This document defines key terminology used in operative dentistry for cavity preparation and restoration. It discusses terms like cavity, cavity preparation, simple/compound/complex cavity preparations, intracoronal and extracoronal preparations, walls (internal, external, floors), angles (line, point, cavosurface), and junctions (dentinoenamel, cementoenamel). Simple cavity involves one surface, compound two surfaces, and complex three or more surfaces. Internal walls are inside the tooth while external walls contact the tooth surface. Angles are where walls meet, and junctions define boundaries between tooth structures.

1. CAVITY NOMENCLATURE
& ITS TERMINOLOGY
Rohan Vadsola

2. contents
Introduction
Nomenclature and Terminology

3. INTRODUCTION
• Nomenclature refers to a set of terms used in
communication by individual in the same
profession that enables them to understand one
another better.
• There are several terms in operative dentistry
used for the purpose of communication and for
explaining various concept.

4. Nomenclature related to cavity
preparation
1. Cavity : This refers to a defect in the tooth
enamel or in both enamel or in both enamel
and dentin due to the carious process.
2. Cavity preparation: This refers to the
mechanical alteration of a defective, injured
or diseased tooth to best receive a restorative
material which will re-establish the normal
form, function and esthetics of the tooth.

5. 3. Simple cavity
preparation : This
refers to a cavity
preparation that
involves only one
surface of a tooth.
Eg. Occlusal cavity
preparation.

6. 4. Compound
cavity preparation
: This refers to a
cavity preparation
that involves two
surfaces of a
tooth.
Eg. Mesial and occlusal
cavity preparation.

7. 5. Complex cavity
preparation : This
refers to a cavity
preparation that
involves three or
more surface of a
tooth.
Eg. Mesial, occlusal and
distal cavity preparation.

8. For ease of communication these may be expressed as
follows:
Occlusal cavity preparation – O
Mesial and occlusal cavity preparation – MO
Mesial, occlusal and distal cavity preparation – MOD
6. Intracoronal cavity preparation : This refers to a cavity
that is prepared in
the interior of a tooth.
7. Extracoronal tooth preparation : this refers to tooth
preparation involving the external surfaces of the tooth
Which requires removal of most or all of the enamel.

9. 8. Walls of the
cavity preparation
: Any surface of a
prepared cavity is
referred to as a
wall.

10. The various walls in a cavity preparation are:
 A) Internal Wall – This is a surface of a prepared
cavity that is inside the tooth and does not extend
onto the external tooth surface. The two internal
walls in cavity preparation are:
1. Axial Wall - an internal wall which is parallel
with the long axis of the tooth.
2. Pulpal Wall – An internal wall which is
perpendicular to the long axis of the tooth. this
wall is occlusal to the dental pulp.

11.  B) External Wall – This is a prepared surface that
extends to the external tooth surface. It takes the
name of the tooth surface that the wall is toward.
eg. Facial, mesial, distal, lingual and gingival walls.
 C) Floor or seat – This term is referred to a prepared
wall that is relatively flat and perpendicular to the
occlusal forces which are directed along the long axis
of the tooth.
eg. Pulpal and Gingival walls.

12.  D) Enamel wall – This is that portion of the prepared
external wall which is composed of enamel.
 E) Dentinal wall – This is that portion of the prepared
external wall which is composed of dentin. This wall
usually incorporates mechanical retentive features.
9. Angles in a cavity preparation : The term angle refers
to the junction of two or more surfaces of a cavity
preparation.

13. There are many angles in a cavity
prepared cavity such as:

14. A) Line angle – This is
the junction of two
walls in a cavity
preparation along a
definite line.
B) Point angle – This
refers to the junction of
three walls in a cavity
preparation at a point.
C) Cavosurface angle –
This refers to the angle
of the tooth structure
formed by the junction
of a prepared wall and
the external tooth
surface.

15. It varies according to the location of the cavity
preparation on the tooth, the type of the restorative
material to be used and the direction of the enamel rods
on the prepared wall.
The actual junction of the prepared wall and the
external tooth surface is called the cavosurface margin.

16. 10) Junctions :
A) Dentinoenamel junction – This is the junction of the
enamel and dentin.
B) Cementoenamel junction – This is the junction of the
enamel and cementum. It is also called the “cervical
line”. Sometimes the enamel and cementum do not
actually meet, in which case a narrow region of exposed
dentin may be present.