Pit and Fissure Sealants

Pit and fissure sealants are preventive dental materials used to protect occlusal surfaces of teeth from caries by sealing the grooves and pits that are difficult to clean. According to Mitchell and Gordon (1990), sealants can be classified based on several criteria, including polymerization methods, resin systems, filler content, and color.

Classification of Pit and Fissure Sealants

1. Polymerization Methods

Sealants can be differentiated based on how they harden or polymerize:

• a) Self-Activation (Mixing Two Components)

  • These sealants harden through a chemical reaction that occurs when two components are mixed together. This method does not require any external light source.

• b) Light Activation

  • Sealants that require a light source to initiate the polymerization process can be further categorized into generations:
    • First Generation: Ultraviolet Light
      • Utilizes UV light for curing, which can be less common due to safety concerns.
    • Second Generation: Self-Cure
      • These sealants harden through a chemical reaction without the need for light, similar to self-activating sealants.
    • Third Generation: Visible Light
      • Cured using visible light, which is more user-friendly and safer than UV light.
    • Fourth Generation: Fluoride-Releasing
      • These sealants not only provide a physical barrier but also release fluoride, which can help in remineralizing enamel and providing additional protection against caries.

2. Resin System

The type of resin used in sealants can also classify them:

• BIS-GMA (Bisphenol A Glycidyl Methacrylate)
  • A commonly used resin that provides good mechanical properties and adhesion.
• Urethane Acrylate
  • Offers enhanced flexibility and durability, making it suitable for areas subject to stress.

3. Filled and Unfilled

Sealants can be categorized based on the presence of fillers:

• Filled Sealants

  • Contain added particles that enhance strength and wear resistance. They may provide better wear characteristics but can be more viscous and difficult to apply.

• Unfilled Sealants

  • Typically have a smoother flow and are easier to apply, but may not be as durable as filled sealants.

4. Clear or Tinted

The color of the sealant can also influence its application:

• Clear Sealants

  • Have better flow characteristics, allowing for easier penetration into pits and fissures. They are less visible, which can be a disadvantage in monitoring during follow-up visits.

• Tinted Sealants

  • Easier for both patients and dentists to see, facilitating monitoring and assessment during recalls. However, they may have slightly different flow characteristics compared to clear sealants.

Application Process

• Sealants are applied in a viscous liquid state that enters the micropores of the tooth surface, which have been enlarged through acid conditioning.
• Once applied, the resin hardens due to either a self-hardening catalyst or the application of a light source.
• The extensions of the hardened resin that penetrate and fill the micropores are referred to as "tags," which help in retaining the sealant on the tooth surface.

Mahler's Stages of Development

1. Normal Autistic Phase (0-1 year):

   • Overview: In this initial phase, infants are primarily focused on their own needs and experiences. They are not yet aware of the external world or the presence of others.
   • Characteristics: Infants are in a state of self-absorption, and their primary focus is on basic needs such as feeding and comfort. They may not respond to external stimuli or caregivers in a meaningful way.
   • Application in Pedodontics: During this stage, dental professionals may not have direct interactions with infants, as their focus is on basic care. However, creating a soothing environment can help infants feel secure during dental visits.

2. Normal Symbiotic Phase (3-4 weeks to 4-5 months):

   • Overview: In this phase, infants begin to develop a sense of connection with their primary caregiver, typically the mother. They start to recognize the caregiver as a source of comfort and security.
   • Characteristics: Infants may show signs of attachment and begin to respond to their caregiver's presence. They rely on the caregiver for emotional support and comfort.
   • Application in Pedodontics: During dental visits, having a parent or caregiver present can help infants feel more secure. Dental professionals can encourage caregivers to hold or comfort the child during procedures to foster a sense of safety.

3. Separation-Individuation Process (5 to 36 months):

   • This process is further divided into several sub-stages, each representing a critical aspect of a child's development of independence and self-identity.

   • Differentiation (5-10 months):

     • Overview: Infants begin to differentiate themselves from their caregivers. They start to explore their environment while still seeking reassurance from their caregiver.
     • Application in Pedodontics: Dental professionals can encourage exploration by allowing children to touch and interact with dental tools in a safe manner, helping them feel more comfortable.

   • Practicing Period (10-16 months):

     • Overview: During this stage, children actively practice their newfound mobility and independence. They may explore their surroundings more confidently.
     • Application in Pedodontics: Allowing children to walk or move around the dental office (within safe limits) can help them feel more in control and less anxious.

   • Rapprochement (16-24 months):

     • Overview: Children begin to seek a balance between independence and the need for closeness to their caregiver. They may alternate between wanting to explore and wanting comfort.
     • Application in Pedodontics: Dental professionals can support this stage by providing reassurance and comfort when children express anxiety, while also encouraging them to engage with the dental environment.

