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

Plain English Summary

Background and study aims
Periodontal (gum) disease is very common, Over time, it can cause the bone in the jaw holding the teeth to decay; the teeth can become loose and eventually fall out. It can be prevented by tooth brushing, using dental floss and other devices designed to remove bacterial plaque from the teeth. However, these measures are often not performed well enough to remove all plaque from the teeth. It is therefore thought that a chemical plaque control method may be of benefit. Porphyromonas gingivalis is thought to be the bacteria that causes most cases of periodontitis. Gingipain is an enzyme that is believed is needed for P. gingivalis to survive and grow in the mouth long enough to cause disease. Anti-Porphyromonas gingivalis egg yolk antibody (IgY-GP) can inhibit the activity of gingipain. In this study, we wanted to investigate how well tablets containing IgY-GP can treat periodontitis when combined with scaling and root planning.

Who can participate?
Healthy adult volunteers with periodontal disease.

What does the study involve?
All participants have their teeth and gums checked for periodontal disease and clinical measures taken. Two weeks after this, all participants are given full-mouth scaling and root planning treatment. Participants are then randomly allocated into one of two groups. Those in group 1 receive the IgY-GP tablets three times a day after a meal or brushing. Participants in group 2 receive placebo tablets. Each participant in both groups are followed up 4 weeks and then 12 weeks after treatment to check for periodontal disease and periodontitis causing bacteria in the mouth.

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

Where is the study run from?
Nihon University School of Dentistry (Japan)

When is the study starting and how long is it expected to run for?
May 2008 to September 2008

Who is funding the study?
Sato Fund, Nihon University School of Dentistry (Japan)

Who is the main contact?
Professor Naoyuki Sugano

Trial website

Contact information



Primary contact

Prof Naoyuki Sugano


Contact details

1-8-13 Kanda-Surugadai

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

The effects of anti-porphyromonas gingivalis egg yolk antibodies in patients with periodontal disease


Study hypothesis

In this study, we investigated the efficacy of IgY-GP-containing tablets as an adjunct to periodontal treatment in patients with periodontitis.

Ethics approval

Nihon University School of Dentistry Institutional Review Board 2006-9

Study design

Randomized double-blind placebo controlled study

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet


Periodontal disease


Eligible subjects (mean age, 51.0 ± 8.5 years; range, 36-66 years) were allocated randomly to the test and control groups according to gender, age, and smoking status, using a randomization table. All subjects had at least two probing pockets with a depth of ≥4 mm and bled after probing. All participants provided written informed consent. The study protocol was a double-blind placebo-controlled trial and approved by the Nihon University School of Dentistry Institutional Review Board. The randomization code was revealed when all microbiological and clinical data were gathered after the 12-week intervention period. Participants were instructed not to change their oral hygiene regimens, and tooth brushing instruction was not given during or before the experimental period.

Clinical measurements were obtained for Ramfjord’s six teeth (16, 21, 24, 36, 41, and 44 in the FDI two-digit notation system) in all subjects). The deepest probing depth (DPD), mean probing depth (PD), bleeding on probing (BOP), and O’Leary plaque control record (PCR) were recorded. When one of the selected teeth was missing from the oral cavity, data were obtained from an adjacent tooth in the same area of the jaw. Two weeks after the first clinical measurement, all participants received full-mouth scaling and root planning, followed by professional mechanical tooth cleaning (PMTC). All procedures were performed by two trained periodontists. After that, the subjects in the test (IgY-GP) group took tablets containing anti-gingipain egg yolk antibodies (100 mg/tablet), without chewing, three times a day after a meal or brushing. Tablets stayed in the mouth for 3 to 5 minutes. Eight hours after two minutes mouth rinse with egg yolk immunoglobulin, active antibodies detected in the saliva from 18 of 19 subjects. The subjects in the control group took placebo tablets containing non-immunized egg yolk antibodies in the same manner.

Intervention type



Drug names

Primary outcome measure

Periodontal tissue conditions

Measured at baseline, 4 weeks and 12 weeks.

Secondary outcome measures

Periodontopathic bacterial number

Measured at baseline, 4 weeks and 12 weeks.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. At least 2 sites of peridontal disease

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Less than 20 teeth
2. Taking medicine
3. Systematic disease
4. Food allergy
5. Need dental treatment

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Nihon University School of Dentistry
1-8-13 Kanda-Surugadai, Chiyoda-ku

Sponsor information


Nihon University School of Dentistry

Sponsor details

1-8-13 Kanda-Surugadai

Sponsor type




Funder type


Funder name

Sato Fund, Nihon University School of Dentistry (Japan)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

Ministry of Education, Culture, Sports, Science and Technology-Japan

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Intention to publish date

Participant level data

Available on request

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes