Correlation between DMFT index andoccurrence of Lactobacillus spp. in the oral cavity

Document Type : Research Article


1 Department of Microbiology, Science and Research Branch, Islamic Azad University, Fars, Iran; Department of Microbiology, Shriaz Branch, Islamic Azad University, Shiraz, Iran

2 Department of Microbiology, Kazeroun Branch, Islamic Azad University Kazeroon, Iran


The human oral cavity includes different bacterial community. Advantage and
disadvantage of these bacteria depend on their ability to adhere to the tooth
surfaces. Some microbiota could cause oral disease, however, some of them inhibit
formation of biofilm on teeth and therefore prevent dental caries. The present study
was undertaken to investigate on the DMFT index (D: decay, M: missing, F: filling,
T: teeth) and the occurrence of different species of Lactobacillus, as the most
important oral microbiota. Ninety swab samples were collected from saliva and
teeth of the patients and subjected to microbiological analysis. Along with
phenotypic and genotypic identifications of the isolates, the DMFT index of each
patient was measured to determine the oral conditions. To continue the study the
antibacterial effect of five commercial toothpastes was evaluated on the isolates.
The results obtained indicated that the frequency of occurrence of L.plantarum,
L.rhamnosus and L.mali was high in the patients with a low DMFT score and
L.otakiensis, L.diolivorans and L.kefiri was high in the patients with a high DMFT
score. Althoughall isolates were susceptible to the commercial tooth pastes,
L.plantarum and L.rhamnosus were relatively more sensitive. Based on the results,
human oral health might be affected by the population of Lactobacillusspp.
Furthermore, use of toothpastes without adequate information concerning to their
antimicrobial effects might eliminate the population of beneficial oral
microbiotaand hence increase the risk of oral diseases.


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