Kingdom of Saudi Arabia
King Khalid University
College of Dentistry
Dr. Sultan Mohammed Kaleem
Bacterial Infection Affecting Teeth
Faisal Moteq Al-Qhtani 431803127
A bacterial oral infection is when bacteria invade the oral cavity
(mouth) and cause infection (the harmful growth of
Most bacteria in the body are harmless or even helpful. However,
some do cause disease and produce pathogens in the body that
make you sick.
The most common bacterial oral infections are gingivitis and
periodontitis. Dental plaque, also called plaque biofilm, is teeming
with bacteria. Some of the bacteria is good and necessary for
health. Others are associated with gum disease. The type and the
virulence of the bacteria change and multiple the longer they are
in the mouth. When the bad bacteria outnumber the good,
disease begins - gingivitis and periodontitis. Because of the biofilm
nature of the plaque, systemic antibiotics are not a good choice
for treating gingivitis and/or periodontitis.
In many cases, a deep cleaning followed by good daily oral
hygiene helps clear up the infection and restore gum health. A
visit with your dental professional can help determine the right
If untreated, a bacterial infection can spread to the bloodstream.
This condition is called bacteremia.
A dental abscess, or tooth abscess, is an accumulation of pus that
forms inside the teeth or gums. The abscess typically originates from
a bacterial infection, often one that has accumulated in the soft pulp
of the tooth.
Bacteria exist in plaque, a by-product of food, saliva and bacteria in
the mouth which sticks to the teeth and damages them, as well as
the gums. If the plaque is not removed by regular and proper tooth
brushing and flossing the bacteria may spread within the soft tissue
inside the tooth or gums, eventually resulting in an abscess.
The main types of dental abscess are:
Periapical abscess: The result of a chronic, localized infection
located at the tip, or apex, of the root of a tooth .
Periodontal abscess: begin in a periodontal pocket .
Gingival abscess: involving only the gum tissue, without affecting
either the tooth or the periodontal ligament .
Pericoronal abscess: involving the soft tissues surrounding the
crown of a tooth.
Combined periodontic-endodontic abscess: a situation in which a
Periapical abscess and a periodontal abscess have combined .
o Periapical abscess :
Bacteria enter the tooth through tiny holes caused by tooth decay (caries)
that form in the tooth enamel (hard outer layer of the tooth). The caries
eventually break down the softer layer of tissue under the enamel, called
dentine. If the decay continues, the hole will eventually penetrate the soft
inner pulp of the tooth - infection of the pulp is called pulpitis. As the pulpitis
progresses the bacteria make their way to the bone that surrounds and
supports the tooth, called the alveolar bone, and a Periapical abscess is
o Periodontal abscess :
When bacteria which are present in plaque infect the gums the patient has
periodontitis. The gums become inflamed, which can make the periodontal
ligament separate from the base of the tooth. A periodontal pocket, a tiny
gap, is formed when the periodontal ligament separates from the root. The
pocket gets dirty easily and is very hard to keep clean. As bacteria build up in
the periodontal pocket, periodontal abscess is formed.
Mortality is rare and is usually due to airway compromise. Morbidity
relates to pain, probable tooth loss, and dehydration .
Race & Sex :
No race or sex predilection is observed.
- Dental abscess is rare in infants because abscesses do not form until
- In children, Periapical abscess is the most common type of dental
- In adults, periodontal abscess is more common than Periapical
Clinical Presentation :
The following may be reported in patients with dental abscess:
Localized pain and swelling ( may progress over a few hours to
days): Examples of swelling are shown in the following images.
Obvious swelling of the right cheek due to dental abscess.
Side view. Fluctuant mass extending toward the buccal side
of the gum end to the gingival-buccal reflection.
Gingiva with swelling and Erythema.
Thermal sensitivity (Periapical abscess) : This is thought to occur
secondary to exposure of the dentine to the external environment
as a result of enamel loss or gingival recession.
Gingival bleeding (on occasion with periodontal abscess) .
Decreased intake of fluid, food, or both .
CT scan showing a large tooth abscess (right in
the image) with significant inflammation of fatty
tissue under the skin
the maxillary right second premolar (upper
right 2nd bicuspid), after extraction.
