NEET MDS Synopsis
Endodontic Filling Techniques
Pedodontics
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is withdrawn 3 mm with each quarter turn of the screw until the canal is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.
COENZYMES
Biochemistry
COENZYMES
Enzymes may be simple proteins, or complex enzymes.
A complex enzyme contains a non-protein part, called as prosthetic group (co-enzymes).
Coenzymes are heat stable low molecular weight organic compound. The combined form of protein and the co-enzyme are called as holo-enzyme. The heat labile or unstable part of the holo-enzyme is called as apo-enzyme. The apo-enzyme gives necessary three dimensional structures required for the enzymatic chemical reaction.
Co-enzymes are very essential for the biological activities of the enzyme.
Co-enzymes combine loosely with apo-enzyme and are released easily by dialysis. Most of the co-enzymes are derivatives of vitamin B complex
COPD and Cancer
PhysiologyCOPD and Cancer
A. Chronic Obstructive Pulmonary Disease (COPD)
1. Common features of COPD
a. almost all have smoking history
b. dyspnea - chronic "gasping" for air
c. frequent coughing and infections
d. often leads to respiratory failure
2. obstructive emphysema - usually results from smoking
a. enlargement & deterioration of alveoli
b. loss of elasticity of the lungs
c. "barrel chest" from bronchiole opening during inhalation & constriction during exhalation
3. chronic bronchitis - mucus/inflammation of mucosa
B. Lung Cancer
1. squamous cell carcinoma (20-40%) - epithelium of the bronchi and bronchioles
2. adenocarcinoma (25-35%) - cells of bronchiole glands and cells of the alveoli
3. small cell carcinoma (10-20%) - special lymphocyte-like cells of the bronchi
4. 90% of all lung cancers are in people who smoke or have smoked
CPP-ACP- casein phosphopeptide-amorphous calcium phosphate
Conservative Dentistry
CPP-ACP, or casein phosphopeptide-amorphous calcium phosphate, is a
significant compound in dentistry, particularly in the prevention and management
of dental caries (tooth decay).
Role and applications in dentistry:
Composition and Mechanism
Composition: CPP-ACP is derived from casein, a milk
protein. It contains clusters of calcium and phosphate ions that are
stabilized by casein phosphopeptides.
Mechanism: The unique structure of CPP-ACP allows it to
stabilize calcium and phosphate in a soluble form, which can be delivered to
the tooth surface. When applied to the teeth, CPP-ACP can release these
ions, promoting the remineralization of enamel and dentin, especially in
early carious lesions.
Benefits in Dentistry
Remineralization: CPP-ACP helps in the remineralization
of demineralized enamel, making it an effective treatment for early carious
lesions.
Caries Prevention: Regular use of CPP-ACP can help
prevent the development of caries by maintaining a higher concentration of
calcium and phosphate in the oral environment.
Reduction of Sensitivity: It can help reduce tooth
sensitivity by occluding dentinal tubules and providing a protective layer
over exposed dentin.
pH Buffering: CPP-ACP can help buffer the pH in the
oral cavity, reducing the risk of acid-induced demineralization.
Compatibility with Fluoride: CPP-ACP can be used in
conjunction with fluoride, enhancing the overall effectiveness of caries
prevention strategies.
Applications
Toothpaste: Some toothpaste formulations include
CPP-ACP to enhance remineralization and provide additional protection
against caries.
Chewing Gum: Sucrose-free chewing gums containing
CPP-ACP can be used to promote oral health, especially after meals.
Dental Products: CPP-ACP is also found in various
dental products, including varnishes and gels, used in professional dental
treatments.
Considerations
Lactose Allergy: Since CPP-ACP is derived from milk, it
should be avoided by individuals with lactose intolerance or milk protein
allergies.
Clinical Use: Dentists may recommend CPP-ACP products
for patients at high risk for caries, those with a history of dental decay,
or individuals undergoing orthodontic treatment.
Primary Bone Healing and Rigid Fixation
Oral and Maxillofacial SurgeryPrimary Bone Healing and Rigid Fixation
Primary bone healing is a process that occurs when bony
fragments are compressed against each other, allowing for direct healing without
the formation of a callus. This type of healing is characterized by the
migration of osteocytes across the fracture line and is facilitated by rigid
fixation techniques. Below is a detailed overview of the concept of primary bone
healing, the mechanisms involved, and examples of rigid fixation methods.
Concept of Compression
Compression of Bony Fragments: In primary bone healing,
the bony fragments are tightly compressed against each other. This
compression is crucial as it allows for the direct contact of the bone
surfaces, which is necessary for the healing process.
