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

Plain English Summary

Background and study aims
Smokers have worse gum disease and are more likely to lose teeth than non-smokers. When smokers stop smoking, the condition of their gums changes and become similar to a non-smoker. E-cigarettes contain nicotine and are gaining popularity, but we do not know what e-cigarettes do to the gums. We plan to study the gum condition of smokers with mild gum disease who stop smoking cigarettes for 2 weeks and use e-cigarettes instead. Gum disease can change the amount of certain chemicals in the blood, saliva and the fluid that collects in the crevice between the gum and the tooth. The amount of those chemicals changes when people stop smoking, but we do not know what happens to them when e-cigarettes are used.

Who can participate?
Smokers with mild gum disease who do not intend to quit smoking but would be prepared to substitute e-cigarettes instead of smoking for 2 weeks

What does the study involve?
We measure the gum condition of a group of smokers who do not intend to quit smoking. We also take blood from a vein in the arm, collect saliva and the fluid that collects in the crevice between the gum and the tooth. The smokers stop smoking cigarettes for 2 weeks and we provide e-cigarettes for them to use instead. After 2 weeks we measure the gum condition again and collect samples of blood, saliva and gum fluid again.

What are the possible benefits and risks of participating?
There are no particular benefits for people who take part except to try out e-cigarettes at no cost to themselves. There are also no particular risks except minor discomfort during the gum examination and during collection of blood.

Where is the study run from?
King's College London (UK)

When is the study starting and how long is it expected to run for?
November 2014 to July 2016

Who is funding the study?
King's College London (UK)

Who is the main contact?
Dr Veronica Booth

Trial website

Contact information



Primary contact

Dr Veronica Booth


Contact details

Floor 21
Guy's Tower Wing
Great Maze Pond
London Bridge
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Changes in the gingival condition and inflammatory mediators of smokers who substitute the use of e-cigarettes for their regular smoking habits.


Study hypothesis

There will be no change in the gingival condition of smokers after 2 weeks of substituting e-cigarette use for normal smoking habits.

Secondary objectives of the project are to compare the concentrations of inflammatory markers in the saliva, gingival crevicular fluid and the plasma after cigarette smoking and e-cigarette use.

Ethics approval

NRES Committee London - London Bridge, 23/01/2015, ref: 14/LO/2092

Study design

Single-centre longitudinal pilot study

Primary study design


Secondary study design

Longitudinal study

Trial setting


Trial type


Patient information sheet

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


Gingival inflammation


The study involves smokers with mild periodontal (gum) disease who do not intend to quit smoking but would be prepared to substitute e-cigarettes instead of smoking for 2 weeks. The aim would be to compare gum inflammation in the smokers when smoking cigarettes with their condition after using e-cigarettes for 2 weeks. Subjects would provide samples of saliva and the gingival crevicular fluid that collects in the crevice between the gums & and teeth (GCF) and also venous blood. Examining the biochemical markers of inflammation within blood, saliva & GCF would help to determine whether the substitution of e-cigarettes modifies the subjects' inflammatory response in mild periodontal disease.

Intervention type



Drug names

Primary outcome measure

The number of gingival sites bleeding after probing, measured at baseline and 2 weeks

Secondary outcome measures

1. The volume of gingival crevicular fluid, measured at baseline and 2 weeks
2. The concentration of biomarkers in plasma and gingival crevicular fluid, measured at baseline and 2 weeks

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Subjects must have at least 24 natural teeth, excluding third molars
2. Subjects must have smoked at least 5 cigarettes/day for at least 5 years
3. They will be systemically healthy individuals who have mild periodontal disease with no pocket depth over 5 mm at any site

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Subjects with any systemic condition known to exacerbate or modulate periodontal disease e.g., diabetes
2. Have taken antibiotics in the previous 3 months
3. Take any anti-inflammatory drugs regularly
4. Take other medication likely to affect the periodontal tissue e.g., calcium channel blocking drugs
5. Pregnant or nursing mothers
6. Patients with nut allergies will be excluded as the nicotine-containing fluid may contain traces of nuts

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

King's College London
Guy's & St Thomas's Hospital Floor 21 Tower Wing
United Kingdom

Sponsor information


King's College London (UK)

Sponsor details

Room 1.1
Hodgkin Building
Guy's Campus
London Bridge
United Kingdom

Sponsor type




Funder type


Funder name

Kings College London

Alternative name(s)

Funding Body Type

private sector organisation

Funding Body Subtype



United Kingdom

Results and Publications

Publication and dissemination plan

M.Clin Dent. project to be submitted by 31/07/2016

Intention to publish date


Participant level data

Not expected to be available

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes