NEET MDS Lessons
Periodontology
Electrosurgery
- Frequency: 1.5 – 7.5 million cycles/sec
Flap Incisions & Blades
- Internal bevel: #15 blade
- Crevicular: #12 blade
- Interdental: Orban's knife
Suturing Techniques
- Horizontal mattress: For diastema/wide spaces
- Anchor suture: For flap closure mesial/distal to tooth
Specific Procedures
- Modified Widman flap: Does not reduce pocket depth
- Apically displaced flap: Increases attached gingiva width
Osseous Surgery Sequence
- Osteoplasty: Vertical grooving, radicular blending
- Ostectomy: Flattening interproximal bone, gradualizing marginal bone
Bone Grafts
- FDBA: Osteoconductive
- DFDBA: Osteoinductive
- Hydroxyapatite: Ca:P ratio 1.67
- Beta – TCP: Ca:P ratio 1.5
Furcation Treatment
- Grade 2: "Cul – de – sac" defect
- Most common hemisection: Distobuccal root of maxillary 1st molar
Root Coverage Procedures
- Laterally displaced pedicle: Grupe & Warren technique
- Subepithelial connective tissue graft: Langer & Langer technique
- Papilla preservation flap: First choice for maxillary anterior (esthetics)
Healing Timeline
Scaling & Curettage
- Epithelialization: 2 – 7 days
- Immature collagen: 21 days
Gingivectomy
- Surface epithelialization: 5 – 14 days
- Complete repair: 1 month
Flap Surgery
- Epithelial attachment: 1 week
Gingival Crevicular Fluid (GCF) is a serum-like exudate found in the gingival sulcus. Initially considered a transudate in healthy gingiva, it transitions to an inflammatory exudate during disease states. GCF serves as a valuable diagnostic medium due to its dynamic composition, reflective of periodontal status.
Composition of GCF
GCF contains a variety of biochemical and cellular components that mirror periodontal health:
| Component | Characteristics & Clinical Importance |
|---|---|
| Glucose | 3–4 times higher than serum levels, indicating microbial metabolism and inflammation |
| Proteins | Albumin, IgG, enzymes like elastase, collagenase, myeloperoxidase |
| Electrolytes | Sodium, potassium, calcium — influence osmotic balance and tissue response |
| Cytokines | IL-1β, TNF-α, IL-6 — markers of inflammation and bone resorption |
| Prostaglandins | PGE2 — associated with tissue destruction and inflammation |
| Lymphocytes | T:B ratio is reversed (1:3) compared to serum (3:1), reflecting immune modulation |
| Microbial Products | Lipopolysaccharides, enzymes from plaque — triggers host response |
| Metabolic Products | Lactate, pyruvate — indicators of anaerobic bacterial activity |
Classification of Periodontal Pockets
Periodontal pockets are an important aspect of periodontal disease, reflecting the health of the supporting structures of the teeth. Understanding the classification of these pockets is essential for diagnosis, treatment planning, and management of periodontal conditions.
Classification of Pockets
-
Gingival Pocket:
- Also Known As: Pseudo-pocket.
- Formation:
- Formed by gingival enlargement without destruction of the underlying periodontal tissues.
- The sulcus is deepened due to the increased bulk of the gingiva.
- Characteristics:
- There is no destruction of the supporting periodontal tissues.
- Typically associated with conditions such as gingival hyperplasia or inflammation.
-
Periodontal Pocket:
- Definition: A pocket that results in the destruction of the supporting periodontal tissues, leading to the loosening and potential exfoliation of teeth.
- Classification Based on Location:
- Suprabony Pocket:
- The base of the pocket is coronal to the alveolar bone.
- The pattern of bone destruction is horizontal.
- The transseptal fibers are arranged horizontally in the space between the base of the pocket and the alveolar bone.
- Infrabony Pocket:
- The base of the pocket is apical to the alveolar bone, meaning the pocket wall lies between the bone and the tooth.
- The pattern of bone destruction is vertical.
- The transseptal fibers are oblique rather than horizontal.
- Suprabony Pocket:
Classification of Periodontal Pockets
-
Suprabony Pocket (Supracrestal or Supraalveolar):
- Location: Base of the pocket is coronal to the alveolar bone.
- Bone Destruction: Horizontal pattern of bone loss.
- Transseptal Fibers: Arranged horizontally.
-
Infrabony Pocket (Intrabony, Subcrestal, or Intraalveolar):
- Location: Base of the pocket is apical to the alveolar bone.
- Bone Destruction: Vertical pattern of bone loss.
- Transseptal Fibers: Arranged obliquely.
Classification of Pockets According to Involved Tooth Surfaces
-
Simple Pocket:
- Definition: Involves only one tooth surface.
- Example: A pocket that is present only on the buccal surface of a tooth.
-
Compound Pocket:
- Definition: A pocket present on two or more surfaces of a tooth.
- Example: A pocket that involves both the buccal and lingual surfaces.
-
Spiral Pocket:
- Definition: Originates on one tooth surface and twists around the tooth to involve one or more additional surfaces.
- Example: A pocket that starts on the mesial surface and wraps around to the distal surface.
Sharpening Stones
- Natural: India, Arkansas
- Artificial: Ruby, Carborundum, Ceramic
Surgical Equipment
- Dental loupes: 1.5 – 6× magnification
- Coe – pak working time: 15 – 20 minutes
Preventive Measures
- Calculus control toothpastes: Contain pyrophosphates
- Antibiotic prophylaxis: Amoxicillin 2.0g, 30 – 60 min before procedure
Abrasion Rates
- Dentin: 25× faster than enamel
- Cementum: 35× faster than enamel
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
Plaque Formation
- Initial colonizers: Gram – positive bacteria
- Mature plaque: Shift to obligate anaerobes, proteolytic, rods, motile
- Plaque weight: 2×10¹¹ bacteria per gram
Bacterial Complexes
- Red Complex (Most pathogenic): P. gingivalis, T. denticola, B. forsythia
- Green Complex: A. actinomycetemcomitans, E. corrodens, Capnocytophaga
- BANA Test: Detects trypsin – like enzyme in T. denticola, P. gingivalis, B. forsythia
Specific Bacteria
- A. actinomycetemcomitans: Invades host cells, secretes leukotoxin (116 – kDa protein)
- P. intermedia: Increases with steroid hormones (pregnancy/puberty)
- S. oralis: Found in treated gingival sulcus
- S. sanguis: First organism on oral mucosa
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