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 This method has largely been replaced by autogenous osseous coagulum and bone blend.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

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

• 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.

• 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

• Composition:

  • Arestin contains minocycline, which is delivered as a biodegradable powder in a syringe.

• 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

• Composition:

  • Atridox contains 10% doxycycline in a syringeable gel system that is biodegradable.

• 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

• Composition:

  • Both Dentamycin and Periocline contain 2% minocycline hydrochloride.

• 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

• Composition:

  • Periochip is a biodegradable chip that contains chlorhexidine.

• 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.

Periodontal Medications and Their Uses

Periodontal medications play a crucial role in the management of periodontal diseases, aiding in the treatment of infections, inflammation, and tissue regeneration. Understanding the various types of medications and their specific uses is essential for effective periodontal therapy.

Types of Periodontal Medications

1. Antibiotics:

   • Uses:
     • Used to treat bacterial infections associated with periodontal disease.
     • Commonly prescribed antibiotics include amoxicillin, metronidazole, and doxycycline.
   • Mechanism:
     • They help reduce the bacterial load in periodontal pockets, promoting healing and reducing inflammation.

2. Antimicrobial Agents:

   • Chlorhexidine:
     • Uses: A topical antiseptic used as a mouth rinse to reduce plaque and gingivitis.
     • Mechanism: It disrupts bacterial cell membranes and inhibits bacterial growth.
   • Tetracycline:
     • Uses: Can be used topically in periodontal pockets to reduce bacteria.
     • Mechanism: Inhibits protein synthesis in bacteria, reducing their ability to cause infection.

3. Anti-Inflammatory Medications:

   • Non-Steroidal Anti-Inflammatory Drugs (NSAIDs):
     • Uses: Used to manage pain and inflammation associated with periodontal disease.
     • Examples: Ibuprofen and naproxen.
   • Corticosteroids:
     • Uses: May be used in severe cases to reduce inflammation.
     • Mechanism: Suppress the immune response and reduce inflammation.

4. Local Delivery Systems:

   • Doxycycline Gel (Atridox):
     • Uses: A biodegradable gel that releases doxycycline directly into periodontal pockets.
     • Mechanism: Provides localized antibiotic therapy to reduce bacteria and inflammation.
   • Minocycline Microspheres (Arestin):
     • Uses: A localized antibiotic treatment that is placed directly into periodontal pockets.
     • Mechanism: Releases minocycline over time to combat infection.

5. Regenerative Agents:

   • Bone Grafts and Guided Tissue Regeneration (GTR) Materials:
     • Uses: Used in surgical procedures to promote the regeneration of lost periodontal tissues.
     • Mechanism: Provide a scaffold for new tissue growth and prevent the ingrowth of epithelium into the defect.

6. Desensitizing Agents:

   • Fluoride Varnishes:
     • Uses: Applied to sensitive areas to reduce sensitivity and promote remineralization.
     • Mechanism: Strengthens enamel and reduces sensitivity by occluding dentinal tubules.

Clinical Significance of Periodontal Medications

1. Management of Periodontal Disease:

   • Medications are essential in controlling infections and inflammation, which are critical for the successful treatment of periodontal diseases.

2. Adjunct to Non-Surgical Therapy:

   • Periodontal medications can enhance the effectiveness of non-surgical treatments, such as scaling and root planing, by reducing bacterial load and inflammation.

3. Surgical Interventions:

   • In surgical procedures, medications can aid in healing and regeneration, improving outcomes for patients undergoing periodontal surgery.

4. Patient Compliance:

   • Educating patients about the importance of medications in their treatment plan can improve compliance and overall treatment success.

Modified Widman Flap Procedure

The modified Widman flap procedure is a surgical technique used in periodontal therapy to treat periodontal pockets while preserving the surrounding tissues and promoting healing. This lecture will discuss the advantages and disadvantages of the modified Widman flap, its indications, and the procedural steps involved.

Advantages of the Modified Widman Flap Procedure

1. Intimate Postoperative Adaptation:

   • The main advantage of the modified Widman flap procedure is the ability to establish a close adaptation of healthy collagenous connective tissues and normal epithelium to all tooth surfaces. This promotes better healing and integration of tissues post-surgery

2. Feasibility for Bone Implantation:

   • The modified Widman flap procedure is advantageous over curettage, particularly when the implantation of bone and other substances is planned. This allows for better access and preparation of the surgical site for grafting .

3. Conservation of Bone and Optimal Coverage:

   • Compared to conventional reverse bevel flap surgery, the modified Widman flap conserves bone and provides optimal coverage of root surfaces by soft tissues. This results in:
     • A more aesthetically pleasing outcome.
     • A favorable environment for oral hygiene.
     • Potentially less root sensitivity and reduced risk of root caries.
     • More effective pocket closure compared to pocket elimination procedures .

