Dental Impression Techniques

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Questions and Answers

What is the recommended storage position for a cast after pouring?

Tray side down (correct)

Flat on a dry surface

Open side up

Inclined at a 45-degree angle

Which of the following factors is NOT evaluated during the quality check of a diagnostic cast?

Voids and nodules

Proper articulation

Color consistency (correct)

Surface detail

What device is used to achieve accurate spatial orientation of the maxillary cast?

Centric relation interocclusal record

Articulator

Facebow (correct)

Protrusive record

Which of the following techniques is used to analyze occlusal contacts throughout mandibular movements?

Evaluating anterior guidance Signup and view all the answers

When should casts be separated after pouring for optimal outcomes?

One hour after pouring Signup and view all the answers

What does maximum intercuspation (MI) refer to in occlusal relationships?

The position of the jaws when the cusps interdigitate maximally Signup and view all the answers

During cast evaluation, which condition indicates a potential need for rejection?

Voids or nodules present Signup and view all the answers

Which record is essential for mandibular cast articulation within an articulator?

Centric relation record Signup and view all the answers

What is a key characteristic of a small nonadjustable articulator?

Leads to restorations with occlusal interferences Signup and view all the answers

Which articulator design is considered anatomically 'correct'?

Arcon design Signup and view all the answers

What is an advantage of using semiadjustable articulators?

They reduce the need for clinical adjustments and are time-efficient Signup and view all the answers

What does the progressive side shift in a semiadjustable articulator simulate?

Lateral movement of the mandible Signup and view all the answers

Which feature distinguishes nonarcon articulators from arcon ones?

Their upper and lower members are rigidly attached Signup and view all the answers

What is a critical purpose of interocclusal records in dental prosthetics?

To transfer the relationship between upper and lower dental arches to the articulator Signup and view all the answers

In which scenario would small nonadjustable articulators likely lead to issues?

When conducting detailed analysis of occlusal relationships Signup and view all the answers

What adjustment does the immediate side shift replicate in a semiadjustable articulator?

The initial lateral movement of the condyle Signup and view all the answers

What is a key purpose of diagnostic casts in fixed prosthodontics?

To facilitate comprehensive examination of tooth relationships Signup and view all the answers

When evaluating occlusocervical dimension in edentulous spaces, what is primarily assessed?

The height from the occlusal plane to the crest of the ridge Signup and view all the answers

Which of the following is NOT a factor to consider when assessing abutment teeth?

Surface color of the teeth Signup and view all the answers

What aspect does occlusal analysis primarily focus on?

Identifying potential interferences in occlusion Signup and view all the answers

In diagnostic wax-up procedures, what is the main benefit?

To visualize and evaluate proposed treatment outcomes Signup and view all the answers

Which principle is essential when considering anterior guidance?

Establishing a harmonious occlusal relationship Signup and view all the answers

What is the significance of spatial relationships in diagnostic casts?

They help assess interactions with adjacent and opposing teeth Signup and view all the answers

When selecting an articulator, which factor is most important?

Its ability to mimic the patient's dynamic occlusal relationships Signup and view all the answers

Study Notes

Material Application

Load tray and wipe material into occlusal crevices.

Tray Seating

Insert tray and remind patient to relax cheek muscles.

Removal

Remove quickly 2-3 minutes after gelation.

Evaluating Alginate Impression

Smooth surface
Rounded periphery
No oral cavity debris

Disinfection

Spray with glutaraldehyde
Place in a sealed bag for 10 minutes

Timing

Pour within 15 minutes of removal for accuracy

Stone Selection

Use vacuum-mixed ADA type IV or V stone.

Cast Storage and Separation

Storage Position: Tray side down
Environment: Covered with wet paper in humidor
Duration: 1 hour
Separation Time: 1 hour after pouring

Diagnostic Cast Quality Evaluation

Accuracy Check
- Examine for voids, nodules, and proper articulation.
Surface Detail
- Ensure adequate reproduction of dental structures.

Repeat if Necessary

Discard questionable impressions and casts.
Repeat the process.

Transferring Casts to Articulators

Use a facebow to transfer the maxillary cast
This ensures accurate spatial orientation.

Centric Relation Record

Utilize a centric relation interocclusal record for mandibular cast articulation

Condylar Element Setting

Set condylar elements using protrusive and excursive interocclusal records.

