Racism and oral health inequities; An overview

Fluoride export is required for the competitive fitness of pathogenic microorganisms in dental biofilm models

Microorganisms resist fluoride toxicity using fluoride export proteins from one of several different molecular families. Cariogenic species Streptococcus mutans and Candida albicans extrude intracellular fluoride using a CLCF F-/H+ antiporter and FEX fluoride channel, respectively, whereas oral commensal eubacteria, such as Streptococcus gordonii, export fluoride using a Fluc fluoride channel. In this work, we examine how genetic knockout of fluoride export impacts pathogen fitness in single-species and three-species dental biofilm models. For biofilms generated using S. mutans with the genetic knockout of the CLCF transporter, exposure to low fluoride concentrations decreased S. mutans counts, synergistically reduced the populations of C. albicans, increased the relative proportion of oral commensal S. gordonii, and reduced properties associated with biofilm pathogenicity, including acid production and hydroxyapatite dissolution. Biofilms prepared with C. albicans with genetic knockout of the FEX channel also exhibited reduced fitness in the presence of fluoride but to a lesser degree. Imaging studies indicate that S. mutans is highly sensitive to fluoride, with the knockout strain undergoing complete lysis when exposed to low fluoride for a moderate amount of time. Biochemical purification of the S. mutans CLCF transporter and functional reconstitution establishes that the functional protein is a dimer encoded by a single gene. Together, these findings suggest that fluoride export by oral pathogens can be targeted by specific inhibitors to restore biofilm symbiosis in dental biofilms and that S. mutans is especially susceptible to fluoride toxicity.

IMPORTANCE

Dental caries is a globally prevalent condition that occurs when pathogenic species, including Streptococcus mutans and Candida albicans, outcompete beneficial species, such as Streptococcus gordonii, in the dental biofilm. Fluoride is routinely used in oral hygiene to prevent dental caries. Fluoride also has antimicrobial properties, although most microbes possess fluoride exporters to resist its toxicity. This work shows that sensitization of cariogenic species S. mutans and C. albicans to fluoride by genetic knockout of fluoride exporters alters the microbial composition and pathogenic properties of dental biofilms. These results suggest that the development of drugs that inhibit fluoride exporters could potentiate the anticaries effect of fluoride in over-the-counter products like toothpaste and mouth rinses. This is a novel strategy to treat dental caries.

Antiracist ethos and the collective oral health as a pathway for life

This article proposes a reflection on the imperative of antiracism in collective oral health, which, as a science, field, core, and praxis, contributes significantly to the reconstruction of an ethos that considers equity and enables citizenship and democracy. As a paradigm, we assumed the concept of "Buccality" and the guidelines of the National Comprehensive Health Policy for the Black Population, emphasizing the defense of the right to health as a prerogative of the right to life and the combat against racism and all forms of discrimination systematically. As a critical exercise, we discussed the status quo of collective oral health. We pointed to adopting a racial pro-equity perspective as an intentional, political choice socially agreed upon with all of society for social justice. Finally, we propose recommendations for dismantling systemic racism in collective oral health.

Association between racial iniquities and oral health status: a systematic review

The present study aimed to investigate the association between racial iniquities and oral health status. This is a systematic review with a protocol registered on the Prospero Platform (CRD42021228417), with searches carried out in electronic databases and in gray literature. Our study identified 3,028 publications. After applying the eligibility criteria and risk of bias analysis, 18 studies were selected. The results indicate that individuals of black/brown race/skin color have unfavorable oral health conditions, mainly represented by self-rated oral health, tooth loss, caries, and periodontitis. The results showed racial iniquities in oral health in different countries, for all analyzed indicators, with a greater vulnerability of the black population.

Dental caries in the permanent dentition and health-related quality of life among children and adolescents with sickle cell disease

The aim was to associate living, health and oral health conditions with the quality of life (QL) of children and adolescents (CA) with sickle cell disease (SCD). Of the 120 eligible users of a public hematological service, 106 CA with SCD from 6 to 18 years of age, and their caregivers, answered semi-structured questions about socio-demographic, health and oral health conditions. For QL, we used the validated instrument PedsQLSCD™. The oral clinical examination occurred according to the guidelines of WHO and SB Brazil 2010. The majority of CA were non-white people (88%), mean age of 10.4 (±2.9) years, family income of up to two monthly minimum wages, for 03 to 05 members, with diagnosis of sickle cell anemia by neonatal screening, hospitalizations were due allergic crises, polypharmacy and dental caries (51%) were present. "About the Impact of My Pain" was the best-fit model for the QLSCD (adjusted R²=56%; AIC=28.67; p=0.04). Dental caries in permanent dentition worsened the QLSCD (OR=0.53; IC95%=0.35-0.78; p<0.05) and was associated with the type of school, car ownership, number of family members, of complications and of the medications. To overcome this scenario, programmatic actions are required, and implementation of public policies specifically directed towards these groups.

