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Periodontology

Plaque Formation

Dental plaque is a biofilm that forms on the surfaces of teeth and is a key factor in the development of dental caries and periodontal disease. The process of plaque formation can be divided into three major phases:

1. Formation of Pellicle on the Tooth Surface

  • Definition: The pellicle is a thin, acellular film that forms on the tooth surface shortly after cleaning.
  • Composition: It is primarily composed of salivary glycoproteins and other proteins that are adsorbed onto the enamel surface.
  • Function:
    • The pellicle serves as a protective barrier for the tooth surface.
    • It provides a substrate for bacterial adhesion, facilitating the subsequent stages of plaque formation.

2. Initial Adhesion & Attachment of Bacteria

  • Mechanism:
    • Bacteria in the oral cavity begin to adhere to the pellicle-coated tooth surface.
    • This initial adhesion is mediated by specific interactions between bacterial adhesins (surface proteins) and the components of the pellicle.
  • Key Bacterial Species:
    • Primary colonizers, such as Streptococcus sanguis and Actinomyces viscosus, are among the first to attach.
  • Importance:
    • Successful adhesion is crucial for the establishment of plaque, as it allows for the accumulation of additional bacteria.

3. Colonization & Plaque Maturation

  • Colonization:
    • Once initial bacteria have adhered, they proliferate and create a more complex community.
    • Secondary colonizers, including gram-negative anaerobic bacteria, begin to join the biofilm.
  • Plaque Maturation:
    • As the plaque matures, it develops a three-dimensional structure, with different bacterial species occupying specific niches within the biofilm.
    • The matrix of extracellular polysaccharides and salivary glycoproteins becomes more pronounced, providing structural integrity to the plaque.
  • Coaggregation:
    • Different bacterial species can adhere to one another through coaggregation, enhancing the complexity of the plaque community.

Composition of Plaque

  • Matrix Composition:
    • Plaque is primarily composed of bacteria embedded in a matrix of salivary glycoproteins and extracellular polysaccharides.
  • Implications for Removal:
    • The dense and cohesive nature of this matrix makes it difficult to remove plaque through simple rinsing or the use of sprays.
    • Effective plaque removal typically requires mechanical means, such as brushing and flossing, to disrupt the biofilm structure.

Flossing Technique

Flossing is an essential part of oral hygiene that helps remove plaque and food particles from between the teeth and along the gumline, areas that toothbrushes may not effectively clean. Proper flossing technique is crucial for maintaining gum health and preventing cavities.

Flossing Technique

  1. Preparation:

    • Length of Floss: Take 12 to 18 inches of dental floss. This length allows for adequate maneuverability and ensures that you can use a clean section of floss for each tooth.
    • Grasping the Floss: Hold the floss taut between your hands, leaving a couple of inches of floss between your fingers. This tension helps control the floss as you maneuver it between your teeth.
  2. Inserting the Floss:

    • Slip Between Teeth: Gently slide the floss between your teeth. Be careful not to snap the floss, as this can cause trauma to the gums.
    • Positioning: Insert the floss into the area between your teeth and gums as far as it will comfortably go, ensuring that you reach the gumline.
  3. Flossing Motion:

    • Vertical Strokes: Use 8 to 10 vertical strokes with the floss to dislodge food particles and plaque. Move the floss up and down against the sides of each tooth, making sure to clean both the front and back surfaces.
    • C-Shaped Motion: For optimal cleaning, wrap the floss around the tooth in a C-shape and gently slide it beneath the gumline.
  4. Frequency:

    • Daily Flossing: Aim to floss at least once a day. Consistency is key to maintaining good oral hygiene.
    • Best Time to Floss: The most important time to floss is before going to bed, as this helps remove debris and plaque that can accumulate throughout the day.
  5. Flossing and Brushing:

    • Order of Operations: Flossing can be done either before or after brushing your teeth. Both methods are effective, so choose the one that fits best into your routine.

Stippling of the Gingiva

  • Stippling refers to the textured surface of the gingiva that resembles the skin of an orange. This characteristic is best observed when the gingiva is dried.

  • Characteristics:

    • Location:
      • The attached gingiva is typically stippled, while the marginal gingiva is not.
      • The central portion of the interdental gingiva may exhibit stippling, but its marginal borders are usually smooth.
    • Surface Variation:
      • Stippling is generally less prominent on the lingual surfaces compared to the facial surfaces and may be absent in some individuals.
    • Age-Related Changes:
      • Stippling is absent in infancy, begins to appear around 5 years of age, increases until adulthood, and may start to disappear in old age.

