13.2 Periodontal Disease

Clinical significance of the gingiva

Improper eating or insufficient oral hygiene can lead to many gum disorders, including gingivitis and periodontitis, which is a major cause of tooth failure. Gingival recession involves an apical retraction of the gingival margin away from the biting (occlusal) surface. It may result from periodontitis or from forceful displacement of the marginal gingiva away from the tooth (harsh brushing or flossing). Gingival retraction exposes the dental neck causing root sensitivity, increasing the risk of caries in the dental root and reducing the area of attachment of the tooth.

Periodontal disease

This is actually not one but a set of inflammatory diseases affecting the tissues that surround the tooth. It involves progressive loss of the alveolar bone around the teeth. If left untreated, it can lead to loosening and subsequent loss of teeth.

Periodontal disease is caused by microorganisms that adhere to the tooth's surfaces along with an over-aggressive immune response against these microorganisms. A diagnosis is reached through inspection the gingivae and radiographs to determine the amount of bone loss around the teeth.

Classification

The 1999 classification system for periodontal diseases listed seven categories:

1. Gingivitis. Irritation and inflamation of the gingiva.

2. Chronic periodontitis. Inflammation with slow detachment from tooth and bone loss.

3. Aggressive periodontitis. Inflammation with rapid detachment from tooth and bone loss.

4. Periodontitis as a manifestation of systemic disease. Gingival inflammation caused by conditions of the heart, respiratory system or diabetes.

5. Necrotizing ulcerative gingivitis/periodontitis. Death of gingival tissues, periodontal ligament and alveolar bone, usually linked to systemic diseases.

6. Abscesses of the periodontium

7. Combined periodontic-endodontic lesions

The severity of disease is assessed with base on the amount of gingival retraction and depth of the gingival sulcus. These determine the area of tooth surface over which periodontal ligament fibers have been lost. The disease can be:

• Mild: 1–2 mm of attachment loss

• Moderate: 3–4 mm of attachment loss 

• Severe: ≥ 5 mm of attachment loss 

Signs and symptoms

Symptoms may include:

• Redness or bleeding of gums while brushing teeth, using dental floss or biting into hard food (e.g., apples.

• Gum swelling that recurs

• Halitosis (bad breath) or a persistent metallic taste in the mouth

• Gingival recession

• Deep pockets between the teeth and the gums

• Loose teeth

Gingival inflammation and bone loss are largely painless, so people may underestimate the importance of the symptoms of periodontitis and allow the condition to develop to an advanced stage before seeking treatment.

Causes

The primary cause of periodontal disease is poor or ineffective oral hygiene, which leads to the accumulation of a mycotic and bacterial matrix at the gum line, called dental plaque. Other contributors are poor nutrition and underlying medical issues such as diabetes. Smoking also increases the occurrence of periodontitis and may hinder its treatment. Genetic predisposition also influences the risk of a person developing the disease.

Progression

As dental plaque accumulates on the tooth near and below the gums, its microbial composition changes from a dominance by Streptococcus to a dominance by Actinomyces. The gingiva becomes irritated and inflamed, a condition called gingivitis. A person can have gingivitis for years and the condition may not progress. When the microorganisms in plaque start attacking the periodontal ligament, the condition changes to periodontitis. The gingiva tends to bleed and a predominantly gram-negative bacterial flora is established.

If left undisturbed, microbial plaque calcifies to form calculus (tartar). Calculus must be removed to prevent damage to the gingival fibers, which is when gingivitis develops into periodontitis. The gingiva progressively separates from the tooth. This widens the gingival sulcus which becomes a deep periodontal pocket. Microorganisms colonize the periodontal pockets and cause further inflammation in the gum tissues with progressive bone loss.

Prevention

Oral hygiene measures to prevent periodontal disease include:

• Brushing and flossing properly to physically remove bacteria and fungi.

• Using an antiseptic Chlorhexidine gluconate-based mouthwash.

• Regular dental check-ups and professional teeth cleaning.

Dental hygienists and dentists use special instruments to remove plaque beyond the reach of toothbrushes and floss. After professional cleaning, microbial plaque growth tends regress. The patient's daily oral hygiene routine is complementary, however, to professional cleaning.

