NEET MDS Lessons
Pedodontics
Composition of Stainless Steel Crowns
Stainless steel crowns (SSCs) are primarily made from a specific type of stainless steel alloy, which provides the necessary strength, durability, and resistance to corrosion. Here’s a breakdown of the composition of the commonly used stainless steel crowns:
1. Stainless Steel (18-8) Austenitic Alloy:
- Common Brands: Rocky Mountain, Unitek
- Composition:
- Iron: 67%
- Chromium: 17%
- Nickel: 12%
- Carbon: 0.08 - 0.15%
This composition provides the crowns with excellent mechanical properties and resistance to corrosion, making them suitable for use in pediatric dentistry.
2. Nickel-Based Crowns:
- Examples: Inconel 600, 3M crowns
- Composition:
- Iron: 10%
- Chromium: 16%
- Nickel: 72%
- Others: 2%
Nickel-based crowns are also used in some cases, offering different properties and benefits, particularly in terms of strength and biocompatibility.
Theories of Child Psychology
Child psychology encompasses a variety of theories that explain how children develop emotionally, cognitively, and behaviorally. These theories can be broadly classified into two main groups: psychodynamic theories and theories of learning and development of behavior. Additionally, Margaret S. Mahler's theory of development offers a unique perspective on child development.
I. Psychodynamic Theories
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Psychosexual Theory / Psychoanalytical Theory (Sigmund Freud, 1905):
- Overview: Freud's theory posits that childhood experiences significantly influence personality development and behavior. He proposed that children pass through a series of psychosexual stages (oral, anal, phallic, latency, and genital) where the focus of pleasure shifts to different erogenous zones.
- Key Concepts:
- Id, Ego, Superego: The id represents primal desires, the ego mediates between the id and reality, and the superego embodies moral standards.
- Fixation: If a child experiences conflicts during any stage, they may become fixated, leading to specific personality traits in adulthood.
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Psychosocial Theory / Model of Personality Development (Erik Erikson, 1963):
- Overview: Erikson expanded on Freud's ideas by emphasizing social and cultural influences on development. He proposed eight stages of psychosocial development, each characterized by a central conflict that must be resolved for healthy personality development.
- Key Stages:
- Trust vs. Mistrust (Infancy)
- Autonomy vs. Shame and Doubt (Early Childhood)
- Initiative vs. Guilt (Preschool Age)
- Industry vs. Inferiority (School Age)
- Identity vs. Role Confusion (Adolescence)
- Intimacy vs. Isolation (Young Adulthood)
- Generativity vs. Stagnation (Middle Adulthood)
- Integrity vs. Despair (Late Adulthood)
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Cognitive Theory (Jean Piaget, 1952):
- Overview: Piaget's theory focuses on the cognitive development of children, proposing that they actively construct knowledge through interactions with their environment. He identified four stages of cognitive development.
- Stages:
- Sensorimotor Stage (0-2 years): Knowledge through sensory experiences and motor actions.
- Preoperational Stage (2-7 years): Development of language and symbolic thinking, but egocentric and intuitive reasoning.
- Concrete Operational Stage (7-11 years): Logical thinking about concrete events; understanding of conservation and reversibility.
- Formal Operational Stage (12 years and up): Abstract reasoning and hypothetical thinking.
II. Theories of Learning and Development of Behavior
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Hierarchy of Needs (Abraham Maslow, 1954):
- Overview: Maslow proposed a hierarchy of needs that motivates human behavior. He suggested that individuals must satisfy lower-level needs before addressing higher-level needs.
- Levels:
- Physiological Needs (food, water, shelter)
- Safety Needs (security, stability)
- Love and Belongingness Needs (relationships, affection)
- Esteem Needs (self-esteem, recognition)
- Self-Actualization (realizing personal potential)
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Social Learning Theory (Albert Bandura, 1963):
- Overview: Bandura emphasized the role of observational learning, imitation, and modeling in behavior development. He proposed that children learn behaviors by observing others and the consequences of those behaviors.
- Key Concepts:
- Reciprocal Determinism: Behavior, personal factors, and environmental influences interact to shape learning.
- Bobo Doll Experiment: Demonstrated that children imitate aggressive behavior observed in adults.
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Classical Conditioning (Ivan Pavlov, 1927):
- Overview: Pavlov's theory focuses on learning through association. He demonstrated that a neutral stimulus, when paired with an unconditioned stimulus, can elicit a conditioned response.
- Example: Pavlov's dogs learned to salivate at the sound of a bell when it was associated with food.
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Operant Conditioning (B.F. Skinner, 1938):
- Overview: Skinner's theory emphasizes learning through consequences. Behaviors followed by reinforcement are more likely to be repeated, while those followed by punishment are less likely to occur.
- Key Concepts:
- Reinforcement: Increases the likelihood of a behavior (positive or negative).
- Punishment: Decreases the likelihood of a behavior (positive or negative).
