Tripoding and Surveying PDF

Surveying Surveying in prosthodontics involves analyzing a dental cast to determine the most favorable path of insertion and removal for an RPD. This process identifies undercuts on teeth that can be used for retention and areas that need modification for optimal prosthesis fit. > A dental surveyor...

Surveying Surveying in prosthodontics involves analyzing a dental cast to determine the most favorable path of insertion and removal for an RPD. This process identifies undercuts on teeth that can be used for retention and areas that need modification for optimal prosthesis fit. > A dental surveyor is used to mark the height of contour on abutment teeth and to identify areas needing adjustment. It helps in planning the placement of clasps and other components. Purpose of Surveying Path of Insertion ○ Establishes a consistent path for inserting and removing the denture, which is crucial for stability and retention. Undercut Identification ○ Detects undercuts on teeth that can be used for clasp retention. Guide Plane Analysis ○ Helps in creating parallel surfaces on teeth that guide the prosthesis during insertion and removal. Correctly Tilting the Cast in a Dental Surveyor Tilting the cast is an essential step in the surveying process for removable partial dentures (RPD). It involves adjusting the position of the cast to find the most advantageous path of insertion and optimize undercuts for retention. Purpose of Tilting Ensures the denture can be inserted and removed smoothly. Increases desirable undercuts while reducing undesirable ones. Helps conceal metal components by adjusting survey lines closer to the gingival margin. Achieves uniform retention across available teeth and tissues. Steps for Tilting 1. Initial Positioning: Begin with a horizontal tilt, where the occlusal surfaces of teeth are parallel to the horizontal plane. This is often the starting point for analysis. >>Horizontal Tilt Steps for Horizontal Tilt 2. Initial Setup: Start by placing the cast on the surveyor table in a horizontal position, which is often referred to as the "zero tilt" or horizontal tilt. This is the baseline position where the occlusal surfaces of the teeth are parallel to the base of the surveyor. 3. Analyze Proximal Surfaces: Use an analyzing rod to evaluate the proximal surfaces of abutment teeth. This helps in determining if any adjustments are needed to achieve parallelism between guiding planes. 4. Adjust Tilt: Anterior Tilt: If necessary, tilt the cast anteriorly to increase mesial undercuts, which can be beneficial for distal extension bases. Posterior Tilt: Lowering the posterior region can increase distal undercuts and decrease mesial ones, useful for balancing retention1. Lateral Tilt: Adjust laterally to equalize undercuts on both sides of the arch, ensuring uniform retention. 5. Evaluating Interferences: Identify and address any hard or soft tissue interferences, such as palatal tori or exostoses, which may affect the path of insertion. 6. Visual Confirmation: Continuously use the analyzing rod to confirm that the desired path of insertion and retention areas are achieved with each tilt adjustment. The goal is to create a path that allows easy insertion and removal of the denture without compromising retention or aesthetics. 7. Mark Survey Lines: Once the optimal tilt is established, use a carbon marker to delineate survey lines and identify undercut areas accurately. 8. Marking Survey Lines: Once the optimal tilt is determined, use a carbon marker to delineate survey lines and identify undercut areas. 9. Preserve Tilt through Tripoding: To ensure consistency in future surveys, preserve this tilt by marking three widely spaced points on the cast (tripoding). This allows you to reposition the cast accurately on the surveyor at a later date Considerations The tilt should not exceed 10 degrees to maintain a practical path of insertion. Ensure that any adjustments made do not compromise esthetics or function. After determining the optimal tilt, preserve this position through a process called "tripoding" to ensure consistency in future surveys. Surveying Tools 1. Analyzing Rod: For preliminary surveys and assessing undercuts. 2. Carbon Marker: Marks survey lines on teeth. 3. Undercut Gauge: Measures depth and location of undercuts. 4. Wax Trimmer: Trims excess wax to prevent overcontouring. Surveying Process 1. Orientation of Cast: Position the cast correctly on the surveyor. 2. Cast Tilting: Adjusts the cast's position to find the best insertion path. 3. Visual Analysis: Use analyzing rods to assess undercuts and tooth angulation. 4. Marking Survey Lines: Use carbon markers to outline survey lines and undercuts. 5. Measuring Undercuts: Use gauges to determine available retention. Types of Blockout in Surveying Parallel Blockout: Ensures guiding planes are parallel. Shaped/Ledge Blockout: Creates ledges for clasp arms. Arbitrary Blockout: Covers non-essential areas to prevent interference. 1. Applications in RPD Design Clasp Design ○ Surveying informs the design and placement of clasps by identifying suitable undercut areas for retention. Framework Design ○ Ensures that all components of the RPD framework are properly aligned with the oral structures. Mouth Preparations ○ Guides necessary tooth modifications to create optimal guide planes and ensure proper fit.  Benefits ○ Enhances precision in RPD design by providing a clear reference for component placement. ○ Streamlines the design process by providing clear guidelines for framework construction. ○ Allows for personalized prosthesis design tailored to individual anatomical variations. Tripoding Tripoding is a technique used during surveying to ensure that the cast can be repositioned in the same orientation on the surveyor after removal. To maintain consistency and accuracy when analyzing or modifying a cast. Three points are marked on the cast, creating a stable tripod configuration. These points allow for precise repositioning, ensuring that any adjustments made are consistent with the original survey. Both surveying and tripoding are crucial for designing effective RPDs, as they ensure that the prosthesis will fit well, function properly, and be comfortable for the patient. Process of Tripoding 1. Selection of Points- Choose three non-collinear points on the cast, typically on stable areas that are not subject to change or wear. 2. Marking - Use a surveyor to mark these points with a pencil or scoring tool. These marks serve as reference points for future adjustments or evaluations. 3. Verification - Reposition the cast on the surveyor using these points to ensure it returns to the same orientation each time. Applications in RPD Design Guide Plane Analysis- Helps in determining the path of insertion and removal for the RPD, ensuring optimal retention and stability. Undercut Identification- Facilitates accurate identification of undercuts that can be used for clasp retention. Framework Design - Ensures that all elements of the RPD framework are designed in harmony with each other and the oral anatomy. Benefits  Enhances the precision of prosthesis design by maintaining a stable reference plane. Reduces time spent on reorienting casts, allowing for more efficient workflow in dental laboratories. Improves the accuracy of fit and function of the final prosthesis by ensuring consistent design parameters.