Factors associated with black tooth stain in Chinese preschool children

Oral microbial profiles of extrinsic black tooth stain in primary dentition: A literature review

The extrinsic black tooth stain (EBS) is commonly found in primary dentition. Patients cannot clean the EBS; this can only be done by professional scaling and debridement. It also has a tendency to reform, which significantly compromises children's aesthetics and even affects their quality of life. However, there is no conclusive evidence on the etiology of the EBS. The associations between the EBS and related oral microbial features is one of the research hot topics. No literature review summarized these research progresses in this area. Therefore, we reviewed the literature on the microbiology of the EBS since 1931 and reported as the following 5 aspects: molecular biotechnology, morphological structure and physiochemical characteristics, microbial etiology hypothesis and core microbial characteristics. The EBS is a special dental plaque mainly composed of Gram-positive bacilli and cocci with scattered calcium deposits that acquired salivary pellicle activates. Early studies showed that the Actinomyces was the main pathogenic bacteria. With advances in biological research techniques, the 'core microbiome' was proposed. The potential pathogenic genera were Actinomyces, Prevotella nigrescens, Pseudotropinibacterium, Leptotrichia, Neisseria and Rothia. However, the pathogenic species of the above genera were still unclear. Currently, it is believed that the EBS consists of iron compounds or black substances that oral bacterial metabolism produces or that the bacterial metabolites formed after chemical reactions in the micro-ecological environment.

Effect of A Fluoride Toothpaste Containing Enzymes and Salivary Proteins on Periodontal Pathogens in Subjects with Black Stain: A Pilot Study

OBJECTIVE

 Black stain (BS) is an extrinsic dental discoloration particularly difficult to treat. Although its etiology is not fully clear yet, chromogenic bacteria inside the oral cavity seem to be involved. In this pilot study, we evaluated whether a toothpaste containing enzymes and salivary proteins could improve oral health and reduce the presence of periodontal pathogens in subjects predisposed to BS discoloration.

MATERIALS AND METHODS

 Twenty-six subjects were enrolled in the study: 10 subjects without BS; 16 subjects with BS, randomly assigned in two groups: test (n = 8) and control (n = 8). The test group used a toothpaste containing sodium fluoride, enzymes, and salivary proteins. The control group used a toothpaste with amine fluoride. At enrollment and after 14 weeks, participants were subjected to professional oral hygiene, evaluation of BS (through Shourie index) and oral health status, collection of saliva and dental plaque samples. The presence of periodontal pathogens in plaque and saliva of all subjects was investigated by molecular analysis (PCR).

STATISTICAL ANALYSIS

 The prevalence of investigated microbial species in patients with/without BS was performed by Chi-squared test. The variation in the prevalence of the investigated species after treatment in test and control group was analyzed by t-test.

RESULTS

 Clinical evaluation showed that 86% of participants with BS had a reduction in the Shourie index, independently from the toothpaste used. In particular, a greater reduction in the Shourie index was observed in subjects using an electric toothbrush. We did not observe an effect of the fluoride toothpaste containing enzymes and salivary proteins on the composition of the oral microbiota of the test subjects in comparison with controls. When comparing all subjects with BS (n = 16) and without BS (n = 10), P. gingivalis detection was significantly higher in saliva samples collected from subjects with BS (p = 0.0129).

CONCLUSION

 We verified that the use of an enzyme-containing toothpaste alone is not sufficient to prevent the formation of BS dental pigmentation in subjects predisposed to this discoloration. Mechanical cleaning, especially using electrical toothbrushes, seems to be useful to counteract BS formation. Moreover, our results suggest a possible association between BS and the presence of P. gingivalis at the salivary level.

Characterization of the oral microbiome and gut microbiome of dental caries and extrinsic black stain in preschool children

Introduction

A lower prevalence of dental caries (hereafter termed “caries”) has been observed in children with dental extrinsic black stain (EBS).

