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.

Summary "BAR-ORAL"

Bariatric surgery, a procedure targeting the gastrointestinal tract, affects most of the body's organ systems. 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 negative for the patient, such as osteoporosis due to malabsorption, or a higher risk of alcohol abuse due to increased bioavailability of ethanol.

Can bariatric surgery also affect the oral cavity? Experienced obesity clinicians may tell you no, but in practice we rarely ask our patients in the obesity clinics to neither open their mouths nor share their experiences. If you ask dental health professionals, the answer is perhaps just as uncertain, as their encounters with bariatric surgery patients are random and not part of a follow-up programme. However, stories of poor oral health in the years after surgery are common on social media for bariatric surgery patients. One experience in particular is highlighted: Teeth chipping.

There is still not much research on oral health in bariatric surgery patients, but some exists. However, many of the 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 comprehensive 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 platform for both patient education and more general information about the development of the research project.


The central aim of the project is to answer various clinical questions related to patients' oral health. However, the purpose extends further and addresses stakeholders beyond the dental community.


The project is a prospective, longitudinal cohort study. Data will consist of self-reported data on oral health, clinical oral examinations, biological material for both immediate analyses and biobanking, as well as registry data.


  • Educating the patients on this new knowledge provides a better basis for informed consent to undergo surgery, and contributes to more evidence-based patient education. Patients may utilize this knowledge to prevent oral pathology.
  • The knowledge will be disseminated to obesity clinicians in order to identify patients at risk of oral complications and provide customised advice to prevent injuries.
  • The knowledge will be shared with dental health professionals as a basis for better patient follow-up.
  • The knowledge can give health bureaucrats insight into a clinical area in need of increased interdisciplinarity and service innovation.
  • The knowledge will provide politicians with a basis for assessing whether the current reimbursement schemes for dental treatment in Norway are appropriate.

Collaborating partners

  • St. Olavs Hospital, Centre for Obesity Research
  • St. Olavs Hospital, Dental team
  • Competence Centre for Dental Health in Central Norway (TkMidt)
  • Dental Health Service Competence Centre East (TkØ)
  • The public dental health service in Trøndelag County
  • The public dental health service in Møre og Romsdal County
  • NTNU, Department of Clinical and Molecular Medicine
  • NTNU, Department of Community Medicine and Nursing
  • University of Oslo, Department of Clinical Dentistry
  • University of Bergen, Department of Clinical Dentistry

Funding from

  • Regional Research Fund Trøndelag (ES674327)
  • Research Council of Norway (ES720146)
  • Joint research committee NTNU/St. Olavs hospital (2023/36515)
  • St. Olavs hospital (2022/11075-7)

Summary "BAR-TEETH"

Poor oral health is a recurring theme on various social forums for former bariatric surgery patients. Patients share experiences of chipping teeth and increased carious activity with subsequent formidable expenses. The BAR-TEETH project focuses on a selection of patients who have experienced deteriourating oral health in order to better understand what characterises oral ill-health and barriers for dental treatment in this selected group.


Qualitative study based on interview data supplemented with copies of the patients' dental records.


A broad exploration of the patients' experiences of poor oral health after bariatric surgery, with a particular focus on the barriers and facilitators for seeking dental treatment.


- The project provides a basis for better implementation of the longitudinal cohort study BAR-ORAL.

- The project can generate hypotheses and identify possible factors that predispose to the development of oral pathology after bariatric surgery.

- This knowledge provides a basis for better patient education for patients undergoing bariatric surgery.

Collaboration partners

  • St. Olavs Hospital, Centre for Obesity Research
  • Competence Centre for Dental Health in Central Norway (TkMidt)
  • NTNU, Department of Clinical and Molecular Medicine


  • St. Olavs Hospital (2022/11075-7)


The patient's diet and oral hygiene provides an opportunity to prevent or slow down oral pathology after bariatric surgery, but requires awareness and personal effort on the part of the patient. This implies that this should also have a special focus in hospitals' preoperative patient education before bariatric surgery. Norwegian hospitals are required to provide patient education. However, the quality and effect of this education is rarely systematically investigated.

The BAR-VANNTANN project investigates the effect of three different educational activities on patients' drinking habits, oral hygiene routines, level of knowledge and self-reported oral health. These educational activities are 1) a website with customised information, 2) group-based education given by healthcare professionals, and 3) distribution of a goodie bag with relevant product samples for oral hygiene. Patients are randomised between the different educational interventions and data are collected prospectively; preoperatively, as well as 6 and 24 months after bariatric surgery.


The project can provide answers to both which of the educational measures has the greatest effect, as well as what characterises the patients who report an effect.


The study is a prospective, group-randomised, open intervention study. Data are primarily self-reported.


  • For the participants in the project, participation may contribute to better understanding and routines for oral hygiene and thus reduce the risk of oral pathology.
  • The knowledge provides a basis for improving patient education for patients undergoing bariatric surgery. The results may point to teaching models that can be applied at other hospitals and thus provide more standardised information nationally.
  • In a broader perspective, the project may have applicability to patient education on other topics, as it illustrates different teaching methods and how these may be evaluated systematically.
  • The information shared with patients provides them with a better basis for informed consent to undergo bariatric surgery.

Collaboration partners

  • St. Olavs Hospital, Centre for Obesity Research
  • Competence Centre for Dental Health in Central Norway (TkMidt)
  • Namsos Hospital, Obesity Outpatient Clinic
  • Ålesund Hospital, Obesity Outpatient Clinic


  • DAM HELSE via the Norwegian Public Health Association (SDAM_HEL517756)

The project has otherwise received free oral hygiene product samples (for the intervention with delivery of relevant oral hygiene items) from the following suppliers:

  • Haleon Healthpartner
  • Karo Healthcare
  • Pharmex
  • Unilever



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.