III. Margaret S. Mahler’s Theory of Development
- Overview: Mahler's theory focuses on the psychological development of infants and young children, particularly the process of separation-individuation. She proposed that children go through stages as they develop a sense of self and differentiate from their primary caregiver.
- Key Stages:
- Normal Autistic Phase: Birth to 2 months; the infant is primarily focused on internal stimuli.
- Normal Symbiotic Phase: 2 to 5 months; the infant begins to recognize the caregiver but does not differentiate between self and other.
- Separation-Individuation Phase: 5 to 24 months; the child starts to separate from the caregiver and develop a sense of individuality through exploration and interaction with the environment.
Devitalisation Pulpotomy (Two-Stage Procedure)
The two-stage devitalisation pulpotomy is a dental procedure aimed at treating exposed primary pulp tissue. This technique involves the use of paraformaldehyde to fix both coronal and radicular pulp tissues, ensuring effective devitalization. The medicaments employed in this procedure possess devitalizing, mummifying, and bactericidal properties, which are crucial for the success of the treatment.
Key Features of the Procedure:
- Two-Stage Approach: The procedure is divided into two stages, allowing for thorough treatment of the pulp tissue.
- Use of Paraformaldehyde: Paraformaldehyde is a key component in the medicaments, providing effective fixation and devitalization of the pulp.
- Medicaments: The following formulations are commonly used in the procedure:
Medicament Formulations:
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Gysi Triopaste:
- Tricresol: 10 ml
- Cresol: 20 ml
- Glycerin: 4 ml
- Paraformaldehyde: 20 ml
- Zinc Oxide: 60 g
Gysi Triopaste is known for its strong devitalizing and bactericidal effects, making it effective for pulp treatment.
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Easlick’s Paraformaldehyde Paste:
- Paraformaldehyde: 1 g
- Procaine Base: 0.03 g
- Powdered Asbestos: 0.05 g
- Petroleum Jelly: 125 g
- Carmine (for coloring)
This paste combines paraformaldehyde with a local anesthetic (Procaine) to enhance patient comfort during the procedure.
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Paraform Devitalizing Paste:
- Paraformaldehyde: 1 g
- Lignocaine: 0.06 g
- Propylene Glycol: 0.50 ml
- Carbowax 1500: 1.30 g
- Carmine (for coloring)
This formulation also includes Lignocaine for local anesthesia, providing additional comfort during treatment.
Cognitive Theory by Jean Piaget (1952)
Overview of Piaget's Cognitive Theory
bb Jean Piaget formulated a comprehensive theory of cognitive development that explains how children and adolescents think and acquire knowledge. His theories were derived from direct observations of children, where he engaged them in questioning about their thought processes. Piaget emphasized that children and adults actively seek to understand their environment rather than being shaped by it.
Key Concepts of Piaget's Theory
Piaget's theory of cognitive development is based on the process of adaptation, which consists of three functional variants:
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Assimilation:
- This process involves observing, recognizing, and interacting with an object and relating it to previous experiences or existing categories in the child's mind. For example, a child who knows what a dog is may see a cat and initially call it a dog because it has similar features.
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Accommodation:
- Accommodation occurs when a child changes their existing concepts or strategies in response to new information that does not fit into their current schemas. This leads to the development of new schemas. For instance, after learning that a cat is different from a dog, the child creates a new category for cats.
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Equilibration:
- Equilibration refers to the process of balancing assimilation and accommodation to create stable understanding. When children encounter new information that challenges their existing knowledge, they adjust their understanding to achieve a better fit with the facts.
Stages of Cognitive Development
Piaget categorized cognitive development into four major stages:
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Sensorimotor Stage (0 to 2 years):
- In this stage, infants learn about the world through their senses and actions. They develop object permanence and begin to understand that objects continue to exist even when they cannot be seen.
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Pre-operational Stage (2 to 6 years):
- During this stage, children begin to use language and engage in symbolic play. However, their thinking is still intuitive and egocentric, meaning they have difficulty understanding perspectives other than their own.
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Concrete Operational Stage (6 to 12 years):
- Children in this stage develop logical thinking but are still concrete in their reasoning. They can perform operations on tangible objects and understand concepts such as conservation (the idea that quantity does not change even when its shape does).
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Formal Operational Stage (11 to 15 years):
- In this final stage, adolescents develop the ability to think abstractly and hypothetically. They can formulate and test hypotheses and engage in systematic planning.
Merits of Piaget’s Theory
- Comprehensive Framework: Piaget's theory is one of the most comprehensive theories of cognitive development, providing a structured understanding of how children think and learn.
- Insight into Learning: The theory suggests that examining children's incorrect answers can provide valuable insights into their cognitive processes, just as much as correct answers can.
Demerits of Piaget’s Theory
- Underestimation of Abilities: Critics argue that Piaget underestimated the cognitive abilities of children, particularly in the pre-operational stage.
- Overestimation of Age Differences: The theory may overestimate the differences in thinking abilities between age groups, suggesting a more rigid progression than may actually exist.
- Vagueness in Change Processes: There is some vagueness regarding how changes in thinking occur, particularly in the transition between stages.