   • Consolidation and Object Constancy (24-36 months):

     • Overview: In this final sub-stage, children develop a more stable sense of self and an understanding that their caregiver exists even when not in sight. They begin to form a more complex understanding of relationships.
     • Application in Pedodontics: By this stage, children can better understand the dental process and may be more willing to cooperate. Dental professionals can explain procedures in simple terms, reinforcing the idea that the dentist is there to help

Stainless Steel Crowns

Stainless steel crowns (SSCs) are a common restorative option for primary teeth, particularly in pediatric dentistry. They are especially useful for teeth with extensive carious lesions or structural damage, providing durability and protection for the underlying tooth structure.

Indications for Stainless Steel Crowns

• Primary Incisors or Canines:
  • SSCs are indicated for primary incisors or canines that have extensive proximal lesions, especially when the incisal portion of the tooth is involved.
  • They are particularly beneficial in cases where traditional restorative materials (like amalgam or composite) may not provide adequate strength or longevity.

Crown Selection and Preparation

1. Crown Selection:

   • An appropriate size of stainless steel crown is selected based on the dimensions of the tooth being restored.

2. Contouring:

   • The crown is contoured at the cervical margin to ensure a proper fit and to minimize the risk of gingival irritation.

3. Polishing:

   • The crown is polished to enhance its surface finish, which can help reduce plaque accumulation and improve esthetics.

4. Cementation:

   • The crown is cemented into place using a suitable dental cement, ensuring a secure fit even on teeth that have undergone significant carious structure removal.

Advantages of Stainless Steel Crowns

• Retention:
  • SSCs provide excellent retention and can remain in place even when extensive portions of carious tooth structure have been removed.
• Durability:
  • They are highly durable and can withstand the forces of mastication, making them ideal for primary teeth that are subject to wear and tear.

Esthetic Considerations

• Esthetic Limitations:

  • One of the drawbacks of stainless steel crowns is their metallic appearance, which may not meet the esthetic requirements of some children and their parents.

• Open-Face Stainless Steel Crowns:

  • To address esthetic concerns, a technique known as the open-face stainless steel crown can be employed.
  • In this technique, most of the labial metal of the crown is cut away, creating a labial "window."
  • This window is then restored with composite resin, allowing for a more natural appearance while still providing the strength and durability of the stainless steel crown.

 Anomalies of Number: problems in initiation stage

 Hypodontia: 6% incidence; usually autosomal dominant (50% chance of passing to children) with variable expressivity (e.g., parent has mild while child has severe); most common missing permanent tooth (excluding 3rd molars) is Md 2nd premolar, 2nd most common is X lateral; oligodontia (at least 6 missing), and anodontia

1. Clincial implications: can interfere with function, lack of teeth → ↓ alveolar bone formation, esthetics, hard to replace in young children, implants only after growth completed, severe cases should receive genetic and systemic evaluation to see if other problems

2. Syndromes with hypodontia: Rieger syndrome, incontinentia pigmenti, Kabuki syndrome, Ellis-van Creveld syndrome, epidermolysis bullosa junctionalis, and ectodermal dysplasia (usually X-linked; sparse hair, unable to sweat, dysplastic nails)

Supernumerary teeth: aka hyperdontia; mesiodens when located in palatal midline; occur sporadically or as part of syndrome, common in cleft cases; delayed eruption often a sign that supernumeraries are preventing normal eruption

1. Multiple supernumerary teeth: cleidocranial dysplasia/dysostosis, Down’s, Apert, and Crouzon syndromes, etc.

Anomalies of Size: problems in morphodifferentiation stage

Microdontia: most commonly peg laterals; also in Down’s syndrome, hemifacial microsomia

Macrodontia: may be associated with hemifacial hypertrophy

Fusion: more common in primary dentition; union of two developing teeth

Gemination: more common in primary; incomplete division of single tooth bud → bifid crown, one pulp chamber; clinically distinguish from fusion by counting geminated tooth as one and have normal # teeth present (not in fusion)

 Anomalies of Shape: errors during morphodifferentiation stage

Dens evaginatus: extra cusp in central groove/cingulum; fracture can → pulp exposure; most common in Orientals

Dens in dente: invagination of inner enamel epithelium → appearance of tooth within a tooth

Taurodontism: failure of Hertwig’s epithelial root sheath to invaginate to proper level → elongated (deep) pulp chamber, stunted roots; sporadic or associated with syndrome (e.g., amelogenesis imperfecta, Trichodento-osseous syndrome, ectodermal dysplasia)

Conical teeth: often associated with ectodermal dysplasia

Anomalies of Structure: problems during histodifferentiation, apposition, and mineralization stages

