Question 1

Each component of a fixed bridge is referred to as a:

Accepted Answer

A fixed bridge is made up of multiple units, each of which includes a crown on either side of the gap and a false tooth (pontic) in between. Therefore, each individual section is referred to as a "unit." Teeth and crowns are also involved in a bridge, but they only comprise part of a larger unit. "Core" is not a commonly used term in relation to bridges.

Question 2

A(n) _____ is a cast restoration that is designed to fit snugly within a tooth preparation such as a class II restoration and that covers only a portion of the occlusal and proximal surface.

Accepted Answer

An inlay is a type of dental restoration that fits within the cusps of a tooth, typically used for class II restorations, covering only a portion of the occlusal and proximal surfaces.

Question 3

When the patient has a fixed prosthesis,such as a three-unit bridge,the area under the pontic is maintained by:

Accepted Answer

Threading dental floss under the pontic with a bridge threader is the best option for cleaning the area under a fixed prosthesis like a three-unit bridge. Brushing and swishing with mouthrinse may not be effective in removing plaque and debris from under the pontic. Irrigation with a cannula may not reach the tight spaces under the pontic. Threading dental floss using a bridge threader ensures effective cleaning and maintenance of the hygiene under the pontic.

Question 4

A _____ crown does not cover the entire anatomic portion of the tooth.

Accepted Answer

A three-quarter crown only covers three-fourths of the anatomic portion of the tooth, leaving some of the natural tooth structure visible. Full crowns cover the entire tooth, porcelain-fused-to-metal and gold crowns can be either full or three-quarter.

Question 5

The material placed under a porcelain restoration to mask tooth discoloration is a(n):

Accepted Answer

The material placed under a porcelain restoration to mask tooth discoloration is called an opaque. It is a type of dental material that is used to hide or mask any existing discoloration on the natural tooth structure so that it does not show through the porcelain.

Question 6

The final appointment in the crown and bridge process involves:

Accepted Answer

Cementation of a permanent crown is the final step in the crown and bridge process. It involves permanently bonding the crown to the prepared tooth using dental cement. Try-in of the casting, picking a shade, and writing the laboratory prescription are all steps that occur earlier in the process.

Question 7

Which of the following is an example of a fixed prosthesis?

Accepted Answer

A three-unit bridge is a fixed dental prosthesis that replaces a missing tooth or several teeth by being anchored to remaining natural teeth or dental implants. The other choices are not examples of fixed prostheses but rather restorative materials used to fill cavities or anchor restorations.

Question 8

Which of the following procedures takes place during the second appointment for the placement of a cast restoration?

Accepted Answer

The try-in appointment is when the cast restoration is tried in the patient's mouth to check for fit, occlusion, and aesthetics. Shade selection, preliminary impressions, and final impressions are typically done during the first appointment.

Question 9

A prosthodontist:

Accepted Answer

A prosthodontist is a dentist who is dedicated to restoring and replacing teeth, focusing on fixed or removable prosthodontics. To become a prosthodontist, a dentist must receive an additional 3 years of training in a program accredited by the American Dental Association. Therefore, both choice A and B are correct. Choice C is not entirely accurate, as while prosthodontists do work with crowns, inlays, onlays, and bridges, they focus specifically on restoring and replacing teeth rather than general dentistry.

Question 10

The metal of choice for inlay and onlay cast restorations is:

Accepted Answer

Gold is the metal of choice for inlay and onlay cast restorations due to its durability, resistance to corrosion, and biocompatibility with the oral tissues. Gold also has a higher accuracy of fit compared to other materials, making it a favorable choice for restorations that require precise fit and minimal occlusal adjustments. Porcelain and ceramics may be used for esthetic purposes, but they are more prone to fracture and chipping, limiting their use in stress-bearing areas. Amalgam, although strong and cost-effective, may not be aesthetically pleasing and may require more tooth preparation.

Question 11

A gingival retraction cord is placed _____ the crown preparation is completed; it is removed _____ the final impression is taken.

Accepted Answer

A gingival retraction cord is placed after the crown preparation is completed and removed before the final impression is taken.
The dentist needs access to the margin of the tooth crown during the preparation,so the cord cannot be placed until after the preparation is completed.In order to get an accurate impression of the margin,the cord must be removed before seating the impression tray.

Question 12

Which of the following statements is true concerning porcelain veneers?

Accepted Answer

The color of the finished veneer can be affected by the shade of the underlying tooth structure and by the color of the luting agent. The other statements are false. Porcelain veneers are usually recommended for improving the appearance of anterior teeth, they involve preparation of tooth structure, and provisional coverage may or may not be required depending on the case.

Question 13

An important step in placing a porcelain veneer is:

Accepted Answer

Matching the tooth color of the veneer to the adjacent teeth is an important step to ensure a natural-looking result. This requires careful shade selection and may involve custom color-matching techniques. While it may also be necessary to create a provisional restoration, ensuring the veneer is thick enough to block out underlying color and using a cement shade darker than the veneer are not critical steps.

Question 14

The component of the bridge that provides support for the replacement teeth is a(n):

Accepted Answer

An abutment is a dental implant or natural tooth used to support the pontic, or replacement tooth, in a dental bridge.

Question 15

When one or more teeth are missing from the same arch,a permanent _____ is recommended.

Accepted Answer

A fixed bridge is recommended when one or more teeth are missing from the same arch. It provides a long-lasting and stable solution for replacing missing teeth without the need for removable appliances like dentures. A fixed bridge is also more efficient in terms of chewing and speaking abilities. Partial dentures and dentures are recommended when multiple teeth are missing in different areas of the mouth, and porcelain-fused-to-metal crowns are recommended for individual tooth restorations, not for replacing missing teeth.

Question 16

The component of a fixed bridge that replaces a missing natural tooth is the:

Accepted Answer

The pontic is the portion of a fixed bridge that replaces a missing natural tooth. The abutments are the teeth on either side of the pontic that support the bridge. Units and cores are not specific components of a fixed bridge.

Question 17

An indirect restoration:

Accepted Answer

An indirect restoration can be an inlay, onlay, crown, or bridge. It is also a permanent restoration and is commonly referred to as a cast restoration.

Question 18

_____ can be used in selected situations,such as a replacement for a congenitally missing lateral incisor,as an alternative to a traditional bridge.

Accepted Answer

Both a resin-bonded bridge (also known as a Maryland bridge) and a traditional bridge can be used as a replacement for a missing lateral incisor. However, a resin-bonded bridge is often preferred because it is less invasive and requires less alteration to the adjacent teeth. Therefore, both options (a and b) are valid choices depending on the individual circumstances. A crown is not a suitable option for a missing tooth as it is used to restore a damaged or decayed tooth rather than replacing a missing one.

Question 19

A post can be used as a retention aid for a crown,provided that the tooth:

Accepted Answer

A post can be used as a retention aid for a crown only if the tooth has been treated endodontically, meaning that the tooth's nerve has been removed, and is no longer vital. In cases where the tooth is vital, other retention aids like bonding or a resin cement can be used instead of a post. If the tooth is non-restorable, it is not feasible to use a post as a retention aid.

Question 20

A full metal crown that has the outer layers covered with a thin layer of porcelain is a(n):

Accepted Answer

A porcelain-fused-to-metal crown has a metal framework covered with a thin layer of porcelain on the outer surface, providing the aesthetic benefits of porcelain with the strength of metal. A porcelain jacket crown consists entirely of porcelain, while an onlay and three-quarter crown are partial coverage restorations that cover less of the tooth than a full crown.

Quiz 50: Fixed Prosthodontics