Physical Examination :
o Swelling .
o Warmth .
o Erythema .
o Fluctuant mass that usually extends toward the buccal side of the
gum and to the gingival-buccal reflection.
o Parulis or "gum boil" (a soft, solitary, reddish papule located facial
and apical to a chronically abscessed tooth that occurs at the
endpoint of a draining dental sinus tract) .
The tooth that is most frequently involved is the lower third molar,
followed by other lower posterior teeth; upper posterior teeth are
involved much less frequently, and anterior teeth are rarely
o Increased mobility (mostly Periapical abscess).
o Pressure or percussion tenderness (mostly Periapical abscess).
Regional lymph node involvement .
More severe infection :
o Trismus, indicating involvement of the masticator space .
o Difficulty swallowing (dysphagia) .
o Respiratory difficulty.
o Necrotizing fasciitis .
Neck or facial swelling .
Signs of dehydration .
Diagnostic approach :
A periodontal abscess may be difficult to distinguish from a Periapical
abscess. Indeed sometimes they can occur together. Since the
management of a periodontal abscess is different from a Periapical
abscess, this differentiation is important to make. The following factors
may help to this:
If the swelling is over the area of the root apex, it is more likely to be a
Periapical abscess; if it is closer to the gingival margin, it is more likely to be a
Similarly, in a periodontal abscess pus most likely discharges via the
periodontal pocket, whereas a Periapical abscess generally drains via a
parulis nearer to the apex of the involved tooth.
If the tooth has pre-existing periodontal disease, with pockets and loss of
alveolar bone height, it is more likely to be a periodontal abscess; whereas if
the tooth with relatively healthy periodontal condition, it is more likely to be
a Periapical abscess.
In periodontal abscesses, the swelling usually precedes the pain, and in
Periapical abscesses, the pain usually precedes the swelling.
A history of toothache with sensitivity to hot and cold suggests previous
pulpitis , and indicates that a Periapical abscess is more likely.
If the tooth which gives normal results on pulp sensibility testing, is free of
dental caries and has no large restorations; it is more likely to be a
A dental radiograph is of little help in the early stages of an dental abscess,
but later usually the position of the abscess, and hence indication of
endodontal/periodontal etiology determined. If there is a sinus, a gutta
percha point is sometimes inserted before the x-ray in the hope that it will
point to the origin of the infection.
Generally, periodontal abscesses will be more tender to lateral percussion
than to vertical, and Periapical abscesses will be more tender to apical
Work up :
Laboratory Studies :
Uncomplicated (ie, simple) dental abscess : No laboratory studies are
Complicated abscess (accompanying cellulitis) :
The CBC count may reveal leukocytosis with neutrophil predominance.
Obtain a blood culture (aerobic and anaerobic) before initiating
Needle aspirate is indicated for Gram stain and aerobic and anaerobic
Imaging Studies :
Depending on severity of abscess based on clinical presentation the
following is recommended:
Periapical radiography is the first level of investigation. It provides a
localized view of the tooth and its supporting structures. Widening of
the periodontal ligament space or a poorly defined radiolucency may
Panoramic radiography (pantomography) is most helpful in
emergency situations because it provides the most information for all
teeth and supporting structures.
If cellulitis swelling extends beyond local area then the following is
Lateral and anteroposterior neck views to rule out a soft tissue neck
mass that impinges on the airway.
CT scanning with intravenous contrast is the most accurate method to
determine the location, size, extent, and relationship of the
inflammatory process to the surrounding vital structures.
Confirm presence of the abscess via needle aspiration.
If pus is obtained, do not aspirate more than 1-2 drops. Leave the
abscess as large as possible to make the area easier to find for
If pus cannot be aspirated, manage medically until a more localized
Incision and drainage may be performed only if pus can be aspirated.
Packing a periapical abscess is generally not necessary.
Histologic Findings :
The flora at different oral sites varies. The surface of the carious tooth
usually contains acid producing aerobic and anaerobic bacteria including
Streptococcus mutans, Lactobacillus acidophilus, and Actinomyces
viscosus. S mutans is the only organism recovered from decaying dental
fissures. Obligate anaerobes such as Propionibacterium, Eubacteria,
Arachnia, Lactobacillus, Bifidobacterium, and Actinomyces constitute
most organisms isolated from carious dentin. The bacteria isolated from
inflamed pulp and root canals are aerobic, facultative anaerobic and strict
anaerobic organisms, in addition to yeast.
Anaerobes usually outnumber aerobes and facultative anaerobes.