Methods

We investigated the epidemiologic characterization of EBS and explored the possible role of the oral microbiome (OM) and gut microbiome (GM) in EBS formation and caries prevention. In an epidemiologic survey, 2,675 children aged 3–6 years were included. Thirty-eight of these children (7 children had both caries and EBS, 10 had EBS only, 11 had caries only, and 10 were healthy children) were recruited for 16S rRNA sequencing and collection of samples of supragingival plaque and feces. Collected plaque samples were divided into four groups: BCP (EBS+, caries+), BP (EBS+, caries−), CP (EBS−, caries+), and P (EBS−, caries−). Fecal samples were also divided into four groups: BCF (EBS+, caries+), BF (EBS+, caries−), CF (EBS−, caries+), and F (EBS−, caries−).

Results

EBS was observed in 12.10% of this population. Children with EBS had a significantly reduced prevalence of caries and a lower mean value of decayed–missing–filled teeth (dmft; p < 0.01). According to analyses of dental plaque, the P group had the most complex microbiome. The BCP group exhibited greater operational taxonomic unit (OTU) richness but a reduced evenness compared with the BP group, and the CP group showed greater OTU richness than the BP group. At the genus level, higher abundance of Actinomyces and Cardiobacterium species was observed in the BCP group. Higher abundance of Lautropia and Pesudopropionibacteriumin species was observed in the BP group compared with P and CP groups, respectively (p < 0.05). Veillonella species were significantly more common in P and CP groups than in BP groups, whereas Porphyromonas and Fusobacterium species were more common in the CP group (p < 0.05). With regard to the GM, the CF group exhibited greater OTU diversity than the BF group. The GM in the BCF group exhibited the most complex relationships across all fecal groups. GM groups could be distinguished by various unique biomarkers, such as Escherichia and Shigella species in the BCF group, Agathobacter and Ruminococcus species in the CF group, Lactobacillus species in the BF group, and Roseburia species in the F group. Our results suggest that EBS is a possible protective factor against early-childhood caries. Dental plaque and the GM may be relevant to EBS in primary dentition.

The association between black stain and lower risk of dental caries in children: a systematic review and meta-analysis

BACKGROUND

Previous literature shows that children with dental black stain might be less susceptible to dental caries. The aim of this study was to systematically review the available literature to determine whether black stain presence could influence the prevalence or severity of dental caries in primary dentition.

METHODS

A systematic search of PubMed, Web of Science, Scopus, Google Scholar, OpenGrey, and Egyptian Universities Libraries Consortium was conducted up to December 2020. Quality assessment was done using a modified version of Down's and Black checklist. Meta-analyses were performed to assess the association between dental black stain and: (i) Likelihood of developing dental caries/being caries-free (ii) Number of teeth affected by dental caries (iii) Number of tooth surfaces affected.

RESULTS

The database search yielded 2164 results, 14 of which matched the eligibility criteria. The meta-analysis showed that the likelihood of developing caries (Fixed effect model: OR [95% CI]: 0.67 [0.54; 0.82]; I²=37%; τ²=0.05), number of teeth affected (Random effects model: MD [95% CI]: -0.98 [-1.54; -0.42]; I²=79%; τ² =0.44), and number of surfaces affected (Random-effects model: MD [95% CI]: -2.34 [-4.23; -0.44]; I²=85%; τ² =2.93), were all lower in children with black stain.

CONCLUSIONS

It is suggested that dental black stain is associated with lower dental caries experience in children with primary dentition. However, it is questionable whether black stain has a protective effect against dental caries, or whether children at low risk of dental caries are more likely to develop BS because their oral microbiome favors BS-forming organisms.

