Condition category
Oral Health
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

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

Trial website

Contact information



Primary contact

Mr Patrick Rijkschroeff


Contact details

Gustav Mahlerlaan 3004
1081 LA

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Characterization of functional oral polymorphonuclear neutrophils in periodontitis patients: an observational case-control study


Study hypothesis

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.

Ethics approval

Medical Ethics Committee of the VU University Medical Center, 29/03/2013, ref: 2012-210#B2012406

Study design

Observational case-control study

Primary study design


Secondary study design

Case-control study

Trial setting


Trial type


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.

Intervention type



Drug names

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

Participant type


Age group




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)

Sponsor information


University of Amsterdam

Sponsor details

Gustav Mahlerlaan 3004
1081 LA
+31 (0)205 980 888

Sponsor type




Funder type


Funder name

Universiteit van Amsterdam

Alternative name(s)

University of Amsterdam, UvA

Funding Body Type

private sector organisation

Funding Body Subtype

Universities (academic only)



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 (

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

2018 results in:

Publication citations

Additional files

Editorial Notes

28/08/2018: Publication reference added. 24/08/2018: The intention to publish date was changed from 01/11/2017 to 21/09/2018.