If a number teeth are missing, a more complex prosthetic appliance known as a removable partial denture may be used. Clasps are used to attach the partial denture to the remaining abutment teeth. Silver-colored metals composed of mainly nikel, cobalt, and chromium are strong and highly resistance to corrotion. Because partial denture are removeable, the clasps must be capable of springlike action without being distorted or broken. Acrylic resin materials that prossess excellent esthetic qualities are used to fabricate artificial teeth on the removeable partial denture. Here, as in other situations, materials are combined in restoration or appliance to use the best properties each.
Finally, if all the natural teeth in an arch are lost, a full denture, or complete denture, ie required. The denture consistsof a base with artificial teeth. Most denture bases are made from acrylic resins that are pigmented to match the pink shades of the oral tissues. The teeth used is constructing a denture may be made with acrylic resin or porcelain. The porcelain teeth are more resistant to wear but more britle than acrylic resins.
Implant have been used to replace the roor of extracted teeth, and after bone growth has stabilized the implant a full crown can be constructedthat is supported by the implant. Manufacturers frequently use titanium or a titanium alloy containing 6% aluminium and 4% vanadium to construct the implant, and ceramic implants also have been used. The surface may be plasma-sprayed with titanium or coated with hydroxyapatite (similar to mineral portion of human enamel).
Resin, alloy. and ceramics, as can be seen from this brief survey of dental restoration, all are used in dentistry, in addition to the many other materials that are used in the fabrication of these restorations. Studying dental material enables members of the dental health team to understand the properties of these dental materials and how best to use them. The correct selection and manipulation of dental material largery determine the service a restoration will give to the patient.
SELF TEST QUESTIONS
In the following multiple-choice, one or more of the responses may be correct.
1. A small portion of an anterior tooth would most likely be restored with which of the following?
a. Amalgam
b. Composite resin
c. Gold alloy
d. Porcelain
2. The restorative material used to restore a small portion of an anterior tooth should have which of the following properties?
a. Esthetics
b. High strength
c. Durability
d. Ease of casting
3. A portion of an posterior tooth that is subjecy to high bitting forces would likely be restored with which of the following?
a. Amalgam
b. Composite resin
c. Gold alloy
d. Acrylic resin
4. A direct restorative material used frequently to restore a portion of a posterior tooth that is subject to large bitting force would prossess which of the following properties?
a. Esthetics
b. High stength
c. Ease of casting
d. Thermal insulation
5. A full crown on a maxillary anterior tooth may be restored with which of the following restorative materials?
a. Ceramic
b. Gold alloy
c. Composite resin
d. Ceramic (porcelain) fused-to-metal
6. An anterior fixed partial denture could have facings constructed of which of the following materials?
a. Composite resin
b. Acrylic resin
c. Ceramic
d. Gold alloy
7. Which of the following sentences describes the construction of removeable partial dentures?
a. They are attached to natural teeth with cements
b. Theyare removeable and attached to teeth with clasps
c. Nickel, cobalt, and chromium alloys are used for framework.
d. Artificial acrylic teeth are attached
8. Full denture baes are usually made from which of the following materials?
a. Composite restorative resins
b. Gold alloy
c. Acrylic resins
d. Ceramic
9. Which of the following metals currently are used in dental alloys?
a. Gold
b. Mercury
c. Cobalt and chromium
d. Nickel
10. Acrylic resins are used in which of the following?
a. Posterior inlays
b. Denture bases
c. Artificial teeth
d. Ceramic (porcelain) fused-to-metal crowns
11. Which of the following materials are used dor dental implants?
a. Gold alloys
b. Cobalt and chromium alloys
c. Titanium
d. Ti6AIAV
12. A posterior restoration that involves the occlusal surfaces, two proximal surfaces, and all cusps is called an…………………………………………….
13. An area in a dep restoration between the tooth and the restorative material used to insulate the pulp is called the………………………………..
14. A restoration that covers the entire coronal portion of the tooth is called a……………
15. After a root canal procedure the canal is frequently filled using……………………………….
16. A restoration that replaces a missing tooth that is supported by and cemented to two adjacent teeth is called a……………………………….
17.A restoration where artificial teeth are mounted on a metal framework containing clasps that attach it to remaining abutment teeth ia called a…………………………….
18. A restoration that replaces all the teeth in the upper or lower arch with artificial teeth that are attached to a plastic base is called a………………………………………
19. A restoration that replaces the root of an extracted tooth and is stabilized by bone growth around it is called an……………………………….
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