• Attached Gingiva Width:
  • Maxillary incisors: 3.5 – 4.5 mm
  • Mandibular incisors: 3.3 – 3.9 mm
  • Least in premolars (~1.8 – 1.9 mm)
• Cementum:
  • Thickest in apical third and furcation (150 – 200 µm)
  • Acellular cementum: cervical third
  • Cellular cementum: forms after occlusal contact
• PDL Fibres:
  • Principal: Type I collagen
  • Reticular: Type III collagen
  • Oblique fibres: Largest group, resist vertical forces
  • Transseptal fibres: Reconstructed post bone loss
  • Alveolar crest fibres: Prevent extrusion

Morphological Classification

Three-Wall Defect (Intrabony Defect)

• Description: Defect contained by three bony walls
• Prognosis: Best regenerative potential
• Treatment: Ideal candidate for GTR procedures

Two-Wall Defect (Crater)

• Description: Defect between two adjacent teeth
• Characteristics: Interdental bone loss
• Prevalence: Most common osseous defect in chronic periodontitis

One-Wall Defect (Hemiseptum)

• Description: Defect with only one remaining bony wall
• Prognosis: Poorest regenerative potential
• Treatment: Often requires resective therapy

Bone Loss Patterns

Horizontal Bone Loss

• Associated Pocket Type: Suprabony pocket
• Pattern: Uniform reduction in alveolar bone height
• Radiographic Appearance: Horizontal radiolucency

Vertical/Angular Bone Loss

• Associated Pocket Type: Infrabony pocket
• Pattern: Uneven bone destruction
• Clinical Significance: More complex treatment requirements

Important Periodontal Indices

PMA Index

• Purpose: Assessment of gingival disease status
• Components: Papillary (P), Marginal (M), and Attached (A) gingiva scoring

Ramfjord Index

• Selected Teeth: 16, 21, 24, 36, 41, 44
• Rationale: Representative sampling of entire dentition

Merin's Classification

• Application: Patient recall scheduling based on periodontal status
• Categories: Maintenance intervals based on disease severity

Clinical Measurements

Gingival Sulcus Depth

• Primary Teeth: 1-2mm (shallower than permanent teeth)
• Permanent Teeth: 2-3mm in health

Level of Attachment

• Definition: Distance from cementoenamel junction (CEJ) to pocket base
• Clinical Significance: True measure of periodontal support loss

Fremitus Test

• Purpose: Diagnosis of tooth mobility
• Technique: Palpation during functional movements

Stage I: Initial Lesion

• Cellular Infiltrate: Polymorphonuclear neutrophils (PMNs) present
• Timeframe: Develops within 2-4 days of plaque accumulation
• Characteristics: Subclinical changes, increased vascular permeability

Stage III: Established Lesion

• Duration: Develops after 2-3 weeks of continuous plaque exposure
• Cellular Changes: Plasma cell dominance, collagen destruction
• Clinical Features: Frank gingivitis with erythema, edema, and bleeding on probing

ANUG (Acute Necrotizing Ulcerative Gingivitis)

Microbiology

• Primary Organisms: Spirochetes and Prevotella species
• Pathogenesis: Opportunistic infection in compromised host defense

Demographics

• Primary Population: Young adults (20-30 years)
• Risk Factors: Stress, smoking, malnutrition, immunocompromise

Clinical Presentation

• Pathognomonic Sign: Crater-like depressions on interdental papilla
• Additional Features: Spontaneous bleeding, halitosis, lymphadenopathy
• Pain: Severe, spontaneous gingival pain

Staging System (7 Stages)

1. Stages 1-2: Necrotizing Ulcerative Gingivitis (NUG)
2. Stages 3-4: Necrotizing Ulcerative Periodontitis (NUP)
3. Stages 5-6: Necrotizing Stomatitis
4. Stage 7: Noma (cancrum oris) - life-threatening condition

