Esthetic Preformed Crowns in Pediatric Dentistry

Esthetic preformed crowns are an important option in pediatric dentistry, providing a functional and aesthetic solution for restoring primary teeth. Here’s a detailed overview of various types of esthetic crowns used in children:

i) Polycarbonate Crowns

• Advantages:
  • Save time during the procedure.
  • Easy to trim and adjust with pliers.
• Usage: Often used for anterior teeth due to their aesthetic appearance.

ii) Strip Crowns

• Description: These are crown forms that are filled with composite material and bonded to the tooth. After polymerization, the crown form is removed.
• Advantages:
  • Most commonly used crowns in pediatric dental practice.
  • Easy to repair if damaged.
• Usage: Ideal for anterior teeth restoration.

iii) Pedo Jacket Crowns

• Material: Made of tooth-colored copolyester material filled with resin.
• Characteristics:
  • Left on the tooth after polymerization instead of being removed.
  • Available in only one shade.
  • Cannot be trimmed easily.
• Usage: Suitable for anterior teeth where aesthetics are a priority.

iv) Fuks Crowns

• Description: These crowns consist of a stainless steel shell sized to cover a portion of the tooth, with a polymeric coating made from a polyester/epoxy hybrid composition.
• Advantages: Provide a durable and aesthetic option for restoration.

v) New Millennium Crowns

• Material: Made from laboratory-enhanced composite resin material.
• Characteristics:
  • Bonded to the tooth and can be trimmed easily.
  • Very brittle and more expensive compared to other options.
• Usage: Suitable for anterior teeth requiring esthetic restoration.

vi) Nusmile Crowns

• Indication: Indicated when full coverage restoration is needed.
• Characteristics: Provide a durable and aesthetic solution for primary teeth.

vii) Cheng Crowns

• Description: Crowns with a pure resin facing that makes them stain-resistant.
• Advantages:
  • Less time-consuming and typically requires a single patient visit.
• Usage: Suitable for anterior teeth restoration.

viii) Dura Crowns

• Description: Pre-veneered crowns that can be placed even with poor moisture or hemorrhage control.
• Challenges: Not easy to fit and require a longer learning curve for proper placement.

ix) Pedo Pearls

• Material: Aluminum crown forms coated with a tooth-colored epoxy paint.
• Characteristics:
  • Relatively soft, which may affect long-term durability.
• Usage: Used for primary teeth restoration where aesthetics are important.

Recurrent Aphthous Ulcers (Canker Sores)

Overview of Recurrent Aphthous Ulcers (RAU)

• Definition:

  • Recurrent aphthous ulcers, commonly known as canker sores, are painful ulcerations that occur on the unattached mucous membranes of the mouth. They are characterized by their recurrent nature and can significantly impact the quality of life for affected individuals.

• Demographics:

  • RAU is most prevalent in school-aged children and young adults, with a peak incidence between the ages of 10 and 19 years.
  • It is reported to be the most common mucosal disorder across various ages and races globally.

Clinical Features

• Characteristics:

  • RAU is defined by recurrent ulcerations on the moist mucous membranes of the mouth.
  • Lesions can be discrete or confluent, forming rapidly in certain areas.
  • They typically feature:
    • A round to oval crateriform base.
    • Raised, reddened margins.
    • Significant pain.

• Types of Lesions:

  • Minor Aphthous Ulcers:
    • Usually single, smaller lesions that heal without scarring.
  • Major Aphthous Ulcers (RAS):
    • Larger, more painful lesions that may take longer to heal and can leave scars.
    • Also referred to as periadenitis mucosa necrotica recurrens or Sutton disease.
  • Herpetiform Ulcers:
    • Multiple small lesions that can appear in clusters.

• Duration and Healing:

  • Lesions typically persist for 4 to 12 days and heal uneventfully, with scarring occurring only rarely and usually in cases of unusually large lesions.

Epidemiology

• Prevalence:
  The condition occurs approximately three times more frequently in white children compared to black children.
  • Prevalence estimates of RAU range from 2% to 50%, with most estimates falling between 5% and 25%. Among medical and dental students, the estimated prevalence is between 50% and 60%.

Associated Conditions

• Systemic Associations:
  • RAS has been linked to several systemic diseases, including:
    • PFAPA Syndrome: Periodic fever, aphthous stomatitis, pharyngitis, and adenitis.
    • Behçet Disease: A systemic condition characterized by recurrent oral and genital ulcers.
    • Crohn's Disease: An inflammatory bowel disease that can present with oral manifestations.
    • Ulcerative Colitis: Another form of inflammatory bowel disease.
    • Celiac Disease: An autoimmune disorder triggered by gluten.
    • Neutropenia: A condition characterized by low levels of neutrophils, leading to increased susceptibility to infections.
    • Immunodeficiency Syndromes: Conditions that impair the immune system.
    • Reiter Syndrome: A type of reactive arthritis that can present with oral ulcers.
    • Systemic Lupus Erythematosus: An autoimmune disease that can cause various oral lesions.
    • MAGIC Syndrome: Mouth and genital ulcers with inflamed cartilage.

