NEET MDS Synopsis
Fluconazole
Pharmacology
Fluconazole: an antifungal used orally, intravenously or vaginally to treat yeast and fungal infections. Side-effects of systemic administration include hepatotoxicity (liver damage).
For vaginal candidiasis (vaginal thrush), a once-only oral dose is often sufficient.
Zones of Periodontal Disease
PeriodontologyZones of Periodontal Disease
Listgarten described four distinct zones that can be observed in periodontal
lesions. These zones may blend with each other and may not be present in every
case.
Zones of Periodontal Disease
Zone 1: Bacterial Zone
Description: This is the most superficial zone,
consisting of a diverse array of bacteria.
Characteristics:
The bacterial zone is primarily composed of various microbial
species, including both pathogenic and non-pathogenic bacteria.
This zone is critical in the initiation and progression of
periodontal disease, as the presence of specific bacteria can
trigger inflammatory responses in the host.
Zone 2: Neutrophil Rich Zone
Description: This zone contains numerous
leukocytes, predominantly neutrophils.
Characteristics:
The neutrophil-rich zone is indicative of the body’s immune
response to the bacterial invasion.
Neutrophils are the first line of defense and play a crucial
role in phagocytosing bacteria and releasing inflammatory mediators.
The presence of a high number of neutrophils suggests an acute
inflammatory response, which is common in active periodontal
disease.
Zone 3: Necrotic Zone
Description: This zone consists of disintegrated
tissue cells, fibrillar material, remnants of collagen fibers, and
spirochetes.
Characteristics:
The necrotic zone reflects tissue destruction and is
characterized by the presence of dead or dying cells.
Fibrillar material and remnants of collagen fibers indicate the
breakdown of the extracellular matrix, which is essential for
maintaining periodontal tissue integrity.
Spirochetes, which are associated with more aggressive forms of
periodontal disease, can also be found in this zone, contributing to
the necrotic process.
Zone 4: Zone of Spirochetal Infiltration
Description: This zone consists of well-preserved
tissue that is infiltrated with large and medium spirochetes.
Characteristics:
The zone of spirochetal infiltration indicates a more chronic
phase of periodontal disease, where spirochetes invade the
connective tissue.
The presence of well-preserved tissue suggests that while
spirochetes are present, the tissue has not yet undergone extensive
necrosis.
This zone is significant as it highlights the role of
spirochetes in the pathogenesis of periodontal disease, particularly
in cases of necrotizing periodontal diseases.
Types of Brain Injury
General SurgeryTypes of Brain Injury
Brain injuries can be classified into two main categories: primary and
secondary injuries. Understanding these types is crucial for effective diagnosis
and management.
1. Primary Brain Injury
Definition: Primary brain injury occurs at the moment
of impact. It results from the initial mechanical forces applied to the
brain and can lead to immediate damage.
Examples:
Contusions: Bruising of brain tissue.
Lacerations: Tears in brain tissue.
Concussions: A temporary loss of function due to trauma.
Diffuse axonal injury: Widespread damage to the brain's white
matter.
2. Secondary Brain Injury
Definition: Secondary brain injury occurs after the
initial impact and is often preventable. It results from a cascade of
physiological processes that can exacerbate the initial injury.
Principal Causes:
Hypoxia: Reduced oxygen supply to the brain, which
can worsen brain injury.
Hypotension: Low blood pressure can lead to
inadequate cerebral perfusion.
Raised Intracranial Pressure (ICP): Increased
pressure within the skull can compress brain tissue and reduce blood
flow.
Reduced Cerebral Perfusion Pressure (CPP):
Insufficient blood flow to the brain can lead to ischemia.
Pyrexia: Elevated body temperature can increase
metabolic demands and worsen brain injury.
Glasgow Coma Scale (GCS)
The Glasgow Coma Scale is a clinical tool used to assess a patient's level of
consciousness and neurological function. It consists of three components: eye
opening, verbal response, and motor response.
Eye Opening (E)
Spontaneous: 4
To verbal command: 3
To pain stimuli: 2
No eye opening: 1
Verbal Response (V)
Normal, oriented: 5
Confused: 4
Inappropriate words: 3
Sounds only: 2
No sounds: 1
Motor Response (M)
Obeys commands: 6
Localizes to pain: 5
Withdrawal flexion: 4
Abnormal flexion (decorticate): 3
Extension (decerebrate): 2
No motor response: 1
Scoring
Best Possible Score: 15/15 (fully alert and oriented)
Worst Possible Score: 3/15 (deep coma or death)
Intubated Cases: For patients who are intubated, the
verbal score is recorded as "T."
Intubation Indication: Intubation should be performed
if the GCS score is less than or equal to 8.
