Morphological Classification

Three-Wall Defect (Intrabony Defect)

• Description: Defect contained by three bony walls
• Prognosis: Best regenerative potential
• Treatment: Ideal candidate for GTR procedures

Two-Wall Defect (Crater)

• Description: Defect between two adjacent teeth
• Characteristics: Interdental bone loss
• Prevalence: Most common osseous defect in chronic periodontitis

One-Wall Defect (Hemiseptum)

• Description: Defect with only one remaining bony wall
• Prognosis: Poorest regenerative potential
• Treatment: Often requires resective therapy

Bone Loss Patterns

Horizontal Bone Loss

• Associated Pocket Type: Suprabony pocket
• Pattern: Uniform reduction in alveolar bone height
• Radiographic Appearance: Horizontal radiolucency

Vertical/Angular Bone Loss

• Associated Pocket Type: Infrabony pocket
• Pattern: Uneven bone destruction
• Clinical Significance: More complex treatment requirements

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.

1. Periodontal Probing

• Assessment Method: Periodontal probing is commonly used to measure probing depth and attachment levels before and after therapy.

• 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

• 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.

• 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

• Assessment Method: Histologic analysis involves examining tissue samples under a microscope to assess the formation of new attachment, including new cementum and periodontal ligament.

• Advantages:

  • Validity: Histologic methods are considered the only valid approach to assess the formation of new attachment accurately.

• 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.

Sutures for Periodontal Flaps

Suturing is a critical aspect of periodontal surgery, particularly when managing periodontal flaps. The choice of suture material can significantly influence healing, tissue adaptation, and overall surgical outcomes.

1. Nonabsorbable Sutures

Nonabsorbable sutures are designed to remain in the tissue until they are manually removed. They are often used in situations where long-term support is needed.

A. Types of Nonabsorbable Sutures

1. Silk (Braided)

   • Characteristics:
     • Excellent handling properties and knot security.
     • Provides good tissue approximation.
   • Applications: Commonly used in periodontal surgeries due to its ease of use and reliability.

2. Nylon (Monofilament) (Ethilon)

   • Characteristics:
     • Strong and resistant to stretching.
     • Less tissue reactivity compared to silk.
   • Applications: Ideal for delicate tissues and areas requiring minimal tissue trauma.

3. ePTFE (Monofilament) (Gore-Tex)

   • Characteristics:
     • Biocompatible and non-reactive.
     • Excellent tensile strength and flexibility.
   • Applications: Often used in guided tissue regeneration procedures and in areas where long-term support is needed.

4. Polyester (Braided) (Ethibond)

   • Characteristics:
     • High tensile strength and good knot security.
     • Less pliable than silk.
   • Applications: Used in situations requiring strong sutures, such as in flap stabilization.

2. Absorbable Sutures

Absorbable sutures are designed to be broken down by the body over time, eliminating the need for removal. They are often used in periodontal surgeries where temporary support is sufficient.

A. Types of Absorbable Sutures

1. Surgical Gut

   • Plain Gut (Monofilament)

     • Absorption Time: Approximately 30 days.
     • Characteristics: Made from sheep or cow intestines; provides good tensile strength initially but loses strength quickly.
     • Applications: Suitable for soft tissue approximation where rapid absorption is desired.

   • Chromic Gut (Monofilament)

     • Absorption Time: Approximately 45 to 60 days.
     • Characteristics: Treated with chromium salts to delay absorption; retains strength longer than plain gut.
     • Applications: Used in areas where a longer healing time is expected.

2. Synthetic Absorbable Sutures

   • Polyglycolic Acid (Braided) (Vicryl, Ethicon)

     • Absorption Time: Approximately 16 to 20 days.
     • Characteristics: Provides good tensile strength and is absorbed predictably.
     • Applications: Commonly used in periodontal and oral surgeries due to its handling properties.

   • Dexon (Davis & Geck)

     • Characteristics: Similar to Vicryl; made from polyglycolic acid.
     • Applications: Used in soft tissue approximation and ligation.

   • Polyglycaprone (Monofilament) (Maxon)

     • Absorption Time: Similar to Vicryl.
     • Characteristics: Offers excellent tensile strength and is absorbed more slowly than other synthetic options.
     • Applications: Ideal for areas requiring longer support during healing.

• Angulation vs Adaptation:
  • Angulation: Angle between blade face and tooth surface.
  • Adaptation: Relationship of blade’s working end to tooth surface.
• Curettes:
  • Gracey: Blade offset at 60°.
  • Universal: Blade angle at 90°.
  • After Five: Extended shank by 3 mm; available in all Gracey numbers except 9 – 10.
  • Mini Five: Blade half the length of conventional curette.
  • Langer Curette: Gracey curette modified with universal blade angle.
• Scaling & Sharpening:
  • Blade angulation for scaling: 45 – 90°; for curettage: >90°.
  • Sharpening angle: 100 – 110°.
  • Chisel scaler: Push motion; Hoe scaler: Blade bent at 99°.
  • Sickle scaler blade-to-shank angle: 70°.
• Microsurgery:
  • Instrument weight: 15 – 20 g.
  • Principles: Butt joint approximation, enhanced motor skills, minimal trauma.
• Suturing:
  • Needle entry: Right angle, 2 – 3 mm from incision.

Some important points about the periodontal pocket :
·Soft tissue of pocket wall shows both proliferative & degenerative changes
·Most severe degenerative changes are seen on the lateral wall of pocket
·Plasma cells are the predominant infiltrate (80%). Others include lymphocytes & a scattering of PMNs
·Height of junctional epithelium shortened to only 50-100µm
·Severity of degenerative changes is not linked to pocket depth
·Junctional epithelium starts to lose attachment to tooth when PMN infiltration in junctional epithelium increases above 60%.

Surgical Considerations

• Minimum implant distance: 3 mm
• Mesio – distal space for 2 implants: 14 mm
• Twist drill speed: 800 – 1500 rpm (2mm drill)
• Piezosurgery: Invented by Vercellotti, developed by Mectron

Biological Considerations

• Peri – implant biological width: 4 – 4.5 mm (epithelial attachment + supracrestal CT)
• Maximum bone loss: First 6 – 24 months post – extraction