• MAP formula: Diastolic + 1/3 Pulse Pressure
• Pulse Pressure: Systolic – Diastolic
• Sphygmomanometer readings: Slightly higher than intra-arterial
• J Curve Phenomenon: Excessive BP lowering → adverse cardiac events
• Best drug for angina with HTN: Metoprolol
• Contraindicated in diabetic HTN: Thiazides
• ACEI side effect: Hyperkalemia
• Aliskiren: Direct renin antagonist

Zones of Periodontal Disease

Listgarten described four distinct zones that can be observed in periodontal lesions. These zones may blend with each other and may not be present in every case.

Zones of Periodontal Disease

1. Zone 1: Bacterial Zone

   • Description: This is the most superficial zone, consisting of a diverse array of bacteria.
   • Characteristics:
     • The bacterial zone is primarily composed of various microbial species, including both pathogenic and non-pathogenic bacteria.
     • This zone is critical in the initiation and progression of periodontal disease, as the presence of specific bacteria can trigger inflammatory responses in the host.

2. Zone 2: Neutrophil Rich Zone

   • Description: This zone contains numerous leukocytes, predominantly neutrophils.
   • Characteristics:
     • The neutrophil-rich zone is indicative of the body’s immune response to the bacterial invasion.
     • Neutrophils are the first line of defense and play a crucial role in phagocytosing bacteria and releasing inflammatory mediators.
     • The presence of a high number of neutrophils suggests an acute inflammatory response, which is common in active periodontal disease.

3. Zone 3: Necrotic Zone

   • Description: This zone consists of disintegrated tissue cells, fibrillar material, remnants of collagen fibers, and spirochetes.
   • Characteristics:
     • The necrotic zone reflects tissue destruction and is characterized by the presence of dead or dying cells.
     • Fibrillar material and remnants of collagen fibers indicate the breakdown of the extracellular matrix, which is essential for maintaining periodontal tissue integrity.
     • Spirochetes, which are associated with more aggressive forms of periodontal disease, can also be found in this zone, contributing to the necrotic process.

4. Zone 4: Zone of Spirochetal Infiltration

   • Description: This zone consists of well-preserved tissue that is infiltrated with large and medium spirochetes.
   • Characteristics:
     • The zone of spirochetal infiltration indicates a more chronic phase of periodontal disease, where spirochetes invade the connective tissue.
     • The presence of well-preserved tissue suggests that while spirochetes are present, the tissue has not yet undergone extensive necrosis.
     • This zone is significant as it highlights the role of spirochetes in the pathogenesis of periodontal disease, particularly in cases of necrotizing periodontal diseases.

• Scaling in 2 appointments within 24 hours
• Tongue brushing with 1% chlorhexidine gel
• 0.2% chlorhexidine rinse
• 1% chlorhexidine pocket irrigation

Oral Hygiene Tools

Toothbrush Bristle Diameter:

• Soft: 0.007" (0.2 mm)
• Medium: 0.012" (0.3 mm)
• Hard: 0.014" (0.4 mm)

Brushing Techniques:

• Roll: Modified Stillman
• Circular: Fones
• Vertical: Leonard
• Horizontal: Scrub

Scaling Instruments

• Gracey curettes: Only outer cutting edge
• Universal curettes: Both edges cutting
• Langer curettes: Gracey shank + Universal blade
• Best grasp: Modified pen grasp (tripod effect)
• Scaling angle: 45 – 90°

Ultrasonic Scaling

• Vibration frequency: 18,000 – 50,000 cycles/sec

Stroke Types

• Exploratory: Light feeling (with probes)
• Scaling: Short powerful pull
• Root planing: Moderate to light pull

• Junctional Epithelium: Attached to enamel via hemidesmosomes; to connective tissue via external basal lamina.
• Corneocyte Formation: Keratinohyalin granules disappear, forming filaggrin.
• Langerhans Cells: Suprabasal level; antigen-presenting with Birbeck granules.
• Keratinization: Oral epithelium is 0.2 – 0.3 mm thick; may be keratinized or parakeratinized.