- Underestimation of Social Environment: Piaget's theory has been criticized for underestimating the role of social interactions and cultural influences on cognitive development.
Pulpotomy Techniques
Pulpotomy is a dental procedure performed to treat a tooth with a compromised pulp, typically in primary teeth. The goal is to remove the diseased pulp tissue while preserving the vitality of the remaining pulp. This procedure is commonly indicated in cases of carious exposure or trauma.
Vital Pulpotomy Technique
The vital pulpotomy technique involves the removal of the coronal portion of the pulp while maintaining the vitality of the radicular pulp. This technique can be performed in a single sitting or in two stages.
1. Single Sitting Pulpotomy
- Procedure: The entire pulpotomy procedure is completed in one appointment.
- Indications: This approach is often used when the pulp is still vital and there is no significant infection or inflammation.
2. Two-Stage Pulpotomy
- Procedure: The pulpotomy is performed in two appointments. The first appointment involves the removal of the coronal pulp, and the second appointment focuses on the placement of a medicament and final restoration.
- Indications: This method is typically used when there is a need for further evaluation of the pulp condition or when there is a risk of infection.
Medicaments Used in Pulpotomy
Several materials can be used during the pulpotomy procedure, particularly in the two-stage approach. These include:
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Formocresol:
- A commonly used medicament for pulpotomy, formocresol has both antiseptic and devitalizing properties.
- It is applied to the remaining pulp tissue after the coronal pulp is removed.
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Electrosurgery:
- This technique uses electrical current to remove the pulp tissue and can help achieve hemostasis.
- It is often used in conjunction with other materials for effective pulp management.
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Laser:
- Laser technology can be employed for pulpotomy, providing precise removal of pulp tissue with minimal trauma to surrounding structures.
- Lasers can also promote hemostasis and reduce postoperative discomfort.
Devitalizing Pastes
In addition to the above techniques, various devitalizing pastes can be used during the pulpotomy procedure:
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Gysi Triopaste:
- A devitalizing paste that can be used to manage pulp tissue during the pulpotomy procedure.
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Easlick’s Formaldehyde:
- A formaldehyde-based paste that serves as a devitalizing agent, often used in pulpotomy procedures.
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Paraform Devitalizing Paste:
- Another devitalizing agent that can be applied to the pulp tissue to facilitate the pulpotomy process.
Endodontic Filling Techniques
Endodontic filling techniques are essential for the successful treatment of root canal systems. Various methods have been developed to ensure that the canal is adequately filled with the appropriate material, providing a seal to prevent reinfection.
1. Endodontic Pressure Syringe
- Developed By: Greenberg; technique described by Speeding and Karakow in 1965.
- Features:
- Consists of a syringe barrel, threaded plunger, wrench, and threaded needle.
- The needle is placed 1 mm short of the apex.
- The technique involves a slow withdrawing motion, where the needle is withdrawn 3 mm with each quarter turn of the screw until the canal is visibly filled at the orifice.
2. Mechanical Syringe
- Proposed By: Greenberg in 1971.
- Features:
- Cement is loaded into the syringe using a 30-gauge needle, following the manufacturer's recommendations.
- The cement is expressed into the canal while applying continuous pressure and withdrawing the needle simultaneously.
3. Tuberculin Syringe
- Utilized By: Aylord and Johnson in 1987.
- Features:
- A standard 26-gauge, 3/8 inch needle is used for this technique.
- This method allows for precise delivery of filling material into the canal.
4. Jiffy Tubes
- Popularized By: Riffcin in 1980.
- Features:
- Material is expressed into the canal using slow finger pressure on the plunger until the canal is visibly filled at the orifice.
- This technique provides a simple and effective way to fill the canal.
5. Incremental Filling
- First Used By: Gould in 1972.
- Features:
- An endodontic plugger, corresponding to the size of the canal with a rubber stop, is used to place a thick mix of cement into the canal.
- The thick mix is prepared into a flame shape that corresponds to the size and shape of the canal and is gently tapped into the apical area with the plugger.
6. Lentulospiral Technique
- Advocated By: Kopel in 1970.
- Features:
- A lentulospiral is dipped into the filling material and introduced into the canal to its predetermined length.
- The lentulospiral is rotated within the canal, and additional paste is added until the canal is filled.
7. Other Techniques
- Amalgam Plugger:
- Introduced by Nosonwitz (1960) and King (1984) for filling canals.
- Paper Points:
- Utilized by Spedding (1973) for drying and filling canals.
- Plugging Action with Wet Cotton Pellet:
- Proposed by Donnenberg (1974) as a method to aid in the filling process.
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
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Crown Selection:
- An appropriate size of stainless steel crown is selected based on the dimensions of the tooth being restored.
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Contouring:
- The crown is contoured at the cervical margin to ensure a proper fit and to minimize the risk of gingival irritation.
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Polishing:
- The crown is polished to enhance its surface finish, which can help reduce plaque accumulation and improve esthetics.
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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
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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.
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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.