Oral microbial community typing of caries and pigment in primary dentition

Abstract

BackgroundBlack extrinsic discoloration in primary dentition is a common clinical and aesthetic problem that can co-occur with dental caries, the most common oral diseases in childhood. Although the role of bacteria in the formation of pigment and caries in primary dentition is important, their basic features still remain a further mystery.MethodsUsing targeted sequencing of the V1-V3 hypervariable regions of bacterial 16S ribosomal RNA (rRNA) genes, we obtained a dataset consisting of 831,381 sequences from 111 saliva samples and 110 supragingival plaque samples from 40 patients with pigment (black extrinsic stain), 20 with caries (obvious decay), and 25 with both pigment and caries and from 26 healthy individuals. We applied a Dirichlet multinomial mixture (DMM)-based community typing approach to investigate oral microbial community types.ResultsOur results revealed significant structural segregation of microbial communities, as indicated by the identification of two plaque community types (A and B) and three saliva community types (C-E). We found that the independent occurrence of the two plaque community types, A and B, was potentially associated with our oral diseases of interest. For type A, three co-occurring bacterial genus pairs could separately play a potential role in the formation of pigment (Leptotrichia and Fusobacterium), caries (unclassified Gemellales and Granulicatella), and mixed caries and pigment (Streptococcus and Mogibacterium). For type B, three co-occurring bacterial genera (unclassified Clostridiaceae, Peptostreptococcus, and Clostridium) were related to mixed pigment and caries. Three dominant bacterial genera (Selenomonas, Gemella, and Streptobacillus) were linked to the presence of caries.ConclusionsOur study demonstrates that plaque-associated oral microbial communities could majorly contribute to the formation of pigment and caries in primary dentition and suggests potential clinical applications of monitoring oral microbiota as an indicator for disease diagnosis and prognosis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2891-z) contains supplementary material, which is available to authorized users.

Leptotrichia species in human infections II

“…L. hongkongensis has been isolated from the blood of metastatic breast carcinoma (MBC) patients [6], the blood and amniotic fluid of a patient with a wound and respiratory difficulties [4], plaque from dental caries [45,47,56], saliva from pancreatic cancer patients and black pigmented stain caries patients (Table 2) [18,63]. …”

“…Leptotrichia species were also isolated from bronchoalveolar lavage fluid, and patients with leukocytosis, hypoxemia, and dyspnea [24]. Further, Leptotrichia species were recovered from healthy patients with oral cancer, premalignant oral lesion [18,28,33,56,91], edentulous infants [29], human vaginal fluid of sexually active and inactive individuals [30,32], HIV-seropositive and -seronegative patients [46], pancreatic cancer patients [18,66], black pigmented stain caries patients [63], and patients with halitosis (Table 2) [42,65,81,82]. Besides, Leptotrichia species were isolated from the blood [4,5,22,74], the amniotic fluid of a patient with a wound and respiratory difficulties [4], breast milk of obese women with gestational diabetes and normal weight [36], oral samples of a patient with new-onset rheumatoid arthritis [20], oral lichen planus patients [88], and even from fermenting Lees liquor [39].…”

Effect of bleaching agents on black tooth stains caused by chromogenic bacteria: 10 years follow-up case report

“…This phenomenon has been confirmed by a reduction of 51% in the caries prevalence when black stains were present, leading to consider the presence of such stains as a protective factor against caries lesion development [7]. The biofilm of black stains is considered differentiated by containing more iron salts and high concentrations of calcium and phosphate [1,2,[5][6][7]. The black pigments are probably insoluble salts formed from the reaction between sulfuric acid, produced by bacteria, with the iron present in saliva and gingival exudate, comprising ferrous sulphate and originating pigmented deposits on the tooth structure.…”

“…The presence of pigmentation from chromogenic bacteria is a relatively common in day-to-day practice finding. There is no consensus in the literature about its etiology and even epidemiology [1][2][3][4][5][6][7][8][9], with their basic features remainining as a mystery [2]. In the same way, it is not established if these bacteria are responsible only for the pigmentation, or if they are influencing other outcomes when associated with pathologies (periodontal disease or caries) in the oral cavity [2,3,[5][6][7][8].…”

“…Black extrinsic tooth stains has been under the scope of clinical evidence in the current days, and could be associated with aesthetics issues and caries, being a concern for millions of children and adults [1][2][3][4][5][6][7][8][9]. Among the bacteria pigments, the black ones are the most studied and occur as a line or bands mainly on the lingual surface near the gingival margin.…”