Black staining: an overview for the general dental practitioner

'Black stain' is a form of extrinsic staining affecting the buccal and palatal surfaces of primary and permanent teeth. It presents as an incomplete line of dark dots formed at the cervical third of the tooth, typically following the gingival margin and not extending to the proximal areas. There is no consensus on its prevalence, though it appears to vary between 2-20%, with an equal male and female distribution. Although the aetiology is not completely understood, its microflora is dominated by chromogenic bacteria, such as actinomyces and prevotella melaninogenica, and there appears to be a low incidence of caries in the presence of the stain. The cause of the dark pigmentation seems to be from iron deposits such as ferric sulphate, present due to a reaction with the products of bacterial metabolism. This paper aims to provide information on the diagnosis, aetiology and treatment considerations for black stain. A patient case report is also explored.

'Black stain' is a poorly understood form of tooth discolouration by dental professionals.

Its aetiology is not completely understood, although the black pigmentation is likely to be an insoluble ferric salt precipitate, produced by chromogenic bacteria.

Treatment should involve a combination of reassurance to the patient/parents, with a minimally invasive approach to remove staining, while avoiding iatrogenic damage.

Epidemiological and Microbiome Characterization of Black Tooth Stain in Preschool Children

OBJECTIVE

To assess the epidemiologic attributes and microbial variations associated with extrinsic black tooth stain (BTS) among Chinese preschool children.

METHODS

This cross-sectional study included 250 preschool children (3-4 years) from three kindergartens in Shanghai, China. Following clinical examination, and using a case-control design, saliva and dental plaque specimens were collected from caries-free participants with (n = 21, BTS group) and without (n = 48, control group) BTS. The chi-square test and logistic regression model were used to evaluate factors associated with BTS. 16S rRNA sequencing were used to characterize the associated microbial communities.

RESULTS

BTS was detected in 12.4% of participants, with a mean of 13.7 black-stained teeth. Participants with BTS had a lower caries burden and better oral hygiene (P = 0.003). Children with less frequent intake of marmalade or honey (P = 0.033) and regular application of fluoride (P = 0.007) had a lower likelihood of having BTS. Microbiota analysis revealed 14 phyla, 35 classes, 63 orders, 113 families, 221 genera, 452 species, and 1,771 operational taxonomic units (OTUs). In terms of microbial diversity, no significant differences were observed in the saliva of the two groups (P > 0.05). Dental plaque from the BTS group exhibited higher OTU richness but lower evenness than that from the control group (Chao P = 0.006, Shannon P = 0.007, respectively) and showed a significant difference in β diversity (P = 0.002). The microbiome in the two groups was characterized by various microbial biomarkers, such as Pseudomonas fluorescens, Leptotrichia sp._HMT_212, Actinomyces sp._HMT_169, and Aggregatibacter sp._HMT_898 in plaques from the BTS group. Functional analysis of the microbial species suggested the existence of a hyperactive metabolic state on teeth surfaces with BTS plaques and revealed that ferric iron, the iron complex transport system, and the iron (III) transport system were more abundant in BTS plaque samples.

CONCLUSIONS

This study provides insights into the epidemiologic and microbial features of BTS in preschool children. The microbiome in BTS is characterized by various microbial biomarkers, which can serve as indicators for BTS diagnosis and prognosis.

Metagenomic analysis of black-stained plaques in permanent dentition

OBJECTIVES

We aimed to determine the aetiologic agent responsible for black staining of permanent dentition using next-generation sequencing and determine the relationship between caries and black stains.

MATERIALS AND METHODS

A total of 52 systemically healthy patients with black-stained and caries-free (n = 13), black-stained and carious (n = 13), black stain-free and caries-free (n = 13), and black stain-free and carious (n = 13) teeth were enrolled in the study. The International Caries Detection and Assessment System (ICDAS II) was used for caries classification. Between 08:00 and 10:00, supragingival plaque samples were collected after a minimum of 8-12 h of accumulation and DNA samples were isolated. The samples were processed using the ZymoBIOMICS™ Service. Bioinformatics analysis was performed using mothur at usegalaxy.org. Data were analysed statistically using the Pearson chi-square and Fisher tests.

