NEET MDS Lessons
Periodontology
Effects of Smoking on the Etiology and Pathogenesis of Periodontal Disease
Smoking is a significant risk factor for the development and progression of periodontal disease. It affects various aspects of periodontal health, including microbiology, immunology, and physiology. Understanding these effects is crucial for dental professionals in managing patients with periodontal disease, particularly those who smoke.
Etiologic Factors and the Impact of Smoking
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Microbiology
- Plaque Accumulation:
- Smoking does not affect the rate of plaque accumulation on teeth. This means that smokers may have similar levels of plaque as non-smokers.
- Colonization of Periodontal Pathogens:
- Smoking increases the colonization of shallow periodontal pockets by periodontal pathogens. This can lead to an increased risk of periodontal disease.
- There are higher levels of periodontal pathogens found in deep periodontal pockets among smokers, contributing to the severity of periodontal disease.
- Plaque Accumulation:
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Immunology
- Neutrophil Function:
- Smoking alters neutrophil chemotaxis (the movement of neutrophils towards infection), phagocytosis (the process by which neutrophils engulf and destroy pathogens), and the oxidative burst (the rapid release of reactive oxygen species to kill bacteria).
- Cytokine Levels:
- Increased levels of pro-inflammatory cytokines such as Tumor Necrosis Factor-alpha (TNF-α) and Prostaglandin E2 (PGE2) are found in the gingival crevicular fluid (GCF) of smokers. These cytokines play a role in inflammation and tissue destruction.
- Collagenase and Elastase Production:
- There is an increase in neutrophil collagenase and elastase in GCF, which can contribute to the breakdown of connective tissue and exacerbate periodontal tissue destruction.
- Monocyte Response:
- Smoking enhances the production of PGE2 by monocytes in response to lipopolysaccharides (LPS), further promoting inflammation and tissue damage.
- Neutrophil Function:
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Physiology
- Gingival Blood Vessels:
- Smoking leads to a decrease in gingival blood vessels, which can impair the delivery of immune cells and nutrients to the periodontal tissues, exacerbating inflammation.
- Gingival Crevicular Fluid (GCF) Flow:
- There is a reduction in GCF flow and bleeding on probing, even in the presence of increased inflammation. This can mask the clinical signs of periodontal disease, making diagnosis more challenging.
- Subgingival Temperature:
- Smoking is associated with a decrease in subgingival temperature, which may affect the metabolic activity of periodontal pathogens.
- Recovery from Local Anesthesia:
- Smokers may require a longer time to recover from local anesthesia, which can complicate dental procedures and patient management.
- Gingival Blood Vessels:
Clinical Implications
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Increased Risk of Periodontal Disease:
- Smokers are at a higher risk for developing periodontal disease due to the combined effects of altered microbial colonization, impaired immune response, and physiological changes in the gingival tissues.
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Challenges in Diagnosis:
- The reduced bleeding on probing and altered GCF flow in smokers can lead to underdiagnosis or misdiagnosis of periodontal disease. Dental professionals must be vigilant in assessing periodontal health in smokers.
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Treatment Considerations:
- Smoking cessation should be a key component of periodontal treatment plans. Educating patients about the effects of smoking on periodontal health can motivate them to quit.
- Treatment may need to be more aggressive in smokers due to the increased severity of periodontal disease and the altered healing response.
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Monitoring and Maintenance:
- Regular monitoring of periodontal health is essential for smokers, as they may experience more rapid disease progression. Tailored maintenance programs should be implemented to address their specific needs.
Pathogens Implicated in Periodontal Diseases
Periodontal diseases are associated with a variety of pathogenic microorganisms. Below is a list of key pathogens implicated in different forms of periodontal disease, along with their associations:
General Pathogens Associated with Periodontal Diseases
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Actinobacillus actinomycetemcomitans:
- Strongly associated with destructive periodontal disease.
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Porphyromonas gingivalis:
- A member of the "black pigmented Bacteroides group" and a significant contributor to periodontal disease.
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Bacteroides forsythus:
- Associated with chronic periodontitis.
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Spirochetes (Treponema denticola):
- Implicated in various periodontal conditions.
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Prevotella intermedia/nigrescens:
- Also belongs to the "black pigmented Bacteroides group" and is associated with several forms of periodontal disease.
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Fusobacterium nucleatum:
- Plays a role in the progression of periodontal disease.
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Campylobacter rectus:
- These organisms include members of the new genus Wolinella and are associated with periodontal disease.
