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. Author manuscript; available in PMC: 2022 Nov 1.
Published in final edited form as: Health Soc Care Community. 2021 Jan 25;29(6):1799–1806. doi: 10.1111/hsc.13289

A paradox of need: Gaps in access to dental care among people who use drugs in Canada’s publicly funded healthcare system

Kaitlyn Jaffe 1,2, JinCheol Choi 1, Kanna Hayashi 1,3, M-J Milloy 1,4, Lindsey Richardson 1,2
PMCID: PMC8310531  NIHMSID: NIHMS1661316  PMID: 33491849

Abstract

In Canada, publicly funded healthcare provides no-cost access to a large but not comprehensive suite of services. Dental care is largely funded by private insurance or patients, creating employment- and income-dependent gaps in care access. Difficulties accessing dental care may be amplified among vulnerable populations, including people who use drugs (PWUD), who may experience greater dental need, due to side effects of substance use and health comorbidities, as well as barriers to care. Using data collected between 2014 and 2018 from two ongoing prospective cohort studies of PWUD in Vancouver, Canada, the aim of this study was to explore factors associated with dental care access. Among 1638 participants, 246 participants (15%) reported never or only occasionally accessing adequate dental care. In generalized linear mixed-effects models, results showed significant negative associations between accessing dental care and using opioids (Adjusted Odds Ratios [AOR]=0.73, 95% Confidence Interval [CI]=0.58–0.91), methamphetamine (AOR=0.75, 95% CI=0.59–0.95), and cannabis (AOR=0.78, 95% CI=0.63–0.97), as well experiencing homelessness (AOR=0.54, 95% CI=0.42–0.70) and street-based income generation (AOR=0.75, 95% CI=0.59–0.94). There were significant positive associations between adequate dental care and accessing opioid agonist treatment (OAT) for opioid dependence (AOR=1.36, 95% CI=1.07–1.72) and receiving income assistance (AOR=1.70, 95% CI=1.05–2.77). These results highlight specific substance use patterns and structural exposures that may hinder dental care access, as well as how direct and indirect benefits of income assistance and OAT may improve access. These findings provide support for recent calls to expand healthcare coverage and address dental care inequities.

Keywords: Canada, oral health, people who use drugs, substance use, health inequalities

Introduction

In Canada, all residents are covered by a universal healthcare system—a point of national pride (Jedwab, 2019). However, this healthcare coverage is not comprehensive, as it fails to include dental care, some medication prescriptions, and a range of other services. Approximately 94% of dental services in Canada are funded by private insurance or out-of-pocket payments (Singhal, Correa, & Quiñonez, 2013), compared to the healthcare sector, in which 98% of physician payments are publicly funded (Leake, 2006). This privately funded dental care system results in significant income-related gaps in dental care utilization (Grignon, Hurley, Wang, & Allin, 2010), even greater than income-related gaps in healthcare utilization (Canadian Academy of Health Sciences, 2014). A 2018 Statistics Canada report estimates only 64.6% of Canadians had dental insurance that covered all or some dental care costs, and 22.4% of Canadians avoided going to the dentist due to cost (Statistics Canada, 2019). Similar analyses have shown cost burdens can result in patients deferring care or limiting the amount or type of dental treatments (Locker, Maggirias, & Quiñonez, 2011), and being forced to choose between addressing dental issues and other material needs (Muirhead, Quiñonez, Figueiredo, & Locker, 2009). Those with lower income and without dental insurance were the least likely to go to the dentist (Statistics Canada, 2019). In British Columbia (BC), Canada, public dental insurance is available to some individuals via longer term social assistance programs (e.g. “Persons with Disabilities” [PWD]). However, these programs may only cover basic dental or emergency services, limit number of treatments, or reimburse just a portion of the cost (BC Ministry of Social Development and Poverty Reduction, 2017). Patients receiving income assistance may also find their dental provider does not accept government insurance plans (Brondani, Wallace, & Donnelly, 2019; Shaw & Farmer, 2015). Research on dental care in Canada has identified the inverse relationship between oral health issues and dental care access as a “paradox of need” in which people with the greatest needs cannot utilized needed dental services (Muirhead et al., 2009; Ramraj, Azarpazhooh, Dempster, Ravaghi, & Quiñonez, 2012; Zangiabadi, Costanian, & Tamim, 2017).