Periodontal Medicaments

Periodontal diseases often require adjunctive therapies to traditional mechanical treatments such as scaling and root planing. Various medicaments have been developed to enhance the healing process and control infection in periodontal tissues.

1. Elyzol

• Composition:
  • Elyzol is an oil-based gel containing 25% metronidazole. It is formulated with glyceryl mono-oleate and sesame oil.
• Clinical Use:
  • Elyzol has been found to be equivalent to scaling and root planing in terms of effectiveness for treating periodontal disease.
  • However, no adjunctive effects beyond those achieved with mechanical debridement have been demonstrated.

2. Actisite

• Composition:

  • Actisite consists of tetracycline-containing fibers.
  • Each fiber has a diameter of 0.5 mm and contains 12.7 mg of tetracycline per 9 inches of fiber.

• Clinical Use:

  • The fibers are placed directly into periodontal pockets, where they release tetracycline over time, helping to reduce bacterial load and promote healing.

3. Arestin

• Composition:

  • Arestin contains minocycline, which is delivered as a biodegradable powder in a syringe.

• Clinical Use:

  • Arestin is indicated for the treatment of periodontal disease and is applied directly into periodontal pockets, where it provides localized antibiotic therapy.

4. Atridox

• Composition:

  • Atridox contains 10% doxycycline in a syringeable gel system that is biodegradable.

• Clinical Use:

  • The gel is injected into periodontal pockets, where it solidifies and releases doxycycline over time, aiding in the management of periodontal disease.

5. Dentamycin and Periocline

• Composition:

  • Both Dentamycin and Periocline contain 2% minocycline hydrochloride.

• Clinical Use:

  • These products are used similarly to other local delivery systems, providing localized antibiotic therapy to reduce bacterial infection in periodontal pockets.

6. Periochip

• Composition:

  • Periochip is a biodegradable chip that contains chlorhexidine.

• Clinical Use:

  • The chip is placed in the gingival crevice, where it releases chlorhexidine over time, providing antimicrobial action and helping to control periodontal disease.

Progression from Gingivitis to Periodontitis

The transition from gingivitis to periodontitis is a critical process in periodontal disease progression. This lecture will outline the key stages involved in this progression, highlighting the changes in microbial composition, host response, and tissue alterations.

Pathway of Progression

1. Establishment and Maturation of Supragingival Plaque:

   • The process begins with the formation of supragingival plaque, which is evident in gingivitis.
   • As this plaque matures, it becomes more complex and can lead to changes in the surrounding tissues.

2. Migration of Periodontopathogenic Bacteria:

   • When the microbial load overwhelms the local host immune response, pathogenic bacteria migrate subgingivally (below the gum line).
   • This migration establishes a subgingival niche that is conducive to the growth of periodontopathogenic bacteria.

Initial Lesion

• Timeline:
  • The initial lesion, characterized by subclinical gingivitis, appears approximately 2 to 4 days after the colonization of the gingival sulcus by bacteria.
• Clinical Manifestations:
  • Vasculitis: Inflammation of blood vessels in the gingival tissue.
  • Exudation of Serous Fluid: Increased flow of gingival crevicular fluid (GCF) from the gingival sulcus.
  • Increased PMN Migration: Polymorphonuclear neutrophils (PMNs) migrate into the sulcus in response to the inflammatory process.
  • Alteration of Junctional Epithelium: Changes occur at the base of the pocket, affecting the integrity of the junctional epithelium.
  • Collagen Dissolution: Perivascular collagen begins to dissolve, contributing to tissue breakdown.

Early Lesion

• Timeline:
  • The early lesion forms within 4 to 7 days after the initial lesion due to the continued accumulation of bacterial plaque.
• Characteristics:
  • Leukocyte Accumulation: There is a significant increase in leukocytes at the site of acute inflammation, indicating an ongoing immune response.
  • Cytopathic Alterations: Resident fibroblasts undergo cytopathic changes, affecting their function and viability.
  • Collagen Loss: Increased collagen loss occurs within the marginal gingiva, contributing to tissue destruction.
  • Proliferation of Basal Cells: The basal cells of the junctional epithelium proliferate in response to the inflammatory environment.