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.
COMPOSITE RESINS -Types
Dental Materials
COMPOSITE RESINS
Types
Amount of filler-25% to 65% volume, 45% to 85% weight
Filler particle size (diameter in microns)
Macrofill 10 to 100 µm (traditional composites)
Midi fill- 1 to 10 µm(small particle composites)
Minifill— 0.l to 1 µm
Microfill-: 0.01 to 0.1 µm (fine particle composites)
Hybrid--blend (usually or microfill and midifill or minifill and microfill)
Polymerization method
Auto-cured (self-cured)
Visible light cured
Dual cured
Staged cure
Matrix chemistry
BIS-GMA type
Urethane dimethacrylate (UDM or UDMA) type
TEGDMA-diluent monomer to reduce viscosity
CROSS INFECTION AND STERLIZATION IN DENTISTRY
General Microbiology
CROSS INFECTION AND STERLIZATION IN DENTISTRY
Cross infection is defined as the transmission of infectious agents amongst patients and staff with in hospital environment.
Routes of Infection
Two routes are important : transdermal and respiratory.
In transdermal route microorganisms enter the tissues of the recipient by means of injection through intact skin or mucosa (usually due to an accident involving a sharp instrument) or via defects in the skin e.g. recent cuts and abrasions.
Microorganisms causing cross infection in dentistry
Transmitted through skin
Bacteria : Treponema pallidum, Staphylococcus aureus
Viruses :Hepatitis virus, HIV ,Herpes simplex virus, Mumps, Measles , Epstein-Barr virus
Fungi: Dermatomycoses, Candidiasis,
Transmitted through aerosols
Bordetella pertussis, Myco.tuberculosis, Streptococcus pyogenes, Influenza virus
Rhinovirus, Rubella
MAXILLARY CUSPIDS
Dental Anatomy
MAXILLARY CUSPIDS (CANINE)
The maxillary cuspid is usually the longest tooth in either jaw. canines are considered the corner stones of the dental arch They are the only teeth in the dentition with a single cusp.
Facial Surface:- The facial surface of the crown differs considerably from that of the maxillary central or lateral incisors. In that the incisal edges of the central and lateral incisor are nearly straight, the cuspid has a definite point, or cusp. There are two cutting edges, the mesioincisal and the distoincisal. The distoincisal cutting edge is the longer of the two. The developmental grooves prominent on the facial surface extending two-thirds of the distance from the tip of the cusp to the cervical line. The distal cusp ridge is longer than the mesial cusp ridge
Lingual Surface: Distinct mesial and distal marginal ridges, a well-devloped cingulum, and the cusp ridges form the boundries of the lingual surface. The prominent lingual ridge extends from the cusp tip to the cingulum, dividing the lingual surface into mesial and distal fossae.
Proximal: The mesial and distal aspects present a triangular outline. They resemble the incisors, but are more robust--especially in the cingulum region
Incisal: The asymmetry of this tooth is readily apparent from this aspect. It usually thicker labiolingually than it is mesiodistally. The tip of the cusp is displaced labially and mesial to the central long axis of this tooth.
Root Surface:-The root is single and is the longest root in the arch. It is usually twice the length of the crown.
FAT-SOLUBLE VITAMINS
Biochemistry
FAT-SOLUBLE VITAMINS
The fat-soluble vitamins, A, D, E, and K, are stored in the body for long periods of time and generally pose a greater risk for toxicity when consumed in excess than water-soluble vitamins.
VITAMIN A: RETINOL
Vitamin A, also called retinol, has many functions in the body. In addition to helping the eyes adjust to light changes, vitamin A plays an important role in bone growth, tooth development, reproduction, cell division, gene expression, and regulation of the immune system.
The skin, eyes, and mucous membranes of the mouth, nose, throat and lungs depend on vitamin A to remain moist. Vitamin A is also an important antioxidant that may play a role in the prevention of certain cancers.
One RAE equals 1 mcg of retinol or 12 mcg of beta-carotene. The Recommended Dietary Allowance (RDA) for vitamin A is 900 mcg/ day for adult males and 700 mcg/ day for adult females.
Vitamin A Deficiency
Vitamin A deficiency is rare, but the disease that results is known as xerophthalmia.
Other signs of possible vitamin A deficiency include decreased resistance to infections, faulty tooth development, and slower bone growth.