Consequences of insufficient coverage and access to dental care include poor dental health outcomes, such as tooth loss, decay, gum disease, and oral cancer. However, poor oral health has also been linked to serious systemic health issues, including cerebrovascular (e.g. stroke), lung and cardiovascular diseases, and dementia (D’Amore et al., 2011; Dietrich et al., 2017). Without preventative care and early treatment of dental issues, patients will eventually require treatment for more serious health problems at greater personal and financial cost. Even when individuals have publicly funded dental coverage, dentists describe frustration treating people on social assistance, citing organizational difficulties (e.g. scheduling), inability to provide adequate care (e.g. treatments not covered), and financial costs (e.g., wasted resources on missed visits; Bedos, Loignon, Landry, Allison, & Richard, 2013). In Vancouver, BC, tooth extraction procedures were 14.2 times more likely to be conducted among patients with government-sponsored insurance (vs. private) and patients with private insurance were 1.27 times more likely to receive restorative treatments compared to those with public insurance (Brondani et al., 2019). Not only can dentists’ negative perceptions impact the care they provide, but patients of lower socioeconomic status may also be deterred from future dental visits (Muirhead et al., 2009).

Additional complexities arise when considering the potentially greater oral health needs of populations of people who use drugs (PWUD), due to the side effects of substance use, including dry mouth, enamel erosion, teeth grinding, increased craving for sugary food, and effects specific to mode of ingestion (Baghaie, Kisely, Forbes, Sawyer, & Siskind, 2017; D’Amore et al., 2011; Shetty et al., 2010). Moreover, co-occurring conditions can exacerbate this need, such as mental health issues linked to poor dental health or taking prescribed psychotropic medications with side effects like dry mouth (Baghaie et al., 2017; Kisely, Baghaie, Lalloo, Siskind, & Johnson, 2015). Despite greater risk of oral and physical health issues, previous research has shown that PWUD have fewer dental restorations, indicating underutilization of dental care by individuals or undertreatment by dentists (Baghaie et al., 2017). In addition to physical health consequences, dental hygiene and appearance can be particularly stigmatizing for PWUD, producing barriers to care. PWUD may feel embarrassed and reluctant to access treatment, perceive dental staff biases, or fear dental procedures or being in pain with dentists who may be unable to prescribe or employ adequate doses of analgesics during treatments (Brondani, Alan, & Donnelly, 2017; Laslett, Dietze, & Dwyer, 2008; Robinson, Acquah, & Gibson, 2005; Wallace, MacEntee, & Pauly, 2015). Difficulties accessing and paying for dental care may also be magnified for PWUD, who are often socioeconomically marginalized due to drug-related criminalization, stigma and discrimination, or limited opportunities for work. Without stable or adequate income and while facing immediate material and drug use needs, paying for dental care is often not possible for socioeconomically marginalized PWUD (Robinson et al., 2005), and consequently, many PWUD may lack adequate dental care. This is a population in which the paradox of need – where highest need occurs among those must unable to access care – may be amplified (Muirhead et al., 2009). Further investigation is critical to understanding specific predictors of dental care need and access among socioeconomically marginalized PWUD.

Recent reports in news media have highlighted issues of cost and access to dental care in Canada and called for expanded coverage (Chung, 2017; Eagland, 2019). During the 2019 federal election, comprehensive dental coverage was on the platform of a major political party (Tunney, 2019). However, little media coverage or research focuses on issues of access among PWUD, a group that experiences both greater oral health issues and social and economic barriers to dental care. In light of recent policy discussions, we conducted a quantitative investigation of inadequate access to dental care among a sample of primarily socioeconomically marginalized PWUD. We hypothesized that lack of access to adequate dental care would be associated with distinct substance use patterns as well as social-structural factors.

Methods

Data for this analysis are derived from the Vancouver Injection Drug Users Study (VIDUS) and the AIDS Care Cohort to evaluate Exposure to Survival Services (ACCESS), two ongoing prospective cohort studies of HIV-seronegative people who inject (VIDUS) or HIV-seropositive people who use drugs other than or in addition to cannabis (ACCESS). Data has been collected continually since 1996 using community-based sampling methods. Participants complete baseline surveys followed by harmonized follow-up surveys every six months, which include information on sociodemographic characteristics, health and healthcare, substance use, income generation, and other social-structural exposures. All participants provided written informed consent prior to participation. Participants are offered $40CAD honorarium at each visit. Both the VIDUS and ACCESS cohort studies have received ethics approval from the Providence Health Care/University of British Columbia Research Ethics Board (ACCESS: H05–50233; VIDUS II: H05–5023).