RESULTS

The number of caries-free teeth (ICDAS 0, 1, and 2) was significantly higher in patients with black stains (p = 0.007).Capnocytophaga (4.8 %), Corynebacterium (3.9 %), and Neisseria (5.4 %) species were the most abundant among all black-stained plaques (carious and caries-free) (p < 0.05). Capnocytophaga (10.8 %), Cardiobacterium (3.6 %), and Rothia (1.72 %) species were detected in the black-stained plaques of caries-free patients (p < 0.05).

CONCLUSION

This study is one of the first studies examining the microbial composition of dental plaques with black staining in carious and caries-free adult patients using next generation sequencing technology. In the presence of black staining, plaques have an ultimate complex microbial structure. A lower caries burden was noted in the presence of black staining.

Salivary Microbiome Variation in Early Childhood Caries of Children 3-6 Years of Age and Its Association With Iron Deficiency Anemia and Extrinsic Black Stain

ECC is a common clinical manifestation of the oral cavity in childhood and Iron deficiency-anemia (IDA) is a high-risk factor but extrinsic black stain on the tooth surface is a protective factor for caries. There is limited information about oral microecological change in early children who suffer from ECC with IDA and extrinsic black stain (BS). This study enrolled 136 children aged 3-6 years. Dental caries and teeth BS were examined. Saliva was collected for 16S rRNA gene and fingertip blood were for Hemoglobin test. There are 93 ECC including 13 with IDA (IDA ECC) and 80 without IDA (NIDA ECC) and 43 caries free (CF) including 17 with BS (BSCF) and 26 without BS (NBS CF). Statistical analysis of microbiota data showed differences of the oral flora in different groups. The oral flora of the IDA ECC group had a high diversity, while the BSCF group had a low diversity. The bacterial genera Bacillus, Moraxella, and Rhodococcus were enriched in the IDA ECC while Neisseria was enriched in the NIDA ECC. Neisseria only exhibited high abundance in the BSCF, and the remaining genera exhibited high abundance in the NBSCF. Interestingly, the BSCF had the same trend as the NIDA ECC, and the opposite trend was observed with IDA ECC. We established random forest classifier using these biomarkers to predict disease outcomes. The random forest classifier achieved the best accuracy in predicting the outcome of caries, anemia and black stain using seven, one and eight biomarkers, respectively; and the accuracies of the classifiers were 93.35%, 94.62% and 95.23%, respectively. Our selected biomarkers can achieve good prediction, suggesting their potential clinical implications.

Black stain and dental caries in primary teeth of Tunisian preschool children

AIM

To assess the prevalence of black tooth stains and to investigate its correlation with caries experience in the primary dentition of 3-5-year-old children in the region of Monastir, Tunisia.

METHODS

It was a descriptive cross-sectional study involving children in preschool establishments in Monastir, Tunisia. It consisted of an oral examination of 393 children and data collection through a questionnaire completed by parents. ANOVA test and Pearson Chi-square test were used to assess the prevalence of black stains and its association with dental caries.

RESULTS

The overall mean decayed, missing, and filled teeth (dmft) index was 1.42 ± 0.1. Caries prevalence was 49.9%. Of all the children involved, 6.1% had black stains. A statistically significant relationship was found between black stain and the prevalence of early childhood caries (p = 0.047). However, the association with the dmft index was not statistically significant (p = 0.08).

CONCLUSION

Preschool children with black tooth stain had lower dental caries experience. The results of the present study suggest that black stains are a protective factor for early childhood caries. More studies are needed to explore the risk factors of black stains.

Comparing dental plaque microbiome diversity of extrinsic black stain in the primary dentition using Illumina MiSeq sequencing technique

Background

Extrinsic black stain (EBS) is characterized by discrete dark dots or lines on the tooth surface. The relationship between EBS and oral microbiota in children remains elusive. The aim of this study was to compare dental plaque microbiome in EBS children with that in EBS-free children in the primary dentition.

