Nomenclature In Operative Dentistry

Guided By Dr. Sandeep Metgud

Dr. Deepali

Presented by Dr Ashish Chhajlani

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Introduction

Tooth Numbering

Terminology Related to various Tooth surface

Terminology Related to Dental caries

Terminology Related to other Defect of Tooth

Nomenclature Related to cavity preparation / Tooth preparation

Classification of cavity preparations

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.

Tooth Numbering System

The combined primary and deciduous dentition result in a total 52 teeth a clear and convenient means of identification of specific teeth is necessary .

There are several systems which are proposed for tooth numbering system . these are :-

South African system

french system

Dutch System

Bosworth System

cincinnati system

The Dane or Haderups System

Reverse numeration system

Latin numeral system

Metcalf system

Crow system

US Army System

US Navy System

LowLands system

Universal System / ADA system

Zsigmonday / Palmer notation method

The 3 popular system which are currently popular. They are :-

1 Zsigmondy / Palmer system

2 American Dental Association (ADA) system or Universal Numbering system

3 Federation Dentaire International (FDI) System

Zsigmondy/Palmer System

It is oldest system also called as Grid or Angular system

In this system Primary Dentition are denoted by English Upper case Latter and Permanent Dentition are denoted by Number

ADA System or Universal System

The Primary Dentition are denoted by consecutive english upper case latter starting from maxillary 2nd Molar

The Permanent Teeth are indicated by number 1 to 32 .

FDI System

it is also referred as Two Digit System.

The first digit identifies the Quadrant to which tooth belong and second digit denotes the tooth. Both digit have to be pronounced separately.

for Permanent Dentition Quadrant are numbered 1 to 4 and tooth are numbered 1 to 8 from the midline

for Deciduous dentition the quadrant are 5 to 8 and teeth are denoted 1 to 5 from the midline

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

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.

Terminology related to Dental caries

Dental caries: Dental caries is an infectious microbiological disease of teeth that results in localised dissolution of the calcified tissue

caries can be Described according to Location, Extent and Rate.

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

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

tooth and may progress under the

restoration

According to Extent

Incipient / Reversible caries : This represents early carious lesion which is in its initial stage. it can be remineralised 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.

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 terminology 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.

Enameloplasty

it is removal of a shallow enamel developmental fissure or pit to create a smooth saucer shaped surface that is self cleansing or easily cleaned

used when the fissure is no deeper than one quarter to one third the thickness of the enamel.

Prophylactic Odontotomy

The procedure involves minimally preparing and filling with amalgam , developmental structural imperfection of enamel such as pit and fissure

Infected Dentin

Carious dentin consist of two distinct layers an outer and inner.

the outer layer is called as Infected Dentin.

it is not remineralizable and it is more discoloured so should be removed.

Affected Dentin

The inner layer of carious dentin is called as Affected dentin. it can be remineralised in tooth so it should be preserved

Non carious Tooth Defects Terminology

1 Abrasion : it is abnormal tooth surface loss resulting from direct friction forces between the teeth and external object.

it is a pathological process , commonly seen as V shaped notch in gingival portion of facial aspect of tooth

2.Attrition : it is mechanical wear of the

incisal or occlusal surface as a result of

functional or parafunctional

movement of mandible (tooth tooth contact )

it is of two type Occlusal surface

attrition and proximal surface attrition

3.Erosion : it is loss of the tooth

structure surface by chemico-

mechanical action without any specific

role of microorganism

4.Abfraction: these are wedge shaped defects in cervical regions of tooth because of heavy eccentric occlusal force . Also termed as

idiopathic erosion

5. Fracture

This refers to any break in continuity of tooth surface as a result of traumatic injuries. fractures are commonly 3 types

1.Incomplete fracture not directly involving vital pulp: also called as Greenstick fracture. its a very sensitive condition

2.complete fracture not involving Vital pulp: In this condition pain is not associated usually , restorative treatment is indicated

3.Fracture involving Vital pulp: it results in pulpal infection and severe pain. immediate root canal therapy is indicated otherwise the tooth must be extracted

6.Non Hereditary Enamel hypoplasia: it occurs when the ameloblast are injured during enamel formation resulting in defective enamel. usually seen in anterior and first molar

7.Amelogenesis Imperfecta: the enamel is defective in form or calcification as a result of heredity.

8.Dentinogenesis Imperfecta: it is a heredity condition in which only dentin is defective due to injury to odontoblast.

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.

Abbreviation

The tooth description of tooth preparation is abbreviated by using first letter capitalised of each tooth surface involved . for example

O: occlusal surface

MO: involving mesial and occlusal surface

MOD : involving the mesial occlusal and distal surface etc ..

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 parellel 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.

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.

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

Classification of Tooth 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

Since Blacks original classification an additional Class VI has been added

Class I Cavity

This includes cavity preparation involving pit and fissure area of teeth. it involves following area :

1 Occlusal pit and fissure in posterior teeth

occlusal 2/3 of facial and lingual surface of molar.

Lingual Pits of maxillary incisors

Class II Cavity

This involves one or both Proximal surface of posterior teeth

Class III cavity

This includes cavity preparation on proximal surface of anterior teeth without involving the incisal angle

Class IV

This includes cavity preparation on proximal surface of anterior teeth with involvement of the incisal angles

Class V cavity

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

Class VI

This involves cavity preparation on incisal edges of anterior teeth or the occlusal cusp heights of posterior teeth

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