This current analysis utilizes data collected between June 2014 and November 2018, during which time a measure that assessed whether participants felt they received adequate dental care for themselves and their family in the past six months – our primary outcome – was included. Response options followed a Likert scale: never (0% of the time); occasionally (25% of the time or less); sometimes (26% to 74% of the time); usually (75% of the time or more); always (100% of the time). In analysis, outcome variable responses were dichotomized as “never” or “occasionally” (lower access) versus “sometimes,” “usually,” or “always” (higher access), because “never” or only “occasionally” accessing dental care are insufficient for the maintenance of oral health. While participants may have differentially interpreted this question to reflect unmet need rather than relative ability to access dental services, the questionnaire item is part of a previously validated scale measuring different components of material security specifically focused on access and we have preserved the language of the question to be consistent with the study instrument’s framing (Ompad et al., 2012).

Independent variables of interest include measures of sociodemographic characteristics (time-updated age; gender; white ethnicity; education), self-rated health (excellent, very good, good vs. fair, poor), and experiencing major or persistent pain. We included social-structural exposures, such as experiencing homelessness, incarceration, area restrictions or warrants, and living in the Downtown Eastside, an area of Vancouver that has been characterized by prevalent substance use, marginalization, and criminalization (Liu & Blomley, 2013), as well as facing greater dental needs and barriers to care (Brondani et al., 2019; Hau, Currie, Ng, Le, & Poh, 2017; Poh et al., 2007). To understand the relationship between income and dental care, we include a measure of engagement in income-generating activities, including regular, part-time or temporary employment, income assistance, street-based activities (e.g. panhandling, informal recycling, squeegeeing), sex work, and illegal activities (e.g. drug dealing, theft). To assess associations with substance use, we include measures of using any illicit opioids (heroin, fentanyl, or illicit prescription opioids), cocaine, crack-cocaine, methamphetamine, cannabis, as well as heavy alcohol use or daily cigarette use. We also include related measures of previous non-fatal overdose, opioid agonist treatment (OAT), and non-OAT treatment (e.g., NA/AA, residential, detox, etc.). Finally, we consider types of income assistance, defined as temporary (income assistance or “Persons with Persistent Multiple Barriers” [PMBB]) or long-term (“Persons with Disabilities” [PWD]) assistance in a sub-analysis. With the exception of baseline demographics, all measures are dichotomous (yes vs. no) and correspond to behaviors or events in the six months prior to interview.

To assess baseline characteristics, we assess associations between each of the independent variables and access to adequate dental care (lower vs. higher), using Pearson’s χ2 test for all categorical variables and the Mann-Whitney test for continuous variables (age). Employing generalized linear mixed models (GLMM), we assess bivariate associations between independent variables and the primary outcome variable and retained all independent variables in the multivariable model. In sub-analysis we explore associations between types of income assistance (temporary vs. long-term) and receiving adequate dental care, using Pearson’s χ2 test.

Results

Between June 2014 and November 2018, 1638 individuals completed at least one VIDUS or ACCESS follow-up, totaling 9898 observations (median = 7, interquartile range [IQR] = 1 to 9). At baseline, 246 (15.0%) participants reported having adequate dental care “never” or “occasionally” in the last six months. Baseline characteristics are listed in Table 1, stratified by reported dental care access, coded as lower (no, occasionally) versus higher (sometimes, usually, always) access. Among those without adequate dental care, 38.2% identified as women, 47.2% had at least a high school education, and were more likely to be white (51.6%) (versus nonwhite) and younger (median age=43; Interquartile Range (IQR)=33—52) than those with adequate dental care.

Table 1.

