s10-finals-Impression Techniques Flashcards
(34 cards)
What is the primary goal of an implant impression?
To accurately relate the implant/abutment analog to surrounding oral structures (gingiva, teeth, occlusion).
What are the two main levels for implant impressions?
Fixture level and abutment level.
Name three components of the armamentarium for implant impressions.
Transfer copings, impression materials, healing caps/abutments.
What is a key advantage of the conventional/transfer technique?
Familiarity to dentists and reduced cost (no analogs/lab fees).
What is a major disadvantage of the conventional/transfer technique?
Abutments are prepared in the mouth, risking screw exposure or cast fracture.
Why is the open tray technique preferred for nonparallel implants?
It eliminates distortion during coping reinsertion and handles angulation better.
What is a key disadvantage of the closed tray technique?
Risk of material deformation when reinserting copings into the impression.
When is the closed tray technique indicated?
For parallel implants, single-tooth restorations, or patients with gagging tendencies.
What is the main advantage of the abutment-level impression?
Prevents coping movement and reduces chairside wait time.
What is a limitation of digital impressions with multiple implants?
Difficulty identifying correct abutment positions due to proximity.
Why avoid latex gloves with polyvinyl siloxane (PVS) impressions?
Latex inhibits polymerization, compromising accuracy.
Which impression material has high tear resistance but is prone to water distortion?
Polyether.
What is the benefit of polyvinyl siloxane (PVS) as an impression material?
High dimensional stability and precision detail capture.
What precaution is critical before making an implant impression?
Verify implant position with radiographs.
How are implant impressions classified by tray type?
Open tray (direct) vs. closed tray (indirect).
What is the first step in the closed tray technique?
Screw indirect transfers onto implants using a hex tool.
What is added to block out screw holes in closed tray impressions?
Wax or similar material.
What is the final step in the closed tray technique?
Attach replicas to transfers in the impression for lab model fabrication.
What is the key advantage of splinting impression copings?
Prevents rotational movement during analog fastening for better accuracy.
Why is the open tray technique called “direct”?
Copings remain in the impression (picked up directly), avoiding reinsertion errors.
What type of coping is used in the open tray technique?
Squared coping.
What is a disadvantage of polyether impression material?
High hardness makes removal difficult; sensitive to moisture.
What is the primary use of an abutment holder?
To stabilize abutments during adjustments outside the mouth.
When is an abutment-level impression most beneficial?
For posterior implants with aligned prosthetic axes.
