Plain English Summary
Background and study aims
Periodontitis is an inflammatory disease that occurs in the oral cavity (mouth) and affects the supportive tissues of the teeth. If the inflammation progresses, this can lead to severe bone destruction and tooth loss. In response to the accumulation of microorganisms (bacteria), white blood cells called polymorphonuclear neutrophils can enter the oral cavity from the blood stream and mix in the oral fluid. The specific role of these oral PMNs (oPMNs) in periodontitis is uncertain. The aim of this study is to compare the PMNs in the mouths of people with and without periodontitis.
Who can participate?
Patients with and without untreated periodontitis
What does the study involve?
Blood and oral rinse samples are collected from patients with untreated periodontitis and people without periodontitis to measure the amount of PMNs, their activation, cell death and the generation of oxygen free radicals.
What are the possible benefits and risks of participating?
This study gives insights into the functioning of the immune response within the mouths of people with periodontitis. No risks or symptoms are expected to occur due to participating in this study.
Where is the study run from?
Academic Centre for Dentistry Amsterdam (Netherlands)
When is the study starting and how long is it expected to run for?
October 2014 to May 2016
Who is funding the study?
University of Amsterdam (Netherlands)
Who is the main contact?
Mr Patrick Rijkschroeff
Mr Patrick Rijkschroeff
Gustav Mahlerlaan 3004
Characterization of functional oral polymorphonuclear neutrophils in periodontitis patients: an observational case-control study
Knowledge about polymorphonuclear neutrophils (PMNs) in the oral cavity periodontitis is limited and controversies exist regarding their function and significance. The rationale of this study was to characterize the PMNs from the oral cavity of patients with untreated periodontitis and compare those to the same cells from healthy subjects without periodontitis, since most of the periodontitis research on PMNs has made use of blood as the source material. Additionally, the characteristics of the oral PMNs were compared to those of the circulatory PMNs.
Medical Ethics Committee of the VU University Medical Center, 29/03/2013, ref: 2012-210#B2012406
Observational case-control study
Primary study design
Secondary study design
Patient information sheet
Not available in web format, please use the contact details to request a patient information sheet
Venous blood and oral rinse samples were obtained from 19 patients with untreated periodontitis and 16 control subjects without periodontitis for PMN isolation. Cell numbers were counted and apoptosis was analysed using propidium iodide labelling. Expression of cell activation markers CD11b, CD63, and CD66b was analysed using flow cytometry. Constitutive ROS generation was detected using dihydrorhodamine123. Additionally, ROS production in response to stimulation was evaluated in samples incubated with 10 µM phorbol myristate acetate (PMA) or Fusobacterium nucleatum.
Primary outcome measure
The presence of PMNs in the oral cavity of periodontitis patients, measured using flow cytometry directly after sampling. All samples were analyzed using flow cytometry on the same day.
Secondary outcome measures
1. Cell counts, measured using a Muse cell counting device
2. Cell membrane integrity, measured with flow cytometric analysis using propidium iodide staining
3. PMN expression markers of cell activation: CD11b, CD63, CD66b and corrected for non-specific binding of isotype control antibodies
4. Presence of constitutive oxygen radicals (ROS), detected using dihydrorhodamine 123
5. Presence of ROS in response to stimulation, determined in samples incubated with phorbol myristate acetate (PMA) or Fusobacterium nucleatum
All outcomes measured at a single timepoint
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Patients with untreated periodontitis
2. The presence of bone loss on ≥ 1/3 of the root length on minimum 2 non-adjacent teeth on vertical bite-wing radiographs not older than 12 months
3. Aged 18 and over
Target number of participants
Participant exclusion criteria
1. A history of pathologic conditions that are known to systemically affect PMN functionality (such as hematological disorders, diabetes mellitus, antibiotics use within the last 6 months, recent history of illness or fever, allergies, alcoholism and pregnancy)
2. Less than 20 teeth
3. Removable partial dentures
4. Night guards
5. Orthodontic banding
6. (Peri) oral piercings
7. Apparent oral lesions
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Academic Centre for Dentistry Amsterdam (ACTA)
Universiteit van Amsterdam
University of Amsterdam, UvA
Funding Body Type
private sector organisation
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication in a high-impact peer reviewed journal.
IPD sharing statement
The datasets generated during and/or analysed during the current study are/will be available upon request from Dr Elena A. Nicu (firstname.lastname@example.org).
Intention to publish date
Participant level data
Available on request
Basic results (scientific)