NEET MDS Synopsis
Diclofenac
Pharmacology
Diclofenac
Short half life (1‐2 hrs), high 1stpass metab., accumulates in synovial fluid after oral admn., reduce inflammation, such as in arthritis or acute injury
Mechanism of action
inhibition of prostaglandin synthesis by inhibition of cyclooxygenase (COX). There is some evidence that diclofenac inhibits the lipooxygenase pathways, thus reducing formation of the
leukotrienes (also pro-inflammatory autacoids). There is also speculation that diclofenac may inhibit phospholipase A2 as part of its mechanism of action. These additional actions may explain the high potency of diclofenac - it is the most potent NSAID on a molar basis.
Inhibition of COX also decreases prostaglandins in the epithelium of the stomach, making it more sensitive to corrosion by gastric acid. This is also the main side effect of diclofenac and other drugs that are not selective for the COX2-isoenzyme.
Urine Formation
Physiology
Urine is a waste byproduct formed from excess water and metabolic waste molecules during the process of renal system filtration. The primary function of the renal system is to regulate blood volume and plasma osmolarity, and waste removal via urine is essentially a convenient way that the body performs many functions using one process. Urine formation occurs during three processes:
Filtration
Reabsorption
Secretion
Filtration
During filtration, blood enters the afferent arteriole and flows into the glomerulus where filterable blood components, such as water and nitrogenous waste, will move towards the inside of the glomerulus, and nonfilterable components, such as cells and serum albumins, will exit via the efferent arteriole. These filterable components accumulate in the glomerulus to form the glomerular filtrate.
Normally, about 20% of the total blood pumped by the heart each minute will enter the kidneys to undergo filtration; this is called the filtration fraction. The remaining 80% of the blood flows through the rest of the body to facilitate tissue perfusion and gas exchange.
Reabsorption
The next step is reabsorption, during which molecules and ions will be reabsorbed into the circulatory system. The fluid passes through the components of the nephron (the proximal/distal convoluted tubules, loop of Henle, the collecting duct) as water and ions are removed as the fluid osmolarity (ion concentration) changes. In the collecting duct, secretion will occur before the fluid leaves the ureter in the form of urine.
Secretion
During secretion some substances±such as hydrogen ions, creatinine, and drugs—will be removed from the blood through the peritubular capillary network into the collecting duct. The end product of all these processes is urine, which is essentially a collection of substances that has not been reabsorbed during glomerular filtration or tubular reabsorbtion.
Enflurane
Pharmacology
Enflurane (Ethrane) MAC 1.68, Blood/gas solubility ratio 1.9
- Extremely stable chemically.
- Less potent and less soluble in blood than is halothane.
- Respiratory depression is similar to that seen with halothane.
- Cardiac output is not depressed as much as with halothane, and the heart is not sensitized to catecholamines to the same degree.
- Enflurane produces better muscle relaxation than does halothane.
- Metabolism of this agent is very low. Inorganic fluoride is a product of metabolism, but is not sufficient to cause renal problems.
- Enflurane differs from halothane and the other inhalational anesthetic agents by causing seizures at doses slightly higher than those that induce anesthesia.
- Nausea appears to occur somewhat more often following Enflurane than it does following halothane.
Social Learning Theory
PedodonticsSocial Learning Theory
Antecedent Determinants:
Definition: Antecedent determinants refer to the
factors that precede a behavior and influence its occurrence. This
includes the awareness of the child regarding the context and the events
happening around them.
Application in Pedodontics: In a dental setting, if
a child is aware of what to expect during a dental visit (e.g., through
explanations from the dentist or caregiver), they are more likely to
feel prepared and less anxious. Providing clear information about
procedures can help reduce fear and promote cooperation.
Consequent Determinants:
Definition: Consequent determinants involve the
outcomes that follow a behavior, which can influence future behavior.
This includes the child’s perceptions and expectations about the
consequences of their actions.
Application in Pedodontics: If a child experiences
positive outcomes (e.g., praise, rewards) after cooperating during a
dental procedure, they are more likely to repeat that behavior in the
future. Conversely, if they perceive negative outcomes (e.g., pain or
discomfort), they may develop anxiety or avoidance behaviors.
Modeling:
Definition: Modeling is the process of learning
behaviors through observation of others. Children often imitate the
actions of adults, peers, or even media figures.
Application in Pedodontics: Dental professionals
can use modeling to demonstrate positive behaviors. For example, showing
a child how to sit still in the dental chair or how to brush their teeth
properly can encourage them to imitate those behaviors. Additionally,
having older children or siblings model positive dental experiences can
help younger children feel more comfortable.
Self-Regulation:
Definition: Self-regulation involves the ability to
control one’s own behavior through self-monitoring, judgment, and
evaluation. It includes setting personal goals and assessing one’s own
performance.
Application in Pedodontics: Encouraging children to
set goals for their dental visits (e.g., staying calm during the
appointment) and reflecting on their behavior afterward can foster
self-regulation. Dental professionals can guide children in evaluating
their experiences and recognizing their progress, which can enhance
their sense of agency and responsibility regarding their oral health.
Griseofulvin
Pharmacology
Griseofulvin
Griseofulvin is an antifungal drug. It is used both in animals and in humans, to treat ringworm infections of the skin and nails. It is derived from the mold Penicillium griseofulvum.
It is administered orally.
