NEET MDS Synopsis
Suspension liners
Dental Materials
Suspension liners
Applications
o Dentin lining under amalgam restorations
o Stimulation of reparative dentin formation
Components
-Calcium hydroxide powder
-Water
-Modifiers
Manipulation
Used as W/P or pastes Paint thin film on dentin → Use forced air for 15 to 30 seconds to dry → Film is thicker (15 µm) than varnishes → Do not use on enamel or cavosurface margins
Properties
Physical
-Electrically insulating barrier
-Too thin to be thermally insulating
Chemical
-High basicity for calcium hydroxide (pH is II)
-Dissolves readily in water and should not be used at exposed cavosurface margins or gaps may form
Mechanical - weak film
Biologic - calcium hydroxide dissolves, diffuses, and stimulates odontoblasts to occlude dentin tubules below cavity preparation
Measurement of Bacterial of Growth
General Microbiology
Measurement of Bacterial of Growth
A convenient method is to determine turbidity by photoelectric colorimeter or spectrophotometer.
The cell number can be counted as total cell number as well as viable count. Viable Count Viable number of bacteria can be counted by inoculating the suspension onto solid growth medium and counting the number of colonies. Since each colony is the end product of one viable bacterium, their count gives the number of viable bacteria in the suspension.
Total number of bacteria can be ascertained in specially designed chambers such as Coulter counter.
Portal hypertension
General Pathology
Portal hypertension
It is elevation of the portal venous pressure (normal 7 m.m Hg).
Causes:-
1- Presinusoidal
2- Sinusoidal
3- Postsinusoidal
Presinusoidal:-
a. Massive splenomegaly and increased splenic blood flow.
b. Portal vein obstruction by thrombosis or outside pressure.
c. Portal venular obstruction at the portal tracts e.g. by fibrosis, granuloma or chronic hepatitis.
Sinusoidal:-
Cirrhosis due to perisinusoidal fibrosis
Postsinusoidal:-
a.Alcoholic hepatitis leading to perivenular fibrosis.
b. Cirrhosis leading to interference with the blood flow and to arterio -venous anastomosis resulting in increased venous blood pressure.
c. Veno -occlusive diseases of the liver caused by some drugs & plant toxins. It results in progressive fibrous occlusion of the hepatic venules and vein radicals.
d. Budd- Chiari syndrome: It is hepatic vein thrombosis. 30% of cases have no apparent cause. It produces portal hypertension and hepatomegaly. It is fatal if not treated.
e. obstruction of major hepatic vein by tumors.
f. Right sided heart failure and constrictive pericarditis
Effects of portal hypertension:
Ascitis
It is intraperitoneal accumulation of serous fluid which is a Transudate . It causes abdominal distension.
Causes
a. Increased hydrostatic pressure` in the portal venous system.
b. Decreased albumin synthesis in the liver…..decreased colloid osmotic pressure of plasma.
c. Sodium and water retension due to secondary hyperaldosteronism and ADH secretion.
d. Leakage of hepatic lymph through the hepatic capsule due to hepatic vein obstruction.
Splenomegaly:- It results from chronic venous congestion.
- The spleen enlarged with capsular adhesions.
- It shows Gamma Gandi nodules. - There may be hyperspelenism.
Porto-Systemic venous anastomosis:- Present in the following sites Esophageal variesis. Rupture of these vessels is the main cause of death.
Around the umbilicus “Caput meduci”. Ano-rectal vessels.
Local Anesthetics
Pharmacology
Local Anesthetics
1. Procaine (Novocaine)
a) Classic Ester type agent, first synthetic injectable local anesthetic.
b) Slow onset and short duration of action
2. Tetracaine (Pontocaine)
a) Ester type agent--ten times as potent and toxic as procaine.
b) Slow onset but long duration of action.
c) Available in injectable and topical applications.
3. Propoxycaine (Ravocaine)
a) Ester type agent–five times as potent and toxic as procaine.
b) Often combined with procaine to increase duration of action.
4. Lidocaine (Xylocaine)
a) Versatile widely used amide type agent.
b) Two - three times as potent and toxic as procaine.
c) Rapid onset and relatively long duration of action.
d) Good agent for topical application.
5. Mepivacaine (Carbocaine)
a) Amide type agent similar to lidocaine.
b) Without vasoconstrictor has only short duration of action.
