The document discusses various laboratory investigations that may be advised by dentists. It describes tests related to hematology, biochemistry including renal function tests, liver function tests, lipid analysis, and electrolyte analysis. It provides reference ranges for common tests and discusses conditions that could cause increases or decreases in certain markers. The tests can help dentists screen for systemic conditions, establish diagnoses, and guide treatment and management of patients.

1. LABORATORY
INVESTIGATIONS

2. Contents
• Introduction
• Tests done by dentists
• Hematological
• Urine Analysis
• Biochemistry :Renal function tests
Tests – diseases of bone
Liver function tests
Lipid Analysis
• Immunological investigations
• Histopathology, cytology and immunofluorescent studies Microbiology
• Radiological
• Conclusion
• References

3. INTRODUCTION
• Diagnosis & identification - disease by careful investigation o
patients signs, symptoms and history
• Carefully crafted history and physical examination -
satisfactory – diagnosis
• Times when more information is required through the use of
diagnostic tests.
• Clinical and/or lab data must be used to distinguish between
different diagnoses.

4. importance of laboratory
investigations
• laboratory tests - important in assisting & management
of the patient during treatment of disease besides
diagnosis.
• Used-
1. screen - disease in asymptomatic individual
2. to establish or exclude presence of diseases in
symptomatic patients
3. assist the practitioner in the management of the patient.

5. important characteristics of a
laboratory test
• Accuracy
• Cost
• Interfering factors
• Precision
• Reference range
• Sensitivity
• Specificity

6. TESTS ADVISED BY DENTISTS
Acc. Sonis, Fazio & Fang

7. Depending upon the specimens
submitted
1. Hematological
2. Biochemical
3. Immunological
4. Histopathological – histological & Immunofluorescent
5. Microbial
6. Radiological

8. Depending upon the organs involved
• Heart • Skin
• Vascular system • Eye
• Respiratory system • Bones & joints
• GIT • Skeletal muscle
• Liver, gallbladder & pancreas
• CVS
• Kidney & genitourinary
• Mental illness
• Female genital
• Endocrine system
• Breast
• Infectious diseases
• Immunological diseases

9. Laboratory investigation
 Biochemistry :
 Urine analysis
 Salivary chemistry
 Histopathology, cytology,
Immunofluorescent studies
 Serology & immunohistochemistry
 Radiology

10. BLOOD CHEMISTRY TESTS
A. . Estimation of electrolytes
B. . Renal function
C. .Liver function
D. .Thyroid Function
E. . Metabolic bone disease
F. . Other tests .

11. A. Estimation of electrolytes
• Maintain fluid levels inside & outside cells
• Osmotic gradient – nerve condtn. Muscle func,hydration
& maintaining Ph levels
1. SODIUM :
• Loss of sodium results extracellular fluid volume
• Circulation, renal function, and central nervous system
function.
• Normal : 136-145 m Eq/l

12. Feel weak,
confusion,
paralysis,
sezuires
Decrease
consciousness,
vomiting, fatigue,
muscle weakness

13. 2. Chloride
• Normal : 95 to 108 mEq/l.
• Important - maintenance of acid-base balance

14. 3. Potassium
• determines neuromuscular irritability.
• or conc. impair - ability of muscle tissue contract
• Normal - 3.5 to 5.2 mEq/l.

15. 4. Bicarbonate
• Bicarbonate–carbonic acid buffer - maintaining normal
pH of body fluids.
• basis for assessing acid-base balance.
• Normal : 24 to 30 mEq/l.

16. Dentists
• Electrolytes -
• Maintain - Ph
• Proteins are denatured and digested
• Enzymes lose their ability to function and death may
occur.
• possibly life threatening.
• could require hospitalization and intravenous
electrolytes.

17. b. renal function test
1. blood urea nitrogen
• Normal value of BUN in adults: 8 – 18 mg %.
10 – 20 mg/dl
sonis
symptom - >50 mg/dl

18. Clinical significance :
• Pre renal causes – reduced flow to kidney, shock, blood
loss, dehydration, increased protein catabolism, injuries,
burns, fever
• Renal causes – acute renal failure, glomerulonephritis,
malignant hypertension, chronic renal failure, DM
• Post renal causes – urinary obstruction by stones,
tumors

19. • Decreased blood urea nitrogen –
• Poor nutrition
• High fluid intake
• Excessive administration of i.v fluids
• Liver damage
• Late pregnancy, infancy, acromegaly.