Baseline characteristics among people who use drugs in Vancouver, Canada, stratified by experiencing adequate dental care, 2014–2018

Characteristic Adequate Dental Care (n=1638)
Total (%) Lower (%) [n=246] Higher (%) [n=1392] p-value x2
Sociodemographic
 Age (median, IQR) 47 (38–54) 43 (33–51) 47 (38–53) <0.001
 Female gender 612 (37.4) 94 (38.2) 518 (37.2) 0.858
 White ethnicity 745 (45.5) 127 (51.6) 618 (44.4) 0.046
 Minimum HS education 789 (48.2) 116 (47.2) 673 (48.4) 0.764
Social-structural exposures †
 DTES residence 976 (59.6) 162 (65.9) 814 (58.5) 0.035
 Homelessness 367 (22.4) 85 (34.6) 282 (20.3) <0.001
 Incarceration 124 (7.6) 27 (11.0) 97 (7.0) 0.041
 Area restrictions/warrants 132 (8.1) 24 (9.8) 108 (7.8) 0.369
Substance use †
 Opioids 906 (55.3) 169 (68.7) 737 (53.0) <0.001
 Cocaine 469 (28.6) 78 (31.7) 391 (28.1) 0.280
 Crack-cocaine 725 (44.3) 118 (48.0) 607 (43.6) 0.234
 Methamphetamine 676 (41.3) 131 (53.3) 545 (39.2) <0.001
 Heavy alcohol 249 (15.2) 38 (15.5) 211 (15.2) 0.944
 Cannabis 836 (51.0) 132 (53.7) 704 (50.6) 0.411
 Daily cigarette use 1324 (80.8) 209 (85.0) 1115 (80.1) 0.078
 Non-fatal overdose 177 (10.8) 39 (15.9) 138 (9.9) 0.008
 Any opioid agonist treatment 892 (54.5) 132 (53.7) 760 (54.6) 0.821
 Any non-OAT 104 (6.4) 19 (7.7) 85 (6.1) 0.414
Health
 Self-rated health‡ 1159 (70.8) 151 (61.4) 1008 (72.4) <0.001
 Major pain† 657 (40.1) 98 (39.8) 559 (40.2) 0.357
Income generation †
 Employment 417 (25.5) 66 (26.8) 351 (25.2) 0.666
 Income assistance 1545 (94.3) 224 (91.1) 1321 (94.9) 0.014
 Street-based activities 346 (21.1) 68 (27.6) 278 (20.0) 0.009
 Sex work 193 (11.8) 35 (14.2) 158 (11.4) 0.243
 Illegal activities 139 (8.4) 42 (17.1) 97 (7.0) <0.001
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IQR, Interquartile range; HS, high school; DTES, Downtown Eastside; OAT, Opioid Agonist Treatment

†

Last 6 months

‡

Excellent, Very Good, Good

In final multivariable GLMM analyses (Table 2), there was a negative association between homelessness and adequate dental care (Adjusted Odds Ratio [AOR]=0.54, 95% Confidence Interval [CI]=0.42–0.70). Across substance use variables, there were negative associations between having adequate dental care and using opioids (AOR=0.73, 95% CI=0.58–0.91), methamphetamine (AOR = 0.75, 95% CI = 0.59–0.95) and cannabis (AOR=0.78, 95% CI=0.63–0.97). Engagement in opioid agonist therapy was positively associated with having adequate dental care (AOR=1.36, 95% CI=1.07–1.72). Across forms of income generation, engaging in street-based activities was negatively associated with adequate dental care (AOR=0.75, 95% CI=0.59–0.94) while receiving income assistance was positively associated with adequate dental care (AOR=1.70, 95% CI=1.05–2.77). In sub-analysis testing associations with forms of income assistance (Table 3), bivariate results indicated lower access to adequate dental care among those receiving short-term assistance, and higher access to adequate dental care among those receiving long-term assistance.

Table 2.

Generalized linear mixed model analysis of factors associated with receiving adequate dental care among people who use drugs in Vancouver, Canada, 2014–2018

