Ecological Study of Streptococcus mutans, Streptococcus sobrinus and Lactobacillus spp. at Sub-Sites from Approximal Dental Plaque from Children

Abstract

Previous immunofluorescence (IF) studies have indicated that Streptococcus mutans may preferentially colonise specific sub-sites within approximal plaque. The present study aimed to extend these observations to other mutans streptococci and lactobacilli in such gingival margin plaque. Two hundred and seventy approximal plaque samples were taken from 90 teeth (3 from each tooth) in 64 children; three gingival margin sub-sites in relation to the contact area: away from (A), to the side of (S) and below (B) the contact area. Samples were processed by indirect IF using high-titred polyclonal anti-S. mutans ‘c’, anti-S. sobrinus ‘d’, anti-L. casei and anti-L. acidophilus antisera. An overall positive association was found between S. mutans ‘c’ and S. sobrinus ‘d’ (p < 0.001). Significant differences (p < 0.1) were found between the proportional counts at each sub-site for S. mutans ‘c’: A = 39%, S = 51% and B = 70%, and for S. sobrinus ‘d’ 21, 33 and 49%. Mutans streptococci (MS) appeared to preferentially colonise the sub-site below the contact area (B = 81%), compared with sub-sites A and S (48 and 62%, respectively). S. mutans ‘c’ and S. sobrinus ‘d’ were detected together at sub-sites A = 12%, S = 22%, and B = 38%, with proportional counts at B sites being higher than those at A (B > A, p < 0.01, and B > S, p < 0.05). Lactobacillus spp. were isolated rarely, and were usually found together with MS. There was a positive relationship between the presence of lactobacilli or MS and caries (white spot lesions only), although these species could frequently be isolated from non-carious sites. The presence of both S. mutans ‘c’ and S. sobrinus ‘d’ were strongly correlated with early caries lesions. In addition, this study confirmed the variation in the microflora at different sub-sites within approximal dental plaque.

In vitro bacterial plaque suppression and recolonization by S. mutans and S. sobrinus

“…The beginning and development of caries are determined by a host-parasite relationship, which can be altered by several environmental factors as demonstrated by in vitro models simulating the in vivo phenomenon in the mouth (9,20). The in vitro studies of the bacterial relationship based on the action of these microorganisms in the plaque formation on tooth surfaces and their potential to induce caries are in agreement with several results reported in the literature (3,(8)(9)(10)14,15).…”

Prevalence of cariogenic streptococci on incisor brackets detected by polymerase chain reaction

“…Many studies have shown that S mutans is isolated more frequently than S sobrinus in the oral cavity. 5,19 A difference in prevalence was also found between the maxillary and the mandibular incisor brackets. Both cariogenic streptococci colonized on the maxillary incisor brackets to a somewhat higher degree than those of the mandible (Table I).…”

“…1,2 Enamel demineralization is caused by organic acids produced mainly by mutans streptococci (MS), which are known to be the prime causative organism of dental caries. [3][4][5] Of these species, S mutans and S sobrinus are the most frequently isolated from human oral cavities and have been implicated as the main causative organisms of dental caries. 5,6 Among the many orthodontic appliances, brackets can play a key role in enamel demineralization because their complex designs increase the retention of food particles and dental plaque by impeding access to the tooth surfaces for cleaning.…”

“…[3][4][5] Of these species, S mutans and S sobrinus are the most frequently isolated from human oral cavities and have been implicated as the main causative organisms of dental caries. 5,6 Among the many orthodontic appliances, brackets can play a key role in enamel demineralization because their complex designs increase the retention of food particles and dental plaque by impeding access to the tooth surfaces for cleaning. A previous report showed that extensive plaque accumulation is associated with bonded orthodontic brackets, 7 and a fixed appliance with orthodontic brackets causes specific changes in the oral environment, such as decreased pH and increased plaque accumulation.…”

Quantitative analysis of adhesion of cariogenic streptococci to orthodontic raw materials

“…6,7 Of these, Streptococcus (S) mutans and S sobrinus have been identified as the main pathogens in dental caries and enamel demineralization. 8 Adhesion and colonization of cariogenic streptococci are considered to play key roles in the development of enamel demineralization related to orthodontic materials, because these materials in the oral cavity present a unique surface that can interact with bacteria, leading to pathogenic plaque formation for enamel demineralization. 9,10 Several studies reported that the placement of fixed orthodontic appliances leads to increases in the volume and number of cariogenic streptococci in dental plaque, 11,12 and the elevated levels of streptococci return to normal after removal of the appliance.…”