edentulous ridge .
Among evaluation of tooth mobility in distal extension base RPDs greater C/R ratio than 1:1 :
Is acceptable as an abutment for a RPD.
Is not acceptable as an abutment for a RPD.
Needs splinting to the neighboring teeth.
Needs evaluation of the existing restorations.
Occlusal rests are not prepared on multi-surface amalgam restorations because:
Amalgam tends to flow under constant pressure.
Difficult preparation of guiding planes on amalgam restorations.
Amalgam is weak under compressive forces.
Amalgam is strong against tensile forces.
Thickening of lamina Dura may occur as a result of:
Syndromic disorder like Paget's disease.
The guide planes in the bounded saddle are:
Longer than those in a free-end saddle.
Shorter than those in a free-end saddle.
Equal to those in a free-end saddle.
In the mesial and distal of the last teeth.
Anatomical final impressions are avoided for distal extension bases because:
Weakening of the abutment tooth occurs due to lever action.
Tissue compressed during rest leading to the vertical denture displacement.
Application of applied occlusal load on the impression.
Decreasing the blood supply to bone stimulating osteoclasts.
When the metal framework fits the stone cast accurately but not in the patient's mouth, the reason for such problem include:
Improperly poured cast.
Properly prepared altered master cast.
Improperly positioned rest seats.
Improper framework fit may result in:
Passive force on the abutment teeth.
Widening of the periodontal ligament space during initial phase process.
Food debris collection between the framework and the teeth.
Polishing the tissue surface of the metal framework
Finished to a high shine.
Sharply defined to provide firm mechanical locks for acrylic base.
67- Lack of connector rigidity during fitting the metal framework may result in:
Traumatic injuries to the teeth and soft tissue.
Improperly positioned direct retainers.
Deficient finish lines.
Fracture rest seats.
68- The best disclosing media to identify areas of interference is:
Rouge and chloroform.
69- The next appointment after fitting the framework for mandibular distal extension bases is:
Corrected cast impression procedures.
Jaw relation records.
70- During fitting the framework the most common areas of are:
Shoulders of circumferential clasps.
Guiding planes surfaces.
An old uneducated patient with good oral hygiene has the following teeth:
The maxillary 17 is slightly over erupted with no undercut. 14 has a high lingual survey line. The mandibular 36 is extremely over erupted with inaccessible endodontic treatment and furcation involvement.
71- In the above case, the tooth number 17 needs:
72- In the above case, the tooth number 25 is called:
73- In the above case, the tooth number 36:
Needs crown preparation.
Can be used as overdenture abutment.
Required for extraction.
74- In the above case the most favorable option for dealing with tooth number 25 is:
Used for support only.
Splinting with tooth number 23.
Used for support and retention.
Extraction because of tapered root form.
75- In the above case, rest seat preparation for maxillary denture will be performed on:
Cingulum rest on 13, mesial rest on 25, distal rest on 14, long rest on 17
Mesial rest on 14, mesial rest on 25, cingulum rest on 23, long rest on 17
Cingulum rest on 13, distal on 14 and long rest on 17
Occlusal rest on 23, distal on 25, distal and mesial rests on 17
76- In the above case, restoration of mandibular anteriors by fixed bridge instead of RPD is:
77- In the above case, recontouring procedure (or s) which is (or are) needed for tooth number 14:
Lingual and buccal recontouring.
Lingual composite build up.
78- In the above case, recontouring procedure (or s) which is (or are) needed for tooth number 14:
Lingual and buccal recontouring.
Lingual composite build up.
79- In the above case, before designing RPD, the following steps should be done EXCEPT:
Assessing vertical dimension of occlusion.
Adjustment of occlusal plane.
Metallic try in.
Sinus lift for maxillary sinus.
80- The way of mounting mandibular cast to maxillary cast in the above case is by using:
Maxillary face bow.
Record made entirely on occlusion rims.
Metal reinforced wafer interocclusal record.
Direct opposition of casts.