Theme 7. Surveying. Goal, task. Clasp classification, indications.

Q1.Which of the following is out of sequence for developing a removable partial denture design:

a. *extent of denture base

b. *rests, guiding planes, major connector, minor connectors

c. select abutments

d. retention, reciprocation

Q2. Flexible major connectors produce

a. *localized stress on isolated support areas

b. necrosis of the mucosa

c. noxious vapors

d. allergic reactions

Q3.Stressbreakers are indicated for use when the clinical exam reveals that the

a. *residual ridge is strong and the teeth are weal

b. denture will be toothborne

c. residual ridge is atrophic and the teeth are strong

d. residual ridge is weak and so are the teeth

Q4.In an extension RPD (class I, II, IV) metal of the framework must not be placed above the survey line anywhere on a tooth between the denture base and the

a. *nearest rest

b. opposing teeth

c. farthest rest

d. stabilizing clasp

Q5. If the path of dislodgement is controlled, an I-bar is most often located in .01” undercut on the

a. *greatest mesio-distal curvature of the buccal or lingual surface

b. cemento-enamel junction

c. mesio-buccal line angle

d. disto-buccal line angle

Q6. If the I-bars are placed in some position other than the area listed in the previous question, their functional motion that is induced by occlusal loading must be plotted in relation to the

a. *location of the terminal rest

b. guiding planes

c. guiding lines

d. tips of the retainers

Q7. The main axis of rotation downward for a Class I RPD will pass through the

a. *terminal rests on either side of the dental arch

b. rigid connectors

c. guidelines

d. tips of the retainers

Q8. Even though multiple rests have been used in a Class I RPD, when the path of dislodgement is not controlled all rests disengage except for those located the

a. *farthest from the denture bases

b. nearest the denture bases

c. none disengage

d. all disengage

Q9. Ordinarily, retentive clasps are not located on the opposite side of the rotational axis from the denture base. If a retainer is used, it must have increase ________ or engage an undercut that is minimal.

a. *flexibility

b. taper

c. nickel content

d. roundness in cross section

Q10. The denture design whose advantages are (1) less contour distortion of abutments, (2) less contact of metal to teeth, (3) cleaner design, (4) more efficient mechanical retention and (5) improved esthetics is the:

a. *RPI design

b. stressbreaker design

c. Aker’s design

d. I-bar, distal rest, guiding plate design

e. precision attachment design

Q11. If I bars are not placed on the height of contour of the abutment (in a frontal plane), their functional motion must be plotted in relation to the

a. *terminal rest location

b. guiding plane location

c. denture base location

d. artificial tooth location

e. Ante’s law

Q12. Dislodging movement of a RPD is resisted by

a. *mechanical retainers

b. stabilizing clasps

c. reciprocating clasps

d. denture base retainers

e. denture base mesh

Q13.A master cast is placed in the cast holder and aligned at the zero degree tilt. A 0.02 “ undercut is found on the mesiolingual of the mandibular right second molar. Tilting the cast to the anterior will

a. *increase the undercut

b. decrease the undercut

c. not effect the undercut

d. none of the above. The cast should not be tilted since all RPD’s are designed at the zero degree tilt.

Q14.Which of the following is not a function of an indirect retainer?

a. *it tends to reduce anteroposterior tilting leverages on the principle abutments

b. a part of the RPD that assists the direct retainers in preventing displacement of distal extension denture bases by functioning through lever action on the opposite side of the fulcrum line

c. contact of the minor connector with vertical tooth surfaces aids in stabilization against horizontal movement of the denture. Such tooth surfaces, when made parallel to the path of placement, may also act as auxiliary guiding planes.

d. anterior teeth supporting indirect retainers are splinted against lingual movement

e. aids in retention of the RPD by increasing the strength of the direct retainers by redistributing the forces to all areas of the mouth.

Q15. All of the following describe a reciprocal clasp arm, except

a. *it must contact the tooth after the retentive clasp arm passes over the height of contour

b. it is a rigid clasp arm

c. it is placed above the height of contour

d. it must contact the tooth before the retentive arm passes over the height of contour

e. ideal placement should be at the junction of the gingival and middle third of the abutment tooth crown

Q16. All of the following are correct statements concerning an occlusal rest, except

a. *the rest seat is prepared such that the deepest portion is at the marginal ridge

b. the rest prep should extend on-third to one-half the mesiodistal width of the tooth

c. the rest prep should extend one-half the buccolingual width of the tooth from cusp tip to cusp tip

d. the rest measures between 1.0 to 1.5 mm thick where it crosses the marginal ridge

e. the occlusal rest seat is prepared so that the enclosed angle formed by the floor of the rest seat and a line dropped down the proximal surface of the tooth must be less than 90 degrees

Q17. All of the following statements concerning major connectors are correct, except

a. *the border of the maxillary major connector should be scalloped to mimic the gingival crevices of the teeth

b. in the maxillary arch, the border of the major connector should be at least 6 mm from the gingival crevice of the teeth

c. in the mandibular arch, the border of the lingual bar major connector should not be closer than 2 - 3 mm to the gingival margins

d. at least 8 mm of vertical space between the active floor of the mouth and gingival margins of the teeth is required for a mandibular lingual bar major connector

e. the border of the mandibular major connector should run parallel to the gingival margin of the teeth

Q18.All of the following are sites of arbitrary blockout of the mandibular RPD master except

a. *tissue undercuts to be crossed by origin of bar clasps

b. gross tissue undercuts situated below areas involved in design of denture framework

c. labial and buccal tooth and tissue undercuts not involved in denture design

d. all gingival crevices

e. all of the above are sites of arbitrary blockout

Q19. All of the following features describe the proximal plate/guiding plate area needed for proper functioning of the RPI clasp assembly, except

a. *the proximal plate contacts approximately 1 mm of the gingival portion of the guiding plane

b. the guiding plane is approximately 2 3 mm in height occlusogingivally

c. an undercut should exist below the guiding plane to permit movement of the proximal plate

d. the proximal plate contacts approximately 1 mm of the occlusal portion of the guiding plane

e. a guiding plane is prepared on the distal surface of the abutment tooth in the occlusal one-third

Q20. 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