Correlation between caries related bacteria in plaque and saliva in different age group children


Background: Dental plaque contains bacteria that are both acidogenic and acidoduric. Different types ofstreptococci were identified in saliva. Although many bacterial subspecies have been shown to be associated withcaries, streptococcus mutans is still believed to be the most important bacterium in the initiation of this disease whilelactobacillus is correlated with the active caries episode. This study was conducted in order to estimate thecorrelation between caries related bacteria in plaque and saliva in different age group children.Materials and methods: Fifty three children aged 3-10 years old were chosen for this study. Recording of dental carieswas carried out by the dmfs index for primary teeth and DMFS index for the permanent teeth according to thecriteria suggested by the WHO. One ml of unstimulated (resting) whole saliva was collected from the children usingspitting method then diluted and applied on the surface of agar media specific for streptococcus mutans andlactobacilli growth. Dental plaque sample was taken from the buccal surface of the maxillary second primary molarby a clean toothpick and store in Epindorf tube which contain 1 ml. normal saline then inoculated in the samegrowth media that were used with the salivary samples. Colonies of the bacteria were counted with the aid ofdissection microscope (15 X) on the basis of their characteristic morphology.Results: Strong positive significant correlation was found between dmfs and ds components of the primary teeth,Positive results was found when correlating dmfs or ds with streptococcus mutans in dental plague while a negativecorrelation was found with lactobacilli. Negative correlation was found when correlating dmfs with streptococcusmutans in saliva while the relation is positive with lactobacilli. In dental plaque and in saliva there was a strongpositive highly significant correlation between the DMF and the DS. Correlation coefficient between DMFS with thebacterial counts of the caries related microorganisms (streptococci and lactobacilli) in the dental plaque and insaliva revealed weak, negative not significant correlations.Conclusion: The relation is not significant between the caries related microorganisms with each other in differentmedia; either the dental plaque or saliva