Dental Prosthesis Surveying (5245)

Bangladesh Technical Education Board curriculum(2013)

Diploma in medical 4th Semester Dental Technology

Technique of partial denture Prosthesis-2 Subject Code (5245)

Surveying:- An analysis and comparison of the prominence of intra-oral contours associated with the fabrication of a dental prosthesis. (এটা একটা পদ্ধতি যার মাধ্যমে PD ডিজাইন করার আগে Master cast এর উপর abutment tooth এর contour, position and structure চিহ্নিত করা হয়)

Parts of surveying Equipment's/Surveyor

1. Level platform

2. Vertical arm

3. Horizontal arm

4. Surveying arm

5. Cast holder

6. Accessory tools

  a. Analyzing rod

  b. Carbon(graphite) marker

  c. Undercut gauges

  d. Wax knife

  e. Milling devices (with handpiece holder)

Purpose of surveying

1. To design a removable partial denture such that it’s rigid and flexible components are appropriately positioned to obtain good retention and bracing.

(Partial denture এর সবচেয়ে নমনীয় এবং দৃড় অংশের অবস্থান নির্নয় করার জন্য কারন যেখান থেকে ভাল রিটেনশন পাওয়া যায়)

2. To determine the path of insertion of prosthesis. (Denture  মুখে প্রবেশ এবং বের করার পথ নির্নয় করা)

3. To mark the height of contour of the area above undercut.( সবচেয়ে স্ফীত অংশ চিহ্নিত করা)

4. To make the survey line. ( Survey Line  তৈরি করা )

5. To mark the undesirable undercuts into which the prosthesis should not extent.( অপ্রত্যাশিত undercuts যাহা ডেনচারে প্রয়োজন না সেগুলো বন্ধ করা ) 

Zone of Tooth

 There are two zone:

1. Near zone:- The zone of tooth near edentulous area is near zone.

2. Far zone:- The zone to tooth far from edentulous area is far zone.

Survey line & there Types

Blatterfein classified survey lines as:

1. High survey Line

2. Medium Survey Line

3. Low Survey line

4. Diagonal Survey Line 

High survey Line (HSL)

Survey line passes from occlusal 1/3 in the near zone to the occlusal 1/3 in the far zone. (Wrought wire clasp can be used here)

• Found near the occlusal surface of a tooth often parallel to the gingival margin

• It results from abnormal inclination of the teeth

• lingual surfaces of the lower teeth and buccal surfaces of the upper teeth.

Medium Survey Line (MSL)

It passes occlusal 1/3 in near zone to the 1/3 of far zone. Circumferential clasp can be used here.

Low Survey Line (LSL)

It Passes in the cervical 1/3 of tooth in both near and far. Modified “T” Clasp Can be used. 

Diagonal Survey Line (DSL)

It  passes from occlusal 1/3 of near zone to cervical 1/3 of far zone. Gingival approaching clasp can be used here. 

Technique of surveying:-

1. Initial set up for surveying includes mounting the cast on a cast holder, locking it in position with ‘zero’ degree tilt.

2. The cast holder is placed on the surveying platform.

3. After positioning the cast surveying area is positioned in relation to the cast.

4. The cast is analyzed after positioning the surveying arm .

5. The cast can be fixed tightly to the clamps on the surveying table.

6. The cast should be mounted such that the occlusal surface of the remaining teeth are parallel to the base.

7. After mounting the cast, the horizontal arm is positioned in the surveyor.

8. The horizontal arm should be vertically adjusted.

9. Once the proper position of the horizontal arm is determined it is locked to the vertical arm with the help of a thumbscrew.