Operative Dentistry

Classification of Dental Caries and Restorations

Updated on: August 1, 2016

Classification of Dental Caries and Restorations


Dental caries are not evenly distributed throughout the mouth.

Certain surfaces of the teeth are particularly susceptible to carious lesions; others are nearly immune.

In the late 1800s, Dr. G.V. Black classified the most common sites for dental caries.

– His classification system adequately describes most simple carious lesions.

– In high-caries patients, a single tooth may have more than one lesion.

These lesions may be of the same class or of different classes.

At times, extensive lesions could be described as being a combination of two classes.


A. Class I

– The pits and fissures of teeth, particularly posterior teeth, are the most susceptible to dental caries.

– Pit and fissure caries are called Class I lesions, and the associated restorations are called Class I restorations.

B. Class II

The area of the tooth just below the interproximal contact is also susceptible to caries.

– If such a lesion occurs in a posterior tooth, it is called a Class II lesion.

Dental radiographs are commonly used to diagnose Class II caries.

C. Class III

If interproximal caries occur in an anterior tooth, it is called a Class III lesion.

– Dental radiographs and clinical examination are commonly used to diagnose Class III lesions.

– Next picture show Class III caries and restorations.Class III

D. Class IV

If a Class III lesion is left untreated, it may progress and involve the incisal angle
of an anterior tooth.

A lesion that involves the incisal angle of an anterior tooth is called a Class IV lesion.

Class IV restorations are also used to restore the incisal angle of an anterior tooth that has been fractured as the result of trauma.

E. Class V

The gingival third of the facial and lingual surfaces of both anterior and posterior teeth
is susceptible
to caries when patients have poor oral hygiene or a high-sugar diet.

F. Class VI

The Class VI lesion was a later addition to Black’s classification.

– A Class VI lesion involves the cusp tip or incisal edge of a tooth.

Actually, a Class VI carious lesion is quite rare.

– For most people retaining a large number of teeth later in life, however, wear of cusp tips and incisal edges is not uncommon.

– When attrition causes dentin to become exposed, it wears much faster than the surrounding enamel because enamel is much harder than dentin.

The result is a “dished out” area of worn dentin.

– Some clinicians call these restorations of such worn cusp tips and incisal edges Class VI restorations.Class VI

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