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.

1. 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 This method has largely been replaced by autogenous osseous coagulum and bone blend.

2. 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.

3. 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.

4. 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:

1. 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.

2. 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).

3. 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.

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

• Actinobacillus actinomycetemcomitans:

  • Strongly associated with destructive periodontal disease.

• Porphyromonas gingivalis:

  • A member of the "black pigmented Bacteroides group" and a significant contributor to periodontal disease.

• Bacteroides forsythus:

  • Associated with chronic periodontitis.

• Spirochetes (Treponema denticola):

  • Implicated in various periodontal conditions.

• Prevotella intermedia/nigrescens:

  • Also belongs to the "black pigmented Bacteroides group" and is associated with several forms of periodontal disease.

• Fusobacterium nucleatum:

  • Plays a role in the progression of periodontal disease.

• Campylobacter rectus:

  • These organisms include members of the new genus Wolinella and are associated with periodontal disease.

Principal Bacteria Associated with Specific Periodontal Diseases

1. Adult Periodontitis:

   • Porphyromonas gingivalis
   • Prevotella intermedia
   • Bacteroides forsythus
   • Campylobacter rectus

2. Refractory Periodontitis:

   • Bacteroides forsythus
   • Porphyromonas gingivalis
   • Campylobacter rectus
   • Prevotella intermedia

3. Localized Juvenile Periodontitis (LJP):

   • Actinobacillus actinomycetemcomitans
   • Capnocytophaga

4. Periodontitis in Juvenile Diabetes:

   • Capnocytophaga
   • Actinobacillus actinomycetemcomitans

5. Pregnancy Gingivitis:

   • Prevotella intermedia

6. Acute Necrotizing Ulcerative Gingivitis (ANUG):

   • Prevotella intermedia
   • Intermediate-sized spirochetes

Desquamative Gingivitis

• Characteristics: Desquamative gingivitis is characterized by intense erythema, desquamation, and ulceration of both free and attached gingiva.
• Associated Diseases:
  • Lichen Planus
  • Pemphigus
  • Pemphigoid
  • Linear IgA Disease
  • Chronic Ulcerative Stomatitis
  • Epidermolysis Bullosa
  • Systemic Lupus Erythematosus (SLE)
  • Dermatitis Herpetiformis

Gingival crevicular fluid is an inflammatory exudate found in the gingival sulcus. It plays a significant role in periodontal health and disease.

A. Characteristics of GCF

• Glucose Concentration: The glucose concentration in GCF is 3-4 times greater than that in serum, indicating increased metabolic activity in inflamed tissues.
• Protein Content: The total protein content of GCF is much less than that of serum, reflecting its role as an inflammatory exudate.
• Inflammatory Nature: GCF is present in clinically normal sulci due to the constant low-grade inflammation of the gingiva.

B. Drugs Excreted Through GCF

• Tetracyclines and Metronidazole: These antibiotics are known to be excreted through GCF, making them effective for localized periodontal therapy.

C. Collection Methods for GCF

GCF can be collected using various techniques, including:

1. Absorbing Paper Strips/Blotter/Periopaper: These strips absorb fluid from the sulcus and are commonly used for GCF collection.
2. Twisted Threads: Placing twisted threads around and into the sulcus can help collect GCF.
3. Micropipettes: These can be used for precise collection of GCF in research settings.
4. Intra-Crevicular Washings: Flushing the sulcus with a saline solution can help collect GCF for analysis.

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.

 Naber’s Probe and Furcation Involvement

Furcation involvement is a critical aspect of periodontal disease that affects the prognosis of teeth with multiple roots. Naber’s probe is a specialized instrument designed to assess furcation areas, allowing clinicians to determine the extent of periodontal attachment loss and the condition of the furcation. This lecture will cover the use of Naber’s probe, the classification of furcation involvement, and the clinical significance of these classifications.

Naber’s Probe

• Description: Naber’s probe is a curved, blunt-ended instrument specifically designed for probing furcation areas. Its unique shape allows for horizontal probing, which is essential for accurately assessing the anatomy of multi-rooted teeth.

• Usage: The probe is inserted horizontally into the furcation area to evaluate the extent of periodontal involvement. The clinician can feel the anatomical fluting between the roots, which aids in determining the classification of furcation involvement.

Classification of Furcation Involvement

Furcation involvement is classified into four main classes using Naber’s probe:

1. Class I:

   • Description: The furcation can be probed to a depth of 3 mm.
   • Clinical Findings: The probe can feel the anatomical fluting between the roots, but it cannot engage the roof of the furcation.
   • Significance: Indicates early furcation involvement with minimal attachment loss.

2. Class II:

   • Description: The furcation can be probed to a depth greater than 3 mm, but not through and through.
   • Clinical Findings: This class represents a range between Class I and Class III, where there is partial loss of attachment but not complete penetration through the furcation.
   • Significance: Indicates moderate furcation involvement that may require intervention.

3. Class III:

   • Description: The furcation can be completely probed through and through.
   • Clinical Findings: The probe passes from one furcation to the other, indicating significant loss of periodontal support.
   • Significance: Represents advanced furcation involvement, often associated with a poor prognosis for the affected tooth.

4. Class III+:

   • Description: The probe can go halfway across the tooth.
   • Clinical Findings: Similar to Class III, but with partial obstruction or remaining tissue.
   • Significance: Indicates severe furcation involvement with a significant loss of attachment.

5. Class IV:

   • Description: Clinically, the examiner can see through the furcation.
   • Clinical Findings: There is complete loss of tissue covering the furcation, making it visible upon examination.
   • Significance: Indicates the most severe form of furcation involvement, often leading to tooth mobility and extraction.

Measurement Technique

• Measurement Reference: Measurements are taken from an imaginary tangent connecting the prominences of the root surfaces of both roots. This provides a consistent reference point for assessing the depth of furcation involvement.

Clinical Significance

• Prognosis: The classification of furcation involvement is crucial for determining the prognosis of multi-rooted teeth. Higher classes of furcation involvement generally indicate a poorer prognosis and may necessitate more aggressive treatment strategies.

• Treatment Planning: Understanding the extent of furcation involvement helps clinicians develop appropriate treatment plans, which may include scaling and root planing, surgical intervention, or extraction.

• Monitoring: Regular assessment of furcation involvement using Naber’s probe can help monitor disease progression and the effectiveness of periodontal therapy.