Osteocyte Migration: Under conditions of compression,
osteocytes (the bone cells responsible for maintaining bone tissue) can
migrate across the fracture line. This migration is essential for the
healing process, as it facilitates the integration of the bone fragments.
Characteristics of Primary Bone Healing
Absence of Callus Formation: Unlike secondary bone
healing, which involves the formation of a callus (a soft tissue bridge that
eventually hardens into bone), primary bone healing occurs without callus
formation. This is due to the rigid fixation that prevents movement between
the fragments.
Haversian Remodeling: The healing process in primary
bone healing involves Haversian remodeling, where the bone is remodeled
along the lines of stress. This process allows for the restoration of the
bone's structural integrity and strength.
Requirements for Primary Healing:
Absolute Immobilization: Rigid fixation must
provide sufficient stability to prevent any movement (interfragmentary
mobility) between the osseous fragments during the healing period.
Minimal Gap: There should be minimal distance (gap)
between the fragments to facilitate direct contact and healing.
Examples of Rigid Fixation in the Mandible
Lag Screws: The use of two lag screws across a fracture
provides strong compression and stability, allowing for primary bone
healing.
Bone Plates:
Reconstruction Bone Plates: These plates are
applied with at least three screws on each side of the fracture to
ensure adequate fixation and stability.
Compression Plates: A large compression plate can
be used across the fracture to maintain rigid fixation and prevent
movement.
Proper Application: When these fixation methods are
properly applied, they create a stable environment that is conducive to
primary bone healing. The rigidity of the fixation prevents interfragmentary
mobility, which is essential for the peculiar type of bone healing that
occurs without callus formation.
Molecular techniques
General Pathology
Molecular techniques
Different molecular techniques such as fluorescent in situ hybridization, Southern blot, etc... can be used to detect genetic diseases.
Anchorage in Orthodontics
Orthodontics
Anchorage in orthodontics refers to the resistance that the anchorage area
offers to unwanted tooth movements during orthodontic treatment. Proper
understanding and application of anchorage principles are crucial for achieving
desired tooth movements while minimizing undesirable effects on adjacent teeth.
Classification of Anchorage
1. According to Manner of Force Application
Simple Anchorage:
Achieved by engaging a greater number of teeth than those being
moved within the same dental arch.
The combined root surface area of the anchorage unit must be at
least double that of the teeth to be moved.
Stationary Anchorage:
Defined as dental anchorage where the application of force tends to
displace the anchorage unit bodily in the direction of the force.
Provides greater resistance compared to anchorage that only resists
tipping forces.
Reciprocal Anchorage:
Refers to the resistance offered by two malposed units when equal
and opposite forces are applied, moving each unit towards a more normal
occlusion.
Examples:
Closure of a midline diastema by moving the two central incisors
towards each other.
Use of crossbite elastics and dental arch expansions.
2. According to Jaws Involved
Intra-maxillary Anchorage:
All units offering resistance are situated within the same jaw.
Intermaxillary Anchorage:
Resistance units in one jaw are used to effect tooth movement in the
opposing jaw.
Also known as Baker's anchorage.
Examples:
Class II elastic traction.
Class III elastic traction.
3. According to Site
Intraoral Anchorage:
Both the teeth to be moved and the anchorage areas are located
within the oral cavity.
Anatomic units include teeth, palate, and lingual alveolar bone of
the mandible.
Extraoral Anchorage:
Resistance units are situated outside the oral cavity.
Anatomic units include the occiput, back of the neck, cranium, and
face.
Examples:
Headgear.
Facemask.
Muscular Anchorage:
Utilizes forces generated by muscles to aid in tooth movement.
Example: Lip bumper to distalize molars.
4. According to Number of Anchorage Units
Single or Primary Anchorage:
A single tooth with greater alveolar support is used to move another
tooth with lesser support.
Compound Anchorage:
Involves more than one tooth providing resistance to move teeth with
lesser support.
Multiple or Reinforced Anchorage:
Utilizes more than one type of resistance unit.
Examples:
Extraoral forces to augment anchorage.
Upper anterior inclined plane.
Transpalatal arch.
Functions of the nervous system
PhysiologyFunctions of the nervous system:
1) Integration of body processes
2) Control of voluntary effectors (skeletal muscles), and mediation of voluntary reflexes.
3) Control of involuntary effectors ( smooth muscle, cardiac muscle, glands) and mediation of autonomic reflexes (heart rate, blood pressure, glandular secretion, etc.)
4) Response to stimuli
5) Responsible for conscious thought and perception, emotions, personality, the mind.