Attached Gingiva

  • Definition: The attached gingiva is the portion of the gingiva that is firmly bound to the underlying alveolar bone and extends from the free gingival groove to the mucogingival junction, where it meets the alveolar mucosa.

  • Characteristics:

    • Structure:
      • The attached gingiva is classified as a mucoperiosteum, tightly bound to the underlying alveolar bone.
    • Width:
      • The width of the attached gingiva is greatest in the incisor region, measuring approximately:
        • 3.5 – 4.5 mm in the maxilla
        • 3.3 – 3.9 mm in the mandible
      • It is narrower in the posterior segments, measuring about:
        • 1.9 mm in the maxillary first premolars
        • 1.8 mm in the mandibular first premolars.
    • Histological Features:
      • The attached gingiva is thick and keratinized (or parakeratinized) and is classified as masticatory mucosa.
      • Masticatory mucosa is characterized by a keratinized epithelium and a thick lamina propria, providing resistance to mechanical forces.

Masticatory vs. Lining Mucosa

  • Masticatory Mucosa:

    • Found in areas subject to high compression and friction, such as the gingiva and hard palate.
    • Characterized by keratinized epithelium and a thick lamina propria, making it resistant to masticatory forces.
  • Lining Mucosa:

    • Mobile, distensible, and non-keratinized.
    • Found in areas such as the lips, cheeks, alveolus, floor of the mouth, ventral surface of the tongue, and soft palate.
  • Specialized Mucosa:

    • Found on the dorsum of the tongue, adapted for specific functions such as taste.

Classification of Embrasures

  1. Type I Embrasures:

    • Description: These are characterized by the presence of interdental papillae that completely fill the embrasure space, with no gingival recession.
    • Recommended Cleaning Device:
      • Dental Floss: Dental floss is most effective in cleaning Type I embrasures. It can effectively remove plaque and debris from the tight spaces between teeth.
  2. Type II Embrasures:

    • Description: These embrasures have larger spaces due to some loss of attachment, but the interdental papillae are still present.
    • Recommended Cleaning Device:
      • Interproximal Brush: For Type II embrasures, interproximal brushes are recommended. These brushes have bristles that can effectively clean around the exposed root surfaces and between teeth, providing better plaque removal than dental floss in these larger spaces.
  3. Type III Embrasures:

    • Description: These spaces occur when there is significant loss of attachment, resulting in the absence of interdental papillae.
    • Recommended Cleaning Device:
      • Single Tufted Brushes: Single tufted brushes (also known as end-tuft brushes) are ideal for cleaning Type III embrasures. They can reach areas that are difficult to access with traditional floss or brushes, effectively cleaning the exposed root surfaces and the surrounding areas.

Hypercementosis

Hypercementosis is a dental condition characterized by the excessive deposition of cementum on the roots of teeth. This condition can have various clinical implications and is associated with several underlying factors. Understanding hypercementosis is essential for dental professionals in diagnosing and managing related conditions.

Characteristics of Hypercementosis

  1. Definition:

    • Hypercementosis is defined as a generalized thickening of the cementum, often accompanied by nodular enlargement of the apical third of the root. It can also manifest as spike-like excrescences known as cemental spikes.
  2. Forms of Hypercementosis:

    • Generalized Type: Involves a uniform thickening of cementum across multiple teeth.
    • Localized Type: Characterized by nodular enlargements or cemental spikes, which may result from:
      • Coalescence of cementicles adhering to the root.
      • Calcification of periodontal fibers at their insertion points into the cementum.

Radiographic Appearance

  • Radiographic Features:
    • On radiographs, hypercementosis is identified by the presence of a radiolucent shadow of the periodontal ligament and a radiopaque lamina dura surrounding the area of hypercementosis, similar to normal cementum.
    • Differentiation:
      • Hypercementosis can be differentiated from other conditions such as periapical cemental dysplasia, condensing osteitis, and focal periapical osteopetrosis, as these entities are located outside the shadow of the periodontal ligament and lamina dura.

