Removable Prosthodontics Surveying

Introduction

• The presentation is on surveying, a procedure for locating and outlining tooth contours.
• The objectives of the lecture are to understand surveying tools and how to use them.

Removable Prosthodontics

• The lecture covers removable prosthodontics, specifically.
• The slides include diagrams and images of removable partial dentures.

Components of Removable Partial Dentures

• Denture base
• Artificial teeth
• Supporting rests
• Connectors (major and minor)
• Retainers (direct and indirect)
• The images and diagrams illustrate these component parts.

Surveying Procedure

• Surveying is a procedure for locating and outlining the contours and positions of abutment teeth and associated structures.
• This procedure takes place before designing the removable partial denture.
• The process aims at determining the appropriate insertion and removal pathways for the denture.

Undercuts on Teeth

• Undercuts are recesses on teeth that can be utilized to enhance denture retention.
• Undercuts are categorized as desirable or undesirable.
• Desirable undercuts are associated with denture retention.
• Undesirable undercuts are those that can potentially cause interference and discomfort.
• Undercuts on teeth are a factor that determines the path of insertion.

Factors Affecting Path of Insertion

• Interferences (changing the path, contouring teeth, removing interfering structures)
• Retentive undercuts (depth and location of clasp tips)
• Esthetics (minimizing visible clasp metal and denture base material)
• Guiding planes

Guiding Planes

• Guiding planes are flat axial surfaces, typically on the proximal or lingual surfaces of teeth.
• Guiding planes run parallel to the insertion path
• Guiding planes enable smooth prosthesis insertion and removal without excessive force.
• The distance between the guide surface and the gingival margin is approximately 3mm.
• The function of guiding planes is to guide the prosthesis into and out of position with a minimum of forces.
• They also contribute to the retention of prosthesis through frictional contact.
• They provide stability when on the axial lingual surface of the tooth.
• They help to minimize wedging stress on the abutment teeth

Parts of the Dental Surveyor

• Base
• Vertical upright column
• Cross arm with spindle housing
• Vertical spindle with tool holder
• Tool to lock the spindle
• Tool holder
• Surveyor table
• Ball retaining ring
• Tool rack
• Storage compartment

Surveying Tools

• Analyzing rods
• Carbon marker
• Undercut gauge
• Wax trimmer

Objectives of Surveying

• Allowing precise charting of required oral preparations.
• Determining most suitable placement and removal paths.
• Determining relative parallelism of tooth surfaces.
• Identifying and measuring tooth undercuts, and defining areas of interferences.
• Creating and marking height-of-contour lines.
• Trimming block-out material parallel to the path of placement.
• Recording the cast's positioning

Surveying the Master Cast

• Selecting the optimal insertion route by adhering to oral preparations.
• Meeting the prerequisites of guiding planes, retention, and non-interference.
• Ensuring aesthetic appeal by determining ideal placement of the clasp arms.
• Measuring areas for retention and positioning of clasp terminals relative to the clasp arm's flexibility
• Identifying and marking undesirable undercuts
• Trimming the blockout material along the path of placement prior to duplication.

Factors Determining Path of Placement and Removal

• Guiding planes
• Retentive areas
• Interferences
• Esthetics

Procedures of Surveying

• Positioning the cast
• Altering cast position to produce parallel proximal surfaces as guiding planes.
• Tilting the cast to enable equal retentive areas along principal abutments
• Removing areas of interference through reshaping of tooth surfaces.
• Enabling more aesthetic placement of clasp arms

Additional Notes

• Surveys will involve identifying the proper path of insertion and removal of the prosthesis
• Illustrations of components of the dental surveyor, diagrams of surveying procedures are also part of the presentation
• The slides use illustrations to show how the position of the cast can affect the path of insertion, along with the importance and effect of undercuts on the path of insertion.