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How is experience of tooth decay counted?

The DMFT index counts permanent teeth that are decayed, missing because of decay or filled because of decay. It describes experience of dental caries using defined examination criteria. It is neither a personal risk prediction nor a complete measure of oral health.

For dental trainees & teams

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D, M and F

D means decayed, M missing because of decay and F filled because of decay. T stands for teeth: the count is of teeth, not individual fillings.

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Each tooth once

A tooth is not counted several times within the index. Classification follows the examination protocol; the age group and dentition being assessed also matter.

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A number with limits

A filled tooth remains part of the caries experience. The total alone does not reveal how many active lesions exist today or what treatment is needed.

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At a glance

What is counted?

Decayed teeth and teeth missing or filled because of decay, under defined rules.

Who is it useful for?

Primarily for comparing groups and describing experience of caries.

What context is needed?

Age, dentition, survey period, methods and the individual components.

Twelve-year-olds in Germany

Survey: October 2022 to July 2023

0.5teeth on average

Weighted mean DMFT · DMS 6

95% confidence interval: 0.5–0.6

Sample: 958 twelve-year-olds examined

What does it count?

Decayed permanent teeth and those missing or filled because of caries. Initial enamel lesions were recorded separately. The value does not mean that an average of 0.5 teeth were currently decayed.

A group mean describes neither every individual nor their future caries risk. This is not an outcome from SMD patients or treatments.

The mean is statistically weighted; the sample size is unweighted. The confidence interval describes statistical uncertainty around the estimated mean. It is not a range of individual DMFT scores.

Original sources

Jordan et al.: Caries experience in DMS 6 (PDF)Published 17 March 2025 · Table 2, p. S33 (twelve-year-olds: n and DMFT); methods p. S31.
Ohm et al.: DMS 6 fieldwork (2025, PDF)Survey dates: p. S15, “Recruiting study participants”. The later extension described there concerned younger adults.

Sources checked on 23 October 2026. Our explanation of the published data.

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Short film (German): How is experience of tooth decay counted?

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Often confused

DMFT or DMFS?

DMFT counts affected teeth. DMFS counts affected tooth surfaces, describing their distribution in more detail.

Quick answers

Does a high score mean many current cavities?

No. Previously restored teeth and teeth lost because of decay also contribute.

What does lowercase dmft mean?

It refers to primary teeth. Primary and permanent dentitions are analysed separately.

Why do study results differ?

Age, included teeth and examination rules can differ. Comparisons require an appropriate context.

At the practice

For your consultation

A question to discuss with Dr. med. dent. Niusha Barahmand Pour:

Which current findings matter for my preventive care, independently of earlier fillings?

At the practice, findings, personal wishes and possible next steps are discussed through a consultation and examination.

Looking at current tooth surfaces matters more for personal prevention than a total alone.

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Meet Dr. med. dent. Niusha Barahmand Pour

Learning for dental trainees & teamsUnderstand clinical terms and build your knowledge

Build on the simple explanation with clinical terms, key distinctions and a knowledge question.

D component: Teeth with untreated caries detected according to the examination protocol.
F component: Teeth filled because of decay without simultaneous decay that takes priority under the protocol.
Caries experience: A record of past and present effects of decay, not just current cavities.

Know the difference

A DMFT total can remain unchanged after successful care: a treated tooth may move from D to F without leaving the total.

Knowledge questionWhat can a DMFT score alone not show?

This question supports learning. It does not assess personal symptoms.

The recorded experience of tooth decay.
Personal future risk of tooth decay.
That filled teeth are included.

Show answer and explanation

Personal future risk of tooth decay.

The index records findings and past care. Risk assessment requires additional information.

Sources for further learning

Sources and context

Editorial research: 23 October 2026. This explanation covers general principles and does not replace a personal examination. Suitable treatment is discussed following individual assessment.