Etiology of Hypercementosis

  • Varied Etiology:

    • The exact cause of hypercementosis is not completely understood, but several factors have been identified:
      • Spike-like Hypercementosis: Often results from excessive tension due to orthodontic appliances or occlusal forces.
      • Generalized Hypercementosis: Can occur in various circumstances, including:
        • Teeth Without Antagonists: In cases where teeth lack opposing teeth, hypercementosis may develop as a compensatory mechanism to keep pace with excessive tooth eruption.
        • Low-Grade Periapical Irritation: Associated with pulp disease, where hypercementosis serves as compensation for the loss of fibrous attachment to the tooth.
  • Systemic Associations:

    • Hypercementosis may also be observed in systemic conditions, including:
      • Paget’s Disease: Characterized by hypercementosis of the entire dentition.
      • Other Conditions: Acromegaly, arthritis, calcinosis, rheumatic fever, and thyroid goiter have also been linked to hypercementosis.

Clinical Implications

  1. Diagnosis:

    • Recognizing hypercementosis is important for accurate diagnosis and treatment planning. Radiographic evaluation is essential for distinguishing hypercementosis from other dental pathologies.
  2. Management:

    • While hypercementosis itself may not require treatment, it can complicate dental procedures such as extractions or endodontic treatments. Understanding the condition can help clinicians anticipate potential challenges.
  3. Monitoring:

    • Regular monitoring of patients with known systemic conditions associated with hypercementosis is important to manage any potential complications.

Some important points about the periodontal pocket :
·Soft tissue of pocket wall shows both proliferative & degenerative changes
·Most severe degenerative changes are seen on the lateral wall of pocket
·Plasma cells are the predominant infiltrate (80%). Others include lymphocytes & a scattering of PMNs
·Height of junctional epithelium shortened to only 50-100µm
·Severity of degenerative changes is not linked to pocket depth
·Junctional epithelium starts to lose attachment to tooth when PMN infiltration in junctional epithelium increases above 60%.

Classification of Cementum According to Schroeder

Cementum is a specialized calcified tissue that covers the roots of teeth and plays a crucial role in periodontal health. According to Schroeder, cementum can be classified into several distinct types based on its cellular composition and structural characteristics. Understanding these classifications is essential for dental professionals in diagnosing and treating periodontal conditions.

Classification of Cementum

  1. Acellular Afibrillar Cementum:

    • Characteristics:
      • Contains neither cells nor collagen fibers.
      • Present in the coronal region of the tooth.
      • Thickness ranges from 1 µm to 15 µm.
    • Function:
      • This type of cementum is thought to play a role in the attachment of the gingiva to the tooth surface.
  2. Acellular Extrinsic Fiber Cementum:

    • Characteristics:
      • Lacks cells but contains closely packed bundles of Sharpey’s fibers, which are collagen fibers that anchor the cementum to the periodontal ligament.
      • Typically found in the cervical third of the roots.
      • Thickness ranges from 30 µm to 230 µm.
    • Function:
      • Provides strong attachment of the periodontal ligament to the tooth, contributing to the stability of the tooth in its socket.
  3. Cellular Mixed Stratified Cementum:

    • Characteristics:
      • Contains both extrinsic and intrinsic fibers and may contain cells.
      • Found in the apical third of the roots, at the apices, and in furcation areas.
      • Thickness ranges from 100 µm to 1000 µm.
    • Function:
      • This type of cementum is involved in the repair and adaptation of the tooth root, especially in response to functional demands and periodontal disease.
  4. Cellular Intrinsic Fiber Cementum:

    • Characteristics:
      • Contains cells but no extrinsic collagen fibers.
      • Primarily fills resorption lacunae, which are areas where cementum has been resorbed.
    • Function:
      • Plays a role in the repair of cementum and may be involved in the response to periodontal disease.
  5. Intermediate Cementum:

    • Characteristics:
      • A poorly defined zone located near the cementoenamel junction (CEJ) of certain teeth.
      • Appears to contain cellular remnants of the Hertwig's epithelial root sheath (HERS) embedded in a calcified ground substance.
    • Function:
      • Its exact role is not fully understood, but it may be involved in the transition between enamel and cementum.

Clinical Significance

  • Importance of Cementum:

    • Understanding the different types of cementum is crucial for diagnosing periodontal diseases and planning treatment strategies.
    • The presence of various types of cementum can influence the response of periodontal tissues to disease and trauma.
  • Cementum in Periodontal Disease:

    • Changes in the thickness and composition of cementum can occur in response to periodontal disease, affecting tooth stability and attachment.

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