Analyzing Occlusal Relationships

Centric Relation
- The position of the mandible in relation to the maxilla where the condyles are in their most upward, backward, and unstrained position within the glenoid fossae.
Maximum Intercuspation
- The occlusal relationship where the cusps of the upper and lower teeth interdigitate maximally when the jaws are closed in their habitual position.
Mandibular Movements
- Analyze occlusal contacts throughout the range of mandibular movements.

Occlusal Plane Analysis

Anterior Guidance
- Evaluate anterior guidance and its influence on posterior disclusion.
Group Function
- Its an occlusal arrangement where multiple posterior teeth on the working side (the side towards which the jaw moves during lateral excursion) come into contact simultaneously during lateral jaw movements.

Articulator Selection for Dental Prostheses

Articulators are mechanical devices that simulate mandibular movement.
They are crucial for analyzing functional relationships in dental prosthetics.
Proper articulator selection can significantly impact treatment outcomes and efficiency.

Types of Articulators

Small Nonadjustable
- Limited capacity to reproduce mandibular movement.
- Can lead to occlusal discrepancies.
Semiadjustable
- Practical for routine fixed prostheses.
- Provides necessary diagnostic information with minimal adjustments.
Fully Adjustable
- Wide range of positions.
- Can follow patient's border movements accurately.

Small Nonadjustable Articulators

Limited Accuracy
- Cannot reproduce full range of mandibular movement.
Occlusal Discrepancies
- May lead to restorations with occlusal interferences.
Hinge Closure Issues
- Distance between hinge and tooth is less than in patients.

Semiadjustable Articulators

Practical Approach
- Suitable for most routine fixed prostheses.
Minimal Adjustments
- Reduces need for clinical adjustments during treatment.
Anatomical Accuracy
- Size similar to anatomic structures they represent.
Time-Efficient
- Does not require excessive time or expertise to use.

Arcon vs Nonarcon Designs

Arcon Design
- Condylar spheres on lower component.
- Anatomically "correct" design.
Nonarcon Design
- Popular in complete denture prosthodontics.
- Rigidly attached upper and lower members.
Movement Simulation
- Arcon easier to understand.
- Nonarcon movements are "backwards".

Semiadjustable Articulator Adjustments

Condylar Inclination
- Adjusts to mimic patient's condylar path.
Progressive Side Shift
- Simulates lateral movement of the mandible.
Immediate Side Shift
- Replicates initial lateral movement of the condyle.

Interocclusal Records

To transform the relation between the upper & lower dental arch from the patient mouth to the articulator.

Diagnostic Casts

A dental diagnostic cast, also known as a study model or diagnostic model, is a three-dimensional replica of a patient's teeth and surrounding oral structures. It is made from a dental impression using materials like dental stone or plaster.

Diagnostic Casts in Fixed Prosthodontics

Diagnostic casts are crucial in fixed prosthodontic treatment planning.
They allow for comprehensive examination of static and dynamic tooth relationships.
These casts provide insights not easily observable intraorally
They are essential for accurate diagnosis and treatment planning.

Evaluating Edentulous Spaces

Occlusocervical Dimension
- Measure the occlusocervical dimension of edentulous spaces.
- This is crucial for prosthesis planning.
Spatial Relationships
- Assess spatial relationships with adjacent and opposing teeth.
- Consider implications for prosthesis design
Soft Tissue Contours
- Evaluate soft tissue contours in edentulous areas.
- This affects emergence profile planning.

Assessing Abutment Teeth

Alignment
- Evaluate the relative alignment of proposed abutment teeth.
- Consider impact on prosthesis design.
Angulation
- Assess angulation of abutment teeth.
- This affects path of insertion and retention.
Tooth Position
- Analyze subtle changes in individual tooth position.
- Note any drifting or rotation.
Structural Integrity
- Examine structural integrity of abutment teeth.
- Consider need for additional restorative work.

Diagnostic Procedures

Tooth Preparation Simulation
- Practice tooth preparations on duplicate casts.
- Refine techniques before intraoral procedure.
Diagnostic Wax-up
- Perform diagnostic wax-up procedures.
- Visualize and evaluate proposed treatment outcomes.
Occlusal Analysis
- Conduct detailed occlusal analysis.
- Identify potential interferences and harmonize occlusion.

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Description

This quiz covers the essential techniques and best practices for making high-quality dental impressions. It includes steps for material application, tray seating, impression evaluation, and disinfection, ensuring the accuracy and quality of diagnostic casts. Test your knowledge on handling the alginate impression process and quality evaluation.