Principal Bacteria Associated with Specific Periodontal Diseases
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Adult Periodontitis:
- Porphyromonas gingivalis
- Prevotella intermedia
- Bacteroides forsythus
- Campylobacter rectus
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Refractory Periodontitis:
- Bacteroides forsythus
- Porphyromonas gingivalis
- Campylobacter rectus
- Prevotella intermedia
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Localized Juvenile Periodontitis (LJP):
- Actinobacillus actinomycetemcomitans
- Capnocytophaga
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Periodontitis in Juvenile Diabetes:
- Capnocytophaga
- Actinobacillus actinomycetemcomitans
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Pregnancy Gingivitis:
- Prevotella intermedia
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Acute Necrotizing Ulcerative Gingivitis (ANUG):
- Prevotella intermedia
- Intermediate-sized spirochetes
Dimensions of Toothbrushes
Toothbrushes play a crucial role in maintaining oral hygiene, and their design can significantly impact their effectiveness. The American Dental Association (ADA) has established guidelines for the dimensions and characteristics of acceptable toothbrushes. This lecture will outline these specifications and discuss their implications for dental health.
Acceptable Dimensions of Toothbrushes
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Brushing Surface Dimensions:
- Length:
- Acceptable brushing surfaces should measure between 1 to 1.25 inches (25.4 to 31.8 mm) long.
- Width:
- The width of the brushing surface should range from 5/16 to 3/8 inch (7.9 to 9.5 mm).
- Rows of Bristles:
- Toothbrushes should have 2 to 4 rows of bristles to effectively clean the teeth and gums.
- Tufts per Row:
- Each row should contain 5 to 12 tufts of bristles, allowing for adequate coverage and cleaning ability.
- Length:
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Filament Diameter:
- The diameter of the bristles can vary, affecting the stiffness and
cleaning effectiveness:
- Soft Filaments:
- Diameter of 0.2 mm (0.007 inches). Ideal for sensitive gums and children.
- Medium Filaments:
- Diameter of 0.3 mm (0.012 inches). Suitable for most adults.
- Hard Filaments:
- Diameter of 0.4 mm (0.014 inches). Generally not recommended for daily use as they can be abrasive to the gums and enamel.
- Soft Filaments:
- The diameter of the bristles can vary, affecting the stiffness and
cleaning effectiveness:
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Filament Stiffness:
- The stiffness of the bristles is determined by the diameter relative to the length of the filament. Thicker filaments tend to be stiffer, which can affect the brushing technique and comfort.
Special Considerations for Children's Toothbrushes
- Size:
- Children's toothbrushes are designed to be smaller to accommodate their smaller mouths and teeth.
- Bristle Thickness:
- The bristles are thinner, measuring 0.005 inches (0.1 mm) in diameter, making them gentler on sensitive gums.
- Bristle Length:
- The bristles are shorter, typically around 0.344 inches (8.7 mm), to ensure effective cleaning without causing discomfort.
Clinical Implications
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Choosing the Right Toothbrush:
- Dental professionals should guide patients in selecting toothbrushes that meet ADA specifications to ensure effective plaque removal and gum protection.
- Emphasizing the importance of using soft or medium bristles can help prevent gum recession and enamel wear.
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Education on Brushing Technique:
- Proper brushing technique is as important as the toothbrush itself. Patients should be educated on how to use their toothbrush effectively, regardless of the type they choose.
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Regular Replacement:
- Patients should be advised to replace their toothbrush every 3 to 4 months or sooner if the bristles become frayed. This ensures optimal cleaning effectiveness.
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Special Considerations for Children:
- Parents should be encouraged to choose appropriately sized toothbrushes for their children and to supervise brushing to ensure proper technique and effectiveness.
Dental Plaque
Dental plaque is a biofilm that forms on the surfaces of teeth and is composed of a diverse community of microorganisms. The development of dental plaque occurs in stages, beginning with primary colonizers and progressing to secondary colonization and plaque maturation.
Primary Colonizers
- Timeframe:
- Acquired within a few hours after tooth cleaning or exposure.
- Characteristics:
- Predominantly gram-positive facultative microbes.
- Key Species:
- Actinomyces viscosus
- Streptococcus sanguis
- Adhesion Mechanism:
- Primary colonizers adhere to the tooth surface through specific adhesins.
- For example, A. viscosus possesses fimbriae that bind to proline-rich proteins in the dental pellicle, facilitating initial attachment.
Secondary Colonization and Plaque Maturation
- Microbial Composition:
- As plaque matures, it becomes predominantly populated by gram-negative anaerobic microorganisms.
- Key Species:
- Prevotella intermedia
- Prevotella loescheii
- Capnocytophaga spp.
- Fusobacterium nucleatum
- Porphyromonas gingivalis
- Coaggregation:
- Coaggregation refers to the ability of different species and genera of plaque microorganisms to adhere to one another.