4. Minimized Gingival Recession:

   • When reattachment or minimal gingival recession is desired, the modified Widman flap is preferred over subgingival curettage, making it a suitable choice for treating deeper pockets (greater than 5 mm) and other complex periodontal conditions.

Disadvantages of the Modified Widman Flap Procedure

1. Interproximal Architecture:
   • One apparent disadvantage is the potential for flat or concave interproximal architecture immediately following the removal of the surgical dressing, particularly in areas with interproximal bony craters. This can affect the aesthetic outcome and may require further management .

Indications for the Modified Widman Flap Procedure

• Deep Pockets: Pockets greater than 5 mm, especially in the anterior and buccal maxillary posterior regions.
• Intrabony Pockets and Craters: Effective for treating pockets with vertical bone loss.
• Furcation Involvement: Suitable for managing periodontal disease in multi-rooted teeth.
• Bone Grafts: Facilitates the placement of bone grafts during surgery.
• Severe Root Sensitivity: Indicated when root sensitivity is a significant concern.

Procedure Overview

1. Incisions and Flap Reflection:

   • Vertical Incisions: Made to access the periodontal pocket.
   • Crevicular Incision: A horizontal incision along the gingival margin.
   • Horizontal Incision: Undermines and removes the collar of tissue around the teeth.

2. Conservative Debridement:

   • Flap is reflected just beyond the alveolar crest.
   • Careful removal of all plaque and calculus while preserving the root surface.
   • Frequent sterile saline irrigation is used to maintain a clean surgical field.

3. Preservation of Proximal Bone Surface:

   • The proximal bone surface is preserved and not curetted, allowing for better healing and adaptation of the flap.
   • Exact flap adaptation is achieved with full coverage of the bone.

4. Suturing:

   • Suturing is aimed at achieving primary union of the proximal flap projections, ensuring proper healing and tissue integration.

Postoperative Care

• Antibiotic Ointment and Periodontal Dressing: Traditionally, antibiotic ointment was applied over sutures, and a periodontal dressing was placed. However, these practices are often omitted today.
• Current Recommendations: Patients are advised not to disturb the surgical area and to use a chlorhexidine mouth rinse every 12 hours for effective plaque control and to promote healing.

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Neutrophil Disorders Associated with Periodontal Diseases

Neutrophils play a crucial role in the immune response, particularly in combating infections, including those associated with periodontal diseases. Various neutrophil disorders can significantly impact periodontal health, leading to increased susceptibility to periodontal diseases. This lecture will explore the relationship between neutrophil disorders and specific periodontal diseases.

Neutrophil Disorders

1. Diabetes Mellitus

   • Description: A metabolic disorder characterized by high blood sugar levels due to insulin resistance or deficiency.
   • Impact on Neutrophils: Diabetes can impair neutrophil function, including chemotaxis, phagocytosis, and the oxidative burst, leading to an increased risk of periodontal infections.

2. Papillon-Lefevre Syndrome

   • Description: A rare genetic disorder characterized by palmoplantar keratoderma and severe periodontitis.
   • Impact on Neutrophils: Patients exhibit neutrophil dysfunction, leading to early onset and rapid progression of periodontal disease.

3. Down’s Syndrome

   • Description: A genetic disorder caused by the presence of an extra chromosome 21, leading to various developmental and health issues.
   • Impact on Neutrophils: Individuals with Down’s syndrome often have impaired neutrophil function, which contributes to an increased prevalence of periodontal disease.

4. Chediak-Higashi Syndrome

   • Description: A rare genetic disorder characterized by immunodeficiency, partial oculocutaneous albinism, and neurological problems.
   • Impact on Neutrophils: This syndrome results in defective neutrophil chemotaxis and phagocytosis, leading to increased susceptibility to infections, including periodontal diseases.

5. Drug-Induced Agranulocytosis

   • Description: A condition characterized by a dangerously low level of neutrophils due to certain medications.
   • Impact on Neutrophils: The reduction in neutrophil count compromises the immune response, increasing the risk of periodontal infections.

6. Cyclic Neutropenia

   • Description: A rare genetic disorder characterized by recurrent episodes of neutropenia (low neutrophil count) occurring every 21 days.
   • Impact on Neutrophils: During neutropenic episodes, patients are at a heightened risk for infections, including periodontal disease.

Zones of Periodontal Disease

Listgarten described four distinct zones that can be observed in periodontal lesions. These zones may blend with each other and may not be present in every case.

Zones of Periodontal Disease

1. Zone 1: Bacterial Zone

   • Description: This is the most superficial zone, consisting of a diverse array of bacteria.
   • Characteristics:
     • The bacterial zone is primarily composed of various microbial species, including both pathogenic and non-pathogenic bacteria.
     • This zone is critical in the initiation and progression of periodontal disease, as the presence of specific bacteria can trigger inflammatory responses in the host.

