Nomenclature of tooth surfaces and cavity preparations

Question 1

How many surfaces does each tooth have?

Answer 1

5

Question 2

What is the occlusal surface characterized by?

Answer 2

-Grooves
-Cusp tips ridges
-Marginal ridges
-Fossa

Question 3

What is a groove?

Answer 3

A linear channel between enamel elevations. Such as cusps and/or ridges.
* Around the cusp, and into the the groove to ensure a smooth margin

Question 4

What is a fissure?

Answer 4

A developmental linear cleft usually found at the base of a groove

Question 5

Where is a fissure found?

Answer 5

At the base of a groove

Question 6

What is a pit?

Answer 6

A small depression in enamel

Question 7

Where are pits found?

Answer 7

In a groove and often at the junction of two or more fissures

Question 8

Where is most of S. mutans found?

Answer 8

Pit and fissure area

Question 9

Simple cavity:

Answer 9

Involves only 1 surface. I.e. Occlusal (O) or buccal (B)

Question 10

Compound cavity:

Answer 10

2 surfaces or more surfaces. mesio-occlusal

Question 11

Complexe cavity:

Answer 11

3 or more surfaces. I.e. MOD

Question 12

Where can a class I be found?

Answer 12

-Pit and fissure caries on the occlusal surface of premolar and molars (posterior teeth)
- The buccal and lingual surfaces of molars
-Palatal surface of maxillary anterior

Question 13

Class I:

Answer 13

Pit & fissure caries

Question 14

Class II:

Answer 14

Any decay within a proximal surface (D or M) on a posterior tooth

Question 15

Class III:

Answer 15

Any decay within a proximal surface (D or M) on an anterior tooth

Question 16

Class IV:

Answer 16

Any decay within a proximal surface (D or M) and on the incisal angle(s) of an anterior tooth

Question 17

Clas VI:

Answer 17

Doesn’t include an of the surfaces of the 1st class’s. Will typically involve a cusp tip, incisal edge or ridge.

Question 18

How does decay usually spread in a Class I?

Answer 18

Decay starts at the pit and will spread to the DEJ.

Question 19

T/F: It doesn’t matter how the amalgam or composite is placed inside of a prep as long as the patient can bite down and chew

Answer 19

False. There should be groove patterns similar to the actual anatomy of the tooth for a composite or amalgam filing

Question 20

T/F: Smooth surface caries include class I

Answer 20

False. Smooth surface caries will include all classes except class I

Question 21

T/F: Class II can only be compound

Answer 21

False. Class II can be classified as compound or complex

Question 22

How are class II caries diagnosed?

Answer 22

Radiographic bitewings

Question 23

Smooth surface caries:

Answer 23

Decay where there is no groove, pit, or ridge. Will occur near the cervical, or inter proximal surface. Decay will start cervical then spread to the DEJ

Question 24

T/F: A class III involves the incisal edge

Answer 24

False. A class III will only involve the proximal surface of an anterior tooth

Question 25

What is the preferred method for accessing a class III ?

Answer 25

From the lingual aspect

Question 26

Can a class IV include a proximal surface?

Answer 26

Yes. A class IV includes the incisal edge/angle but can also include a proximal surface (MIL)

Question 27

Pulpal floor:

Answer 27

Perpendicular to the long axis of the tooth

Question 28

T/F: The walls are parallel to the pulp

Answer 28

True

Question 29

T/F: a class II is considered a pit &fissure

Answer 29

False. A class II is considered a smooth surface caries

Question 30

What are the internal walls of a prep?

Answer 30

Pulpal and axial wall

Question 31

What are the external walls of a prep?

Answer 31

Facial, lingual, distal, mesial and gingival

Question 32

What walls are used to extend a prep?

Answer 32

The external walls are used to extend a prep. Extension will be lateral (away) from the pulp.

Question 33

Axial wall:

Answer 33

Parallel to the long axis of the tooth and used for proximal cavity preps

Question 34

How can depth be created for a cavity prep?

Answer 34

Depth can be created by prepping towards the internal walls (axial and pulpal)

Question 35

Enamel wall:

Answer 35

Portion of the prep composed of just enamel

Question 36

Dentin wall:

Answer 36

Portion of prep composed pf dentin

Question 37

Line angle:

Answer 37

The angle formed by the junction of two walls meeting; i.e. mesiolingual

Question 38

Point angle:

Answer 38

Formed by the junction of three walls meeting; I.e. distolingopulpal

Question 39

Cavosurface angle:

Answer 39

Formed by junction of the prepared tooth surface and the external surface of the tooth

Question 40

T/F: The cavosurface angle should be 90 degrees

Answer 40

True

Question 41

Acute junction:

Answer 41

Referred to as the preparation margin or cavosurface. Where the prep ends and the tooth surface begins

Question 42

Dovetail:

Answer 42

The extension of the preparation designed to create an interlock for the restorative material

Question 43

Purpose of a dovetail for a class II:

Answer 43

Prevents the restoration from moving laterally (prevents retention)

Question 44

Purpose of a dovetail for a class I:

Answer 44

Prevents decay

Question 45

Isthmus:

Answer 45

The narrowest part of the prep that is in between the buccal and lingual cusp. The smaller the better