This document provides definitions of key terminology used in operative dentistry for describing tooth surfaces, dental caries, cavity preparations, and classifications of cavity preparations. It defines surfaces of the tooth like mesial, distal, facial, lingual, incisal, and occlusal. It describes primary and secondary caries and classifications based on extent and rate. It also defines preparation walls, angles, cavosurface angle and margin, and Black's classification system for cavity preparations including Class I-VI.

1. NOMENCLATURE IN
OPERATIVE DENTISTRY

2. CONTENTS
1. Introduction
2. Terminology Related to various Tooth
surface
3. Terminology Related to Dental caries
4. Nomenclature Related to cavity
preparation / Tooth preparation
5. Classification of cavity preparations

3. INTRODUCTION
Nomenclature refer to a set of terms used in communication by individuals in the same profession
that enables them to understand one another better.

4. TERMINOLOGY RELATED TO
VARIOUS TOOTH SURFACES
The coronal portion of tooth is divided into surface :
Mesial: The surface of the tooth closest to the anterior midline.
Distal: The surface of tooth away from the anterior midline.
labial: The surface of the tooth toward the lip.
Buccal: The tooth surface that is towards the cheek
Facial: The surface of tooth towards patients face

5. Lingual: The tooth surface that is towards the tongue.
Incisal: The Functional edge of an anterior tooth.
Occlusal: The masticating surface of a posterior tooth
Cervical: The surface of the tooth close to the neck or cervix of
tooth.
Gingival: The surface of the tooth close to the gingiva

7. TERMINOLOGIES RELATED TO
DENTAL CARIES
Dental caries: Dental caries is an infectious microbiological disease of teeth that results in localized
dissolution of the calcified tissue. Caries can be Described according to Location, Extent and Rate.

8. According to Location
Primary caries : primary caries is the original carious lesion of the tooth. Morphologically 3 types of
primary caries are evident
1. Pits and fissure caries : caries involving pit and fissure area of teeth because of imperfect
coalescence of the developmental enamel lobe
2. Smooth surface caries : caries originating on smooth surface area of teeth that are usually
covered by plaque.
3. Root surface caries / Senile caries : caries may occur on the tooth root that has been exposed to
the oral environment and habitually covered with plaque

9. 2.secondary caries /Recurrent caries: it occurs at junction of a tooth restoration and the tooth and
may progress under the restoration

10. According to Extent
Incipient / Reversible caries : This represents early carious lesion which is in its initial stage. it can be
remineralized if immediate corrective measures alter the stage.
Cavitated / Irreversible caries: in this condition enamel surface is broken and usually lesion has advanced
into dentin. Restoration is usually indicated.

11. According to Rate
Acute / Rampant caries : it refers to disease that is rapidly damaging the tooth .
Chronic / Arrested caries : it is slow or it may be arrested after several active phase.
Other terminologies related to caries :
Backward caries : when the spread of caries along DEJ exceeds the caries in the contiguous enamel
caries extended in to this enamel from junction and is termed Backward caries.
Forward caries : when caries cone in enamel is larger or at least the same size as that dentin.
Residual caries : Caries that remains in a completed tooth preparation whether by intention or
accident.

12. TOOTH PREPARATION
TERMINOLOGY
Cavity : This refers to a defect in the tooth enamel or both in enamel and dentin due to carious progress.
Tooth (Cavity) Preparations: it is mechanical alteration of a defective injured or diseased tooth to receive
a restorative material that reestablishes a healthy state for the tooth including aesthetic correction
where indicated and normal form and function.
Simple tooth preparation: A cavity preparation involving only one tooth surface.
Compound tooth preparation: If two surface are involved den termed as compound tooth preparation.
Complex tooth preparation: When preparation involves 3 or more surfaces then it is called as complex
tooth preparations.

13. TOOTH PREPARATION WALLS
Internal wall: it is Prepared surface that does not extend to the external tooth surface.
External wall: An external wall is prepared surface that extends to the external tooth surface.
Axial wall: An axial wall is an internal wall parallel to tooth surface
Pulpal Wall: A pulpal wall is wall perpendicular to long axis of the tooth and occlusal of the pulp
Floor or Seat : A seat or floor is prepared wall that is
reasonably flat and perpendicular to the occlusal force that are directed occlusogingivally
Enamel wall: The enamel wall is that portion of prepared external wall consisting of enamel
Dentinal wall: The Dentinal wall is that portion of prepared wall consisting of dentin, in which mechanical
retention features may be located.

15. TOOTH PREPARATION ANGLES
Here Angle refers to junction of two or more surfaces of cavity preparation.
Line Angle : It is junction of two planar surface of different orientation along a line. it is of two types
:-
1. internal line angle: line angle whose apex points into the tooth
2. external line angle: whose apex point away from the tooth.
Point Angle : It is junction of 3 planar surfaces of different orientation.

17. Cavosurface angle and
Cavosurface margin
The Cavosurface Angle is the angle of tooth structure formed by junction of prepared wall and the
external surface of the tooth.
The actual junction is referred to as Cavosurface margin.

18. CLASSIFICATION OF CAVITY
PREPARATION
classification of tooth preparation according to anatomic area and by the associated type of
treatment was presented by Black and designated as :
Class I
Class II
Class III
Class IV
Class V
An additional Class VI has been added

19. Class 1 Cavity
This includes cavity preparation involving pit and fissure area of teeth. it involves following area :
One Occlusal pit and fissure in posterior teeth
occlusal 2/3 of facial and lingual surface of molar.
Lingual Pits of maxillary incisors

20. Class 2 Cavity
This involves one or both Proximal surface of posterior teeth

21. Class 3 Cavity
This includes cavity preparation on proximal surface of anterior teeth without involving the incisal
angle

22. Class 4 Cavity
This includes cavity preparation on proximal surface of anterior teeth with involvement of the
incisal angles

23. Class 5 Cavity
This involves cavity preparation on the gingival 1/3 of the facial and lingual surfaces of all the teeth.

24. Class 6 Cavity
This involves cavity preparation on incisal edges of anterior teeth or the occlusal cusp heights of
posterior teeth

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