NEET MDS Lessons
Periodontology
- Gingival Conditions:
- Pregnancy gingivitis: Bleeding.
- Desquamative gingivitis: Fiery red, painful sloughing.
- Gingival hyperplasia: Most commonly caused by phenytoin.
- Gingival enlargement covering 3/4 of tooth: Grade III.
- ANUG:
- Organism: Spirochetes.
- Seen in: Young adults.
- First-day management: Avoid deep scaling.
- Stages: Superficial zone = bacterial contamination.
- Granulomatous Lesion: Pyogenic granuloma.
- Gingival Recession: Most commonly due to traumatic brushing.
- Chlorhexidine:
- Minimum: 0.12%; Optimum: 0.2%.
- Chip degrades in 7 – 10 days.
- Floss & Brushes:
- Preferred floss: Unwaxed thin.
- Floss length: 12 – 18 inches.
- Toothbrush: 2 – 4 rows, 5 – 12 tufts per row.
- Soft bristle diameter: 0.2 mm.
- Powered Brushes: Invented in 1939; use oscillating/rotating motion.
- Fones Technique: Circular brushing method.
- Antiplaque Agents:
- Bisbiguanides: 2nd generation.
- Pyrophosphate: Inhibits calculus formation.
| Type | Features |
|---|---|
| Unconjugated | Absent in urine (bound to albumin); hemolysis |
| Conjugated | Seen in Dubin-Johnson |
| Diagnosis | BSP test (Dubin-Johnson) |
| Genetics | Crigler-Najjar Type II – Autosomal recessive |
| Cholestasis | ↑ 5’-nucleotidase |
| Hypothyroid | ↓ Alk Phos |
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.
| ECG Component | Notes |
|---|---|
| Heart rate | 1500 / RR interval |
| P wave | Atrial depolarization |
| PR interval | Reduced in WPW syndrome |
| QT interval | Shortened in hypercalcemia |
| Hypokalemia | ↑ PR interval + ST depression |
| Acute MI | Earliest sign is Tall T wave |
Acquired Pellicle in the Oral Cavity
The acquired pellicle is a crucial component of oral health, serving as the first line of defense in the oral cavity and playing a significant role in the initial stages of biofilm formation on tooth surfaces. Understanding the composition, formation, and function of the acquired pellicle is essential for dental professionals in managing oral health.
Composition of the Acquired Pellicle
-
Definition:
- The acquired pellicle is a thin, organic layer that coats all surfaces in the oral cavity, including both hard (tooth enamel) and soft tissues (gingiva, mucosa).
-
Components:
- The pellicle consists of more than 180 peptides, proteins,
and glycoproteins, which include:
- Keratins: Structural proteins that provide strength.
- Mucins: Glycoproteins that contribute to the viscosity and protective properties of saliva.
- Proline-rich proteins: Involved in the binding of calcium and phosphate.
- Phosphoproteins: Such as statherin, which helps in maintaining calcium levels and preventing mineral loss.
- Histidine-rich proteins: May play a role in buffering and mineralization.
- These components function as adhesion sites (receptors) for bacteria, facilitating the initial colonization of tooth surfaces.
- The pellicle consists of more than 180 peptides, proteins,
and glycoproteins, which include:
Formation and Maturation of the Acquired Pellicle
-
Rapid Formation:
- The salivary pellicle can be detected on clean enamel surfaces within 1 minute after exposure to saliva. This rapid formation is crucial for protecting the enamel and providing a substrate for bacterial adhesion.
-
Equilibrium State:
- By 2 hours, the pellicle reaches a state of equilibrium between adsorption (the process of molecules adhering to the surface) and detachment. This dynamic balance allows for the continuous exchange of molecules within the pellicle.
-
Maturation:
- Although the initial pellicle formation occurs quickly, further maturation can be observed over several hours. This maturation process involves the incorporation of additional salivary components and the establishment of a more complex structure.
Interaction with Bacteria
-
Bacterial Adhesion:
- Bacteria that adhere to tooth surfaces do not contact the enamel directly; instead, they interact with the acquired enamel pellicle. This interaction is critical for the formation of dental biofilms (plaque).
-
Active Role of the Pellicle:
- The acquired pellicle is not merely a passive adhesion matrix. Many
proteins within the pellicle retain enzymatic activity when
incorporated. Some of these enzymes include:
- Peroxidases: Enzymes that can break down hydrogen peroxide and may have antimicrobial properties.
- Lysozyme: An enzyme that can lyse bacterial cell walls, contributing to the antibacterial defense.
- α-Amylase: An enzyme that breaks down starches and may influence the metabolism of adhering bacteria.
- The acquired pellicle is not merely a passive adhesion matrix. Many
proteins within the pellicle retain enzymatic activity when
incorporated. Some of these enzymes include:
Clinical Significance
-
Role in Oral Health:
- The acquired pellicle plays a protective role by providing a barrier against acids and bacteria, helping to maintain the integrity of tooth enamel and soft tissues.
-
Biofilm Formation:
- Understanding the role of the pellicle in bacterial adhesion is essential for managing plaque-related diseases, such as dental caries and periodontal disease.
-
Preventive Strategies:
- Dental professionals can use knowledge of the acquired pellicle to develop preventive strategies, such as promoting saliva flow and maintaining good oral hygiene practices to minimize plaque accumulation.
-
Therapeutic Applications:
- The enzymatic activities of pellicle proteins can be targeted in the development of therapeutic agents aimed at enhancing oral health and preventing bacterial colonization.
Papillon-Lefevre Syndrome
Classic Triad
- Plantar Hyperkeratosis: Thickening of palms and soles
- Early-Onset Periodontitis: Severe periodontal destruction in primary and permanent dentition
- Dural Calcification: Intracranial calcifications
Genetics and Pathogenesis
- Inheritance: Autosomal recessive
- Gene: CTSC gene mutation affecting cathepsin C
Drug-Induced Gingival Hyperplasia
Most Common Causative Drug
- Primary Agent: Phenytoin (anti-seizure medication)
- Other Drugs: Cyclosporine, nifedipine, amlodipine
Grading System
- Grade III: Three-quarters of tooth crown covered by hyperplastic tissue
- Management: Drug substitution when possible, surgical reduction