Classification of Cerebral Palsy

Cerebral palsy (CP) is a group of neurological disorders that affect movement, muscle tone, and motor skills. The classification of cerebral palsy is primarily based on the type of neuromuscular dysfunction observed in affected individuals. Below is an outline of the main types of cerebral palsy, along with their basic characteristics.

1. Spastic Cerebral Palsy (Approximately 70% of Cases)

• Definition: Characterized by hypertonicity (increased muscle tone) and exaggerated reflexes.
• Characteristics:
  • A. Hyperirritability of Muscles: Involved muscles exhibit exaggerated contractions when stimulated.
  • B. Tense, Contracted Muscles:
    • Example: Spastic Hemiplegia affects one side of the body, with the affected hand and arm flexed against the trunk. The leg may be flexed and internally rotated, leading to a limping gait with circumduction of the affected leg.
  • C. Limited Neck Control: Difficulty controlling neck muscles results in head rolling.
  • D. Trunk Muscle Control: Lack of control in trunk muscles leads to difficulties in maintaining an upright posture.
  • E. Coordination Issues: Impaired coordination of intraoral, perioral, and masticatory muscles can result in:
    • Impaired chewing and swallowing
    • Excessive drooling
    • Persistent spastic tongue thrust
    • Speech impairments

2. Dyskinetic Cerebral Palsy (Athetosis and Choreoathetosis) (Approximately 15% of Cases)

• Definition: Characterized by constant and uncontrolled movements.
• Characteristics:
  • A. Uncontrolled Motion: Involved muscles exhibit constant, uncontrolled movements.
  • B. Athetoid Movements: Slow, twisting, or writhing involuntary movements (athetosis) or quick, jerky movements (choreoathetosis).
  • C. Neck Muscle Involvement: Excessive head movement due to hypertonicity of neck muscles, which may cause the head to be held back, with the mouth open and tongue protruded.
  • D. Jaw Involvement: Frequent uncontrolled jaw movements or severe bruxism (teeth grinding).
  • E. Hypotonicity of Perioral Musculature:
    • Symptoms include mouth breathing, tongue protrusion, and excessive drooling.
  • F. Facial Grimacing: Involuntary facial expressions may occur.
  • G. Chewing and Swallowing Difficulties: Challenges in these areas are common.
  • H. Speech Problems: Communication difficulties may arise.

3. Ataxic Cerebral Palsy (Approximately 5% of Cases)

• Definition: Characterized by poor coordination and balance.
• Characteristics:
  • A. Incomplete Muscle Contraction: Involved muscles do not contract completely, leading to partial voluntary movements.
  • B. Poor Balance and Coordination: Individuals may exhibit a staggering or stumbling gait and difficulty grasping objects.
  • C. Tremors: Possible tremors or uncontrollable trembling when attempting voluntary tasks.

4. Mixed Cerebral Palsy (Approximately 10% of Cases)

• Definition: A combination of characteristics from more than one type of cerebral palsy.
• Example: Mixed spastic-athetoid quadriplegia, where features of both spastic and dyskinetic types are present.

Rubber Dam in Dentistry

The rubber dam is a crucial tool in dentistry, primarily used for isolating teeth during various procedures. Developed by Barnum in 1864, it enhances the efficiency and safety of dental treatments.

Rationale for Using Rubber Dam

1. Maintains Clean and Visible Field

   • The rubber dam isolates the treatment area from saliva and blood, providing a clear view for the clinician.

2. Patient Protection

   • Prevents aspiration or swallowing of foreign bodies, such as dental instruments or materials, ensuring patient safety.

3. Clinician Protection

   • Reduces the risk of exposure to blood and saliva, minimizing the potential for cross-contamination.

4. Reduces Risk of Cross-Contamination

   • Particularly important in procedures involving the root canal system, where maintaining a sterile environment is critical.

5. Retracts and Protects Soft Tissues

   • The dam retracts the cheeks, lips, and tongue, protecting soft tissues from injury during dental procedures.

6. Increases Efficiency

   • Minimizes the need for patient cooperation and frequent rinsing, allowing for a more streamlined workflow.

7. Application of Medicaments

   • Facilitates the application of medicaments without the fear of dilution from saliva or blood.

