Acute Periodontal Problems

The majority of periodontal abscesses occur in a pre-existing periodontal pocket. If the pocket is occluded, then infectious materials within the pocket can accumulate and the build-up of a purulent discharge can result in the formation of the clinical signs and symptoms of a periodontal abscess. Occlusion of pockets can be caused by the impaction of a foreign body such as a seed lodged within the gingival sulcus. 

Drainage of a pocket may also be blocked following healing of the coronal gingival tissues, while debris and bacteria remain at the base of a deep pocket. This may be evident when a patient has had a "scale and clean", without adequate instrumentation to clean the base of a deep periodontal pocket or a furcation area. Periodontal abscesses can also arise following secondary infection of lateral periodontal cysts or as a result of` trauma to the periodontium, for example perforation of a root canal. 

Compromised host immune response may predispose a patient to the formation of periodontal abscesses. The presence of multiple periodontal abscesses is typically seen in poorly controlled diabetic patients. Examination of the microbial factors involved in the formation of acute periodontal abscesses has revealed the predominance of` gram negative anaerobic rods , and the presence of fungi resembling Candida species (assumed to be secondary invaders in the area of pre-existing infection). 

Factors influencing microbial virulence may trigger the formation of a periodontal abscess. One of the most common of these is the formation of resistant bacterial species following the use of systemic antibiotics. Bacterial samples, taken from patients with multiple periodontal abscesses which developed 1-3 weeks after penicillin or tetracycline therapy,revealed the presence of` resistant strains to antibiotics in 55 percent of samples.

The most common symptom of a periodontal abscess is pain. The tissues surrounding the painful tooth or teeth are usually swollen, varying from a small localised enlargement to diffuse swelling involving the gingival, alveolar mucosa and oral mucosa. The tissues often appear to be red or a deep red-blue in colour. Facial or neck cellulitis are rare, although lymphadenopathy and fever may be present. 

The affected tooth, and often the adjacent teeth, are usually tender to bite on and sensitive to clinical percussion. The tooth is usually mobile and high in the occlusion. Periodontal probing usually reveals the presence of a deep pocket, through which a purulent discharge can be drained. There may also be evidence of a sinus tract draining the abscess.

Radiographs are often useful in confirming the diagnosis, revealing the presence of a radiolucent area along the lateral aspect of the tooth involved. However, if the abscess is located on the buccal or palatal aspects of the tooth, then no radiographic evidence may be detected.

The signs and symptoms of a periodontal abscess - pain, swelling, colour changes, formation of pus, extrusion of the tooth and radiolucency - are not always present, nor are they unique to a periodontal abscess. Other conditions that may cause similar signs to those observed with periodontal abscess are: 

• Periapical abscess: this occurs in the presence of a pulpless infected root canal, and hence the response to pulp vitality testing will be negative. It is worth remembering, however, that the status of`the pulp may be difficult to ascertain if the patient is in severe pain, and has taken analgesics in an attempt to dull the pain.
• Acute pulpitis: this lacks most of the signs and symptoms of a periodontal abscess, except pain. The pain is diffuse, and can be affected by thermal changes.
• Tooth or root fracture: inflammation, pocketing and/or suppuration may be the presenting signs of a vertical root fracture. The presence of a narrow pocket along the root of a root-filled tooth may indicate a root fracture.
• Pericoronitis: this is an acute infection occurring around the crown of a partially erupted tooth.
• Periodontal cyst: a periodontal cyst appears radiographically as a well defined oval radiolucency on the lateral surf`ace of a root. It most commonly occurs in the mandibular canine-premnolar region. The cyst can become infected, and develop into a periodontal abscess.

Once a periodontal abscess has been diagnosed, emergency treatment needs to be provided to resolve the infection. Drainage is usually achieved through the pocket as part of the root planing procedure to clean the plaque and calculus deposits from the root surfaces. After adequate anaesthesia has been achieved, drainage can be started by inserting a sharp curette to the base of the abscess.

Antibiotics are only indicated if systemic symptoms are present, or if the patient is medically compromised. The patient should be advised to use a chlorhexidine mouthwash. Review appointments should be scheduled after 2-4 days, and then after one week, to monitor the resolution of the abscess.

If the root surface has been difficult to debride due to the presence of anatomical features such as furcations or deep grooves, periodontal surgery may be required in order to minimise the risk of recurrence of the abscess.

Although it is accepted that bacteria play a causative role in the aetiology of ANUG, the specific aetiology is yet to be established. The role of the immune response in the pathogenesis of ANUG has received some attention ,with research indicating that the neutrophil may play an important role. More recently, it has been suggested that ANUG shares many features with super-antigen related staphylococcal; streptococcal infections.

There are a number of predisposing factors that appear to precipitate the onset of the disease. These include:

Local factors

• poor oral hygiene
• plaque retentive factors such as overhangs, crowded teeth and calculus
• cigarette smoking

Systemic factors

• emotional stress
• poor nutrition
• hormonal imbalance
• systemic diseases affecting immune responsiveness

The clinical features of ANUG characteristically include necrosis of the crest of the marginal gingival tissues, usually commencing at the interdental papillae. The destruction of tissue is rapid, and is associated with spontaneous bleeding, halitosis and pain. It is usually self-limiting, but it may spread laterally and apically to involve the entire gingival complex.

It is sometimes seen in recurrent forms. The gingival alteration seen in ANUG is characterised by punched-out and cratered depression in the interdental sites, with the surfaces of the lesions covered with a grey or greyish-yellow pseudomembrane. Patients often comment on having a "metallic" taste. In severe cases, there can be systemic symptoms including high fever, malaise and lymphadenopathy.

The diagnosis of ANUG is usually straight forward, given its characteristic presentation. However, there are several other oral mucosal lesions that may be confused with ANUG. These include acute herpetic gingivostomatitis, desquamative gingivitis, HIV- related periodontitis, streptococcal gingivostomatitis, advanced marginal gingivitis, apthous stomatitis, acute leukaemia, and dermatoses (including pemphigus, benign mucous membrane pemphigoid, lichen planus and erythema multiforme).

Due to the pain associated with ANUG, emergency treatment can sometimes pose a challenge. However, the principles of management of any infection still hold - that is, it is important to remove bacteria and local factors. This can be achieved by anaesthetising the area, and gently debriding the supra- and subgingival surfaces with ultrasonic and hand instruments. The patient should be instructed to use a chlorhexidine mouthwash, and the adjunctive use of antibiotics (Metronidazole 200mg tid for 5 days; or Tinidazole 2g stat) is usually recommended.

Healing should be checked after one week, and additional cleaning and oral hygiene instruction provided at that visit. Depending on the amount of soft tissue damage caused by the infection, gingivoplasty may be required in order to recontour the gingival defects.