NEET MDS Lessons
Periodontology
Periodontics: Dental specialty deals with the supporting and surrounding tissues of the teeth.
1. Periodontium: tissues that invest and support teeth Includes Gingiva, Alveolar mucosa Cementum, Periodontal ligament, Alveolar bone, Support bone
2. Periodontal disease: changes to periodontium beyond normal range of variation
a. Specific plaque hypothesis: specific microorganisms cause periodontal disease; mostly anaerobes. Three implicated: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteriodes forsythus
b. Contributing factors: often a combination of factors
i. Local: calculus (tarter, home for bacteria, with age), traumatic occlusal forces, caries (root caries), overhangs and over-contoured restorations, open contacts with food impaction, missing/malaligned teeth
Invasion of biological width: from free gingival margin -> attached gingiva need ~ 3 mm. If enter this area -> problems (e.g., resorption)
ii. Host factors: exacerbate periodontal problems; e.g., smoking/tobacco use, pregnancy and puberty (hormonal changes, blood vessel permeability), stress, poor diet
iii.Medications: often -> tissue overgrowth; e.g., oral contraceptives, antidepressants, heart medicines, transplant anti-rejection drugs
iv.Systemic diseases: e.g., diabetes, immunosuppression
B. Gingivitis: inflammation of gingiva; with age; generally reversible
C. Periodontitis: inflammation of supporting tissues of teeth, characterized by loss of attachment (PDL) and bone; generally irreversible
D. Periodontal disease as risk factor for systemic diseases:
1. Causes difficulty for diabetics to control blood sugar
2. Pregnant women with periodontal disease ~ 7 times more likely to have premature and/or underweight baby
3. Periodontal diseased patients may be at risk for heart 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
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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.
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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.
Trauma from Occlusion
Trauma from occlusion refers to the injury sustained by periodontal tissues when occlusal forces exceed their adaptive capacity.
1. Trauma from Occlusion
- This term describes the injury that occurs to periodontal tissues when the forces exerted during occlusion (the contact between opposing teeth) exceed the ability of those tissues to adapt.
- Traumatic Occlusion: An occlusion that produces such injury is referred to as a traumatic occlusion. This can result from various factors, including malocclusion, excessive occlusal forces, or parafunctional habits (e.g., bruxism).
2. Clinical Signs of Trauma to the Periodontium
The most common clinical sign of trauma to the periodontium is:
- Increased Tooth Mobility: As the periodontal tissues are subjected to excessive forces, they may become compromised, leading to increased mobility of the affected teeth. This is often one of the first observable signs of trauma from occlusion.
3. Radiographic Signs of Trauma from Occlusion
Radiographic examination can reveal several signs indicative of trauma from occlusion:
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Increased Width of Periodontal Space:
- The periodontal ligament space may appear wider on radiographs due to the increased forces acting on the tooth, leading to a loss of attachment and bone support.
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Vertical Destruction of Inter-Dental Septum:
- Trauma from occlusion can lead to vertical bone loss in the inter-dental septa, which may be visible on radiographs as a reduction in bone height between adjacent teeth.
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Radiolucency and Condensation of the Alveolar Bone:
- Areas of radiolucency may indicate bone loss, while areas of increased radiopacity (condensation) can suggest reactive changes in the bone due to the stress of occlusal forces.
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Root Resorption:
- In severe cases, trauma from occlusion can lead to root resorption, which may be observed as a loss of root structure on radiographs.
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
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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.
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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.
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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.
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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.
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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.
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
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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.
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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
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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.
- The exact cause of hypercementosis is not completely understood, but
several factors have been identified:
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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.
- Hypercementosis may also be observed in systemic conditions,
including:
Clinical Implications
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Diagnosis:
- Recognizing hypercementosis is important for accurate diagnosis and treatment planning. Radiographic evaluation is essential for distinguishing hypercementosis from other dental pathologies.
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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.
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Monitoring:
- Regular monitoring of patients with known systemic conditions associated with hypercementosis is important to manage any potential complications.
Stippling of the Gingiva
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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.
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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.
- Location:
Attached Gingiva
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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.
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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.
- The width of the attached gingiva is greatest in the incisor
region, measuring approximately:
- 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.
- Structure:
Masticatory vs. Lining Mucosa
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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.
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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.
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Specialized Mucosa:
- Found on the dorsum of the tongue, adapted for specific functions such as taste.
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. This lecture will discuss several periodontal medicaments, their compositions, and their clinical applications.
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
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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.
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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
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Composition:
- Arestin contains minocycline, which is delivered as a biodegradable powder in a syringe.
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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
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Composition:
- Atridox contains 10% doxycycline in a syringeable gel system that is biodegradable.
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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
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Composition:
- Both Dentamycin and Periocline contain 2% minocycline hydrochloride.
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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
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Composition:
- Periochip is a biodegradable chip that contains chlorhexidine.
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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.