Treatment

Periodontal treatment starts with establishing a routine of brushing twice a day and flossing once. Removal of microbial plaque and calculus may involve mechanical cleaning below the gumline in a procedure called scaling and root planing. This may require multiple visits and local anesthesia.

Nonsurgical scaling and root planing are usually successful if the periodontal pockets are shallower than 4-5 mm (0.16–0.20 in). The need for further treatment is determined through monitoring of gingival inflammation. Pocket depths greater than 5-6 mm (0.20–0.24 in) with bleeding upon probing indicate an active disease with further bone loss over time.

Surgery may be needed to stop progressive bone loss and regenerate lost bone. The goal is complete calculus removal and correction of bony irregularities which have resulted from the disease process to reduce pockets as much as possible. In flap surgery, the gum is detached from the tooth for complete removal of tartar. Sutures are used to position the gum back into place until the tissue reattaches to the tooth. In more advanced cases, bone and tissue grafts may be required. These involve the placement of synthetic or natural tissues in the area of tissue loss. The transferred material is taken from another part of the patients body.

Other animals

Periodontal disease is the most common disease found in dogs. It affects more than 80% of dogs aged three years or older. Its prevalence increases with age, but it is less common in large than in small animals. Systemic disease may develop because the gums are very vascular (have a good blood supply). The blood stream transports these anaerobic micro-organisms to the kidneys and liver, the organs that are most commonly damaged. They may also attack the heart valves and lungs.

Gingival recession

It is the exposure in the roots of the teeth caused by a loss of gum tissue and/or retraction of the gingival margin from the crown of the teeth.

The main causes are:

• Periodontal disease.

• Overaggressive brushing or flossing.

• Genetic predisposition through fragile or insufficient gingival tissue.

• Dipping tobacco, which weakens the mucous membrane lining in the mouth.

Gum recession is a common problem in adults over the age of 40, but it may also occur in adolescents or children. It occurs with or without a decrease in crown-to-root ratio, which indicates recession of the alveolar bone. In most cases, the condition progresses gradually over the years and patients tend not to notice the recession. It may remain undetected until severe symptoms start to occur.

Elimination of the cause of gingival recession is frequently enough to resolve it. In advanced cases, however, soft-tissue graft surgery may be used to create more gingiva. Depending on the extent and shape of the gum recession, it can be regenerated with new gum tissue using a variety of grafting procedures. These procedures are typically conducted under local anesthesia. The graft may be a:

• Pedicle graft. Repositioning of adjacent gum tissue to cover the recession.

• Free gingival graft. A thin layer of skin from the palatal gingiva.

• Subepithelial connective tissue graft. Tissue removed deeper in the palate.

• Acellular dermal matrix. Processed skin from a human donor.

Figure 9. Receded gingiva near maxillary lateral incisor, canine and first premolar before grafting (left), immediately after (middle) and at the end of the treatment (right). More details (left, center, right).

Healing from such procedures requires 2–4 weeks. The new tissue may need some adjustment for improved results. Nearly complete coverage of the recession area is achievable, especially in cases that do not involve alveolar bone loss.

Acute Necrotizing Ulcerative Gingivitis

Colloquially known as trench mouth, this is a common, non-contagious infection of the gums with sudden onset. The main features are painful bleeding gums and ulceration of inter-dental papillae. This disease normally develops from the non-acute form which has milder symptoms. The name "trench mouth" arose during World War I as many soldiers developed the disease, probably because of poor conditions and extreme psychological stress.

The cause is mostly anaerobic bacteria, including fusobacteria and spirochete species. Predisposing factors include poor oral hygiene, smoking, malnutrition, psychological stress and immunosuppression. When the attachments of the teeth to the bone are involved, the disease is called necrotizing ulcerative peritonitis. Treatment is by debridement (removal of dead and infected tissue) and antibiotics in the acute phase, and improving oral hygiene to prevent recurrence. Although the condition has a rapid onset and is debilitating, it can usually be resolved quickly without further complications.

Dental abscess

A dental abscess (dentoalveolar abscess, tooth abscess or root abscess), is a localized collection of pus associated with a tooth. The most common type of dental abscess is a periapical abscess and the second most common is a periodontal abscess.