Characteristic Adequate Dental Care (n=1638)
Odds Ratio Confidence Interval
Sociodemographic
 Age (median, IQR) 1.02* (1.00 – 1.03)
 Female gender 1.01 (0.75 – 1.36)
 White ethnicity 0.78 (0.60 – 1.01)
 Minimum HS education 0.86 (0.66 – 1.12)
Social-structural exposures †
 DTES residence 0.88 (0.70 – 1.11)
 Homelessness 0.54*** (0.42 – 0.70)
 Incarceration 0.96 (0.62 – 1.48)
 Area restrictions or warrant 0.85 (0.58 – 1.26)
Substance use †
 Opioids 0.73** (0.58 – 0.91)
 Cocaine 1.08 (0.85 – 1.37)
 Crack-cocaine 0.91 (0.74 – 1.13)
 Methamphetamine 0.75* (0.59 – 0.95)
 Heavy alcohol 1.10 (0.82 – 1.47)
 Cannabis 0.78* (0.63 – 0.97)
 Daily cigarette use 0.88 (0.66 – 1.17)
 Non-fatal overdose 0.96 (0.72 – 1.29)
 Any opioid agonist treatment 1.36* (1.07 – 1.72)
 Any non-OAT 1.29 (0.87 – 1.93)
Health
 Self-rated health‡ 1.17 (0.96 – 1.43)
 Major pain† 0.83 (0.68 – 1.01)
Income generation †
 Employment 1.11 (0.88 – 1.41)
 Income assistance 1.70* (1.05 – 2.77)
 Street-based activities 0.75* (0.59 – 0.94)
 Sex work 0.78 (0.54 – 1.14)
 Illegal or prohibited activities 1.09 (0.72 – 1.63)
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*

p <.05

**

p <.01

***

p<.001

IQR, Interquartile range; HS, high school; DTES, Downtown Eastside; OAT, Opioid Agonist Treatment

†

Last 6 months

‡

Excellent, Very Good, Good

Table 3.

Type of income assistance at baseline among people who use drugs in Vancouver, Canada, stratified by experiencing adequate dental care, 2014–2018

Characteristic Adequate Dental Care (n=1638)
Total (%) Lower (%) [n=246] Higher (%) [n=1392] p-value x2
Income assistance
 Short-term† 352 (21.5) 82 (33.3) 270 (19.4) <0.001
 Long-term ‡ 1137 (69.4) 128 (52.0) 1009 (72.5) <0.001
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†

Income Assistance or Persons with Persistent Multiple Barriers programs

‡

Persons with Disabilities program

Discussion

Among a sample of marginalized PWUD, our findings demonstrate significant associations between having limited access to adequate dental care and specific patterns of substance use, structural vulnerability, and institutional engagement, after controlling for sociodemographic characteristics, health, and income generation. Echoing earlier research highlighting dental care gaps in the broader Canadian population, these findings underscore the specific barriers and facilitators to accessing dental care among PWUD and point to measures that could promote increased access within disadvantaged drug-using populations.

Results highlighted some positive associations between having adequate dental care and being enrolled in opioid agonist therapies and receiving income assistance—forms of institutional engagement that may function to link individuals to health and social services. People accessing OAT may be engaged in lower risk substance use practices and have fewer negative oral health outcomes and treatment needs, versus those not accessing OAT. People on OAT may also be better connected to care via their doctors or treatment providers and have greater support to manage their health needs (Robbins, Wenger, Lorvick, Shiboski, & Kral, 2010). Additionally, people receiving income assistance typically have access to supplementary healthcare benefits, including dental care, and so it is unsurprising that we found an increased likelihood of having adequate dental care among this group, though access may not be consistent nor care comprehensive. As sub-analysis results showed, compared to those in shorter term assistance programs, receiving long-term assistance was associated with higher access to adequate dental care, which may be due to additional dental coverage as well as higher levels of monetary assistance. It may also be that people who successfully navigate systems to access income assistance benefits may employ those same skills to manage their healthcare needs, such as scheduling dental visits, or learning about available services. It should be noted that not all eligible individuals enroll in income assistance programs or access dental care benefits, nor do all PWUD experience socioeconomic marginalization or receive income assistance. Even formal employment may not ensure comprehensive dental coverage for PWUD, particularly for those engaged in precarious or low status work (Muirhead et al., 2009), as suggested by the non-significant relationship between adequate dental care and employment in the results.

Beyond these potential facilitators of dental care, results also identify associations between adequate dental care and indicators of social and structural vulnerability. The negative association with experiencing homelessness may point to greater dental need among homeless PWUD, particularly if they are unable to practice dental hygiene due to a lack of access to running water, privacy, or adequate nutrition or due to competing demands and risks associated with homelessness (e.g. police ticketing, exposure to violence; Robinson et al., 2005). People experiencing homelessness may have fewer resources to manage the organizational tasks involved in dental care, such as finding a dental clinic, scheduling an appointment, and traveling to a clinic (Bedos et al., 2003; Laslett et al., 2008; Poh et al., 2007; Robinson et al., 2005). Findings demonstrated an additional negative association between access to adequate dental care and engaging in street-based activities for income generation. Like those experiencing homelessness, people engaged in street-based activities may have competing priorities or demands on their time (e.g., long work hours to generate enough income). Given the visibility of many street-based activities, it may be physically difficult for individuals to access services such as free dental clinics, without leaving their belongings outside at risk of being lost or stolen (e.g., shopping carts with recyclables), being ticketed by police, or subjected to discrimination at clinics based on their physical appearance (Jaffe et al., 2018; Wittmer & Parizeau, 2016).

