DENA 1350 Review Chapters 50, 51, & 52, Elastomeric Impression Materials & Dental Waxes

What material is sticky to the touch and is used to increase the length of an impression tray?

Utility wax

Not including esthetic reasons, list at least three functions of a provisional or temporary crown:

To reduce sensitivity and discomfort of the prepped tooth, To maintain the function and esthetic of the tooth, To protect the margins of the prep, To prevent shifting of adjacent or opposing teeth.

What is the metal skeleton of a partial denture called?

Framework

What is a pontic?

The component of a fixed bridge that replaces the missing tooth

What is an abutment?

The natural tooth that serves as a support for the replacement tooth or teeth in a fixed bridge

List and describe the four types of elastomeric materials are used to take a final impression:

• Polysulfide (rubber base), stinks;

• Polyether(impregum) more rigid, stiff;

• Silicone, more flexible, shrinks over time;

• Polysiloxane, best for dimensional stability, comes in variety of consistencies

What is an overdenture?

A complete denture supported by two or more remaining natural teeth or implants

What type of material(s) are artificial teeth on partials and dentures made of?

Acrylic or porcelain

What is a triple tray and what is it used for?

Type of final impression tray made of plastic rim and mesh, takes final impression of prep, opposing bite and bite registration

Which part of a partial denture encircles an abutment tooth and what is its purpose?

The retainer or clasp; Directly supports and provides stability to the partial denture.

Which wax is supplied in pink sheets and is a common form of bite registration?

Baseplate wax

What is the difference between the die and the master cast?

The die is an exact replica of the prepped portion of the tooth, and constructed to be taken in and out of the master cast

If a tooth has been treated endodontically, what may be placed into the pulp canal for better retention of a crown?

The part of a denture that extends over the attached mucosa from the margin of the teeth to the border of the denture

What is a flange?

Placement and removal of the gingival retraction cord

On a partial denture, what is the difference between a retainer and a clasp?

Nothing

In a crown and bridge procedure, what important step is performed after the tooth is prepped and before the impression is taken?

Placement and removal of the gingival retraction cord

Which wax is not sticky to the touch, is brittle and when heated or melted, it is used to hold things together

Sticky wax

What is an occlusal rim and what four things does the dentist use it to record

Pg 892 Used as the wax try-in, It is

removed from the articulator, disinfected and rinsed, used to record:

1) Vertical dimension (space occupied by the height of the teeth in normal occlusion);

2) Occlusal relationship: Centric, protrusive, retrusive, & lateral excursions;

3) Smile line

4) Canine eminence (vertical line that indicates the location of the canines).

If a tooth is vital but the coronal portion has lost much of its structure, what may be used or added for support and retention of the cast restoration?

Core build-up, made of amalgam or composite; retention pins

What component of a partial denture controls how it is seated, aids in distributing the pressure and is placed on the occlusal or lingual surface of a tooth?

The rest

When dentures are not in the mouth, how should they be stored?

In water or a moist, airtight container

What is used to form a wall around the base of models?

Boxing wax

An immediate denture is one that is placed immediately after?

Extraction of remaining teeth

List at least four items that are included in the instructions on the laboratory prescription, to make the cast restoration:

• Type of prosthesis

• Type of alloy or other materials to be used

• Exact shade

• Anatomic characterization(if required)

• Date on which the case is expected back

Describe what the post dam is:

Suction seal or posterior palatal seal on the maxillary denture

How many teeth are in a full set of dentures?

28

What is a Maryland bridge?

A resin-bonded bridge consisting of a pontic with wing-like extensions on mesial & distal sides that are bonded to the lingual surfaces of the adjacent teeth supporting the pontic

Why would you need to reline a denture?

Dentures are loose or ill-fitting, A loss in vertical dimension, Inflammatory hyperplasia, traumatic ulcers.

What is the the gingival retraction cord and what is its purpose?

Plain or twisted cords packed into the sulcus forcing the tissues away from the tooth

What is the name of the wax that is used to make a wax try-in for dentures?

Occlusal Rim or Bite Rim

Explain what the following terms have in common: Hemostatic solution, vasoconstrictor, aluminum chloride, impregnated, epinephrine.

All are chemicals that may be infused into the gingival retration cord to shrink the tissue and/or control bleeding

The soft wax used for bite registration, with metal foil between the outer layers that gives more detail is the:

Bite Wafer

What type of crown would be better on a posterior tooth of a person that grinds their teeth?

A gold crown

What three things are necessary to send to the lab with the prescription to make a cast restoration?

• Final impression

• Opposing impression

• Bite registration

Describe the two-step or "putty & wash" final impression technique

The dentist injects a light body or "wash" impression material around the prepped tooth or teeth just before the impression tray with the heavier tray material or putty is placed and seated. The purpose is to get a more accurate and detailed margin.

Besides the final impression, describe the other two impressions that are taken at a crown & bridge procedure and their functions.

An impression of the tooth/ teeth before they are prepped to use to construct a temporary and an opposing impression to articulate with the prepped tooth/ teeth.

Describe the different consistencies of polysiloxane, their uses and how they are mixed:

• Light-bodied, washed, applied directly to prepped tooth, auto-mixed with extruder gun

• Regular or heavy-bodied, for the tray, same Putty

• For tray mixed by hand. All may be mixed with a mixing unit such as a Pentamix

What does provisional coverage refer to and what is its purpose?

A temporary protective crown or bridge that is temporarily cemented to a tooth that has been prepped. Its purpose is to restore and maintain function to that area of the mouth and keeps the patient comfortable while waiting for permanent cementation.

What are four indications for using provisional coverage?

1) To prevent or reduce sensitivity and discomfort of the prepped tooth,

2) Maintain function and esthetics,

3) Protect margins of the prep,

4) Prevent shifting of adjacent or opposing teeth

What are the types of prefabricated temporary crowns?

• Preformed polymer

• Polycarbonate

• Stainless steel

What is the most common type of provisional and why?

A custom provisional, they provide the best-fitting and most natural-looking restoration

Briefly describe the steps in fabricating a custom provisional crown:

Obtain impression of arch before teeth are prepped. Place material into impression, place on prepped tooth/ teeth, when set, remove, trim & polish. Place in mouth, check occlusion, remove from mouth to make any adjustments. When complete, cement onto prep with ZOE

What seven criteria must be followed for a fabricated provisional crown or bridge

1) Must esthetically acceptable,

2) Contours are similar to natural tooth w/ adequate contacts and alignment

3) Cervical margin is smooth & fits snugly, no more than .5mm of space,

4) Doesn't extend below margin of prep,

5) Occ surface is aligned w/ adjacent teeth

6) When cemented, it remains stable, in place and is comfortable,

7) Can be readily removed without damage to teeth or tisues.

What are the home care instructions you should provide to a patient with a provisional crown or bridge?

• Bite & chew carefully

• Avoid sticky foods

• Be careful when flossing, pull through contact instead of popping out. If it loosens or comes out, contact us immediately to have it received or replaced.

It is used to make patterns for metallic restorations.

2. Patterns for inlays,

3. crowns and bridges is first made in wax and then converted into metal or ceramic by casting

Inlay / casting wax