Lecture Notes on Gingivitis and Periodontitis

Overview

• Gingivitis: Inflammation of the gums (gingiva).
• Periodontitis: Inflammation and destruction of supporting structures around teeth.
• Both conditions exist on a spectrum from gingivitis to severe periodontitis.

Anatomy of a Tooth

• Mandible: Bone below the bottom row of teeth.
• Maxilla: Bone above the top row of teeth.
• Alveolus: Socket for each tooth, lined by periodontal ligament.
• Gingiva: Soft tissue covering alveolus, provides support.

Tooth Structure

1. Root: Sits within alveolus, covered by cementum (where periodontal ligaments attach).
2. Neck: Transition zone between root and crown.
3. Crown: Visible part of the tooth covered in enamel (hardest substance in the human body).
4. Free Gingiva: Portion of gingiva not anchored to the tooth.
5. Gingival Crevice: Space between free gingiva and crown, contains gingival crevicular fluid.

Gingival Crevicular Fluid

• Contains immune proteins and cells (neutrophils, complement proteins, antibodies).

Oral Microbiome

• Healthy mouth has a balance of commensal bacteria.
• Dysbiosis: Imbalance leads to increased pathogenic bacteria.
• Dental Plaque Formation: Bacteria, saliva proteins, and dead cells create biofilm.

Biofilm vs. Microcolony

• Microcolony: Small group of bacteria working independently.
• Biofilm: Complex system with communication and specialized tasks among bacteria.

Progression of Gum Disease

• Plaque Buildup: Hard to brush away, can invade gingiva.
• Dental Calculus: Hard mass formed from plaque, facilitating bacterial growth.
• Gingivitis Symptoms: Redness, swelling, and bleeding.
• Reversibility: Gingivitis is reversible with treatment.

Periodontitis Details

• Orange Complex Bacteria: Initial step in periodontitis (e.g., Fusobacterium nucleatum, Prevotella intermedia).
• Red Complex Bacteria: Later stage (e.g., Porphyromonas gingivalis).
• Immune Response: Dilation of blood vessels, recruitment of immune cells, cytokine release.

Damage Mechanisms

• Increased blood flow provides nutrients for bacteria.
• Positive feedback loop between bacteria and immune response.
• Osteoclast Activation: Leads to bone loss supporting the tooth.

Diagnosis

• Signs include swollen/bleeding gums and probing gingival sulcus.
• X-rays to evaluate bone level.

Treatment Options

• Prevention: Daily brushing and flossing, antimicrobial mouthwashes.
• Severe Cases: May require antibiotics or surgery.

Recap

• Gingivitis leads to periodontitis if untreated.
• Diagnosis involves visual inspection, probing, and x-rays.
• Treatment may include tissue removal, antibiotics, and surgery.