20. 2. creatinine
• Creatinine - catabolic product of creatinine phosphate - used for
skeletal muscle contraction.
• excreted entirely - kidneys
• amount in blood - directly proportional to renal excretory
function
• diagnose impaired renal function
• Normal range – 0.5 – 1.6mg% or 1.5 mg/dl
• symptom > 4mg/dl

21. INCREASED CREATININE LEVELS:
• Kidney disease
• Decreased: Pregnancy – NS
• decreased – improve function

22. Dentists
• O/E : Pale, fluid retention – edema, Inc IJP, asitics' -
advice Investigations
• Anemic, Acidosis – K+ retention
• BT prolonged
• Rx – avoid anti platelet drugs –
Aspirin NSAIDs, nephrotoxic drugs
• Consent – physician

23. C. LIVER FUNCTION
Serum bilirubin
Urine urobilinogen
Serum albumin – globulin
Serum alkaline phosphatase
AST & ALT

24. 1.serum bilirubin
• Bilirubin : excreted - intestines.
• Intestines converted - colorless compound - urobilinogen.
• Level of bilirubin elevates - excessive hemolysis
• Inability of liver to eliminate bilirubin (liver damage or
obstruction of bile duct)
• yellow color - product
• skin, mucous membranes, sclera of the eye, plasma and urine
• Excess bilirubin - associated - hepatitis

25. • Jaundice - total serum bilirubin rises
• Normal Value → 0.1 to 1.2 mg / 100 ml
5.1–17.0 micro mol/L
High values:
• Hemolytic Anemia
• Biliary obstruction
• Hepatitis
• Malignant Hepatic Disease

26. 2. SERUM GLUTAMIC OXALOACETIC TRANSAMINASE (SGOT)
SERUM GLUTAMIC PYRUVIC TRANSAMINASE (SGPT)
• enzymes -large amounts - liver, heart, kidney and skeletal muscle
• metabolism of amino acids and carbohydrates.
• NORMAL VALUES :
• SGOT also called Aspartate Aminotransferase 6 -25 I U/ L
• SGPT also called Alanine Aminotransferase 3– 26 I U/ L

27. • SGOT -sensitive indicator - myocardial necrosis, significant rises
occurs
• Hepatitis & other liver disease + associated liver necrosis- SGOT
and SGPT

28. screening for hepatitis b &c
• Detection of hepatitis B surface antigen:
• Hepatitis B virus (HBV) is a double stranded DNA spherical particle with
a double shell. - referred as the Dane particle.
• Antigens which have so far been associated with HBV are as follows ;
• Hepatitis B surface antigen (HBsAg) : This was first noticed in the blood
of an Australian aborigine hence earlier was termed as Australia antigen.
• Hepatitis B core antigen (HBcAg)
• Hepatitis B e antigen (HBeAg).

29. • Infection - HBV i- entry of virus through the skin or mucous
membranes into the blood or body fluids.
Routes of transmission
• transfusion of blood or blood products.
• HBV contaminated needles, syringes or prickers.
• Close personal contact with a person with hepatitis B
• Contact with blood specimen (Laboratory personnel those who
handle the specimen)
• Transmission by blood sucking insects or bed bugs.

30. Clinical Significance :

31. • detection of hepatitis – b surface
antigen (hbsag) by direct enZyme
linKed immunosorbent assay (elisa) :
• HBsAg formerly called Australia antigen is
• Reduce incidence of post-transfusion hepatitis,
testing for HbsAg is mandatory for blood
products intended for human use.
• Care – Rx – viral particles – saliva & other body
secretions.

32. • Hepatitis A – SGOT, SGPT –
• Hepatitis B – SGOT,SGPT & LDH –
• Hepatitis C – SGOPT & SGPT
• Dentists – possible signs – icterus, fever ../ H/O
• Lab inv -
• Viral hepatitis – infectious B
• Exposed inf blood & saliva- Precautions

33. • Signs
• H/O: Alcohol abuse, hepatitis ,abnormal bleeding
• Features – improper function Liver – Def production
clotting factors – PT elevated
• So investigation & physicians opinion – needed –
precautions

34. 3. serum albumin and globulin
• total protein
• important - coagulation, transport hormones,
act on antibodies
• act - buffers with enzymes
• help - maintain osmotic pressure.