Fluoride export is required for competitive fitness of pathogenic microorganisms in dental biofilm models

Microorganisms resist fluoride toxicity using fluoride export proteins from one of several different molecular families. Cariogenic species Streptococcus mutans and Candida albicans extrude intracellular fluoride using a CLCF F-/H+ antiporter and FEX fluoride channel, respectively, whereas commensal eubacteria, such as Streptococcus gordonii, export fluoride using a Fluc fluoride channel. In this work, we examine how genetic knockout of fluoride export impacts pathogen fitness in single-species and three-species dental biofilm models. For biofilms generated using S. mutans with genetic knockout of the CLCF transporter, exposure to low fluoride concentrations decreased S. mutans counts, synergistically reduced the populations of C. albicans, increased the relative proportion of commensal S. gordonii, and reduced properties associated with biofilm pathogenicity, including acid production and hydroxyapatite dissolution. Biofilms prepared with C. albicans with genetic knockout of the FEX channel also exhibited reduced fitness in the presence of fluoride, but to a lesser degree. Imaging studies indicate that S. mutans is highly sensitive to fluoride, with the knockout strain undergoing complete lysis when exposed to low fluoride for a moderate amount of time, and biochemical purification the S. mutans CLCF transporter and functional reconstitution establishes that the functional protein is a dimer encoded by a single gene. Together, these findings suggest that fluoride export by oral pathogens can be targeted by specific inhibitors to restore biofilm symbiosis in dental biofilms, and that S. mutans is especially susceptible to fluoride toxicity.

Discrimination and Dignity Experiences in Prior Oral Care Visits Predict Racialized Oral Health Inequities Among Nationally Representative US Adults

Racism, an oppressive and fallacious sociopolitical hierarchy, is a fundamental cause of oral health inequities worldwide. Everyday discrimination is associated with worse self-rated oral health, toothache and adult tooth loss, and lower oral care utilization. Few studies examine discrimination or microaggressions within oral care settings or their effects on oral health outcomes. We adapted the seven-item Everyday Discrimination Scale to the oral care setting (EDSOC); developed a four-item Dignity in Oral Care Scale (DOCS); fielded them to a probability-based nationally representative sample of US households as part of the 2022 State of Oral Health Equity in America survey (SOHEA, n = 5682); and examined associations between EDSOC and DOCS scores and three outcomes: self-rated oral health, duration since last oral care visit, and planning for future preventive/routine oral care. Nearly, all EDSCOC and DOCS measures were significantly associated with oral health outcomes. Discrimination experience in dental settings had an additive effect on reporting fair/poor oral health and a suppressive effect on planning a future dental visit. Indignity experience doubled-to-quadrupled the likelihood of reporting fair/poor oral health, not having visited a dentist in 2 years, and not planning a future oral care visit. Racio-ethnically minoritized patients may experience the unjust double bind of resolving urgent dental or completing preventive services needs amidst being treated in a discriminatory manner or without dignity. Oral health stakeholders should invest more effort to understand relationships between racism and oral health outcomes and introduce evidence-based interventions to ultimately abolish this societal harm.

The Global Prevalence and Severity of Dental Caries among Racially Minoritized Children: A Systematic Review and Meta-Analysis