Additional Assessments
Pupil Examination
Pupil Reflex: Assess size and light response.
Uncal Herniation: In cases of mass effect on the
ipsilateral side, partial third nerve dysfunction may be noted,
characterized by a larger pupil with sluggish reflex.
Hutchinson Pupil: As third nerve compromise increases,
the ipsilateral pupil may become fixed and dilated.
Signs of Base of Skull Fracture
Raccoon Eyes: Bilateral periorbital hematoma,
indicating possible skull base fracture.
Battle’s Sign: Bruising over the mastoid process,
suggesting a fracture of the temporal bone.
CSF Rhinorrhea or Otorrhea: Leakage of cerebrospinal
fluid from the nose or ear, indicating a breach in the skull base.
Hemotympanum: Blood in the tympanic cavity, often seen
with ear bleeding.
Antiarrhythmic Drugs-Class I Sodium Channel Blockers
Pharmacology
Class I Sodium Channel Blockers
• Block movement of sodium into cells of the cardiac conducting system
• Results in a stabilizing effect and decreased formation and conduction of electrical impulses
• Have a local anesthetic effect
• Are declining in use due to proarrhythmic effects and increased mortality rates
• Na channel blockers - Class 1 drugs are divided into 3 subgroups
• 1A. 1B, 1C based on subtle differences in their mechanism of action.
• Blockade of these channels will prevent depolarization.
• Spread of action potential across myocardium will slow and areas of pacemaker activity is suppressed.
Class IA Sodium Channel Blockers
• Treatment of: symptomatic premature ventricular contractions, supraventricular tachycardia, and ventricular tachycardia, prevention of ventricular fibrillation
– Quinidine (Cardioquin, Quinaglute)
– Procainamide (Pronestyl, Procanbid)
– Disopyramide (Norpace)
• Quinidine – prototype
• Low therapeutic index
• High incidence of adverse effects
Class IB Sodium Channel Blockers
• Treatment of: symptomatic premature ventricular contractions and ventricular tachycardia, prevention of ventricular fibrillation
– Lidocaine (Xylocaine)
– Mexiletine (Mexitil)
– Tocainide (Tonocard)
– Phenytoin (Dilantin)
Side Effects: Lidocaine
• Drowsiness • Paresthesias • Muscle twitching • Convulsions • Changes in mental status (disorientation, confusion) • Hypersensitivity reactions (edema, uticaria, anaphylaxis)
Side Effects: Phenytoin (Dilantin)
• Gingival hyperplasia
• Nystagmus
• Ataxia, slurring of speech
• Tremors
• Drowsiness
• Confusion
• Lidocaine – prototype
• Must be given by injection
• Used as a local anesthetic
• Drug of choice for treating serious ventricular arrhythmias associated with acute myocardial infarction, cardiac surgery, cardiac catheterization and electrical conversion
Class IC Sodium Channel Blockers
• Treatment of: life-threatening ventricular tachycardia or fibrillation and supraventricular tachycardia unresponsive to other drugs
– Flecainide
– Propafenone
Adverse Effects
• CNS - dizziness, drowsiness, fatigue, twitching, mouth numbness, slurred speech vision changes, and tremors that can progress to convulsions.
• GI - changes in taste, nausea, and vomiting. CV - arrhythmias including heart blocks, hypotension, vasodilation, and potential for cardiac arrest.
• Other Rash, hypersensitivity reactions loss of hair and potential bone marrow depression.
Drug-Drug Interactions
• Increased risk for arrhythmias if combined with other drugs that are know to cause arrhythmias- digoxin and beta blockers
• Increased risk of bleeding if combined with oral anticoagulants.
Drug Food Interactions
• Quinidine needs an acidic urine for excretion. Increased levels lead to toxicity
• Avoid foods that alkalinize the urine- citrus juices, vegetables, antacid, milk products
Glasgow Coma Scale
Oral and Maxillofacial SurgeryGlasgow Coma Scale (GCS): Best Verbal Response
The Glasgow Coma Scale (GCS) is a clinical scale used to
assess a patient's level of consciousness and neurological function,
particularly after a head injury. It evaluates three aspects: eye opening,
verbal response, and motor response. The best verbal response (V) is one of the
components of the GCS and is scored as follows:
Best Verbal Response (V)
5 - Appropriate and Oriented:
The patient is fully awake and can respond appropriately to
questions, demonstrating awareness of their surroundings, time, and
identity.
4 - Confused Conversation:
The patient is able to speak but is confused and disoriented. They
may answer questions but with some level of confusion or incorrect
information.
