Is there a connection between bariatric surgery and oral health?

BAR-ORAL is a longitudinal observational study of oral health in patients undergoing various forms of obesity treatment. Here you can read more about the project, which is a collaboration between several Norwegian counties, health regions and research institutions. The project starts in 2024.


Bariatric surgery, which is essentially a gastrointestinal procedure, affects most of the body's organ systems. Such systemic effects may be desirable, such as remission of type 2 diabetes or normalisation of high blood pressure. But systemic effects of bariatric surgery can also be detrimental to the patient, such as osteoporosis due to malabsorption, or increased risk of alcohol abuse due to increased bioavailability of ethanol.

Does bariatric surgery also affect the oral cavity? Experienced obesity clinicians may say no, but in practice we have never asked patients to either open their mouths or to share their experiences. If you ask dentists, the answer is perhaps just as uncertain, as they have an even more random follow-up of patients in the years after surgery. On the other hand, stories of poor oral health in the years after surgery flourish on social media among bariatric surgery patients. One experience in particular is highlighted: Teeth breaking.

There is still not much research on oral health in bariatric surgery patients, but some exists. However, several studies have significant limitations. We therefore want to establish a new study that follows patients prospectively from before bariatric surgery and for several years afterwards. The project will be based on rich data on the patients' health (self-reported data and registry data), as well as clinical examinations of the oral cavity.

We will use this website as a shared platform for both patient education and more general information about the development of the research project.


The knowledge generated shall:

  • be organised to strengthen the patient's basis for giving an informed consent to undergo surgery.
  • be available to obesity clinicians so that they can identify patients at increased risk of oral complications and provide customised advice to prevent harm.
  • provide the health bureaucrat with input on relevant areas for interdisciplinarity and collaboration between obesity clinicians and dental professionals.
  • provide politicians with a basis for assessing whether current reimbursement schemes for dental treatment are appropriate.

Status for the BAR-ORAL study

The project is still under development and is therefore not open for participation. The website will be updated when the project starts.

The study will recruit participants among patients undergoing obesity treatment at public hospitals in Central Norway.

Collaborating partners

  • St. Olavs Hospital, Centre for Obesity Research
  • St. Olavs Hospital, The dental team
  • Center for Oral Health Services and Resarch, Mid-Norway (TkMidt)
  • Oral Health Centre of Expertise in Eastern Norway (TkØ)
  • Public Dental Health Competence Center of Northern Norway (TkNN)
  • The Public Dental Services, Trøndelag County
  • The Public Dental Services, Møre og Romsdal County
  • NTNU, Dept. of Clinical and Molecular Medicine
  • NTNU, Dept. of Public Health and Nursing
  • University of Oslo, Inst. of Clinical Dentistry
  • University of Bergen, Dept. of Clinical Dentistry



Coverage in media

Lectures and presentations

  • 14.4.2023: “Hva om vi ba sykehuspasienten om å gape opp? Oral helse ved systemisk sykdom». Fredagsforelesningen, St. Olavs hospital, Trondheim.
  • 27.1.2023: «Fedmekirurgi og oral helse». Fremtidens operasjonsrom-seminaret 2023, Røros.
  • 17.11.2022: «Fedmekirurgi og oral helse». Oral helse KAG-dagen 2022, Trondheim.
  • 21.9.2022: «Fedmekirurgi og munnhelse». Tannhelsedagene 2022 i regi av Den offentlige tannhelsetjenesten i Trøndelag, Stjørdal.