Phenoxymethylpenicillin (penicillin V)
Pharmacology
Phenoxymethylpenicillin (penicillin V) Phenoxymethylpenicillin, commonly known as penicillin V, is the orally-active form of penicillin. It is less active than benzylpenicillin
Indications:
infections caused by Streptococcus pyogenes, tonsillitis, pharyngitis, skin infections, prophylaxis of rheumatic fever, moderate-to-severe gingivitis (with metronidazole)
Indirect Pulp Capping
Pedodontics
Indirect Pulp Capping
Indirect pulp capping is a dental procedure designed to treat teeth with deep
carious lesions that are close to the pulp but do not exhibit pulp exposure. The
goal of this treatment is to preserve the vitality of the pulp while allowing
for the formation of secondary dentin, which can help protect the pulp from
further injury and infection.
Procedure Overview
Initial Appointment:
During the first appointment, the dentist excavates all superficial carious
dentin. However, any dentin that is affected but not infected (i.e., it is
still healthy enough to maintain pulp vitality) is left intact if it is
close to the pulp. This is crucial because leaving a thin layer of affected
dentin can help protect the pulp from exposure and further damage.
Pulp Dressing:
After the excavation, a pulp dressing is placed over the remaining affected
dentin. Common materials used for this dressing include:
Calcium Hydroxide: Promotes the formation of
secondary dentin and has antibacterial properties.
Glass Ionomer Materials: Provide a good seal and
release fluoride, which can help in remineralization.
Hybrid Ionomer Materials: Combine properties of
both glass ionomer and resin-based materials.
The tooth is then sealed temporarily, and the patient is scheduled for a
follow-up appointment, typically within 6 to 12 months.
Second Appointment:
At the second appointment, the dentist removes the temporary restoration and
excavates any remaining carious material. The floor of the cavity is
carefully examined for any signs of pulp exposure. If no exposure is found
and the tooth has remained asymptomatic, the treatment is deemed successful.
Permanent Restoration:
If the pulp is intact, a permanent restoration is placed. The materials used
for the final restoration can vary based on the tooth's location and the
clinical situation. Options include:
For Primary Dentition: Glass ionomer, hybrid
ionomer, composite, compomer, amalgam, or stainless steel crowns.
For Permanent Dentition: Composite, amalgam,
stainless steel crowns, or cast crowns.
Indications for Indirect Pulp Capping
Indirect pulp capping is indicated when the following conditions are met:
Absence of Prolonged Pain: The tooth should not have a
history of prolonged or repeated episodes of pain, such as unprovoked
toothaches.
No Radiographic Evidence of Pulp Exposure: Preoperative
X-rays must not show any carious penetration into the pulp chamber.
Absence of Pathology: There should be no evidence of
furcal or periapical pathology. It is essential to assess whether the root
ends are completely closed and to check for any pathological changes,
especially in anterior teeth.
No Percussive Symptoms: The tooth should not exhibit
any symptoms upon percussion.
Evaluation and Restoration After Indirect Pulp Therapy
After the indirect pulp therapy, the following evaluations are crucial:
Absence of Subjective Complaints: The patient should
report no toothaches or discomfort.
Radiographic Evaluation: After 6 to 12 months,
periapical and bitewing X-rays should show deposition of new secondary
dentin, indicating that the pulp is healthy and responding well to
treatment.
Final Restoration: If no pulp exposure is observed
after the removal of the temporary restoration and any remaining soft
dentin, a permanent restoration can be placed.
Dens in Dente
PedodonticsDens in Dente (Tooth Within a Tooth)
Dens in dente, also known as "tooth within a tooth," is a developmental
dental anomaly characterized by an invagination of the enamel and dentin,
resulting in a tooth structure that resembles a tooth inside another tooth. This
condition can affect both primary and permanent teeth.
Diagnosis
Radiographic Verification:
The diagnosis of dens in dente is confirmed through radiographic
examination. Radiographs will typically show the characteristic
invagination, which may appear as a radiolucent area within the tooth
structure.
Characteristics
Developmental Anomaly:
Dens in dente is described as a lingual invagination of the enamel,
which can lead to various complications, including pulp exposure,
caries, and periapical pathology.
Occurrence:
This condition can occur in both primary and permanent teeth,
although it is most commonly observed in the permanent dentition.
Commonly Affected Teeth
Permanent Maxillary Lateral Incisors:
Dens in dente is most frequently seen in the permanent maxillary
lateral incisors. The presence of deep lingual pits in these teeth
should raise suspicion for this condition.
Unusual Cases:
There have been reports of dens invaginatus occurring in unusual
locations, including:
Mandibular primary canine
Maxillary primary central incisor
Mandibular second primary molar
Genetic Considerations
Inheritance Pattern:
The condition may exhibit an autosomal dominant inheritance pattern,
as evidenced by the occurrence of dens in dente within the same family,
where some members have the condition while others present with deep
lingual pits.
Variable Expressivity and Incomplete Penetrance:
The variability in expression of the condition among family members
suggests that it may have incomplete penetrance, meaning not all
individuals with the genetic predisposition will express the phenotype.
Clinical Implications
Management:
Early diagnosis and management are crucial to prevent complications
associated with dens in dente, such as pulpitis or abscess formation.
Treatment may involve restorative procedures or endodontic therapy,
depending on the severity of the invagination and the health of the
pulp.