Vitamin A toxicity The Tolerable Upper Intake Level (UL) for adults is 3,000 mcg RAE.
VITAMIN D
Vitamin D plays a critical role in the body’s use of calcium and phosphorous. It works by increasing the amount of calcium absorbed from the small intestine, helping to form and maintain bones.
Vitamin D benefits the body by playing a role in immunity and controlling cell growth. Children especially need adequate amounts of vitamin D to develop strong bones and healthy teeth.
RDA From 12 months to age fifty, the RDA is set at 15 mcg.
20 mcg of cholecalciferol equals 800 International Units (IU), which is the recommendation for maintenance of healthy bone for adults over fifty.
Vitamin D Deficiency
Symptoms of vitamin D deficiency in growing children include rickets (long, soft bowed legs) and flattening of the back of the skull. Vitamin D deficiency in adults may result in osteomalacia (muscle and bone weakness), and osteoporosis (loss of bone mass).
Vitamin D toxicity
The Tolerable Upper Intake Level (UL) for vitamin D is set at 100 mcg for people 9 years of age and older. High doses of vitamin D supplements coupled with large amounts of fortified foods may cause accumulations in the liver and produce signs of poisoning.
VITAMIN E: TOCOPHEROL
Vitamin E benefits the body by acting as an antioxidant, and protecting vitamins A and C, red blood cells, and essential fatty acids from destruction.
RDA One milligram of alpha-tocopherol equals to 1.5 International Units (IU). RDA guidelines state that males and females over the age of 14 should receive 15 mcg of alpha-tocopherol per day.
Vitamin E Deficiency Vitamin E deficiency is rare. Cases of vitamin E deficiency usually only occur in premature infants and in those unable to absorb fats.
VITAMIN K
Vitamin K is naturally produced by the bacteria in the intestines, and plays an essential role in normal blood clotting, promoting bone health, and helping to produce proteins for blood, bones, and kidneys.
RDA
Males and females age 14 - 18: 75 mcg/day; Males and females age 19 and older: 90 mcg/day
Vitamin K Deficiency
Hemorrhage can occur due to sufficient amounts of vitamin K.
Vitamin K deficiency may appear in infants or in people who take anticoagulants, such as Coumadin (warfarin), or antibiotic drugs.
Newborn babies lack the intestinal bacteria to produce vitamin K and need a supplement for the first week.
Frankel appliance
Orthodontics
Frankel appliance is a functional orthodontic device
designed to guide facial growth and correct malocclusions. There are four main
types: Frankel I (for Class I and Class II Division 1
malocclusions), Frankel II (for Class II Division 2), Frankel
III (for Class III malocclusions), and Frankel IV (for
specific cases requiring unique adjustments). Each type addresses different
dental and skeletal relationships.
The Frankel appliance is a removable orthodontic device that
plays a crucial role in the treatment of various malocclusions. It is designed
to influence the growth of the jaw and dental arches by modifying muscle
function and promoting proper alignment of teeth.
Types of Frankel Appliances
Frankel I:
Indications: Primarily used for Class I and Class
II Division 1 malocclusions.
Function: Helps in correcting overjet and improving
dental alignment.
Frankel II:
Indications: Specifically designed for Class II
Division 2 malocclusions.
Function: Aims to reposition the maxilla and
improve the relationship between the upper and lower teeth.
Frankel III:
Indications: Used for Class III malocclusions.
Function: Encourages forward positioning of the
maxilla and helps in correcting the skeletal relationship.
Frankel IV:
Indications: Suitable for open bites and
bimaxillary protrusions.
Function: Focuses on creating space and improving
the occlusion by addressing specific dental and skeletal issues.
Key Features of Frankel Appliances
Myofunctional Design: The appliance is designed to
utilize the forces generated by muscle function to guide the growth of the
dental arches.
Removable: Patients can take the appliance out for
cleaning and during meals, which enhances comfort and hygiene.
Custom Fit: Each appliance is tailored to the individual
patient's dental anatomy, ensuring effective treatment.
Treatment Goals
Facial Balance: The primary goal of using a Frankel
appliance is to achieve facial harmony and balance by correcting
malocclusions.
Functional Improvement: It promotes the establishment of
normal muscle function, which is essential for long-term dental health.