Racially minoritized children often bear a greater burden of dental caries, but the overall magnitude of racial gaps in oral health and their underlying factors are unknown. A systematic review and meta-analysis were conducted to fill these knowledge gaps. We compared racially minoritized (E) children aged 5-11 years (P) with same-age privileged groups (C) to determine the magnitude and correlates of racial inequities in dental caries (O) in observational studies (S). Using the PICOS selection criteria, a targeted search was performed from inception to December 1, 2021, in nine major electronic databases and an online web search for additional grey literature. The primary outcome measures were caries severity, as assessed by mean decayed, missing, and filled teeth (dmft) among children and untreated dental caries prevalence (d > 0%). The meta-analysis used the random-effects model to calculate standardized mean differences (SMD) and 95% confidence intervals (95% CI). Subgroup analysis, tests for heterogeneity (I2, Galbraith plot), leave-one-out sensitivity analysis, cumulative analysis, and publication bias (Egger's test and funnel plots) tests were carried out. The New Castle Ottawa scale was used to assess risk of bias. This review was registered with PROSPERO, CRD42021282771. A total of 75 publications were included in the descriptive analysis. The SMD of dmft score was higher by 2.30 (95% CI: 0.45, 4.15), and the prevalence of untreated dental caries was 23% (95% CI: 16, 31) higher among racially minoritized children, compared to privileged groups. Cumulative analysis showed worsening caries outcomes for racially marginalized children over time and larger inequities in dmft among high-income countries. Our study highlights the high caries burden among minoritized children globally by estimating overall trends and comparing against factors including time, country, and world income. The large magnitude of these inequities, combined with empirical evidence on the oral health impacts of racism and other forms of oppression, reinforce that oral health equity can only be achieved with social and political changes at a global level.

Caries risk and social determinants of health: A big data report

BACKGROUND

Oral health is influenced by social determinants of health (SDH), predisposing people and communities to greater risk of developing caries. This study evaluated the association between caries risk in adults and SDH such as ZIP Codes, systemic diseases, payment methods, and race or ethnicity.

METHODS

The BigMouth Dental Data Repository (n = 57,211) was used to extract clinical and SDH data from patients' dental electronic health records for 2019. Caries risk categories were used as ZIP Code data was merged with the Social Deprivation Index, a composite measure of area-level deprivation based on 7 demographic characteristics collected in the American Community Survey.

RESULTS

The results showed that the odds of being in the high caries risk group were higher for people in the 49- to 64-year age group (adjusted odds ratio [aOR], 2.24; 95% CI, 2.08 to 2.40; P ≤ .001), men (aOR, 1.19; 95% CI, 1.13 to 1.25; P ≤ .001), people who had comorbidities (diabetes: aOR, 1.16; 95% CI, 1.08 to 1.24; P ≤ .001; cardiovascular disease: aOR, 1.40; 95% CI, 1.32 to 1.50), and people with an Social Deprivation Index score above the 75th percentile (aOR, 2.39; 95% CI, 2.21 to 2.58; P ≤ .001). In addition, Hispanic and Black people had higher odds of being at high caries risk than other races or ethnicities (Hispanic: aOR, 3.05; 95% CI, 2.32 to 4.00; Black: aOR, 2.05; 95% CI, 1.02 to 4.01).

CONCLUSIONS

This study shows the association of caries risk with higher social deprivation, reinforcing the role of structural and upstream factors in oral health. This study is unique in using recorded ZIP Code information and assessing caries risk levels for those regions.

PRACTICAL IMPLICATIONS

The physical and structural environment should be considered contributors to caries risk in people.

Conceptualizing inequities and oppression in oral health research

Major sociohistorical processes have profound effects on oral health, with impacts experienced through structural oppression manifested in policies and practices across the lifespan. Structural oppression drives oral health inequities and impacts population-level oral health. In this global perspective paper, we challenge old assumptions about oral health inequities, address misleading conceptualizations in their description and operation and reframe oral health through the lens of intersecting systems of oppression. Furthermore, we emphasize the need for oral health researchers to explore causal pathways through which oppression harms oral health and engage in social science concepts to understand the root causes of oral health inequities fully. Finally, we call on policymakers, dental scholars and decision makers to consider health equity in all policies and to take a systems-oriented approach to effectively address oral health inequities.

An intersectionality approach to Indigenous oral health inequities; the super-additive impacts of racism and negative life events

OBJECTIVES

Indigenous Australians experience cumulative forms of oppression. Using intersectionality as the underlying analytical framework, and with oral health as an outcome, we demonstrate how oppressions are interlinked and cannot be treated in isolation. The study aimed to quantify the cumulative effect of two forms of oppression on Indigenous Australian oral health inequities.

METHODS

This observational study was conducted Feb 2018-Jan 2020. Recruitment occurred through Aboriginal Community Controlled Health Organisations in South Australia, Australia. Eligibility included identifying as Indigenous, residing in South Australia and aged 18+ years. Socio-demographic factors, health-related characteristics, experience of racism, negative life events and self-reported oral health outcomes were collected. The main outcomes were fair/poor self-rated oral health and oral health related quality of life, measured by OHIP-14. Effect-measure modification was used to verify differences on effect sizes per strata of negative life events and racism. The presence of modification was indicated by Relative Excess Risk due to Interactions (RERIs).

