NEET MDS Lessons
Periodontology
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.
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
Keratinized Gingiva and Attached Gingiva
The gingiva is an essential component of the periodontal tissues, providing support and protection for the teeth. Understanding the characteristics of keratinized gingiva, particularly attached gingiva, is crucial for assessing periodontal health.
Keratinized Gingiva
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Definition:
- Keratinized gingiva refers to the gingival tissue that is covered by a layer of keratinized epithelium, providing a protective barrier against mechanical and microbial insults.
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Areas of Keratinized Gingiva:
- Attached Gingiva:
- Extends from the gingival groove to the mucogingival junction.
- Marginal Gingiva:
- The free gingival margin that surrounds the teeth.
- Hard Palate:
- The roof of the mouth, which is also covered by keratinized tissue.
- Attached Gingiva:
Attached Gingiva
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Location:
- The attached gingiva is the portion of the gingiva that is firmly bound to the underlying alveolar bone.
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Width of Attached Gingiva:
- The width of attached gingiva varies based on location and can increase with age and in cases of supraerupted teeth.
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Measurements:
- Greatest Width:
- Found in the incisor region:
- Maxilla: 3.5 mm - 4.5 mm
- Mandible: 3.3 mm - 3.9 mm
- Found in the incisor region:
- Narrowest Width:
- Found in the posterior region:
- Maxillary First Premolar: 1.9 mm
- Mandibular First Premolar: 1.8 mm
- Found in the posterior region:
- Greatest Width:
Clinical Significance
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Importance of Attached Gingiva:
- The width of attached gingiva is important for periodontal health, as it provides a buffer zone against mechanical forces and helps maintain the integrity of the periodontal attachment.
- Insufficient attached gingiva may lead to increased susceptibility to periodontal disease and gingival recession.
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Assessment:
- Regular assessment of the width of attached gingiva is essential during periodontal examinations to identify potential areas of concern and to plan appropriate treatment strategies.
PERIOTEST Device in Periodontal Assessment
The PERIOTEST device is a valuable tool used in dentistry to assess the mobility of teeth and the reaction of the periodontium to applied forces. This lecture covers the principles of the PERIOTEST device, its measurement scale, and its clinical significance in evaluating periodontal health.
Function: The PERIOTEST device measures the reaction of the periodontium to a defined percussion force applied to the tooth. This is done using a tapping instrument that delivers a controlled force to the tooth.
Contact Time: The contact time between the tapping head and the tooth varies between 0.3 and 2 milliseconds. This duration is typically shorter for stable teeth compared to mobile teeth, allowing for a quick assessment of tooth stability.
PERIOTEST Scale
The PERIOTEST scale ranges from -8 to +50, with specific ranges indicating different levels of tooth mobility:
| Readings | Inference |
|---|---|
| -8 to 9 | Clinically firm teeth |
| 10 to 19 | First distinguishable sign of movement |
| 20 to 29 | Crown deviates within 1 mm of its normal position |
| 30 to 50 | Mobility is readily observed |
Clinical Significance
Assessment of Tooth Mobility:
The PERIOTEST device provides a quantitative measure of tooth mobility,
which is essential for diagnosing periodontal disease and assessing the
stability of teeth.
Correlation with Other Measurements:
The PERIOTEST values correlate well with:
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Tooth Mobility Assessed with a Metric System: This allows for a standardized approach to measuring mobility, enhancing the reliability of assessments.
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Degree of Periodontal Disease and Alveolar Bone Loss: Higher mobility readings often indicate more severe periodontal disease and greater loss of supporting bone, making the PERIOTEST a useful tool in monitoring disease progression.
Treatment Planning:
Understanding the mobility of teeth can aid in treatment planning,
including decisions regarding periodontal therapy, splinting of mobile teeth, or
extraction in cases of severe mobility.
Periodontal Bone Grafts
Bone grafting is a critical procedure in periodontal surgery, aimed at restoring lost bone and supporting the regeneration of periodontal tissues.
1. Bone Blend
Bone blend is a mixture of cortical or cancellous bone that is procured using a trephine or rongeurs, placed in an amalgam capsule, and triturated to achieve a slushy osseous mass. This technique allows for the creation of smaller particle sizes, which enhances resorption and replacement with host bone.
Particle Size: The ideal particle size for bone blend is approximately 210 x 105 micrometers.
Rationale: Smaller particle sizes improve the chances of resorption and integration with the host bone, making the graft more effective.
2. Types of Periodontal Bone Grafts
A. Autogenous Grafts
Autogenous grafts are harvested from the patient’s own body, providing the best compatibility and healing potential.