- This process occurs primarily through highly specific stereochemical interactions of protein and carbohydrate molecules on cell surfaces, along with hydrophobic, electrostatic, and van der Waals forces.
Plaque Hypotheses
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Specific Plaque Hypothesis:
- This hypothesis posits that only certain types of plaque are pathogenic.
- The pathogenicity of plaque depends on the presence or increase of specific microorganisms.
- It predicts that plaque harboring specific bacterial pathogens leads to periodontal disease due to the production of substances that mediate the destruction of host tissues.
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Nonspecific Plaque Hypothesis:
- This hypothesis maintains that periodontal disease results from the overall activity of the entire plaque microflora.
- It suggests that the elaboration of noxious products by the entire microbial community contributes to periodontal disease, rather than specific pathogens alone.
Automated Probing Systems
Automated probing systems have become increasingly important in periodontal assessments, providing enhanced accuracy and efficiency in measuring pocket depths and clinical attachment levels. This lecture will focus on the Florida Probe System, the Foster-Miller Probe, and the Toronto Automated Probe, discussing their features, advantages, and limitations.
1. Florida Probe System
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Overview: The Florida Probe System is an automated probing system designed to facilitate accurate periodontal assessments. It consists of several components:
- Probe Handpiece: The instrument used to measure pocket depths.
- Digital Readout: Displays measurements in real-time.
- Foot Switch: Allows for hands-free operation.
- Computer Interface: Connects the probe to a computer for data management.
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Specifications:
- Probe Diameter: The end of the probe is 0.4 mm in diameter, allowing for precise measurements in periodontal pockets.
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Advantages:
- Constant Probing Force: The system applies a consistent force during probing, reducing variability in measurements.
- Precise Electronic Measurement: Provides accurate and reproducible measurements of pocket depths.
- Computer Storage of Data: Enables easy storage, retrieval, and analysis of patient data, facilitating better record-keeping and tracking of periodontal health over time.
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Disadvantages:
- Lack of Tactile Sensitivity: The automated nature of the probe means that clinicians do not receive tactile feedback, which can be important for assessing tissue health.
- Fixed Force Setting: The use of a fixed force setting throughout the mouth may not account for variations in tissue condition, potentially leading to inaccurate measurements or patient discomfort.
2. Foster-Miller Probe
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Overview: The Foster-Miller Probe is another automated probing system that offers unique features for periodontal assessment.
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Capabilities:
- Pocket Depth Measurement: This probe can measure pocket depths effectively.
- Detection of the Cemento-Enamel Junction (CEJ): It is capable of coupling pocket depth measurements with the detection of the CEJ, providing valuable information about clinical attachment levels.
3. Toronto Automated Probe
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Overview: The Toronto Automated Probe is designed to enhance the accuracy of probing in periodontal assessments.
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Specifications:
- Probing Mechanism: The sulcus is probed with a 0.5 mm nickel titanium wire that is extended under air pressure, allowing for gentle probing.
- Angular Control: The system controls angular discrepancies using a mercury tilt sensor, which limits angulation within ±30 degrees. This feature helps maintain consistent probing angles.
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Limitations:
- Reproducible Positioning: The probe requires reproducible positioning of the patient’s head, which can be challenging in some clinical settings.
- Limited Access: The design may not easily accommodate measurements of second or third molars, potentially limiting its use in comprehensive periodontal assessments.
Periodontal Diseases Associated with Neutrophil Disorders
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Acute Necrotizing Ulcerative Gingivitis (ANUG)
- Description: A severe form of gingivitis characterized by necrosis of the interdental papillae, pain, and foul odor.
- Association: Neutrophil dysfunction can exacerbate the severity of ANUG, leading to rapid tissue destruction.
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Localized Juvenile Periodontitis
- Description: A form of periodontitis that typically affects adolescents and is characterized by localized bone loss around the permanent teeth.
- Association: Impaired neutrophil function contributes to the pathogenesis of this condition.
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Prepubertal Periodontitis
- Description: A rare form of periodontitis that occurs in children before puberty, leading to rapid attachment loss and bone destruction.
- Association: Neutrophil disorders can play a significant role in the development and progression of this disease.
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Rapidly Progressive Periodontitis
- Description: A form of periodontitis characterized by rapid attachment loss and bone destruction, often occurring in young adults.
- Association: Neutrophil dysfunction may contribute to the aggressive nature of this disease.
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Refractory Periodontitis
- Description: A form of periodontitis that does not respond to conventional treatment and continues to progress despite therapy.
- Association: Neutrophil disorders may be implicated in the persistent nature of this condition.
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.