2. Zone 2: Neutrophil Rich Zone

   • Description: This zone contains numerous leukocytes, predominantly neutrophils.
   • Characteristics:
     • The neutrophil-rich zone is indicative of the body’s immune response to the bacterial invasion.
     • Neutrophils are the first line of defense and play a crucial role in phagocytosing bacteria and releasing inflammatory mediators.
     • The presence of a high number of neutrophils suggests an acute inflammatory response, which is common in active periodontal disease.

3. Zone 3: Necrotic Zone

   • Description: This zone consists of disintegrated tissue cells, fibrillar material, remnants of collagen fibers, and spirochetes.
   • Characteristics:
     • The necrotic zone reflects tissue destruction and is characterized by the presence of dead or dying cells.
     • Fibrillar material and remnants of collagen fibers indicate the breakdown of the extracellular matrix, which is essential for maintaining periodontal tissue integrity.
     • Spirochetes, which are associated with more aggressive forms of periodontal disease, can also be found in this zone, contributing to the necrotic process.

4. Zone 4: Zone of Spirochetal Infiltration

   • Description: This zone consists of well-preserved tissue that is infiltrated with large and medium spirochetes.
   • Characteristics:
     • The zone of spirochetal infiltration indicates a more chronic phase of periodontal disease, where spirochetes invade the connective tissue.
     • The presence of well-preserved tissue suggests that while spirochetes are present, the tissue has not yet undergone extensive necrosis.
     • This zone is significant as it highlights the role of spirochetes in the pathogenesis of periodontal disease, particularly in cases of necrotizing periodontal diseases.

Theories Regarding the Mineralization of Dental Calculus

Dental calculus, or tartar, is a hard deposit that forms on teeth due to the mineralization of dental plaque. Understanding the mechanisms by which plaque becomes mineralized is essential for dental professionals in managing periodontal health. The theories regarding the mineralization of calculus can be categorized into two main mechanisms: mineral precipitation and the role of seeding agents.

1. Mineral Precipitation

Mineral precipitation involves the local rise in the saturation of calcium and phosphate ions, leading to the formation of calcium phosphate salts. This process can occur through several mechanisms:

A. Rise in pH

• Mechanism: An increase in the pH of saliva can lead to the precipitation of calcium phosphate salts by lowering the precipitation constant.
• Causes:
  • Loss of Carbon Dioxide: Bacterial activity in dental plaque can lead to the loss of CO2, resulting in an increase in pH.
  • Formation of Ammonia: The degradation of proteins by plaque bacteria can produce ammonia, further elevating the pH.

B. Colloidal Proteins

• Mechanism: Colloidal proteins in saliva bind calcium and phosphate ions, maintaining a supersaturated solution with respect to calcium phosphate salts.
• Process:
  • When saliva stagnates, these colloids can settle out, disrupting the supersaturated state and leading to the precipitation of calcium phosphate salts.

C. Enzymatic Activity

• Phosphatase:
  • This enzyme, released from dental plaque, desquamated epithelial cells, or bacteria, hydrolyzes organic phosphates in saliva, increasing the concentration of free phosphate ions and promoting mineralization.
• Esterase:
  • Present in cocci, filamentous organisms, leukocytes, macrophages, and desquamated epithelial cells, esterase can hydrolyze fatty esters into free fatty acids.
  • These fatty acids can form soaps with calcium and magnesium, which are subsequently converted into less-soluble calcium phosphate salts, facilitating calcification.

2. Seeding Agents and Heterogeneous Nucleation

The second theory posits that seeding agents induce small foci of calcification that enlarge and coalesce to form a calcified mass. This concept is often referred to as the epitactic concept or heterogeneous nucleation.

A. Role of Seeding Agents

• Unknown Agents: The specific seeding agents involved in calculus formation are not fully understood, but it is believed that the intercellular matrix of plaque plays a significant role.
• Carbohydrate-Protein Complexes:
  • These complexes may initiate calcification by chelating calcium from saliva and binding it to form nuclei that promote the deposition of minerals.

Clinical Implications

1. Understanding Calculus Formation:

   • Knowledge of the mechanisms behind calculus mineralization can help dental professionals develop effective strategies for preventing and managing calculus formation.

2. Preventive Measures:

   • Maintaining good oral hygiene practices can help reduce plaque accumulation and the conditions that favor mineralization, such as stagnation of saliva and elevated pH.

3. Treatment Approaches:

   • Understanding the role of enzymes and proteins in calculus formation may lead to the development of therapeutic agents that inhibit mineralization or promote the dissolution of existing calculus.

4. Research Directions:

   • Further research into the specific seeding agents and the biochemical processes involved in calculus formation may provide new insights into preventing and treating periodontal disease.