6. Prilocaine (Citanest)
a) Amide type agent — less potent than lidocaine.
b) Without vasoconstrictor has only short duration of action.
c) Metabolized to o-toluidine which can cause methemoglobinemia — significant only with large doses of prilocaine.
d) Higher incidences of paresthesia reported with 4 % preparation
7. Bupivacaine (Marcaine)
a) Amide type agent of high potency and toxicity.
b) Rapid onset and very long duration of action even without vasoconstrictor.
8. Articaine (Septocaine)
a) Amide type agent
b) Only amide-type local anesthetic that contains an ester group, therefore metabolized both in the liver and plasma.
c) Approved by the FDA in 2000
d) Evidence points to improved diffusion through hard and soft tissues as compared to other local anesthetics.
e) Reports of a higher incidence of paresthesia, presumably due to the 4% concentration
f) Not recommended for use in children under 4 years of age
Gracey Curettes
PeriodontologyGracey Curettes
Gracey curettes are specialized instruments designed for periodontal therapy,
particularly for subgingival scaling and root planing. Their unique design
allows for optimal adaptation to the complex anatomy of the teeth and
surrounding tissues. This lecture will cover the characteristics, specific uses,
and advantages of Gracey curettes in periodontal practice.
Gracey curettes are area-specific curettes
that come in a set of instruments, each designed and angled to adapt to
specific anatomical areas of the dentition.
Purpose: They are considered some of the best
instruments for subgingival scaling and root planing due to their ability to
provide excellent adaptation to complex root anatomy.
Specific Gracey Curette Designs and Uses
Gracey 1/2 and 3/4:
Indication: Designed for use on anterior teeth.
Application: Effective for scaling and root planing
in the anterior region, allowing for precise access to the root
surfaces.
Gracey 5/6:
Indication: Suitable for anterior teeth and
premolars.
Application: Versatile for both anterior and
premolar areas, providing effective scaling in these regions.
Gracey 7/8 and 9/10:
Indication: Designed for posterior teeth,
specifically for facial and lingual surfaces.
Application: Ideal for accessing the buccal and
lingual surfaces of posterior teeth, ensuring thorough cleaning.
Gracey 11/12:
Indication: Specifically designed for the mesial
surfaces of posterior teeth.
Application: Allows for effective scaling of the
mesial aspects of molars and premolars.
Gracey 13/14:
Indication: Designed for the distal surfaces of
posterior teeth.
Application: Facilitates access to the distal
surfaces of molars and premolars, ensuring comprehensive treatment.
Key Features of Gracey Curettes
Area-Specific Design: Each Gracey curette is tailored
for specific areas of the dentition, allowing for better access and
adaptation to the unique contours of the teeth.
Offset Blade: Unlike universal curettes, the blade of a
Gracey curette is not positioned at a 90-degree angle to the lower shank.
Instead, the blade is angled approximately 60 to 70 degrees from
the lower shank, which is referred to as an "offset blade." This design
enhances the instrument's ability to adapt to the tooth surface and root
anatomy.
Advantages of Gracey Curettes
Optimal Adaptation: The area-specific design and offset
blade allow for better adaptation to the complex anatomy of the roots,
making them highly effective for subgingival scaling and root planing.
Improved Access: The angled blades enable clinicians to
access difficult-to-reach areas, such as furcations and concavities, which
are often challenging with standard instruments.
Enhanced Efficiency: The design of Gracey curettes
allows for more efficient removal of calculus and biofilm from root
surfaces, contributing to improved periodontal health.
Reduced Tissue Trauma: The precise design minimizes
trauma to the surrounding soft tissues, promoting better healing and patient
comfort.
Symptoms of Legionella pneumonia
Pathology
L: Lungs - Atypical pneumonia.
Relatively nonproductive cough
Dyspnea
Pleuritic or non pleuritic chest pain
Confluent or patchy infiltrates on x-ray
Random fact: Interstitial infiltrates aren’t seen often like in other atypical pneumonias.
E: Encephalon - Neurologic abnormalities.
Headache
Confusion or changes in mental status
Encephalopathy
G: Gastrointestinal symptoms.
Abdominal pain
Nausea
Vomiting
Watery diarrhea
ION: Na ion decreases.
