Bacteria of periodontits powerpointPresentation Transcript
Many people get Periodontitis and
Periodontal Disease confused. They
think they are the same thing, but they
are not. They are not interchangeable.
Periodontal Disease is inflammation of
the periodontium. Periodontal Disease
that involves all the structures of the
periodontium is called periodontitis.
Periodontitis is a form of periodontal
-bacterial infection of all parts of the periodontium
including the gingiva, periodontal ligament, bone
-The tissue damage that occurs in periodontitis
results in irreversible destruction of tissues of the
-chronic inflammation due to bacteria filled plaque.
-destruction of the alveolar bone and periodontal
-apical migration of the junctional epithelium
causing periodontal pockets
-gums and bones pull away from
teeth causing large pockets.
Debris and bacteria collect in
there and causes infections
Structures that hold the teeth
together wear down
-causes loss and exfoliation of
- Not a continuous process but occurs in
an intermittent matter with extended
periods or disease inactivity followed
by short periods of destruction.
Destruction is site specific, it does not
occur in all parts of the mouth
Signs and Symptoms:
Gums can be bright red, inflamed, or
Dental plaque forms on teeth - this is a pale-yellow biofilm
that develops naturally on teeth. It is formed by bacteria that try
to attach themselves to the tooth's smooth surface.
If it is not removed, within two or three days it hardens
into calculus. It is much harder to remove than plaque.
Plaque can gradually and progressively damage teeth and
surrounding tissue. At first, the patient may develop gingivitis -
inflammation of the gum around the base of the teeth.
Persistent gingivitis can result in pockets developing
between the teeth and gums. These pockets fill up with bacteria.
Bacterial toxins and our immune system's response to
infection start destroying the bone and connective tissue that
hold teeth in place. Eventually the teeth start becoming
loose, and can even fall out.
Bacteria are microorganisms too small to
see with the naked eye that exists in
virtually all environments in the world.
They exist in dirt, water, caves and hot
springs, organic materials like fallen
trees and dead animals, and inside the
bodies of virtually every living animal on
Bacteria comes in three main shapes:
Spherical (like a ball)
These are usually the simplest ones. Bacteria shaped like
this are called cocci (singular coccus).
These are known as bacilli (singular bacillus).
Some of the rod-shaped bacteria are curved; these are
known as vibrio.
These known are as spirilla (singular spirillus).
If their coil is very tight they are known as spirochetes.
BIOFilm is a living, organized community of
bacteria that grows on a surface. One of
the main advantages to bacteria to form
biofilm is protection. It is harder to kill just
by adding antimicrobial substances without
first breaking through biofilm attachments.
Plaque is a biofilm, and is therefore difficult
to control. This is the reason flossing and
brushing twice a day is so important,
because it helps to break up biofilm
There are 5 phases to the development of
Dental Plaque Biofilm.
Phase 1 – Film Coating
Acquired pellicle – the purpose of this
coating is to protect enamel, however it
changes the electric charge of the
tooth, which allows for easier bacterial
Phase 2 – Initial Attachment of Bacteria to
Hours after Pellicle is formed, bacteria
attach themselves using structures such as
fimbriae to the pellicle.
Phase 3 – New Bacteria join
After initial attachment, bacteria send
chemical signals to other bacteria to
help form community.
Phase 4 – Extracellular Slime Layer and
› Extracellular Slime layer
The bacteria attached to the tooth surface are
stimulated to excrete slime, which anchors the bacteria
and provides protection.
› Microcolony Formation – once the tooth has been
covered with attached bacteria, the growth of the
biofilm occurs through the cellular division of the
adherent bacteria. That means that the growth of
the biolfilm is from the bacteria that’s already
there, not new bacteria joining the gang.
› Bacterial Blooms – periods when specific species or
groups of species grow at accelerated rates.
Phase 5 – Mature Biofilm – now the
bacteria form mushroom shaped
microcolonies. This allows different
colonies to attach to each other.
After Phase 5, parts of the biofilm can
break off, and travel to other places to
form new colonies.
-Periodontitis is associated with an
enormous number of Gram Negative
-The number of bacteria in Periodontitis
that can be cultured from an individual
tooth surface ranges from 100,000 to 100
-Gram Negative rods compromise about
74% of the bacteria associated with
-Chronic periodontitis is associated with
high proportions of gram negative and
-Bacteria composition of periodontitis
differs significantly from patient to
patient and site to site within the same
actinonmycetemcomitans -is an
microorgranism that is strongly
associated with periodontitis. It is
capable of invading normal hosts in
immune response and of destroying
gingival connective tissue and bone. It
secretes a protein toxin, leukotoxin
(LtxA), which evades the host immune
response during infection.
Tannerella forsythia –It has been
determined by researchers to be the
most significant microbial risk factor
that distinguishes subject with
periodontitis from those who are
periodontally healthy. The risk of
periodontal attachment loss is higher in
adolescents who are colonized with this
bacteria than in those whom the species
is not detected.
Porphyromonas gingivalis- Is commonly
seen in sites that exhibit recurrence of
disease or persistence of deep
periodontal pockets after periodontal
therapy. The species has been shown to
induce elevated host response in
subjects with various forms of
Streptococcus intermedius- contributes to
the formation of biofilms that act as a
protective layer against antibiotics in
Campylobacter rectus- it induces bone
loss. It is gram negative and anaerobic.
Can cause oral absesses.
Eubacterium nodatum- anaerobic, gram
positive rod shaped bacteria that is more
present in people who have moderate to
severe periodontitis. They live and multiply
close together on a tooth surface.
Fusobacterium nucleatum-is a bacteria that is
commonly found in plaque of the mouth. It is a
key component of plaque due to its abundance
and its ability to closely live together with
other species in the oral cavity. The cells are
rods and spindle-shaped of many different
lengths. This bacteria has been shown to play
a central role in plaque formation and
periodontitis due to its ability to adhere to a
wide range of both Gram-positive and Gram-
negative plaque microorganisms. It is very
much associated with periodontitis, along with
invasive human infections of the head and
neck, chest, lung, liver and abdomen. It acts as
a bridge between early and late colonizers on
surfaces of teeth.
Fusobacterium nucleatum, subspecies
polymorphyum- acts as an intermediate
between early and late colonizers in the
oral cavity. It binds to any salivary
component. A rod-shaped bacterium in
which the cell is thicker in the center
and tapers toward the ends.
Prevotella intermedia- are
anaerobic, non-spore forming, gram-
negative rods that live in the periodontal
pockets in between the teeth where they
co-exist with other microbes.
Peptosteptococcus micros- anaerobic
gram positive non spore forming
bacteria found supra-gingivally
Prevotella nigrescens- located in
subgingival plaque of patients with
periodontitis. Gram negative. Aids in
attachment loss and irregular bone loss.
Prevotella nigrescens- located in subgingival
plaque of patients with periodontitis. Gram
negative. Aids in attachment loss and irregular
Treponella denticola- Gram negative
anaerobic. Considered one of the main agents
for periodontitis. Forms within plaque.
Destruction of surrounding tissue and alveolar
Foundations of Periodontics for the Dental
Hygienist Text Book by Jill S. Nield-Gehrig and
Donald E. Willmann Third Edition