The Power Course

Which one of the following is a major limitation of DMFT index


1 ) Recording of temporary filling as decayed
2 ) Not used to assess individuals caries risk
3 ) initial caries is recorded as sound
4 ) to include all the third molars


DMFT index was given by Henry Klein, palmer and Knutson JW in 1938. The purpose of the DMFT index is to assess the lifetime caries experience of the individual. This index is applicable only for coronal surfaces of permanent teeth. Following are the scoring criteria for DMFT index:

D (Decayed) teeth:

- Black or brown dicolurisation of teeth

- Presence of catch

- Presence of a soft base

- Presence of cavitation

- A tooth which is both decayed and filled recorded as decayed teeth

M (Missing):

This included the number of permanent teeth that are missing only for the reason of dental caries.

F (Filled): 

A teeth with a sound permanent restoration without any secondary caries.

All the teeth are counted only once. 


Individual DMF scores are added to get overall DMFT scores.

Limitations of DMFT index:

1. DMFT does not record root caries as DMFT is applicable only for coronal caries.

2. The values of DMFT does not indicate the teeth at risk. For example, individual 1 has a DMFT value of 4 with only 22 teeth in the mouth whereas individual 2 also has a DMFT value of 4 but with 32 teeth. But when we look at DMFT values of both individuals which are 4, it does not explain who is actually at risk for caries. 

3. In older adults tooth can be missing for reasons other than caries. This makes the Missing (M) component of DMFT index invalid.

4. DMFT index only counts the number of DMF teeth but it does not tell the extent or severity of the carious lesion.

5. Teeth with preventive fillings are recorded as Filled (F). This overestimates the DMFT values as these filling are given even before the occurrence of carious lesions.

6. All the components of DMFT are given the same weight.

7. DMFT index is not applicable for primary dentition.



Not used to assess individuals caries risk

Last Modified : 17-Dec-2019

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