35. • Serum albumin - synthesized in liver
• globulins - produced - plasma cell
• Normal Values:
• Total Protein 6.0 to 7.8 g / 100 ml or 6.0 to 8.3 gm/dL
• Albumin 3.2 to 5.6 g / 100 ml
• Globulin 2.3 to 3.5 g / 100 ml
• A / G Ratio 1.5 to 1 to 2.5:1

36. Total proteins
High Albumin - rare but dehydration and shock.
Low Albumin : same as proteins.
High Globulin : Multiple myeloma, Nephrosis, Chronic infections,
Collagen diseases, Liver diseases
Low Globulin : Burns and severe malnutrition.

37. 5.Alkaline phosphatase
• high concentration - growing bone, bile, placenta.
• Normal level: 30 to 115 U/l.
Increased
A. In children
B. Osteoblastic bone disease
C. Hepatic disease / bileobstruction - stone, stricture,
neoplasm.
D. Pregnancy.
Decreased:
• Hypophosphatasia, hypothyroidism, malnutrition.

38. Normal values and changes in two types of Jaundice
Hepatocellular Uncomplicated
Tests Normal Values
Jaundice Obstructive Jaundice
Bilirubin
- Direct 1. – 0.3 mg/dL Increased Increased
-Indirect 2. – 0.7 mg/dL Increased Increased
Urine bilirubin None Increased Increased
Serum albumin/Total Albumin, 3.5-5.5 g/dL Albumin decreased Unchanged
protein Total protein, 6.5-8.4
g/dL
Alkaline phosphatase 30-115 units /L Increased (+) Increased (++++)
Prothrombin time INR of 1.0 – 1.4 After Prolonged if damage Prolonged if obstruction
Vitamin K, 10% increase severe and does not marked, but responds to
in 24 hours respond to parenteral parenteral vitamin K
Vit K
ALT, AST ALT, 5-35 units/L, AST, 5-40 Increased in Minimally increased
units/L hepatocellular damage,
viral hepatitis

39. D. THYROID FUNCTION

40. Reference values of thyroid
function test
Test Range
TSH 0.5 - 4.7mU/L
T3 0.92-2.78nmol/L
T4 58-140 nmol/L
FT4 10.3-35pmol/L

42. HYPO THYROIDISM HYPER THYROIDISM
• Catecholamines in LA + • CNS depression – present
stress in dental operatory • Administration of narcotic
• Ppt thyroid Astorm analgesics increase risk
• Characterised High fever, CNS depression& collapse
psycosis, CNS depresssion,
vomiting diaorrhea – risk
CHF
Pt asked for Heat & cold intolerance, wt gain /loss, change in appetite bowel
habits , muscle weakness and palpitations

43. E. Metabolic Bone Disease
• Jaw lesions – radiographic examination
• Systemic jaw diseases-
• Pagets disease, FD, Primary & Sec.
Hyperparathyroidism, Osteoporosis, MM, Osteogenic
sarcoma or metastatic malignancy
• Serum Ca, P,& alkaline phosphatase -

44. Serum Ca, P
• Serum cal I / serum phosphorus
• Measured : mg/dl
• serum Ca conc. X serum P conc. = constant
• 30 to 40 mg/dl = Normal adults
• 50 to 60 mg/ dl = growing children

45. • GA & surgical procedures – cardiac arrythmmias, heart block
• Hypercalcaemia - excessive skeletal calcium release, increased intestinal
calcium absorption, or decreased renal calcium excretion.
• serum Ca – hypo proteinmia, due decreased binding by serum protein &
renal disease.

46. 2. Alkaline phosphatase
• Oestoblasts
• enzyme - produced - small amounts –liver
• larger amounts by osteoblasts.
• active in bone formation and therefore is found at higher levels there.
• result increased osteoblastic activity
• In association – obstructive liver disease, amyloid disease, leukemia
& sarcoidosis

47. • Normal values for serum Alkaline phosphatase
• King Armstrong Units – 4 to 13
• Brodansky Units - 1.5 to 4.5
• International Units - 30 to 85 IU

48. High Alkaline Phosphatase values :
• Obstructive liver disease
• Metastatic carcinoma involving bones
• Hyper parathyroidism
• Pagets Disease of Bone
• Osteo malacia
• Rickets
• Amyloid Disease
• Leukemia
• Sarcoidosis
Low Alkaline Phosphatase :
• Hypophosphatasia
• Hypothyroidism
• Scurvy