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Cortical Bone Chips
- History: First used by Nabers and O'Leary in 1965.
- Characteristics: Composed of shavings of cortical bone removed during osteoplasty and ostectomy from intraoral sites.
- Challenges: Larger particle sizes can complicate placement and handling, and there is a potential for sequestration. This method has largely been replaced by autogenous osseous coagulum and bone blend.
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Osseous Coagulum and Bone Blend
- Technique: Intraoral bone is obtained using high- or low-speed round burs and mixed with blood to form an osseous coagulum (Robinson, 1969).
- Advantages: Overcomes disadvantages of cortical bone chips, such as inability to aspirate during collection and variability in quality and quantity of collected bone.
- Applications: Used in various periodontal procedures to enhance healing and regeneration.
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Intraoral Cancellous Bone and Marrow
- Sources: Healing bony wounds, extraction sockets, edentulous ridges, mandibular retromolar areas, and maxillary tuberosity.
- Applications: Provides a rich source of osteogenic cells and growth factors for bone regeneration.
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Extraoral Cancellous Bone and Marrow
- Sources: Obtained from the anterior or posterior iliac crest.
- Advantages: Generally offers the greatest potential for new bone growth due to the abundance of cancellous bone and marrow.
B. Bone Allografts
Bone allografts are harvested from donors and can be classified into three main types:
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Undermineralized Freeze-Dried Bone Allograft (FDBA)
- Introduction: Introduced in 1976 by Mellonig et al.
- Process: Freeze drying removes approximately 95% of the water from bone, preserving morphology, solubility, and chemical integrity while reducing antigenicity.
- Efficacy: FDBA combined with autogenous bone is more effective than FDBA alone, particularly in treating furcation involvements.
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Demineralized (Decalcified) FDBA
- Mechanism: Demineralization enhances osteogenic potential by exposing bone morphogenetic proteins (BMPs) in the bone matrix.
- Osteoinduction vs. Osteoconduction: Demineralized grafts induce new bone formation (osteoinduction), while undermineralized allografts facilitate bone growth by providing a scaffold (osteoconduction).
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Frozen Iliac Cancellous Bone and Marrow
- Usage: Used sparingly due to variability in outcomes and potential complications.
Comparison of Allografts and Alloplasts
- Clinical Outcomes: Both FDBA and DFDBA have been compared to porous particulate hydroxyapatite, showing little difference in post-treatment clinical parameters.
- Histological Healing: Grafts of DFDBA typically heal with regeneration of the periodontium, while synthetic bone grafts (alloplasts) heal by repair, which may not restore the original periodontal architecture.
Assessing New Attachment in Periodontal Therapy
Assessing new attachment following periodontal therapy is crucial for evaluating treatment outcomes and understanding the healing process. However, various methods of assessment have limitations that must be considered. This lecture will discuss the reliability of different assessment methods for new attachment, including periodontal probing, radiographic analysis, and histologic methods.
1. Periodontal Probing
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Assessment Method: Periodontal probing is commonly used to measure probing depth and attachment levels before and after therapy.
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Limitations:
- Coronal Positioning of Probe Tip: After therapy, when the inflammatory lesion is resolved, the probe tip may stop coronal to the apical termination of the epithelium. This can lead to misleading interpretations of attachment gain.
- Infrabony Defects: Following treatment of infrabony defects, new bone may form so close to the tooth surface that the probe cannot penetrate. This can result in a false impression of improved attachment levels.
- Interpretation of Results: A gain in probing attachment level does not necessarily indicate a true gain of connective tissue attachment. Instead, it may reflect improved health of the surrounding tissues, which increases resistance to probe penetration.
2. Radiographic Analysis and Reentry Operations
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Assessment Method: Radiographic analysis involves comparing radiographs taken before and after therapy to evaluate changes in bone levels. Reentry operations allow for direct inspection of the treated area.
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Limitations:
- Bone Fill vs. New Attachment: While radiographs can provide evidence of new bone formation (bone fill), they do not document the formation of new root cementum or a new periodontal ligament. Therefore, radiographic evidence alone cannot confirm the establishment of new attachment.
3. Histologic Methods
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Assessment Method: Histologic analysis involves examining tissue samples under a microscope to assess the formation of new attachment, including new cementum and periodontal ligament.
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Advantages:
- Validity: Histologic methods are considered the only valid approach to assess the formation of new attachment accurately.
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Limitations:
- Pre-Therapy Assessment: Accurate assessment of the attachment level prior to therapy is essential for histologic analysis. If the initial attachment level cannot be determined with certainty, it may compromise the validity of the findings.