Laser Classifications

Hard Tissue Lasers

• Er:YAG and Er:YSGG: Highest water absorption coefficients
• Applications: Calculus removal, root surface modification, bone surgery

Soft Tissue Applications

• CO2 Laser: Excellent for soft tissue procedures
• Diode Lasers: Hemostasis and bacterial reduction

Microsurgery Principles

Wound Approximation

• Technique: Butt joint approximation for optimal healing
• Instrumentation: Instruments weighing ≤15-20g for precision

Smoking

• Pack years = Packs/day × Years of smoking

Diabetes

• Causes collagen cross – linking via AGEs formation

AIDS

• Most common oral lesion: Candidiasis
• Most common oral malignancy: Kaposi sarcoma

• Scaling in 2 appointments within 24 hours
• Tongue brushing with 1% chlorhexidine gel
• 0.2% chlorhexidine rinse
• 1% chlorhexidine pocket irrigation

Oral Hygiene Tools

Toothbrush Bristle Diameter:

• Soft: 0.007" (0.2 mm)
• Medium: 0.012" (0.3 mm)
• Hard: 0.014" (0.4 mm)

Brushing Techniques:

• Roll: Modified Stillman
• Circular: Fones
• Vertical: Leonard
• Horizontal: Scrub

Scaling Instruments

• Gracey curettes: Only outer cutting edge
• Universal curettes: Both edges cutting
• Langer curettes: Gracey shank + Universal blade
• Best grasp: Modified pen grasp (tripod effect)
• Scaling angle: 45 – 90°

Ultrasonic Scaling

• Vibration frequency: 18,000 – 50,000 cycles/sec

Stroke Types

• Exploratory: Light feeling (with probes)
• Scaling: Short powerful pull
• Root planing: Moderate to light pull

• Normal count + ↑ BT: Platelet functional defect
• Small platelets: Wiskott – Aldrich syndrome
• ITP: Antibody against platelets, ↑ bleeding time
• Platelet transfusion not indicated in immunologic thrombocytopenia
• Thrombocytopenia not seen in Henoch – Schönlein purpura

Calculus Composition

• Brushite: More common in mandibular anterior
• Magnesium whitlockite: More common in posterior
• Ca:P ratio: Higher subgingivally
• Mineralization: 50% in 2 days, 60 – 90% in 12 days

Microbiology

• First colonizers: S. salivarius and S. mitis
• Red complex: P. gingivalis, T. denticola, T. forsythia (cause BOP)
• Growth enhancement: P. gingivalis grows better with succinate (C. ochracea) and protoheme (C. rectus)

Pellicle Structure

• Basal layer: Thin, difficult to remove
• Globular layer: 1 μm thick, easier to detach

Bacterial Recognition

• Gram positive: Activate TLR2 → IL – 8
• Gram negative: Activate TLR4 → TNF – α

• 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