A study published in PLOS One on October 21, 2026, using national Statistics Canada survey data, found that Canadian adults who reported oral pain, dry mouth, bleeding gums or poor oral health had higher odds of short sleep, insomnia symptoms, unrefreshing sleep or difficulty staying awake. Dry mouth and oral pain showed the strongest associations for insomnia, unrefreshing sleep and difficulty staying awake. The authors say dental professionals should routinely ask about sleep in these patients and treat dry mouth on waking as a possible sign of undiagnosed sleep-disordered breathing.
As of October 2026, the study, "The oral-sleep interface: Associations between oral health status and sleep outcomes in Canadian adults," was written by researchers at the University of Saskatchewan and Jordan University of Science and Technology. It draws on the 2017–2018 Canadian Community Health Survey (CCHS), so its data were collected in 2017–2018 and say nothing about the effect of more recent programs such as the Canadian Dental Care Plan (CDCP). It also describes associations rather than cause and effect. Even so, its findings speak directly to the medical history questions your team asks every day.
What data did the researchers use?
The CCHS is Statistics Canada's ongoing survey of health status, health determinants and healthcare use among non-institutionalized Canadians aged 12 and older. According to the paper, the 2017–2018 cycle included 113,290 respondents across the ten provinces and three territories. The researchers restricted their analysis to adults aged 18 and older, a sample of 104,636.
The survey excluded people living on First Nations reserves or Aboriginal settlements, youth in foster care, full-time members of the Canadian Armed Forces, residents of institutions and those in selected health regions of Quebec. The authors state these exclusions accounted for less than 3% of the target population.
The four oral health indicators
- Self-reported oral health, grouped as good (excellent, very good, good) or poor (fair, poor)
- Oral pain: persistent or ongoing pain anywhere in the mouth
- Bleeding gums, including while brushing or flossing
- Dry mouth: persistent dry mouth
For the three symptom questions, "often" or "sometimes" counted as yes.
The four sleep outcomes
- Short sleep duration: under seven hours a night
- Insomnia symptoms: trouble going to sleep or staying asleep most or all of the time
- Unrefreshing sleep: sleep that is never or rarely refreshing
- Difficulty staying awake when you want to, most or all of the time
The fully adjusted models accounted for sex, age, education, body mass index, smoking, alcohol use, income, marital status and self-rated general and mental health, using the survey weights Statistics Canada recommends for nationally representative estimates.
What did the study find?
Of the 16 combinations of oral health indicator and sleep outcome, 13 remained statistically significant in the fully adjusted model, and all 13 stayed significant after correction for multiple testing. The figure below shows the adjusted odds ratios.
Dry mouth and oral pain stood out
For insomnia symptoms, dry mouth (AOR 1.904) and oral pain (AOR 1.826) had the strongest associations. For unrefreshing sleep, oral pain (AOR 1.937) and dry mouth (AOR 1.808) led. For difficulty staying awake, the two were close again: dry mouth at 1.720 and oral pain at 1.701.
Poor oral health and short sleep
For short sleep duration, poor self-rated oral health had the strongest association (AOR 1.623). Oral pain, bleeding gums and dry mouth were also linked to sleeping under seven hours.
Bleeding gums were the weakest signal
Bleeding gums were associated with short sleep and insomnia, but not significantly with unrefreshing sleep or difficulty staying awake after full adjustment. The authors suggest one reason: gingival bleeding is often painless and "may not directly impair sleep through discomfort or nocturnal awakening."
Why is dry mouth a referral question, not just a comfort question?
The most practical part of the paper is its discussion of direction. The authors note that dry mouth may disturb sleep through nocturnal discomfort and repeated awakenings, but they call the reverse explanation "equally plausible": nocturnal mouth breathing caused by obstructive sleep apnea, allergic rhinitis or nasal obstruction can itself produce dry mouth, and dry mouth on waking is a recognized correlate of sleep apnea severity.
Their clinical recommendation follows from that. In the authors' words, dry mouth complaints, especially on waking, "should raise suspicion of undiagnosed sleep-disordered breathing and prompt referral, rather than symptomatic management alone." They also suggest considering dry mouth when evaluating sleep complaints in older adults with polypharmacy.
Pro Tip: Add one sleep question to your medical history update, such as "How often do you wake up with a dry mouth?" The answer can help you decide whether to raise the question with the patient's physician.
What does this mean for Ontario and GTA practices?
This study does not change any regulation, fee guide or standard of practice. It does give your team a data-backed reason to connect three things that often sit in separate parts of the chart: oral pain, xerostomia and sleep.
- Hygiene appointments: patients who report dry mouth or persistent oral pain are, in this data, more likely to also report poor sleep. A short follow-up question can surface it.
- Pain management: the authors note, citing earlier research, that unmanaged dental pain may contribute to insomnia and daytime fatigue, which adds weight to timely treatment of painful conditions.
- Interprofessional communication: the paper calls for stronger collaboration between dental and sleep medicine professionals. In practice, that starts with a clear referral note to the patient's physician.
Pro Tip: When you refer for a suspected sleep issue, put the oral findings in the first two lines of the letter, for example "persistent dry mouth on waking, reported at the last two recall visits." Leading with the observation makes the reason for referral hard to miss.
Public health and the CDCP
The authors write that public health initiatives, including the Canadian Dental Care Plan, "should address the interconnected nature of sleep and oral health, particularly in populations with limited dental access." The study does not evaluate the CDCP, and its data come from 2017–2018. It is a recommendation from researchers, not a policy change.
What are the study's limits?
The authors list them plainly:
- Cross-sectional design. The data cannot show whether poor oral health disrupts sleep, poor sleep worsens oral health, or both.
- Self-reported measures. No clinical examinations or objective sleep tests were used, so misclassification is possible.
- Missing confounders. The public CCHS file lacked detail on medication use and obstructive sleep apnea, both of which can affect dry mouth and sleep.
They call for longitudinal studies and randomized trials testing whether treatments for pain, periodontal disease or xerostomia improve sleep.
EBIKO Dental will continue monitoring Canadian oral health research and what it means for practices in Toronto, the GTA and across the country. Read more updates at ebiko.ca.
Sources
- Mistareehi AJ, Hoja I, Mohamoud W, Lieffers JRL, Katselis GS. The oral-sleep interface: Associations between oral health status and sleep outcomes in Canadian adults. PLOS One 21(10), published online October 21, 2026. doi:10.1371/journal.pone.0350313 (open access; Europe PMC)
Frequently Asked Questions
Q: Is poor oral health linked to poor sleep in Canadian adults?
Yes. A 2026 PLOS One analysis of the 2017–2018 Canadian Community Health Survey found that poor self-rated oral health, oral pain, bleeding gums and dry mouth were associated with most of the sleep outcomes studied (13 of 16 combinations of short sleep, insomnia symptoms, unrefreshing sleep and difficulty staying awake) after adjusting for other factors. The design shows association, not cause.
Q: Why should a dentist ask about sleep when a patient has dry mouth?
The study's authors note that dry mouth may be a marker of sleep-disordered breathing such as obstructive sleep apnea, which they call an equally plausible explanation for the link. They recommend that such complaints prompt suspicion of undiagnosed sleep-disordered breathing and referral, not only symptom relief.
Q: Which oral symptoms had the strongest link to poor sleep?
Dry mouth and oral pain, for insomnia, unrefreshing sleep and difficulty staying awake; for short sleep, poor self-rated oral health was strongest. Dry mouth had an adjusted odds ratio of 1.904 for insomnia symptoms, and oral pain had 1.937 for unrefreshing sleep.