Periapical abscess

It is usually caused by a bacterial infection in the soft, often dead, pulp of the tooth. The infection may derive from tooth decay, a broken tooth or extensive periodontal disease. A failed root canal treatment may also create an abscess.

A dental abscess usually produces increased pressure inside the pulp chamber, which leads to a continuous pain that may be described as extreme, sharp, or throbbing. The area may be swollen and sensitive to touch. Adding pressure or warmth on the tooth may induce extreme pain. Swelling may be present at either the base of the tooth, the gum, and/or the cheek. In some cases, a tooth abscess may perforate bone and start draining into the surrounding tissues creating local facial swelling. The closest lymph nodes in the neck may become swollen in response to the infection.

Treatment

Successful treatment of a dental abscess centers on the reduction and elimination of the offending organisms. If the tooth can be restored, root canal therapy is performed. Non-restorable teeth must be extracted and the infected tissues removed by curettage of all apical soft tissue. The infection is also treated with drainage and antibiotics.

If left untreated, a severe tooth abscess may become large enough to perforate the jaw bone and spread either internally or externally. External drainage may begin as a boil which bursts allowing pus to drain from the abscess intraorally (usually through the gum) or extraorally. Chronic drainage will allow an epithelial lining to form in this communication establishing a pus draining canal called fistula. Sometimes this type of drainage will relieve some of the painful symptoms associated with the pressure buit up in the pulp chamber.

Internal drainage is more dangerous as the growing infection affects the tissues surrounding it. The infection can cause severe complications requiring immediate hospitalization if it spreads into the mediastinum where it can affect vital organs such as the heart. Another complication is a risk of infection of the blood (septicemia), which is a life-threatening condition.

Periodontal abscess

A periodontal abscess (lateral abscess or parietal abscess) is a type of dental abscess that is localized within the tissues of the periodontium. It occurs alongside a living tooth, therefore the infection does not originate in a dead tooth, like in a periapical abscess. Periodontal abscesses are acute bacterial infections classified primarily by location.

A periodontal abscess most commonly occurs as a complication of advanced periodontal disease. An inflammatory response occurs if bacteria invade and multiply within the soft tissue of the gingival sulcus and periodontal pocket. A pus-filled abscess forms when the immune system responds and attempts to isolate the infection from spreading. Communication with the oral environment is usually maintained via the opening of the periodontal pocket.

The main symptom is pain, which can be deep and throbbing. The closest tooth may feel raised and prominent in the bite and it may become mobile due to destruction of the periodontal ligament and alveolar bone by the infection. When pus forms, the pressure increases, with increasing pain, until it spontaneously drains and relieves the pain. When pus drains into the mouth, a bad taste and smell are perceived. Usually drainage occurs via the periodontal pocket, or else the infection may spread into the surrounding tissues.

Periodontal abscesses may be difficult to distinguish from periapical abscesses. This distinction is important because while root canal therapy is the main component in the treatment of periapical abscess, it may be unnecessary in a periodontal abscess.

The treatment of a periodontal abscess involves pain relief and control of the infection through drainage and antibiotics. The pulp of the closest tooth is usually alive and the tooth can be maintained throughout the treatment. Sometimes the periodontal support is significantly compromised, however, and extraction or root canal therapy may be considered.

Summary

Peritoneal disease starts with gingivitis when microbes in the dental plaque irritate the gums. Without proper oral hygiene, the microbes can infect the gingival tissue and attack the fibers that attach it to the tooth causing gingival recession. They also attack the periodontal ligament, loosening the tooth. Exposure of the roots increase the risk of cavities on the tooth. If the pulp of the tooth is infected and the infection extends down to the roots, it can pass through the apical foramina and infect the gum tissue. The body responds with immune defenses and pus is produced in the area around the apex of the root, forming a dental abscess.

Key terms

Periodontitis, oral hygiene, bone loss, periodontal disease, gingivitis, necrotizing ulcerative gingivitis, necrotizing ulcerative peritonitis, trench mouth, dental abscess,

periapical abscess, periodontal abscess.

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