Dentinogenesis imperfecta: problem during histodifferentiation where defective dentin matrix → disorganized and atubular circumpulpal dentin; autosomal dominant inheritance; three types, one occurs with osteogenesis imperfecta (brittle bone syndrome); not sensitive despite exposed dentin; primary dentition has bulbous crowns, obliterated pulp chambers, bluish-grey or brownish-yellow teeth that are easily worn; permanent teeth often stained but can be sound

Amelogenesis imperfecta: heritable defect, independent from metabolic, syndromes, or systemic conditions (though similar defects seen with syndromes or environmental insults); four main types (hypoplastic, hypocalcified, hypomaturation, hypoplastic/hypomaturation with taurodontism); proper treatment addresses sensitivity, esthetics, VDO, caries and gingivitis prevention

Enamel hypoplasia: quantitative defect of enamel from problems in apposition stage; localized (caused by trauma) or generalized (caused by infection, metabolic disease, malnutrition, or hereditary disorders) effects; more common in malnourished children; least commonly Md incisors affected, often 1st molars; more susceptible to caries, excessive wearing → lost VDO, esthetic problems, and sensitivity to hot/cold

Enamel hypocalcification: during calcification stage

Fluorosis: excess F ingestion during calcification stage → intrinsic stain, mottled appearance, or brown staining and pitting; mild, moderate, or severe; porous enamel soaks up external stain

Digit Sucking and Infantile Swallow

Introduction to Digit Sucking

Digit sucking is a common behavior observed in infants and young children. It can be categorized into two main types based on the underlying reasons for the behavior:

1. Nutritive Sucking

   • Definition: This type of sucking occurs during feeding and is essential for nourishment.
   • Timing: Nutritive sucking typically begins in the first few weeks of life.
   • Causes: It is primarily associated with feeding problems, where the infant may suck on fingers or digits as a substitute for breastfeeding or bottle-feeding.

2. Non-Nutritive Sucking

   • Definition: This type of sucking is not related to feeding and serves other psychological or emotional needs.
   • Causes: Non-nutritive sucking can arise from various psychological factors, including:
     • Hunger
     • Satisfying the innate sucking instinct
     • Feelings of insecurity
     • Desire for attention
   • Examples: Common forms of non-nutritive sucking habits include:
     • Thumb or finger sucking
     • Pacifier sucking

Non-Nutritive Sucking Habits (NMS Habits)

• Characteristics: Non-nutritive sucking habits are often comforting for children and can serve as a coping mechanism in stressful situations.
• Implications: While these habits are generally normal in early childhood, prolonged non-nutritive sucking can lead to dental issues, such as malocclusion or changes in the oral cavity.

Infantile Swallow

• Definition: The infantile swallow is a specific pattern of swallowing observed in infants.
• Characteristics:
  • Active contraction of the lip musculature.
  • The tongue tip is positioned forward, making contact with the lower lip.
  • Minimal activity of the posterior tongue and pharyngeal musculature.
• Posture: The tongue-to-lower lip contact is so prevalent in infants that it often becomes their resting posture. This can be observed when gently moving the infant's lip, causing the tongue tip to move in unison, suggesting a strong connection between the two.
• Developmental Changes: The sucking reflex and the infantile swallow typically diminish and disappear within the first year of life as the child matures and develops more complex feeding and swallowing patterns.

Moro Reflex and Startle Reflex

Moro Reflex

• The Moro reflex, also known as the startle reflex, is an involuntary response observed in infants, typically elicited by sudden movements or changes in position of the head and neck.

• Elicitation:

  • A common method to elicit the Moro reflex is to pull the baby halfway to a sitting position from a supine position and then suddenly let the head fall back a short distance.

• Response:

  • The reflex consists of a rapid abduction and extension of the arms, accompanied by the opening of the hands.
  • Following this initial response, the arms then come together as if in an embrace.

• Clinical Importance:

  • The Moro reflex provides valuable information about the infant's muscle tone and neurological function.
  • An asymmetrical response may indicate:
    • Unequal muscle tone on either side.
    • Weakness in one arm.
    • Possible injury to the humerus or clavicle.
  • The Moro reflex typically disappears by 2 to 3 months of age, which is a normal part of development.

Startle Reflex

• The startle reflex is similar to the Moro reflex but is specifically triggered by sudden noises or other unexpected stimuli.

• Response:

  • In the startle reflex, the elbows are flexed, and the hands remain closed, showing less of an embracing motion compared to the Moro reflex.
  • The movement of the arms may involve both outward and inward motions, but it is less pronounced than in the Moro reflex.

• Clinical Importance:

  • The startle reflex is an important indicator of an infant's sensory processing and neurological integrity.
  • It can also be used to assess the infant's response to environmental stimuli and overall alertness.