Methods

The Illumina MiSeq sequencing technique was utilized in the cross-sectional pilot study to investigate the diversity and composition of the supragingival plaque microbiota from 10 EBS-positive and 10 EBS-free children. The results were analysed with nonparametric Mann-Whitney U test, Pearson Chi-Square test, Fisher’s Exact test and one-way ANOVA tests.

Results

We identified 13 different phyla, 22 classes, 33 orders, 54 families, 105 genera, and 227 species from a total of 52,646 high-quality sequences. Between two groups, no statistical differences were observed in the estimators of community richness and diversity at 97% similarity, as well as in the Unweighted Unifrac principal co-ordinates analysis (PCoA). At the species level, higher level of relative abundance of Actinomyces naeslundii and lower level of relative abundance of a species belonging to Candidate_division_TM7 was observed in dental plaque of EBS-positive subjects, compared to dental plaque of EBS-free subjects (P < 0.05). This indicated that some species might be involved in the EBS process.

Conclusion

Changes in dental plaque microbiota is possibly relevant to the process of EBS in the primary dentition.

Do Patients with Extrinsic Black Tooth Stains Have a Lower Dental Caries Experience? A Systematic Review and Meta-Analysis

Studies have suggested that individuals affected by extrinsic black tooth stains have less dental caries experience in comparison to those without this condition. The aim of the present study was to perform a systematic review and meta-analysis to determine whether there is scientific evidence demonstrating that extrinsic black stains are a protective factor for the occurrence of dental caries. This systematic review was developed in accordance with the PRISMA statement and the research question was determined using the PECO strategy. Electronic searches were conducted in the PubMed, Science Direct, Virtual Health Library, Cochrane, Web of Science, and Google Scholar databases for relevant articles published up to September 2018. All articles included were submitted to an appraisal of methodological quality using the Newcastle-Ottawa Scale and the data were extracted for meta-analysis. The search strategy resulted in the retrieval of 9,108 publications. After the application of the eligibility criteria, 18 articles were selected for analysis, 13 of which were included in the meta-analysis. The meta-analysis demonstrated that individuals with extrinsic black stains involving primary (median, MD: -0.78 [-1.09; -0.48]; I2 = 44%) and permanent (MD: -0.50 [-0.93; -0.08]; I2 = 86%) teeth have a lower dental caries experience in comparison to those without this condition. Patients with extrinsic black tooth stains have a lower dental caries experience in cross-sectional studies.

Risk factors for the presence of dental black plaque

In order to evaluate risk factors related to the presence of extrinsic dental black stain, a total of 94 orally healthy volunteers (47 individuals with dental black stain and 47 individuals without dental black stain) were recruited from ten different dental clinics in Valencia and Castellón (Spain). Data regarding their oral hygiene, dietary habits, and oral health status were gathered by questionnaire. Samples of dental plaque, saliva and drinking water were collected for chemical analysis. Three factors were found to be statistically significantly associated with dental black stain, (i) consuming water with high iron content, (ii) consuming water with high pH, and (iii) having a high salivary pH. Other factors such as smoking, taking iron supplements or consuming caffeinated drinks were not found to be risk factors for the presence of black stain. A multivariate logistic regression analysis showed that drinking tap or osmosis-purified water and lower levels of salivary iron increase the risk of having dental black stain. Overall, several risk factors for the presence of dental black stain have been identified. The main modifiable risk factor identified in this study was the consumption of tap or osmosis drinking water.

Mobile Apps for Oral Health Promotion: Content Review and Heuristic Usability Analysis

BACKGROUND

There has been an increase in consumer-facing mobile health (mHealth) apps in recent years. Prior reviews have characterized the availability, usability, or quality of popular mHealth apps targeting a range of health behaviors, but none has examined apps that promote better oral health care. Oral disease affects billions of people worldwide and mobile phone use is on the rise, so the market for well-designed and effective oral health apps is substantial.

