Finger Rests in Dental Instrumentation

Use of finger rests is essential for providing stability and control during procedures. A proper finger rest allows for more precise movements and reduces the risk of hand fatigue.

Importance of Finger Rests

• Stabilization: Finger rests serve to stabilize the hand and the instrument, providing a firm fulcrum that enhances control during procedures.
• Precision: A stable finger rest allows for more accurate instrumentation, which is crucial for effective treatment and patient safety.
• Reduced Fatigue: By providing support, finger rests help reduce hand and wrist fatigue, allowing the clinician to work more comfortably for extended periods.

Types of Finger Rests

1. Conventional Finger Rest:

   • Description: The finger rest is established on the tooth surfaces immediately adjacent to the working area.
   • Application: This is the most common type of finger rest, providing direct support for the hand while working on a specific tooth. It allows for precise movements and control during instrumentation.

2. Cross Arch Finger Rest:

   • Description: The finger rest is established on the tooth surfaces on the other side of the same arch.
   • Application: This technique is useful when working on teeth that are not directly adjacent to the finger rest. It provides stability while allowing access to the working area from a different angle.

3. Opposite Arch Finger Rest:

   • Description: The finger rest is established on the tooth surfaces of the opposite arch (e.g., using a mandibular arch finger rest for instrumentation on the maxillary arch).
   • Application: This type of finger rest is particularly beneficial when accessing the maxillary teeth from the mandibular arch, providing a stable fulcrum while maintaining visibility and access.

4. Finger on Finger Rest:

   • Description: The finger rest is established on the index finger or thumb of the non-operating hand.
   • Application: This technique is often used in areas where traditional finger rests are difficult to establish, such as in the posterior regions of the mouth. It allows for flexibility and adaptability in positioning.

Effects of Smoking on the Etiology and Pathogenesis of Periodontal Disease

Smoking is a significant risk factor for the development and progression of periodontal disease. It affects various aspects of periodontal health, including microbiology, immunology, and physiology. Understanding these effects is crucial for dental professionals in managing patients with periodontal disease, particularly those who smoke.

Etiologic Factors and the Impact of Smoking

1. Microbiology

   • Plaque Accumulation:
     • Smoking does not affect the rate of plaque accumulation on teeth. This means that smokers may have similar levels of plaque as non-smokers.
   • Colonization of Periodontal Pathogens:
     • Smoking increases the colonization of shallow periodontal pockets by periodontal pathogens. This can lead to an increased risk of periodontal disease.
     • There are higher levels of periodontal pathogens found in deep periodontal pockets among smokers, contributing to the severity of periodontal disease.

2. Immunology

   • Neutrophil Function:
     • Smoking alters neutrophil chemotaxis (the movement of neutrophils towards infection), phagocytosis (the process by which neutrophils engulf and destroy pathogens), and the oxidative burst (the rapid release of reactive oxygen species to kill bacteria).
   • Cytokine Levels:
     • Increased levels of pro-inflammatory cytokines such as Tumor Necrosis Factor-alpha (TNF-α) and Prostaglandin E2 (PGE2) are found in the gingival crevicular fluid (GCF) of smokers. These cytokines play a role in inflammation and tissue destruction.
   • Collagenase and Elastase Production:
     • There is an increase in neutrophil collagenase and elastase in GCF, which can contribute to the breakdown of connective tissue and exacerbate periodontal tissue destruction.
   • Monocyte Response:
     • Smoking enhances the production of PGE2 by monocytes in response to lipopolysaccharides (LPS), further promoting inflammation and tissue damage.

3. Physiology

   • Gingival Blood Vessels:
     • Smoking leads to a decrease in gingival blood vessels, which can impair the delivery of immune cells and nutrients to the periodontal tissues, exacerbating inflammation.
   • Gingival Crevicular Fluid (GCF) Flow:
     • There is a reduction in GCF flow and bleeding on probing, even in the presence of increased inflammation. This can mask the clinical signs of periodontal disease, making diagnosis more challenging.
   • Subgingival Temperature:
     • Smoking is associated with a decrease in subgingival temperature, which may affect the metabolic activity of periodontal pathogens.
   • Recovery from Local Anesthesia:
     • Smokers may require a longer time to recover from local anesthesia, which can complicate dental procedures and patient management.

Clinical Implications

1. Increased Risk of Periodontal Disease:

   • Smokers are at a higher risk for developing periodontal disease due to the combined effects of altered microbial colonization, impaired immune response, and physiological changes in the gingival tissues.

