1. WEL-COME

2. COLLEGE OF DENTISTRY, AZ-ZULFI, KSA.
Assalam-alekum
SURVEYOR AND
SURVEYING OF RPD.
DR. TAJMULLA AHMED
UNIVERSITY OF MAJMAAH,
COLLEGE OF DENTISTRY, AZ-ZULFI, KSA.

3. SPECIFIC LEARNING OBJECTIVE;
At the end of the class students should be able to;
Define the surveyor [surveying instrument] and surveying.
Enumerate the purpose of surveyor.
Enumerate types of surveyor.
Enumerate in brief the surveying procedures.

4. Introduction.
a) This RPD cannot be inserted in the mouth because of failure to eliminate unwanted undercut on the cast.
b) This denture has been processed on a correctly prepared cast and, as a result, there is no interference with insertion

5. Dental surveyor; Introduction.
The surveyor was first introduced to the dental profession in 1918 by A.J Fortuniti.
Definition:
A dental surveyor has been defined as an instrument used to determine the relative parallelism of two or more surfaces of the teeth or other parts of the cast of a dental arch.
The primary purpose of surveying ;
A dental surveyor is vitally important for the planning, execution, and verification of appropriate mouth modifications for a RPD.

6. Purpose of Surveyor 1. Survey cast;
-Locates desirable and undesirable cast features
2. Block-out of cast ;
-Eliminates undesirable tooth and soft tissue undercuts
-Reduces the possibility of distortion during duplication.
3. Shaping wax patterns/ milling castings ;
-Used to shape the axial surfaces of crown patterns for RPD abutment teeth
4. Positioning precision attachments for fixed and removable appliances

7. Types of surveyors 1. Ney surveyor Parts of Surveyor
1. Horizontal base
2. Upright column
3. Cross arm with spindle housing
The jointed horizontal arm of the Ney is fixed.
4. Spindle with tool holder
5. Survey table
Base
Tilt top with cast, clamp and lock screw
6. Surveying tools

8. 6. Surveying tools B. Undercut gauges consists of a shaft and a lip-
A. Analyzing rod-
used to check the presence or absence of undercuts.
B. Undercut gauges consists of a shaft and a lip-
Used to locate and mark desirable undercut
When the shaft and the lip contact the tooth simultaneously the desired undercut is present in inches , ,
C. Carbon [graphite] marker; -
marks survey lines on tooth & soft tissue surface of the cast.
D. Block out tools;-
used to trim the block-out wax

9. Types of survey line;
According to Devan:
-Supra bulge
-Infra bulge
Other classification;
-high
-low
-medium
-diagonal

10. 2. Jelenko surveyor 2. William’s surveyor
The principal parts of the Jelenko surveyor are essentially the same as those for the Ney surveyor except that by loosening the nut at the top of the vertical arm, the horizontal arm may be made to swivel.
2. William’s surveyor
The jointed horizontal arm of the Williams surveyor differs from both the Ney and Jelenko surveyors.
This feature permits the vertical arm to be moved to scribe the survey lines without moving the cast.

11. SURVEYING

12. Orientation of the cast
The standard position considered for all casts are as lower casts.
The position for description is from cast, behind the cast or from the position of the tongue.
To further standardize descriptions, casts are oriented so that the anterior teeth are always toward the vertical member of the surveyor and away from the person making the survey.

13. All references to the right side of the cast apply thus to the right side of the cast from this position; for instance,
Mandibular casts on the right side would be the actual right side of the lower arch.
For maxillary casts, however, the right side, would be the maxillary left quadrant .
If a clasp is described as being low on a given tooth, it means that the clasp is toward the gingiva, regardless of whether it is a mandibular or a maxillary cast. For instance,
high on a maxillary cast means toward the gingiva, whereas high on the mandibular cast is toward incisal or occlusal surfaces