Finally, characteristics specific to distinct substance use patterns may limit PWUD from accessing care in several ways. Results showed negative associations between adequate dental care and using illicit opioids, methamphetamine, and cannabis. It may be that people with these substance use patterns suffer from oral health issues and perceive greater unmet needs, compared to other PWUD. Opioid and methamphetamine use can have side effects like dry mouth or teeth grinding that are linked to dental issues (Baghaie et al., 2017; D’Amore et al., 2011; Shetty et al., 2010). The link between cannabis and dental health is less clear but clinical studies have shown people smoking cannabis may also have untreated oral health needs. Long-term cannabis use can contribute to gum disease and changes in the oral mucosa (e.g., gum enlargement, leukoplakia patches), issues collectively referred to as “cannabis stomatitis” that can increase risk for oral cancers (Chisini et al., 2019; Cho, Hirsch, & Johnstone, 2005; Versteeg, Slot, van der Velden, & van der Weijden, 2008). In addition, the use of opioids, methamphetamine, or cannabis may temporarily relieve dental pain and so PWUD may be delaying or rejecting treatment for underlying causes of dental pain (Bungay, Johnson, Varcoe, & Boyd, 2010; Robinson et al., 2005). Finally, it may be that PWUD, particularly those who use opioids and methamphetamine, experience drug-related stigma in healthcare settings like dental offices, which can deter PWUD from accessing care for fear of shaming from dental staff (Brondani et al., 2017). A long-term hiatus in dental care may exacerbate existing dental problems and pain, and further discourage PWUD from accessing care.

There are some limitations to this study. First, the outcome measure of interest, access to adequate dental care, may be obscuring the presence of dental need. For instance, it is not possible to know whether participants without adequate care necessarily needed care or, in contrast, needed care but did not realize they could access care (e.g. via free clinics). Future measures of dental care access should specifically and separately address dental care need from dental care access. Second, only 15% of participants reported little or no access to dental care, which was lower than expected given previous research on dental care coverage in British Columbia and Canada (Grignon et al., 2010; Leake, 2006; Statistics Canada, 2019) and dental health status among PWUD (D’Amore et al., 2011; Laslett et al., 2008; Robinson et al., 2005). This could be attributed to dental coverage and care limitations for many socioeconomically marginalized PWUD; respondents may not see themselves as entitled to adequate dental care (for instance, due to experiences with discrimination in healthcare). Further, street-based individuals who have only experienced dental care as emergency tooth extraction may not perceive this as “adequate dental care” or may consider dental care unimportant. Future research could include direct measures of frequency of accessing care, details of care received, and oral health concerns among PWUD. Third, the ACCESS and VIDUS studies employ non-probability sampling and findings may not be generalizable to the broader population of PWUD. There are also instances where participants missed follow-up visits, however GLMMs are able to handle unbalanced longitudinal data in analyses and we do not anticipate significant bias resulting from missed observations in these analyses. Finally, there may be additional factors related to dental care and access that are not considered in this analysis, including the subsequent health impacts of inadequate care, and further research is needed to explore different dimensions of dental care and assess possibilities for the expansion of services.

