Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT01712672 |
| Other study ID # |
130014 |
| Secondary ID |
13-D-0014 |
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
January 16, 2013 |
Study information
| Verified date |
October 4, 2023 |
| Source |
National Institutes of Health Clinical Center (CC) |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Background:
- Dental plaque is a coating of bacteria on the teeth. It contributes to poor dental health
and diseases such as gingivitis, cavities and periodontal disease. Researchers who study
plaque know that many different types of oral bacteria stick to each other in test-tube
experiments. However, it is not clear if these interactions occur in natural dental plaque.
By studying how bacteria interact, researchers can better understand how bacteria come
together and grow to form plaque.
Objectives:
- To look at how bacteria interact with one another to form dental plaque.
Eligibility:
- Healthy nonsmoking volunteers at least 18 years of age.
Design:
- Participants will be screened with a medical history and dental exam. They will also
have dental impressions taken for a stent (a device similar to Invisalign(SqrRoot)
braces).
- Participants will wear the stent for up to 8 hours a day on selected study visit days.
It will contain enamel chips made from sterilized human teeth. The mouth bacteria will
stick to the chips and grow. Chips will be taken out of the stent twice during these
study visit days.
- Participants will have other study visits to provide saliva and plaque samples. They
will also have gum swabs to collect bacteria.
- Some participants may have a second set of study visits. At these visits, they will chew
gum to increase their saliva production. Afterwards, they will wear the stent with the
enamel chips for 4 hours. Samples from the stent will be taken once on these study visit
days.
Description:
Dental caries and periodontal disease are closely associated with the oral biofilm known as
dental plaque. Much is known about the makeup of this biofilm, especially at its early stage
of development (i.e. up to 12 hrs following tooth cleaning). The primary initial colonizers
are streptococci, and actinomyces. These bacteria coaggregate frequently with one another by
a mechanism that involves binding of protein adhesins on the surface of one cell to
complementary cell surface receptor polysaccharides (RPS) on streptococci.
Coaggregation profiles are known for a wide range of oral actinomyces and streptococci.
However, despite the potential significance of these interactions in biofilm formation,
little is known about their occurrence within oral biofilms in situ.
Objective
The objective of this study is to determine and compare the influence of coaggregation on the
spatial organization of bacteria in supragingival dental plaque formed under conditions of
normal salivary flow (Arm 1 of the protocol) or increased salivary flow (Arm 2 of the
protocol).
Study Population
The study population will consist of up to twenty-five (25) healthy adult subjects 18 years
of age and older. All subjects will participate in Arm 1 of the protocol. In addition, at
least three volunteers from Arm 1 will participate in Arm 2 of the protocol.
Study Design
This will be an observational, longitudinal protocol to determine the spatial organization of
bacteria found within dental plaque of normal healthy subjects. Enrolled subjects will have a
standard oral examination (including oral cancer screening) performed in the NIDCR clinic by
protocol-listed dental clinicians. A mandibular stent will be custom fabricated based on
impressions taken during the exam. Enamel chips cut from previously extracted third molars
will be sterilized by ethylene oxide then inserted into the stent on each side over the molar
area. We currently have enough extracted third molars in storage to accommodate tooth chips
for the entire protocol if four subjects complete the study as projected. If additional chips
are needed, the NIDCR is currently in the process of preparing a protocol that will provide
extracted teeth, if needed, for this and other protocols. In Arm 1 of the study, a
custom-fitted stent will be worn in the mouth of each subject, and chips removed for analysis
after 4 or 8 hours of wearing. The bacterial biofilm on the chips will be stained with
fluorescent antibodies against specific microbial adhesins or receptors, after which the
spatial organization of labeled cells within the biofilm will be documented by laser confocal
microscopy. Chips may be used for bacterial isolation and subjects will be asked to provide
saliva samples, and site-specific plaque samples (curette scrapings, gum swabs) for molecular
taxonomic analysis. Decisions on which subjects will have these samples taken will be based
on the reactivity of available antibodies with bacterial communities. Subjects from Arm 1 of
the study who are chosen to participate in Arm 2, will chew a gum base for 10 minutes to
increase salivary flow while wearing their stent. The stent from these individuals will be
removed after 4 hours of additional wear and analyzed as above. Prior to participation in Arm
2 of the protocol, subjects will be advised that the experiments are supported by a CRADA
agreement. Through this agreement, only coded research information will be exchanged. The
samples will remain with the NIH research team. Individuals may participate in the first arm
only, or in both arms of the study, as indicated in their consent document.
Outcome Measures
Outcome measures for this protocol will be the qualitative and quantitative description of
the oral bacterial community during development of initial plaque.