Hyponatremia (serum sodium level of 131 meq/L)
Gingival Crevicular Fluid
PeriodontologyGingival Crevicular Fluid (GCF)
Gingival crevicular fluid is an inflammatory exudate found in the gingival
sulcus. It plays a significant role in periodontal health and disease.
A. Characteristics of GCF
Glucose Concentration: The glucose concentration in GCF
is 3-4 times greater than that in serum, indicating
increased metabolic activity in inflamed tissues.
Protein Content: The total protein content of GCF is
much less than that of serum, reflecting its role as an inflammatory
exudate.
Inflammatory Nature: GCF is present in clinically
normal sulci due to the constant low-grade inflammation of the gingiva.
B. Drugs Excreted Through GCF
Tetracyclines and Metronidazole: These antibiotics are
known to be excreted through GCF, making them effective for localized
periodontal therapy.
C. Collection Methods for GCF
GCF can be collected using various techniques, including:
Absorbing Paper Strips/Blotter/Periopaper: These strips
absorb fluid from the sulcus and are commonly used for GCF collection.
Twisted Threads: Placing twisted threads around and
into the sulcus can help collect GCF.
Micropipettes: These can be used for precise collection
of GCF in research settings.
Intra-Crevicular Washings: Flushing the sulcus with a
saline solution can help collect GCF for analysis.
Cells Of The Exudate
General Pathology
Cells Of The Exudate
Granulocytes (Neutrophils, eosinophils, and basophils)
Monocytes (and tissue macrophages)
Lymphocytes
Neutrophils (polymorphs).
Characteristics
(1) Cell of acute inflammation.
(2) Actively motile.
(3) Phagocytic.
(4) Respond to chemotactic agents like.
Complement products.
Bacterial products.
Tissue breakdown
Lysosomal enzymes of other polymorphs
Functions
(1) Phagocytosis and intracellular digestion of bacteria.
(2) Exocytosis of lysosomal enzymes to digest dead tissue as the first step in the process of repair.
Eosinophils
Characteristics
(I) Cell of allergjc and immunologic inflammation.
(2) Motile and phagocytic but less so than a neutrophil.
(3) Response to chemotaxis similar to neutrophil. In addition, it is also responsive to antigens and antigen-antibody complexes.
(4) Steroids cause depletion of eosinophils.
Functions
(1) Contain most of the lysosomal enzymes that polymorphs have
(2) control of Histamine release and degradation in inflammation
Basophils (and mast cells)
Characteristics
(1) Contain coarse metachromatic granules.
(2) Contain, histamine and proteolytic enzymes
Functions
Histamine: release which causes some of the changes of inflammation and allergic
reactions. .
Monocytes .
Blood monocytes form a component of. the mononuclear phagocytic system (MPS), the other being tissue macrophages The tissue macrophages may be :
(a) Fixed phagocytic. cells:
Kuffer cell of liver.
Sinusoidal lining cells of spleen and lymph nodes.
Pleural and peritoneal macrophages
Alveolar macrophages.
Microglial cells.
(b) Wandering macrophages or tissue histiocytes.
The tissue histiocytes are derived from blood monocytes.
Characteristics
.(1)Seen in inflammation of some duration, as they -outlive polymorphs.
(2) Actively phagocytic and motile.
(3) Fuse readily to from giant cells in certain situations.
Function
(1) Phagocytosis.
(2) Lysosomal enzyme secretion.
(3) Site of synthesis of some components of complement.
(4) Antigen handling and processing before presenting it to the Immune competent cell.
(5) Secretion of lysosyme and interferon.
Giant cells can be
(A) Physiological
Syncytiotrophoblast, megakatyocytes, striated muscle, osteoclast.
(B) Pathological:
Foreign body: in the presence of particulate foreign matter like talc, suture material etc. and in certain infections_e g fungal.
Langhan's type: a variant of foreign body giant cell seen in tuberculosis.
Touton type in lipid rich situations like Xanthomas, lipid granulomas etc.
(iv) Aschoff cell in rheumatic carditis.
(v) Tumour gjant cells e.g. Reid-Sternberg cell in Hodgkin's Lymphoma, giant cells in any malignancy.
Lymphocytes and Plasma cells
These are the small mononuclear cell comprising the immune system
They are less motile than_macrophages and neutrophils and are seen in chronic inflammation and immune based diseases.