Contraindications and Limitations

Gingivectomy

• Major Contraindication: When pocket bottom is apical to mucogingival junction
• Risk: Inadequate attached gingiva post-surgery

Curettage Protocol

• Prerequisite: Should always be preceded by scaling and root planing
• Rationale: Reduce bacterial load before surgical intervention

GTR (Guided Tissue Regeneration)

Membrane Placement Technique

• Apical Extension: 3-4mm apical to defect margin
• Lateral Extension: 2-3mm laterally beyond defect
• Objective: Exclude epithelial and connective tissue cells

Implant Considerations

Placement Guidelines

• Distance from Mental Foramen: ≥5mm to avoid nerve damage
• Primary Stability: Critical for osseointegration

Micro-movement Tolerance

• Critical Threshold: >150μm causes fibrous tissue formation instead of osseointegration
• Clinical Implication: Importance of proper implant stability

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

Sharpening Stones

• Natural: India, Arkansas
• Artificial: Ruby, Carborundum, Ceramic

Surgical Equipment

• Dental loupes: 1.5 – 6× magnification
• Coe – pak working time: 15 – 20 minutes

Preventive Measures

• Calculus control toothpastes: Contain pyrophosphates
• Antibiotic prophylaxis: Amoxicillin 2.0g, 30 – 60 min before procedure

Abrasion Rates

• Dentin: 25× faster than enamel
• Cementum: 35× faster than enamel

Classification of Cementum According to Schroeder

Cementum is a specialized calcified tissue that covers the roots of teeth and plays a crucial role in periodontal health. According to Schroeder, cementum can be classified into several distinct types based on its cellular composition and structural characteristics. Understanding these classifications is essential for dental professionals in diagnosing and treating periodontal conditions.

Classification of Cementum

1. Acellular Afibrillar Cementum:

   • Characteristics:
     • Contains neither cells nor collagen fibers.
     • Present in the coronal region of the tooth.
     • Thickness ranges from 1 µm to 15 µm.
   • Function:
     • This type of cementum is thought to play a role in the attachment of the gingiva to the tooth surface.

2. Acellular Extrinsic Fiber Cementum:

   • Characteristics:
     • Lacks cells but contains closely packed bundles of Sharpey’s fibers, which are collagen fibers that anchor the cementum to the periodontal ligament.
     • Typically found in the cervical third of the roots.
     • Thickness ranges from 30 µm to 230 µm.
   • Function:
     • Provides strong attachment of the periodontal ligament to the tooth, contributing to the stability of the tooth in its socket.

3. Cellular Mixed Stratified Cementum:

   • Characteristics:
     • Contains both extrinsic and intrinsic fibers and may contain cells.
     • Found in the apical third of the roots, at the apices, and in furcation areas.
     • Thickness ranges from 100 µm to 1000 µm.
   • Function:
     • This type of cementum is involved in the repair and adaptation of the tooth root, especially in response to functional demands and periodontal disease.

4. Cellular Intrinsic Fiber Cementum:

   • Characteristics:
     • Contains cells but no extrinsic collagen fibers.
     • Primarily fills resorption lacunae, which are areas where cementum has been resorbed.
   • Function:
     • Plays a role in the repair of cementum and may be involved in the response to periodontal disease.

5. Intermediate Cementum:

   • Characteristics:
     • A poorly defined zone located near the cementoenamel junction (CEJ) of certain teeth.
     • Appears to contain cellular remnants of the Hertwig's epithelial root sheath (HERS) embedded in a calcified ground substance.
   • Function:
     • Its exact role is not fully understood, but it may be involved in the transition between enamel and cementum.

Clinical Significance

• Importance of Cementum:

  • Understanding the different types of cementum is crucial for diagnosing periodontal diseases and planning treatment strategies.
  • The presence of various types of cementum can influence the response of periodontal tissues to disease and trauma.

• Cementum in Periodontal Disease:

  • Changes in the thickness and composition of cementum can occur in response to periodontal disease, affecting tooth stability and attachment.

• 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

Gracey Curettes

Gracey curettes are specialized instruments designed for periodontal therapy, particularly for subgingival scaling and root planing. Their unique design allows for optimal adaptation to the complex anatomy of the teeth and surrounding tissues. This lecture will cover the characteristics, specific uses, and advantages of Gracey curettes in periodontal practice.

• Gracey curettes are area-specific curettes that come in a set of instruments, each designed and angled to adapt to specific anatomical areas of the dentition.

• Purpose: They are considered some of the best instruments for subgingival scaling and root planing due to their ability to provide excellent adaptation to complex root anatomy.

Specific Gracey Curette Designs and Uses

1. Gracey 1/2 and 3/4:

   • Indication: Designed for use on anterior teeth.
   • Application: Effective for scaling and root planing in the anterior region, allowing for precise access to the root surfaces.

2. Gracey 5/6:

   • Indication: Suitable for anterior teeth and premolars.
   • Application: Versatile for both anterior and premolar areas, providing effective scaling in these regions.

3. Gracey 7/8 and 9/10:

   • Indication: Designed for posterior teeth, specifically for facial and lingual surfaces.
   • Application: Ideal for accessing the buccal and lingual surfaces of posterior teeth, ensuring thorough cleaning.

4. Gracey 11/12:

   • Indication: Specifically designed for the mesial surfaces of posterior teeth.
   • Application: Allows for effective scaling of the mesial aspects of molars and premolars.

5. Gracey 13/14:

   • Indication: Designed for the distal surfaces of posterior teeth.
   • Application: Facilitates access to the distal surfaces of molars and premolars, ensuring comprehensive treatment.

Key Features of Gracey Curettes

• Area-Specific Design: Each Gracey curette is tailored for specific areas of the dentition, allowing for better access and adaptation to the unique contours of the teeth.

• Offset Blade: Unlike universal curettes, the blade of a Gracey curette is not positioned at a 90-degree angle to the lower shank. Instead, the blade is angled approximately 60 to 70 degrees from the lower shank, which is referred to as an "offset blade." This design enhances the instrument's ability to adapt to the tooth surface and root anatomy.

Advantages of Gracey Curettes

1. Optimal Adaptation: The area-specific design and offset blade allow for better adaptation to the complex anatomy of the roots, making them highly effective for subgingival scaling and root planing.

2. Improved Access: The angled blades enable clinicians to access difficult-to-reach areas, such as furcations and concavities, which are often challenging with standard instruments.

3. Enhanced Efficiency: The design of Gracey curettes allows for more efficient removal of calculus and biofilm from root surfaces, contributing to improved periodontal health.

4. Reduced Tissue Trauma: The precise design minimizes trauma to the surrounding soft tissues, promoting better healing and patient comfort.