Surveyor

Question 1

List Steps of construction of RPD

Answer 1

1-diagnosis and treatment plan.
2-primary impression and diagnostic cast.
3-survey of diagnostic cast (primary survey )
4-mouth preparation then make secondary impression

5- master cast modification ‘‘preparation’‘ as block out and relief.
6-duplication of master cast to make refractory cast
7-metal try-in intraoral and jaw relation.

Question 2

Surveyor is

Answer 2

Instrument used to determine relative parallelism of two or more teeth surfaces or other parts of cast in dental arches

Question 3

Parts of surveyor:

Answer 3

1-plate form which base is attached
2-base which table is attached by universal joint 3-table which cast is attached
4-vertical arm
5-horizontal arm
6-mandrill for holding tools (analyzing rods-carbon marker-undercut gauge-wax trimmer)
آخر نقطه رتن

Question 4

analyzing rods used for

Answer 4

selection of path of insertion as it determine
relative parallelism of proximal surfaces of abutments ‘‘guiding planes’’

Question 5

carbon marker

Answer 5

represent maximum height of contour (maximum convexity of the tooth) or maximum bulge of the tooth

Parts of tooth above it are non-undercut areas, parts of teeth below it are undercut areas

Question 6

Wax trimmer used to

Answer 6

Used to trim wax

Question 7

undercut gauge use and size

Answer 7

measure the extent of undercut that used for clasp retention
*usually 3 sizes (10,20,30) thousands of inch꞊ (.01-.02-.03 inch)

Question 8

Uses of surveyor

Answer 8

a-surveying of diagnostic cast

b-tripoding of cast

c-transfer tripod marks to master cast ‘‘has mouth preparation’’ (retripoding)

d-surveying of master cast

e-contouring of crown and cast restoration

f-placement of internal attachment and rest
g-surveying of refractory cast (working cast )

Question 9

Uses of surveyor , surveying of diagnostic cast

Answer 9

1-determine the relative parallelism of abutment teeth

Begin with zero tilt position,

If parallelism present between proximal surfaces of abutments → path of insertion will be vertical. If parallelism not present. So achieved by:
1- if slight undercut → make enameloplasty.
2- tilt cast anteroposterior to equalize undercut.

2-scribe survey line after final tilt, Its significance (all rigid components of RPD must be occlusal to it ,only terminal third of retentive arm
‘‘flexibale’‘ gingival to it

If there is no undercut at zero tilt, must be created by:
a-enameloplasty within enamel b-class V restoration c-crown restoration

3-determine tooth or bony interference(torus palatinus, mandibularis)
If small interference → make relief in acrylic
If moderate → tilt cast and change path of insertion If large → surgical removal

Question 10

tripoding of cast record …

Answer 10

final tilt of diagnostic cast

Question 11

principle of surveying

Answer 11

surveying started at zero tilt ‘‘horizontal tilt’‘

Question 12

Methods of determination of path of insertion:

Answer 12

First method → horizontal tilt ‘‘zero tilt’’

second method → average the undercut (not use surveyor)

Third method → factors affecting path of insertion

1-guiding planes ‘‘parallelism’’
*on proximal surfaces of abutments teeth,
*In occlusogingival height 2;3mm in free end saddle

2-retentive undercut, *If there isn’t undercut in zero tilt created by → enameloplasty (dippling) or crown.

3-esthetics (class IV)

4-interference

Any interference in bone or teeth lingually inclined eliminated by relief or tilt cast or surgery (bilateral need surgical removal, if unilateral by tilting cast or relief)