Most odontogenic infections involve plaque organisms.
Supragingival plaque mainly consists of gram-positive facultative
anaerobes or microaerophilic cocci and rods.
Subgingival plaque consists of anaerobic gram-negative rods with
motile form, including spirochetes.
Treatment & Management :
Medical Care :
In patients with dental abscess, assess the airway upon respiratory
distress, oropharyngeal tissue swelling, or inability to handle secretions;
then, secure the airway via endotracheal intubation or tracheostomy.
Properly collect specimen for Gram stain and aerobic and anaerobic
Administer empiric antibiotic therapy if necessary.
Hydrate the patient.
Surgical Care :
The primary therapeutic modality is surgical drainage of any pus
collection. A pulpectomy or incision and drainage is the recommended
management of a localized acute apical abscess in the permanent
dentition. Incision and drainage or spontaneous rupture of the abscess
quickly accelerates resolution of the infection. The addition of antibiotics
is not recommended for a localized dental abscess.
Emergent surgery is indicated in the operating room if the airway is
threatened or if the patient's condition is rapidly deteriorating.
Third molar removal is a common surgical procedure.
Consult a dentist if the patient has an uncomplicated abscess.
Consult a maxillofacial oral surgeon if the patient has a complicated
Diet is as tolerated. However, a soft bland diet is usually preferred.
Activity is as tolerated.
Penicillin (Pfizerpen, Pen-Vee K)
Traditionally been considered the DOC for the treatment of a dental
abscess. Antibiotic therapy alone, without surgical drainage, may not be
effective because of poor antibiotic penetration into the abscess cavity,
ineffectiveness at low pH levels, and the inoculum effect.
May be an option for the treatment of a dental abscess in patients who
are allergic to penicillin or beta-lactam.
Effective against obligate anaerobic organisms. It can be combined with
penicillin if anaerobic organisms that produce beta-lactamase enzymes
are a concern.
Can be used in patients who are penicillin or beta-lactam allergic.
Amoxicillin and clavulanate (Augmentin)
Amoxicillin works by binding to one or more of the penicillin-binding
proteins, which interferes with bacterial cell wall synthesis during active
Binds to one or more of the penicillin binding proteins, which interferes
with bacterial cell wall synthesis during active replication.
Further Inpatient Care :
Criteria for hospital admission in patients with dental abscesses include
the following :
Unable to handle secretions.
Involvement of facial spaces of head and neck.
Failure of outpatient therapy.
Need for intravenous (IV) hydration.
Further Outpatient Care :
Follow-up care should be obtained as recommended by a physician.
The most effective preventive measure against dental caries and,
thus, dentoalveolar abscess is fluoridation of communal drinking
water. In fluoride-deficient areas, prevention can be obtained with
dietary fluoride supplements.
The other effective preventive measure against dental caries and
dentoalveolar abscess is proper dental hygiene. This includes
brushing teeth after meals and regular dental check-ups.
Complications include the following:
Dentocutaneous fistulae arise from chronic dental infections
Acute suppurative osteomyelitis was common before the era of antibiotic
therapy. The mandible is more commonly involved than the maxilla because
the maxilla has a better blood supply.
Cavernous sinus thrombosis (CST) may be a complication. Approximately
10% of patients with CST have an odontogenic focus.
Ludwig angina is rapidly spreading cellulitis of the bilateral sublingual,
submandibular, and submental spaces. Abscesses of the second and third
mandibular molars account for 75% of cases.
Maxillary sinusitis may occur from direct extension of an odontogenic
infection or from perforation of the floor of the sinus during extraction.
Facial-space swelling secondary to spread of the infection , most often
involves the following areas:
o Submandibular swelling.
o Sublingual swelling .
o Buccal swelling
o Less frequently involved facial-space swellings include submental,
masticator, canine, lateral pharyngeal, and retropharyngeal.
Necrotizing fasciitis of the face or neck that results from an odontogenic
abscess is very rare.
The prognosis is excellent with proper incision, drainage, antibiotic . therapy, tooth
extraction, root canal therapy and follow-up care .
Patient Education :
Most dentoalveolar abscesses are preventable.
Inquire if drinking water is fluorinated. If not, counsel parents about fluoride
Instruct patients about proper dental hygiene, including brushing teeth after
meals, flossing, and regular dental check-ups.