OBJECTIVE

We examined the content and usability of popular oral health promotion apps to better understand the current state of these self-help interventions and inform the need and opportunity for future app development.

METHODS

Between February and March 2018, we identified oral health-focused apps that were designed for Android or iOS, available in English, and targeted adult consumers (as opposed to children or dental health professionals). The sample was limited to the most popular and highly rated apps on each platform. For each app reviewed, we assessed its basic descriptive characteristics (eg, platform, cost), evidence of a theoretical basis or empirical validation, key program functionality, and the extent to which the app addressed diet and tobacco and alcohol use as risk factors for oral disease. We characterized the framing (ie, gain vs loss) of all persuasive messaging and conducted a heuristic analysis to assess each app's usability as a persuasive health technology.

RESULTS

Thirty-three apps were eligible for review based on the selection criteria. Two-thirds (22/33, 67%) were geared toward the general public as opposed to dental clinic patients, insurance plan members, or owners of specific electric toothbrushes. Most (31/33, 94%) were free to download, and a majority (19/33, 58%) were sponsored by software developers as opposed to oral health experts. None offered any theoretical basis for the content or had been empirically validated. Common program features included tools for tracking or reminding one to brush their teeth and assistance scheduling dental appointments. Nineteen apps (58%) included educational or persuasive content intended to influence oral health behavior. Only 32% (6/19) of these included a larger proportion of gain-framed than loss-framed messaging. Most of the apps did not mention diet, alcohol or tobacco-important risk factors for oral disease. Overall, the apps performed poorly on standard usability heuristics recommended for persuasive health technologies.

CONCLUSIONS

The quality of the reviewed apps was generally poor. Important opportunities exist to develop oral health promotion apps that have theoretically grounded content, are empirically validated, and adhere to good design principles for persuasive health technologies.

Analysis of the Microbiota of Black Stain in the Primary Dentition

Black tooth stain is a characteristic extrinsic discoloration commonly seen on the cervical enamel following the contour of the gingiva. To investigate the relationship between black tooth stain and the oral microbiota, we used 16S rRNA gene sequencing to compare the microbial composition of dental plaque and saliva among caries-free children with and without black stain. Dental plaque and saliva, as well as black stain, were sampled from 10 children with and 15 children without black stain. Data were analyzed using the pipeline tool MOTHUR. Student’s t-test was used to compare alpha diversities and the Mann-Whitney U test to compare the relative abundances of the microbial taxa. A total of 10 phyla, 19 classes, 32 orders, 61 families and 102 genera were detected in these samples. Shannon and Simpson diversity were found to be significantly lower in saliva samples of children with black stain. Microbial diversity was reduced in the black stain compared to the plaque samples. Actinomyces, Cardiobacterium, Haemophilus, Corynebacterium, Tannerella and Treponema were more abundant and Campylobacter less abundant in plaque samples of children with black stain. Principal component analysis demonstrated clustering among the dental plaque samples from the control group, while the plaque samples from the black stain group were not and appeared to cluster into two subgroups. Alterations in oral microbiota may be associated with the formation of black stain.

Black stain and dental caries: a review of the literature

Black stain is characterized as a dark line or an incomplete coalescence of dark dots localized on the cervical third of the tooth. Over the last century, the etiology of black stain has been the subject of much debate. Most of the studies concerning this issue were conducted in pediatric population. According to the reviewed articles published between 2001 and 2014, the prevalence of black stain varies from 2.4% to 18% with equal sex distribution. The majority of the authors confirm the correlation between the presence of black stain and lower caries experience. The microflora of this deposit is dominated by Actinomyces spp. and has lower cariogenic potential than nondiscolored dental plaque. Iron/copper and sulfur complexes are thought to be responsible for the dark color. In patients with black stain saliva has higher calcium concentrations and higher buffering capacity. Factors such as dietary habits, socioeconomic status, and iron supplementation may be contributing to the formation of black stain.