3 - Inappropriate Words:
The patient uses words but they are inappropriate or irrelevant to
the context. The responses do not make sense in relation to the
questions asked.
2 - Incomprehensible Sounds:
The patient makes sounds that are not recognizable as words. This
may include moaning or groaning but does not involve coherent speech.
1 - No Sounds:
The patient does not make any verbal sounds or responses.
MAGNESIUM
Biochemistry
MAGNESIUM
The normal serum level of Magnesium is 1.8 to 2.2. mg/dl.
Functions of Magnesium
(a) Irritability of neuromuscular tissues is lowered by Magnesium
(b) Magnesium deficiency leads to decrease in Insulin dependent uptake of glucose
(c) Magnesium supplementation improves glucose tolerance
Causes such as liver cirrhosis, protein calorie malnutrition and hypo para thyroidism leads to hypomagnesemia
The main causes of hypermagnesemia includes renal failure, hyper para thyroidism, rickets, oxalate poisoning and multiple myeloma.
APPLICATIONS OF LASERS IN ENDODONTICS
Endodontics
I. VASCULAR VITALITY ASSESSMENT OF PULP
Traditional vitality assessment methods such as heat, cold, and electric pulp testers assess neural vitality and often cause false-positive
errors. As the histological assessment of pulpal status is not feasible clinically, a tool to assess the vascular flow of the pulp would be
very useful.
Laser Doppler flowmetry (LDF) is an accurate method to assess the blood flow in a microvascular
system
II. PULP CAPPING AND PULPOTOMY
Pulp capping and pulpotomy constitute a more conservative form of pulp therapy in comparison to pulpectomy. Although the outcome
of pulp capping procedure is variable ranging from 44 to 97%, the procedure is recommended when the exposure is 1.0 mm or less
and especially when the patient is young. Pulpotomy is recommended in immature permanent teeth, where pulpectomy is not advised.
The most commonly used agents for both the procedures are calcium hydroxide and MTA (mineral trioxide aggregate). The use of a
laser in these procedures leads to a potentially bloodless field as the laser has the ability to coagulate and seal small blood vessels. The
laser-tissue interactions make the treated wound surface sterile and also improve the prognosis of the procedure.
III. DISINFECTION OF ROOT CANALS
The ability of bacterial pathogens to persist after shaping and cleaning is one of the main reasons for endodontic failures. This is
attributed to the complex nature of the root canal system, the presence of a smear layer, and the fact that large areas (over 35%) of the
canal surface area remain unchanged following instrumentation with various Ni-Ti techniques.
IV. OBTURATION
Thermoplasticized gutta-percha obturation systems are one of the most efficient methods is achieving a fluid-impervious seal.
Softening of the gutta-percha has been attempted with various lasers. These include argon, CO
, Nd:YAG, and Er:YAG.
V.APICAL SURGERY
Apical surgery including apical resection is indicated when the previously performed root canal therapy fails and nonsurgical means
are inadequate to ensure the complete removal of the pathological process.
The potential for using lasers is on the basis of the following observations:
• Ability of lasers to coagulate and seal small blood vessels, thereby enabling a bloodless surgical field
• Sterilization of the surgical site
• Potential of lasers (Er:YAG) to cut hard dental tissues without causing elaborate thermal damage to the adjoining tissues .
CARIDEX and CARISOLV
PedodonticsCARIDEX and CARISOLV
CARIDEX and CARISOLV are both dental
products designed for the chemomechanical removal of carious dentin. Here’s a
detailed breakdown of their components and mechanisms:
CARIDEX
Components:
Solution I: Contains sodium hypochlorite (NaOCl)
and is used for its antimicrobial properties and ability to dissolve
organic tissue.
Solution II: Contains glycine and aminobutyric acid
(ABA). When mixed with sodium hypochlorite, it produces N-mono
chloro DL-2-amino butyric acid, which aids in the removal of
demineralized dentin.
Application:
CARIDEX is particularly useful for deep cavities, allowing for the
selective removal of carious dentin while preserving healthy tooth
structure.
CARISOLV
Components:
Syringe 1: Contains sodium hypochlorite at a
concentration of 0.5% w/v (which is equivalent to
0.51%).
Syringe 2: Contains a mixture of amino acids (such
as lysine, leucine, and glutamic acid) and erythrosine dye, which helps
in visualizing the removal of carious dentin.
pH Level:
The pH of the CARISOLV solution is approximately 11,
which helps in the dissolution of carious dentin.
Mechanism of Action:
The sodium hypochlorite in CARISOLV softens and dissolves carious
dentin, while the amino acids and dye provide a visual cue for the
clinician. The procedure can be stopped when discoloration is no longer
observed, indicating that all carious dentin has been removed.