Objectives: To detect the presence of
Streptococcus mutans
and
Streptococcus sobrinus
in dental plaque of children from
Cartagena and correlate it to dental caries precavity stages, applying a standardized PCR-based technique for epidemiological
purposes.
Methods: Descriptive study using a non-probabilistic sample of 50 children between 3 and 5 years of age, preschoolers
from a Caribbean population in Colombia. Criteria for selection were that children should exhibit plaque accumulations on
the surface of the cervical margins of the rearmost molars, and placed in one of two study groups: carious lesions and sound
surfaces. Dental plaque samples from both groups were subjected to molecular analysis and statistical analysis was applied
to determine the difference between the two groups using the frequencies of presence of
S. mutans,
S. sobrinus or both in the
two groups applying Fisher’s exact test for association between the presence of microorganisms and the state of the tooth
surface from where the dental plaque was taken.
Results: The frequency of
S. mutans in carious lesions was 76% and 24% in healthy surfaces. The frequency of
S. sobrinus
in carious lesions was 81.9% and 18.1% in caries-free surfaces. There was statistical significance between the presence of
S. mutans and the presence of caries (p=0.001) and between the presence of
S. sobrinus (p=0.02) and the presence of caries.
There was no statistical significance between the presence of caries and the simultaneous presence of both microorganisms
(p=0.08).
Conclusions: The presence of
S. mutans and
S. sobrinus in dental plaque samples is highly prevalent and associated to
non cavitated carious lesions, being the molecular identification of these microorganisms by PCR a sensitive, fast, and easy
to use detection method for the mutans group of oral bacteria.