RESULTS

Data were obtained for 1,011 participants, median age 37 years, 66% female and 63% residing in non-metropolitan locations. Over half (52%) had experienced racism in the past 12 months and 85% had experienced one or more negative life events. Around one-third (34%) rated their oral health as fair/poor and the mean OHIP-14 score was 17. A higher proportion of participants who had experienced both racism and negative life events (46%) were male (52%), aged 37+ years (47%), resided in metropolitan locations (57%), reported difficulty paying a $100 dental bill (47%), had fair/poor self-rated oral health (54%) and higher mean OHIP-14 scores (20). The RERIs observed were 0.31 for fair/poor self-rated oral health and 0.23 for mean OHIP-14. The positive RERIs indicated a super-additive effect between racism, negative life events (effect modifier) and self-reported oral health outcomes.

CONCLUSION

The more oppressions participants experienced, in the form of racism and negative life events, the greater the burden of poor self-reported oral health. The study is one of the first to use intersectionality as a theory to explain oral health inequities as experienced by Indigenous Australians.

The influence of patient race on the outcome of endodontic treatments: a pooled analysis of one-year recall data from four cone beam computed tomography outcome studies

Objectives The aim of this pooled data analysis was to establish if there is an association between a patient's race and the proportion of successful outcomes of endodontic treatments, and if so, what factors may determine this association.Methodology Data collected from four prospective clinical outcome studies were pooled. Patients were recalled 12 months after the completion of the treatment. Treatment outcome was determined by clinical findings and cone beam computed tomography examination. Statistical analysis included the description of categorical and continuous variables and simple binary logistic regression models, chi-squared tests and Kruskal-Wallis tests.Results Data from 301 patients were available. Of these patients, 43 were Black (14.3%), 50 were from a Non-Black Minority Ethnic (NBME) group (16.6%) and 208 were white (69.1%). The risk of an unfavourable outcome was higher in teeth with short root canal fillings (OR = 3.36; p = 0.002), when a preoperative radiolucency was present (OR = 2.59; p = 0.019) and when an intra-operative root canal perforation was detected (OR = 5.25; p = 0.016).Multiple regression models showed that Black (OR = 2.28; p = 0.05) and NBME patients (OR = 3.07; p = 0.008) had a higher risk of an unfavourable result compared to white patients.Conclusions Black and NBME patients had a significantly higher failure rate of root canal treatments compared to white patients. All other known pre-, intra- and post-operative risk factors for root canal treatment failure were present in similar proportions in BME and white patients.

Where are race-based oral health inequities bound? Protocol for a systematic review on interventions to tackle racial injustice in dental outcomes

BACKGROUND

Only three literature reviews have assessed the impact of interventions on the reduction of racial inequities in general health to date; none has drawn from attempts at promoting racial oral health equity. This protocol aims to increase transparency and reduce the potential for bias of an ongoing systematic review conceived to answer the following questions: Are there any interventions to mitigate racial oral health inequities or improve the oral health of racially marginalized groups? If so, how successful have they been at promoting racial oral health equity? How do conclusions of previous reviews change by taking the findings of oral health interventions into account?

METHODS

Reviewed studies must deploy interventions to reduce racial gaps or promote the oral health of groups oppressed along ancestral and/or cultural lines. We will analyze randomized clinical trials, natural experiments, pre-post studies, and observational investigations that emulate controlled experiments by assessing interactions between race and potentially health-enhancing interventions. Either clinically assessed or self-reported oral health outcomes will be considered by searching for original studies in MEDLINE, LILACS, PsycInfo, SciELO, Web of Science, Scopus, and Embase from their earliest records to March 2022. Upon examining abstracts of conference proceedings, trial registries, reports of related stakeholder organizations, as well as contacting researchers for unpublished data, we will identify studies in the grey literature. If possible, we will carry out a meta-analysis with subgroup and sensitivity analysis, including formal meta-regression, to address potential heterogeneity and inconsistency among selected studies.

DISCUSSION

Conducting a systematic review of interventions to mitigate racial oral health inequities is crucial for determining which initiatives work best and under which conditions they succeed. Such knowledge will help consolidate an evidence base that may be used to inform policy and practice against persistent and pervasive racial inequities in general and oral health.

SYSTEMATIC REVIEW REGISTRATION

This protocol has been registered at the International Prospective Register of Systematic Reviews, under the identification number CRD42021261450 .