8. Improved Properties of Restorative Material

   • Ensures that restorative materials set properly by keeping the area dry and free from contamination.

9. Psychological Benefit to the Patient

   • Provides a sense of security and comfort, as patients may feel more at ease knowing that the area is isolated and protected.

Rubber Dam Sheet Specifications

Rubber dam sheets are available in various thicknesses, which can affect their handling and application:

• Thin: 0.15 mm
• Medium: 0.20 mm
• Heavy: 0.25 mm
• Extra-Heavy: 0.30 mm
• Special Heavy: 0.35 mm

Sizes and Availability

• Rubber dam sheets can be purchased in rolls or prefabricated sizes, typically 5” x 5” or 6” x 6”.
• Non-latex rubber dams are available only in the 6” x 6” size.

Color Options

• Rubber dams come in various colors. Darker colors provide better visual contrast, while lighter colors can illuminate the operating field and facilitate the placement of radiographic films beneath the dam.

Surface Characteristics

• Rubber dam sheets have a shiny and a dull surface. The dull surface is typically placed facing occlusally, as it is less reflective and reduces glare, enhancing visibility for the clinician.

Soldered Lingual Holding Arch

The soldered lingual holding arch is a classic bilateral mixed dentition space maintainer used in the mandibular arch. It is designed to maintain the space for the canines and premolars during the transitional dentition period, preventing unwanted movement of the molars and retroclination of the incisors.

Design and Construction

1. Components:

   • Bands: Fitted to the first permanent molars, which serve as the primary anchorage points for the appliance.
   • Wire: A 0.036- or 0.040-inch stainless steel wire is used, which is contoured to the arch form.

2. Arch Contouring:

   • The wire is extended forward to make contact with the cingulum area of the incisors, providing stability and maintaining the position of the lower molars.
   • The design must ensure that the wire does not interfere with the normal eruption paths of the incisors and provides an anterior arch form to facilitate alignment.

Functionality

• Space Maintenance:

  • The soldered lingual holding arch stabilizes the position of the lower molars, preventing mesial movement, and maintains the incisor relationships, thereby preserving the leeway space for the eruption of canines and premolars.

• Eruption Considerations:

  • The appliance should not interfere with the eruptive movements of the permanent canines and premolars, allowing for normal dental development.

Clinical Considerations

1. Placement Timing:

   • The lingual arch should not be placed before the eruption of the permanent incisors due to their frequent lingual eruption path.
   • If placed too early, the wire may interfere with the normal positioning of the incisors, particularly before the eruption of the lateral incisors.

2. Anchorage:

   • Using primary incisors as anterior stops does not provide sufficient anchorage to prevent significant loss of arch length. Therefore, the appliance should rely on the permanent molars for stability.

3. Durability and Maintenance:

   • The soldered lingual holding arch is designed to present minimal problems with breakage and oral hygiene concerns.
   • It should not interfere with the child’s ability to wear the appliance, ensuring compliance and effectiveness.

Conditioning and Behavioral Responses

This section outlines key concepts related to conditioning and behavioral responses, particularly in the context of learning and emotional responses in children.

1. Acquisition

• Acquisition refers to the process of learning a new response to a stimulus through conditioning. This is the initial stage where an association is formed between a conditioned stimulus (CS) and an unconditioned stimulus (US).
• Example: A child learns to associate the sound of a bell (CS) with receiving a treat (US), leading to a conditioned response (CR) of excitement when the bell rings.

2. Generalization

• Generalization occurs when the conditioned response is evoked by stimuli that are similar to the original conditioned stimulus. This means that the learned response can be triggered by a range of similar stimuli.
• Example: If a child has a painful experience with a doctor in a white coat, they may generalize this fear to all doctors in white coats, regardless of the specific individual or setting. Thus, any doctor wearing a white coat may elicit a fear response.

3. Extinction

• Extinction is the process by which the conditioned behavior diminishes or disappears when the association between the conditioned stimulus and the unconditioned stimulus is no longer reinforced.
• Example: In the previous example, if the child visits the doctor multiple times without any unpleasant experiences, the fear associated with the doctor in a white coat may gradually extinguish. The lack of reinforcement (pain) leads to a decrease in the conditioned response (fear).

4. Discrimination

• Discrimination is the ability to differentiate between similar stimuli and respond only to the specific conditioned stimulus. It is the opposite of generalization.
• Example: If the child is exposed to clinic settings that are different from those associated with painful experiences, they learn to discriminate between the two environments. For instance, if the child visits a friendly clinic with a different atmosphere, they may no longer associate all clinic visits with fear, leading to the extinction of the generalized fear response.