Arch Development: The appliance aids in the development
of the dental arches, providing adequate space for the eruption of permanent
teeth.
IMMUNO PATHOLOGY
General Pathology
IMMUNO PATHOLOGY
Abnormalities of immune reactions are of 3 main groups
- Hypersensitivity,
- Immuno deficiency,
- Auto immunity.
Hypersensitivity (ALLERGY)
This is an exaggerated or altered immune response resulting in adverse effects
They are classified into 4 main types.
I. Type I-(reaginic, anaphylactic). This is mediated by cytophylic Ig E antibodies, which get bound to mast cells. On re-exposure, the Ag-Ab reaction occurs on the mast cell surface releasing histamine.
Clinical situations
I. Systemic anaphylaxis, presenting with bronchospasm oedema hypertension, and even death.
2. Local (atopic) allergy.
- Allergic rhinitis (hay fever)
- Asthma
- Urticaria.
- Food allergies.
2. Type II. (cytotoxic). Antibody combines with antigen present on-cell surface. The antigen may be naturally present on the surface or an extrinsic substance (e.g.drug) attached to cell surface.
The cell is then destroyed by complement mediated lysis (C89) or phagocytosis of the antibody coated cell.
Clinical situations
- Haemolytic anemia.
- Transfusion reaction
- Auto immune haemolytic anemia.
- Haemolysis due to some drugs like Alpha methyl dopa
2. Drug induced thrombocytopenia (especially sedormid).
3 Agranulocytosis due to sensitivity to some drugs.
4 Goodpasture’s syndrome-glomermerulonephritis due to anti basement membrane antibodies.
3. Type III. (Immune complex disease). Circulating immune complexes especially small soluble complexes tend to deposit in tissues especially kidney, joints, heart and arteries.
These then cause clumping of platelets with subsequent release of histamine. and serotonin resulting in increased permeability. Also, complement activation occurs which being chemotactic results in aggregation of polymorphs and necrotising vasculitis due to release of lysosmal enzymes
Clinical situations
- Serum sickness.
- Immune complex glomerulonephritis.
- Systemic lupus erythematosus.
- Allergic alveolitis.
- Immune based vasculitis like
o Drug induced vasculitis.
o Henoch – Schonlein purpura
4. Type IV. (Cell mediated). The sensitized lymphocytes may cause damage by cytotoxicity or by lymphokines and secondarily involving macrophages in the reaction.
Clinical situations
I. Caseation necrosis in tuberculosis.
2. Contact dermatitis to
- Metals.
- Rubber.
- Drugs (topical).
- Dinitrochlorbenzene (DNCB).
5. Type V. (stimulatory) This is classed by some workers separately and by other with cytotoxic type (Type II) with a stimulatory instead of toxic effect
Clinical Situations :
LATS (long acting thyroid stimulator) results in thyrotoxicosis (Grave’s disease)
Cardiac Muscle
Anatomy
Cardiac Muscle
Fibres anastomose through cross bridges
Fibres are short, connected end to end at intercalated discs, also striated, contract automatically
Light microscopic Structure:
Short fibres connected at intercalated disks, 85 - 100 µm long, 15 µm
same bands as in skeletal muscle, 1 or 2 nuclei - oval and central, in perinuclear area is a sarcoplasmic reticulum, intercalated discs lie at the Z line
Electron microscopic structure:
Between myofibrils lie the mitochondria, 2,5 µm long mitochondria, dense cristae
and are as long as the sarcomere, fibres have more glycogen than skeletal muscle fibres
myofilaments, actin and myosin are the same as in skeletal muscle, the sarcoplasmic reticulum differs in that there is no terminal sisterna. The sarcotubules end in little feet that
sit on the T-tubule
Intercalated Disc:
on Z lines, fibres interdigitate,
3 types of junctions in the disc
Transverse Part:
zonula adherens
desmosomes
Lateral Part:
Gap junctions (nexus) - for impulse transfer
Mechanism of Contraction:
slide - ratchet like in skeletal muscle, certain fibres are modified for conduction, Impulses spread from cell to cell through gap junctions, Purkinje cells are found in the AV bundle
they have less myofibrils, lots of glycogen and intercalated discs
Connective tissue coverings:
Only endomycium in cardiac muscle, Blood vessels, lymph vessels and nerves lie in the endomycium