2. Challenges in Diagnosis:

   • The reduced bleeding on probing and altered GCF flow in smokers can lead to underdiagnosis or misdiagnosis of periodontal disease. Dental professionals must be vigilant in assessing periodontal health in smokers.

3. Treatment Considerations:

   • Smoking cessation should be a key component of periodontal treatment plans. Educating patients about the effects of smoking on periodontal health can motivate them to quit.
   • Treatment may need to be more aggressive in smokers due to the increased severity of periodontal disease and the altered healing response.

4. Monitoring and Maintenance:

   • Regular monitoring of periodontal health is essential for smokers, as they may experience more rapid disease progression. Tailored maintenance programs should be implemented to address their specific needs.

Necrotizing Ulcerative Gingivitis (NUG)

Necrotizing Ulcerative Gingivitis (NUG), also known as Vincent's disease or trench mouth, is a severe form of periodontal disease characterized by the sudden onset of symptoms and specific clinical features.

Etiology and Predisposing Factors

• Sudden Onset: NUG is characterized by a rapid onset of symptoms, often following debilitating diseases or acute respiratory infections.
• Lifestyle Factors: Changes in living habits, such as prolonged work without adequate rest, poor nutrition, tobacco use, and psychological stress, are frequently noted in patient histories .
• Smoking: Smoking has been identified as a significant predisposing factor for NUG/NDP .
• Immune Compromise: Conditions that compromise the immune system, such as poor oral hygiene, smoking, and emotional stress, are major contributors to the development of NUG .

Clinical Presentation

• Symptoms: NUG presents with:
  • Punched-out, crater-like depressions at the crest of interdental papillae.
  • Marginal gingival involvement, with rare extension to attached gingiva and oral mucosa.
  • Grey, pseudomembranous slough covering the lesions.
  • Spontaneous bleeding upon slight stimulation of the gingiva.
  • Fetid odor and increased salivation.

Microbiology

• Mixed Bacterial Infection: NUG is caused by a complex of anaerobic bacteria, often referred to as the fusospirochetal complex, which includes:
  • Treponema vincentii
  • Treponema denticola
  • Treponema macrodentium
  • Fusobacterium nucleatum
  • Prevotella intermedia
  • Porphyromonas gingivalis

Treatment

1. Control of Acute Phase:

   • Clean the wound with an antibacterial agent.
   • Irrigate the lesion with warm water and 5% vol/vol hydrogen peroxide.
   • Prescribe oxygen-releasing mouthwash (e.g., hydrogen peroxide DPF, sodium perborate DPF) to be used thrice daily.
   • Administer oral metronidazole for 3 to 5 days. If sensitive to metronidazole, prescribe penicillin; if sensitive to both, consider erythromycin or clindamycin.
   • Use 2% chlorhexidine in select cases for a short duration.

2. Management of Residual Condition:

   • Remove predisposing local factors (e.g., overhangs).
   • Perform supra- and subgingival scaling.
   • Consider gingivoplasty to correct any residual gingival deformities.

PERIOTEST Device in Periodontal Assessment

The PERIOTEST device is a valuable tool used in dentistry to assess the mobility of teeth and the reaction of the periodontium to applied forces. This lecture covers the principles of the PERIOTEST device, its measurement scale, and its clinical significance in evaluating periodontal health.

Function: The PERIOTEST device measures the reaction of the periodontium to a defined percussion force applied to the tooth. This is done using a tapping instrument that delivers a controlled force to the tooth.

Contact Time: The contact time between the tapping head and the tooth varies between 0.3 and 2 milliseconds. This duration is typically shorter for stable teeth compared to mobile teeth, allowing for a quick assessment of tooth stability.

PERIOTEST Scale

The PERIOTEST scale ranges from -8 to +50, with specific ranges indicating different levels of tooth mobility:

Clinical Significance

Assessment of Tooth Mobility:
The PERIOTEST device provides a quantitative measure of tooth mobility, which is essential for diagnosing periodontal disease and assessing the stability of teeth.

Correlation with Other Measurements:
The PERIOTEST values correlate well with:

• Tooth Mobility Assessed with a Metric System: This allows for a standardized approach to measuring mobility, enhancing the reliability of assessments.

• Degree of Periodontal Disease and Alveolar Bone Loss: Higher mobility readings often indicate more severe periodontal disease and greater loss of supporting bone, making the PERIOTEST a useful tool in monitoring disease progression.

Treatment Planning:
Understanding the mobility of teeth can aid in treatment planning, including decisions regarding periodontal therapy, splinting of mobile teeth, or extraction in cases of severe mobility.

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.

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.