• Bone Defects:
  • Most common: Osseous craters.
  • Best graft success: Three-walled defects.
  • Bone graft types:
    • Autogenous cancellous: Most osteogenic.
    • Xenograft: From different species.
  • Osteoplasty: Recontouring without removing supporting bone.
  • Osteotomy: Removes supporting bone.
• Implants:
  • Minimum 5 mm from mental foramen.
  • Blade implants: Linkow; Cylindrical: Schroeder.
  • Micro-movement >150 µm: Fibrous tissue formation.
  • Connective tissue near implant: No blood vessels, many fibroblasts.
  • Probing: Use plastic probes; max force = 25 N.
  • Florida probe tip: 0.4 mm.

• Perinatal transmission (90%)
• Window phase: HBsAg ↓, anti-HBs ↑
• Infectivity: HBsAg + HBeAg
• First marker post-infection: HBsAg
• IgM anti-HBc = acute infection
• Reverse transcriptase → P gene
  | Hepatitis C | Most chronic & linked to liver disease
  | Hepatitis A | Prophylaxis: Human IgG
  | Hepatitis E | Most epidemic-prone in India
  | Councilman bodies | Seen in acute viral hepatitis

🧂 Sodium Imbalance

• SIADH: Hyponatremia, convulsions
• Osmotic demyelination syndrome → too rapid correction
• Pseudohyponatremia: Seen in hyperlipidemia

⚖️ Acid-Base Disorders

• Normal pH: 7.36 – 7.44
• Metabolic alkalosis seen in mineralocorticoid excess

🧬 Risk Factors

• Increased homocysteine levels
• Raised lipoprotein(a)
• Nephrotic syndrome increases CAD risk
• Unsaturated fatty acid intake: Protective
• Best probability predictor in elderly: LDL/HDL ratio

⚕️ Diagnosis & Presentation

🧪 Enzymes & Drugs

• Enzyme ↑ at 4 – 6 hrs, ↓ in 3 – 4 days: CPK
• Stress ECHO agent: Dobutamine
• Intervention of choice: Streptokinase + Heparin
• Thrombolytics window: Within 12 hrs of MI

🚨 Prognosis & Complications

• Day 1: Maximum MI mortality
• Post-MI valvular lesion: Mitral regurgitation
• Best predictor of morbidity: LVEF
• Fatal thrombolysis complication: Intracranial hemorrhage
• LAD artery nicknamed: Widow’s artery

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.