Relationship among dental plaque composition, daily sugar exposure and caries in the primary dentition

The relationship among daily sugar exposure, dental plaque composition and caries patterns in the primary dentition is not known. Three groups of 20 children (18-48 months old) were studied: (1) caries-free (CF), (2) presenting pit and fissure caries (PFC), and (3) with nursing caries (NC). Dental caries index (dmfs) was assessed and the frequency of daily sugar exposure (TS) and its forms were estimated by questionnaires. Fluoride (F), calcium (Ca), inorganic phosphorus (P(i)), insoluble polysaccharide (IP) and mutans streptococci were quantified in dental plaque. The three groups of children were statistically different regarding daily sugar exposure. Concentrations of F, Ca and P(i) were lower and the IP and mutans streptococci statistically higher in dental plaque from NC children than those from CF children. PFC children also showed statistically lower F and P levels in their plaque than CF children. Statistically significant correlations were found between IP, TS and dmfs from NC and PFC children. A statistically significant correlation between mutans streptococci in plaque from anterior teeth and dmfs for NC children was also observed. These results suggest that the dietary sugar experience changes the biochemical and microbiological composition of dental plaque, which could partly explain the different caries patterns observed in primary dentition.