Drug – Induced Enlargement

• Phenytoin: Fibrotic nature
• Cyclosporine: Vascular nature

Pregnancy Gingivitis

• Angiogranuloma: Appears after 3rd month
• Raspberry appearance: Characteristic finding
• Peak severity: 8th month, decreases in 9th month
• Cause: Increased progesterone levels

Children vs Adults

• Children: T – lymphocyte dominated response

Desquamative Gingivitis

• 75% have dermatological origin
• 50% localized to gingiva only

Periodontal Bone Grafts

Bone grafting is a critical procedure in periodontal surgery, aimed at restoring lost bone and supporting the regeneration of periodontal tissues.

1. Bone Blend

 Bone blend is a mixture of cortical or cancellous bone that is procured using a trephine or rongeurs, placed in an amalgam capsule, and triturated to achieve a slushy osseous mass. This technique allows for the creation of smaller particle sizes, which enhances resorption and replacement with host bone.

Particle Size: The ideal particle size for bone blend is approximately 210 x 105 micrometers.

Rationale: Smaller particle sizes improve the chances of resorption and integration with the host bone, making the graft more effective.

2. Types of Periodontal Bone Grafts

A. Autogenous Grafts

Autogenous grafts are harvested from the patient’s own body, providing the best compatibility and healing potential.

1. Cortical Bone Chips

   • History: First used by Nabers and O'Leary in 1965.
   • Characteristics: Composed of shavings of cortical bone removed during osteoplasty and ostectomy from intraoral sites.
   • Challenges: Larger particle sizes can complicate placement and handling, and there is a potential for sequestration. This method has largely been replaced by autogenous osseous coagulum and bone blend.

2. Osseous Coagulum and Bone Blend

   • Technique: Intraoral bone is obtained using high- or low-speed round burs and mixed with blood to form an osseous coagulum (Robinson, 1969).
   • Advantages: Overcomes disadvantages of cortical bone chips, such as inability to aspirate during collection and variability in quality and quantity of collected bone.
   • Applications: Used in various periodontal procedures to enhance healing and regeneration.

3. Intraoral Cancellous Bone and Marrow

   • Sources: Healing bony wounds, extraction sockets, edentulous ridges, mandibular retromolar areas, and maxillary tuberosity.
   • Applications: Provides a rich source of osteogenic cells and growth factors for bone regeneration.

4. Extraoral Cancellous Bone and Marrow

   • Sources: Obtained from the anterior or posterior iliac crest.
   • Advantages: Generally offers the greatest potential for new bone growth due to the abundance of cancellous bone and marrow.

B. Bone Allografts

Bone allografts are harvested from donors and can be classified into three main types:

1. Undermineralized Freeze-Dried Bone Allograft (FDBA)

   • Introduction: Introduced in 1976 by Mellonig et al.
   • Process: Freeze drying removes approximately 95% of the water from bone, preserving morphology, solubility, and chemical integrity while reducing antigenicity.
   • Efficacy: FDBA combined with autogenous bone is more effective than FDBA alone, particularly in treating furcation involvements.

2. Demineralized (Decalcified) FDBA

   • Mechanism: Demineralization enhances osteogenic potential by exposing bone morphogenetic proteins (BMPs) in the bone matrix.
   • Osteoinduction vs. Osteoconduction: Demineralized grafts induce new bone formation (osteoinduction), while undermineralized allografts facilitate bone growth by providing a scaffold (osteoconduction).

3. Frozen Iliac Cancellous Bone and Marrow

   • Usage: Used sparingly due to variability in outcomes and potential complications.

Comparison of Allografts and Alloplasts

• Clinical Outcomes: Both FDBA and DFDBA have been compared to porous particulate hydroxyapatite, showing little difference in post-treatment clinical parameters.
• Histological Healing: Grafts of DFDBA typically heal with regeneration of the periodontium, while synthetic bone grafts (alloplasts) heal by repair, which may not restore the original periodontal architecture.