Anatomy and Structure of the Periodontium
The periodontium is located in the space between the tooth root cementum and the alveolar bone. Histologically, it is composed of dense fibrous connective tissue rich in cells (fibroblasts, cementoclasts), as well as collagen and elastic fibers.
The framework consists of thick bundles of collagen fibers whose orientation varies depending on the region. The primary fixation elements are Sharpey's fibers (transitional fibers): they emerge from the cementum, cross the periodontal space, and insert into the alveolar bone. A circular dental ligament surrounds the cervical region, featuring an exceptionally high concentration of these fibers.
Contents and Functions of the Periodontium
The periodontal tissue is richly vascularized and innervated. It contains:
- Blood vessels;
- Lymphatic vessels;
- Nerve fibers — forming diverse sensory nerve endings.
Due to this architecture, the periodontium performs the following functions:
- Mechanical — attaching the tooth to the jawbone;
- Cushioning (shock absorption) — buffering masticatory forces transmitted to the jawbone;
- Sensory — mediated by nerve fibers and specialized sensory endings.
Radiographic Appearance
On a normal dental radiograph, the periodontium appears as a uniform radiolucent (dark) line, 0.2–0.25 mm in width, that mirrors the contours of the root cementum and the alveolar socket.
During pathological processes, this appearance changes. For example, in chronic granulomatous periodontitis, widening of the periodontal ligament space or round/flame-shaped radiolucencies around the root apex may be observed.
Clinical Significance: Periodontitis
Inflammation of the periodontium is termed periodontitis. Apical periodontitis occurs when bacteria spread to the periodontium due to untreated or inadequately treated pulpitis; pulp breakdown products, microorganisms, and their toxins reach the apical periodontium and trigger inflammation.
- Acute apical periodontitis is characterized by constant pain that worsens with touching or biting on the affected tooth. The "elongated tooth" sensation is characteristic.
- Chronic granulomatous periodontitis may present with mild discomfort, periodic dull aching pain, and the formation of a sinus tract on the gingiva or skin.
- Marginal periodontitis features pain localized to the gingival margin.
The primary infectious pathogen is Aggregatibacter actinomycetemcomitans (identified in 25–30% of cases), along with other periodontal pathogens (Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia).
Principles of Periodontal Inflammation Management
Treatment objectives include eliminating microflora from macro- and micro-canals, resolving periodontal inflammation, and stimulating reparative processes in the periodontium and surrounding bone. Endodontic therapy involves mechanical and chemical cleaning of the root canal followed by obturation.
To ensure precise instrumentation, the working length of the tooth must be determined. The true canal length is calculated from a radiograph with an inserted instrument using the formula: K = (i × K₁)/i₁ (where i is the actual length of the instrument, K₁ is the radiographically measured canal length, and i₁ is the radiographically measured instrument length).
In acute normergic periodontitis, antibiotics are generally not prescribed. Their use is justified only in debilitated patients with sluggish inflammatory responses or in complicated cases accompanied by systemic intoxication.