Implications for Policy

This analysis is situated amidst growing public calls for expansion of dental care coverage in British Columbia and Canada (Chung, 2017; Eagland, 2019; Stewart, 2019), a setting with assumed universal healthcare coverage but where people experience acute health, financial, and emotional impacts of limited dental care coverage (Grignon et al., 2010; Locker et al., 2011; Shaw & Farmer, 2015; Statistics Canada, 2019). By analyzing associations specific to PWUD, a population with potentially greater and more complex health and material needs, we provide preliminary evidence of inadequate dental care that is consistent with previous calls for healthcare coverage policy changes in BC and highlights the need for further research on the oral health needs of PWUD. In addition to healthcare policy changes, addressing the limitations in care and systematic barriers to care identified by the current study will require existing care services for PWUD to be expanded, funded, and publicized to PWUD who are not institutionally engaged (Wallace et al., 2015). As previous research has highlighted, additional measures could promote the acceptance of public insurance plans and the dedication of a portion of their practice time to serving socioeconomically marginalized populations among dental care providers, and adequately reimbursing providers for these services to incentivize equitable access to care (Bedos et al., 2013; Shaw & Farmer, 2015). The expansion of dental services may also be aided by extending dental care delivery to healthcare sites that already serve PWUD, with experienced frontline staff and where PWUD are already comfortable receiving care (Main, Leake, & Burman, 2006). There are approximately 20 community dental clinics in BC operating as volunteer charity clinics or with not-for-profit models where patients are treated for free or low cost (Brondani et al., 2019), but many of these clinics lack the resources to be sustainable or to adequately treat the population in need, beyond emergency extractions and pain management (Ross, 2019; Wallace et al., 2015). Finally, dental care staff can be adequately trained to address the specific dental care needs of PWUD, as well as in assisting PWUD with anxiety or misconceptions around receiving dental care (Bedos et al., 2013; Cheah, Pandey, Daglish, Ford, & Patterson, 2017). Such changes may improve dental care access and may result in immediate and long-term health benefits for PWUD (Canadian Academy of Health Sciences, 2014).

The lack of dental care coverage in Canada’s publicly funded healthcare system poses treatment barriers for many people, but socioeconomically marginalized PWUD may face additional challenges in accessing dental care. Given the links between oral health and systemic health outcomes, untreated oral health issues can become critical medical issues, and only then will they be covered by the universal healthcare system. To address the expansion and implementation of publicly funded dental coverage that considers the needs of marginalized groups, future research should explore in-depth experiences of PWUD accessing dental care and their oral health needs, novel policies for the inclusion of dental care coverage, and potential strategies for linking PWUD to responsive dental providers.

What is known on this topic:

  • Dental care is necessary but remains privately funded in Canada’s universal healthcare system

  • Negative impacts of lacking dental care may be amplified for groups at greater risk of dental health issues, such as people who use drugs

  • Little is known about access to dental care among people who use drugs and how health and social factors shape access

What this paper adds:

  • Evidence of negative associations between access to adequate dental care and substance use and social-structural vulnerability, and positive associations with opioid agonist treatment and receiving income assistance

  • Results illustrate specific barriers and facilitators to adequate dental care among PWUD and provide further support to calls for the expansion of dental care coverage

Acknowledgements

The authors thank the study participants for their contribution to the research, as well as current and past researchers and staff.

Funding The study was supported by the US National Institutes of Health [U01DA038886, U01DA021525] and the Canadian Institutes of Health Research (CIHR) [MOP-137068]. Funders had no role in the study design, data collection, analysis or interpretation of the data, writing of the article or submission for publication. LR, MJM and KH are supported by a Michael Smith Foundation for Health Research (MSFHR) Career Scholar Awards and CIHR New Investigator Awards [MSH 217672, MSH 360816, MSH 141971]. LR’s research is additionally supported by a CIHR Foundation Grant [FDN-154320]. MJM is also supported by the US National Institutes of Health [U01-DA0251525]. KH also holds the St. Paul’s Hospital Chair in Substance Use Research and is supported by the St. Paul’s Foundation. KJ is supported by a Vanier Canada Graduate Scholarship from CIHR and by the University of British Columbia Public Scholars Initiative.

Footnotes

Conflict of Interest The authors declare that there is no conflict of interest. MJM’s institution has received an unstructured gift to support him from NG Biomed, Ltd., a private firm applying for a government license to produce cannabis, to support his research. He holds the Canopy Growth professorship in cannabis science which was established through unstructured gifts to the University of British Columbia from Canopy Growth, a licensed producer of cannabis, and the Ministry of Mental Health and Addictions of the Government of British Columbia. Funders had no role in study design, preparation of the manuscript, or decision to publish.

Ethics approval VIDUS and ACCESS have received ethics approval from Providence Health Care/University of British Columbia’s Research Ethics Board (H05-50233; H01-50086; H05-50234; H14-01396).

Informed consent Informed consent was obtained from all individual participants included in the study.

Data availability statement:

Research data are not available due to dynamics of collecting data on illegal activities from criminalized and marginalized populations.

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Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

Research data are not available due to dynamics of collecting data on illegal activities from criminalized and marginalized populations.

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