Condition category
Digestive System
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
If you have gum disease, your gums become swollen, sore or infected and may bleed when you brush your teeth, and you may have bad breath. This stage of gum disease is known as gingivitis. If gingivitis is not treated, a condition called periodontitis can develop, which can lead to the bone in your jaw to decay and your teeth to fall out. Periodontitis is diagnosed once irreversible tissue destruction has already occurred, so we need to find a way to diagnose the disease at an earlier stage. The aim of this study was to assess the levels of signalling proteins called cytokines in fluid sampled from the inflamed gums of patients with gingivitis and periodontitis. The secondary aim was to investigate the effect of periodontal treatment with and without omega-3 supplementation on the cytokine levels and the bone density of the tooth sockets.

Who can participate?
Adults aged over 18 with periodontitis or gingivitis.

What does the study involve?
Periodontitis patients were randomly allocated to take either omega-3 supplements or placebo (dummy) tablets for 4 months. All patients received oral hygiene instructions and scaling and root planing (deep cleaning between the gums and the teeth down to the roots) under local anesthestic. Fluid was sampled from the gums of gingivitis patients and periodontitis patients and the levels of cytokines were analyzed in the lab.

What are the possible benefits and risks of participating?
Not provided at time of registration.

Where is the study run from?
Rio de Janeiro State University (Brazil).

When is the study starting and how long is it expected to run for?
October 2010 to October 2012.

Who is funding the study?
National Council for Scientific and Technological Development (Brazil).

Who is the main contact?
Dr Gisele Martinez

Trial website

Contact information



Primary contact

Dr Gisele Martinez


Contact details

SQSW 303 BL G APTO 305 Sudoeste

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

The adjunctive effects of Omega-3 dietary supplementation in the treatment of periodontitis: a clinical and immunological study


Study hypothesis

The general aim of this randomized controlled double-blind trial was to test the hypothesis that an adjunct dietary supplementation of Omega-3 on chronic periodontitis non-surgical treatment improves clinical and immunological outcomes.

Ethics approval

The Ethics Committee of the Pedro Ernesto University Hospital, 15/12/2010, protocol 2714/2010

Study design

Parallel double-blinded randomized controlled trial

Primary study design


Secondary study design

Randomised parallel trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Periodontal diseases, gingivitis and periodontitis


Periodontitis patients were randomized using a coin toss into 4 months supplementation with omega-3 or placebo in a parallel double-blinded design. All patients received non-surgical periodontal treatment which consisted of oral hygiene instructions and supra- and sub-gingival scaling and root planing (SRP) under local anesthesia. The treatment was performed by an experienced periodontist (GLM) with manual (Gracey and McCall curettes, Hu-Friedy, Chicago, IL, USA) and ultrasonic (Cavitron select, Dentsply, York, PA, USA) instruments. On average, the treatment required four 50-min sessions. The intervention group received omega-3 dietary supplementation (3 capsules of 300 mg omega-3 (180 mg EPA/120 mg DHA)/day), and the control group received placebo (3 capsules of 450 mg gelatin/day) (Quintaessencia, Rio de Janeiro, Brazil). Patients of both groups received three containers of 30 capsules/month. Compliance was assessed by the return of empty containers, and assessed weekly at visits to the clinic or by telephone calls. The bottles were not decoded until follow-up evaluations and analyses had been performed to ensure a proper double-blind study protocol.

Intervention type



Drug names

Primary outcome measure

Periodontal examination included bleeding on probing (BOP), O'Leary's plaque index (PI), probing depth (PD), and clinical attachment level (CAL). The PD and CAL were recorded at 6 sites per tooth (mesio-buccal, mid-buccal, disto-buccal, mesio-lingual, mid-lingual, and disto-lingual), excluding the third molars, using a periodontal computerized probe (Florida Probe, Gainesville, FL, USA). The intra-examiner concordance was 98% within the interval of ± 0.5 mm for PD and CAL. Timepoints: baseline, 4th month and 12th month

Secondary outcome measures

Gingival crevicular fluid was collected between 8 h and 12 h as previously described [Figueredo and Gustafsson 1998]. Measurements of a panel of cytokines and chemokines in GCF were performed using a Luminex 200 analyzer (Alameda, CA, USA) with Milliplex kits (Millipore, Billerica, MA, USA) according to the manufacturer’s instructions. Fifty μL of GCF was used to analyze the levels of IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, interferon (IFN)-γ, osteocalcin (OC), osteoprotegerin (OPG) and RANK-L. Timepoints: baseline, 4th month and 12th month

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Adults aged over 18 with generalized chronic periodontitis seeking treatment at the dental school of the Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil between 2010 and 2011. An experienced specialist in periodontology diagnosed patients according to the criteria of the American Academy of Periodontology (AAP).
2. Having moderate-severe periodontitis (attachment loss ≥ 3 mm and periodontal pocket ≥ 5 mm) in at least 4 interproximal sites from different teeth, and having at least 15 own teeth
3. A group of plaque-induced gingivitis patients was used as controls: at least 20 own teeth with no interproximal attachment loss and presence of bleeding in ≥ 30% of sites

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Diagnosed systemic disease
2. The use of antibiotics or non-steroidal anti-inflammatory drugs (NSAIDs) in the previous 6 and 3 months, respectively
3. Ongoing use of medication known to affect periodontal condition such as anticonvulsants (phenytoin) or immunosuppressives (cyclosporine, nifedipine, nitrendipine, oxidipine, felodipine, amlodipine, verapamil and diltiazem)
4. Ongoing use of omega nutritional supplements, or previous periodontal and/or orthodontic treatment in the last 12 months

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Rio de Janeiro State University (UERJ)

Sponsor information


Rio de Janeiro State University (UERJ) (Brazil)

Sponsor details

Vila Isabel
Rio de Janeiro

Sponsor type




Funder type


Funder name

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Alternative name(s)

National Council for Scientific and Technological Development, CNPq

Funding Body Type

government organisation

Funding Body Subtype

National government



Results and Publications

Publication and dissemination plan

We plan to submit the manuscript in September 2015

Intention to publish date

Participant level data

Available on request

Basic results (scientific)

Publication list

2015 results in

Publication citations

Additional files

Editorial Notes

04/11/2015: Publication reference added.