14. Cast tilting Basic cast tilts
Changing the tilt also will change the position of the survey line in relation to the horizontal plane.
Tilting is simply changing the position of the cast, which thus changes the long axis of each tooth on the cast relative to the horizontal plane.
Basic cast tilts
The basic position or tilt of the cast on the surveyor should be the horizontal tilt, or, a zero tilt .
In the horizontal tilt, Occlusal surfaces of the teeth are at or near parallelism to the horizontal plane.
This is the standard reference position from which further tilts originate.
Basic cast tilts
The basic tilt of the cast on the surveyor should be the horizontal tilt. Here, Occlusal surfaces of the teeth are at or near parallelism to the horizontal plane.
This is the standard reference position from which further tilts originate.

15. The four basic tilts from the horizontal, or reference, position are
(1) the anterior tilt, in which the anterior teeth are tilted downward .
(2) the posterior tilt, in which the posterior portion of the cast is tilted downward .
(3) the right lateral tilt, in which the right portion of the cast is tilted downward and
(4) the left lateral tilt, in which the left portion of the cast is tilted downward.

16. Tripoding Methods of tripoding.
Once a tilt has been selected for a given removable partial denture design, this tilt should be preserved, so that it can be reestablished accurately. This procedure is termed tripoding.
Methods of tripoding.
Common method is to place the cast on the survey table at the desired tilt and, lowering the spindle of the surveyor with the analyzing rod in position, move the cast until three widely spaced points on the anatomical portion of the cast can be touched . This must be done with the analyzing rod at one vertical height.
Cast may also be tripoded by making vertical marks on cast.
Anterior mark,
Right posterior mark,
Left posterior mark.

17. Surveying procedure
This may be divided into the following distinct phases:
Preliminary visual assessment of the study cast.
Initial survey.
Analysis.
Final survey.

18. A. Preliminary visual assessment of study cast
This stage has been described as 'eyeballing' the cast & is a useful preliminary, to the surveying procedure proper.
The cast is held in the hand and inspected from above.
Shows an anterior tilt
('heels up')
 shows a posterior tilt
('heels down').

19. B. Initial survey
The cast is positioned with the Occlusal plane horizontal.
The amount of undercut can be judged approximately from the size of the 'triangle of light' between the marker and the cervical part of the tooth, or measured more precisely by using an undercut gauge.

20. C. Analysis
An RPD can be designed on a cast which has been surveyed with the occlusal plane horizontal.
Following aspects, in final survey with the cast tilted, are considered:
Appearance.
Interference.
Retention.

21. i. Appearance
When anterior edentulous area is surveyed, undercuts on the mesial aspects of the abutment teeth can be found.
If the RPD is constructed with this vertical path of insertion there will be an unsightly gap between the denture saddle and the abutment teeth gingival to the contact point.
This unsightly gap can be avoided by giving the cast a posterior (heels down) tilt so that the analyzing rod is parallel with the mesio-labial surface of the abutment tooth.

22. ii. Interferance
For example, if a bony undercut is present labially, insertion of a flanged denture along a path at right angles to the Occlusal plane will only be possible if the flange stands away from the mucosa or is finished short of the undercut.
This can result in poor retention.
If the cast is given a posterior tilt, the path of insertion will be parallel to the labial surface of the ridge.
Then it is possible to insert a flange that fits the ridge accurately.

23. iii. Retention
To obtain retention, undercuts must be present on teeth relative to the horizontal survey.
In this example, providing retention by engaging the distal undercut (*) of the canine may well look more pleasing than a clasp arm on the same tooth

24. D. Final Survey
If it is decided that the cast should be tilted, the analyzing rod is exchanged for a marker different in color from that used in the first survey, and the final survey is carried out.
It will then usually be found that the teeth to be clasped have two separate survey lines which cross each other.
Using the tripod method, the tilt of the cast can be preserved.

25. Conclusion
Surveying is very important step towards achieving a successful restoration .
A well-executed design on the cast serves as a blue print for fabrication of RPD.
Thus Principles & methods for surveying & designing should be thoroughly understood.

26. THANK YOU