Theme 6. Cast RPD. Diagnostic models. Selection of abutment teeth.

Q1.Increased loading of a periodontally involved abutment may hasten the progress of the pathologic process.

*T or F

Q2.Which of the following is not a criterion for selecting an abutment for a removable partial denture?

a. *estimated cost

b. mobility

c. crown to root ratio

d. alveolar support

Q3.During diagnosis a good “rule of thumb” is to extract teeth with more than 50% bone loss as shown on radiographs.

T or *F

Q4.A good source of bone for periodontal grafting is in an extraction site that is about 6 months old.

T or *F

Q5.During construction, the framework whose metal covers exostoses or inclined slopes of alveolar bone located between the edentulous segment and its nearest rest must be

a. *relieved

b. stripped

c. polished

d. deplated

Q6.According to the Kennedy Classification of partially edentulous arches, a single, but bilateral edentulous area crossing the midline, and located anterior to the remaining teeth would be a

a. *Class IV

b. Class II

c. Class III

d. Class I

e. Class V

Q7.The textbook authors and your lecturers recommend that, after mouth preparations, an impression be made in irreversible hydrocolloid and a cast poured in quick-setting stone. The purpose of this is to

a. *verify that proper contours have been provided on the potential abutment teeth

b. maximum resident benefit

c. make a cast available to the laboratory for final waxing and casting

d. evaluate the contours of the occlusal rests for adequate reduction

e. determine the proper size of stock tray for reversible hydrocolloid

Q8.The location of the clasp arms will be determined by the height of contour of the abutment teeth.

*T or F

Q9. For a distal extension removable partial denture, the jaw relations should be recorded ____________ the secondary impression is made and __________ the framework in place.

a. *after; with

b. before; without

c. before; with

d. after; without

e. as; with

Q10.All of the following are principal objections to the use of a U-shaped maxillary removable partial denture major connector, except

a. *the lack of interfacial surface tension between the metal and tissues reduces the amount of retention of the prosthesis

b. the design fails to provide good support characteristics and may permit impingement of tissues underlying its palatal borders when subjected to occlusal loading

c. bulk to enhance rigidity results in increased thickness in areas most frequented by the tongue

d. movement is particularly noticeable and is traumatic to the residual ridge in distal extension removable partial dentures when posterior tooth support is nonexistent

e. its lack of rigidity, compared to other designs, may induce torque or direct lateral force to abutment teeth

Q11.The direction that dislodging forces unseat a RPD depends upon

a. *guideplates, retainers, and minor connectors

b. denture base retainers

c. the location of rests

d. chance

e. holding power of denture base adhesives

Q12.Two or more parallel axial surfaces of abutment teeth shaped to direct the prosthesis during placement and removal are called

a. *guiding planes

b. indirect retainers

c. reciprocal clasp arms

d. undercuts

e. retentive clasp guidance

Q13.The part of a removable partial denture that assists the direct retainers in preventing displacement of distal extension bases by functioning as part of the resistance arm of a lever anterior to the fulcrum line is termed a (an)

a. *indirect retainer

b. reciprocal clasp arm

c. inadvertent retainer

d. guiding plane

e. rester

Q14.As dislodgement occurs, clasps act to keep a RPD seated. This action is enhanced by the anteriorly located occlusal rest which is known as an occlusal rest serving the function of an

a. *indirect retainer

b. fulcrum relocator

c. lever arm lengthener

d. impingement protector

e. direct retainer

Q15.The part of an RPD framework that transmits stress to the abutment tooth and also serves as a vertical stop for the framework is called a

a. *rest

b. minor connector

c. clasp

d. crown

e. reciprocating arm

Q16.The part of an RPD framework that resists lateral functional stress and provides support for mobile teeth is called a

a. *bracing component

b. major connector

c. rest

d. retentive clasp

e. indirect retainer

Q17. The rests of a RPD must be free to move in function (except gingivally) in Kennedy Class

a. *I, II, IV

b. I, II, III, IV

c. I, III, IV

d. II, III, IV

e. none. Rests should never move in function

Q18.In order to attain symmetry of form in major connectors of the palate, they should cross the midline at

a. *right angles

b. an acute angle

c. an ugly angle

d. an obtuse angle

e. midnight, when traffic is least likely

Q19.Like halitosis, single palatal bars are objectionable. Single palatal bars are objectionable because they lack

a. *rigidity

b. alcoholic beverages and sushi

c. flexibility

d. undercuts

e. simplicity

Q20. Plates, minor connectors, guiding plates, and proximal contacts of natural teeth all contribute to

a. *reciprocation

b. esthetics

c. good oral hygiene

d. the United Fund

e. rigidity