49. Values Serum calcium Serum Serum phosphates
mg/dl phosphorus Units /dl
P/dl
Normal 8.8 to 10.5 2 to 5 1-4
Rickets Normal Decreased – Increased 20 to 40 x
Exc tetany normal
Osteomalacia Decreased Decreased Little if any change
Paget’s Disease Normal Normal Occasionally
elevated
Hyperparathyroidism Increased Decreased Increased 2 to 50 x
normal
Osteogenic normal Normal Slightly increase
Imperfecta
Solitary Bone cysts normal normal normal
Metatstatic Oseous May be elevated Normal Normal / slightly
Disorders elevated
Tetany 7 mg ca/dl or less Normal / elevated Normal

51. G. Other Tests
1. Acid phosphatase
• Phosphatases active at pH 4.9 are present - high
conc.
• prostate gland, erythrocytes, platelets,
reticuloendothelial cells, liver, spleen, and kidney.
• Normal levels: 0.8 IU/l.
• Increased:
carcinoma of the prostate

52. 2. Serum amylase
• Normal level: 5 to 75 IU/l.
• Increased:
• Acute pancreatitis, pseudocyst of the pancreas,
• obstruction of pancreatic ducts (carcinoma, stone,
stricture,duct sphincter spasm after morphine), and parotitis.
• Decreased:
• Acute and chronic hepatitis
• Pancreatic insufficiency,
• toxemia of pregnancy.

53. 3. Serum lipase
Normal level: 0.2 to 1.5 units.
Increased:
• acute or exacerbated pancreatitis
• obstruction of pancreatic ducts- stone or neoplasm.

54. 4. Serum cholesterol
• Normal Range : 160 to 300 mg/dl
• > 300 mg/dl : dietary reduction – animal fats, eggs &
foods cholesterol levels
• Risk – artherosclerotic CVD
• Elevated :
• hypothyroidism, obese; elderly diabetic & nephrotic
syndrome

56. Check on
triglycerides
• HDL : good" cholesterol - removes excess cholesterol
from the blood and takes it to the liver
• LDL: BAD: High levels- linked - increased risk of heart
and blood vessel disease, inlcuding coronary artery
disease, heart attack and death.

57. 5. Creatine phosphokinase
(CPK)
• Male: 50 to 180 IU/l, female: 50 to 60 IU/l.
• Myocardial infarction, trauma to muscle, malignant
• Hyperthermia muscular dystrophies, polymyositis,
severe Muscular exertion (jogging), hypothyroidism

58. 6. Lactate dehydrogenase
(LDH)
• Normal level: 45 to 100 U/l.
• Increased:
• Tissue necrosis, particularly those
involving acute injury to heart, red cells,
kidney, skeletal muscle, liver, lung

59. • In all these Pt where CVS disease – suspected
• Signs – cyanosis, clubbing, peripheral edema
• H/O : Palpitations, dizziness
• Lab inv : cholesterol > 240mg/dl

60. 7. Serum uric ACID
• Range : 4 mg /dl to 8.5 mg/dl - Males
• 2.8 to 7.5 mg/dl – females
• Metabolic end product – nucleoprotein metabolism –
derived purine mol

62. URINE ANALYSIS

63. The Function of Urinary System
A)  Excretion & Elimination:
removal of organic wastes
products from body fluids
(urea, creatinine, uric acid)
B)  Homeostatic regulation:
Water -Salt Balance
Acid - base Balance
C)  Enocrine function:
Hormones

64. Indication
• Disease of kidney & UI
• As a screening procedure in systemic Disease –
diabetes , Jaundice
• Diagnosis – metabolic diseases , enteric fever
• Hormonal studies – pregnancy, steroid metabolites &
catecholamine's

65. URINANALYSIS
Normal constituents
• Water – 95%
• Organic – Urea, uric Acid,
Creatinine
• Inorganic – NaCl,
sulphates & phosphates
• Pigments – derived bile
pigments – colour

66. Divided into 3 categories
1. general physical characteristics
& measurements
• Appearance - clear : white &
cloudy,
• Colour – straw , yellow,amber
• Odour – ammonia
• Quantity – 1500ml
• Specific gravity – 1.010 to
1.030

67. 2. Chemical Examination
• Reaction – ph acidic 4.5-8
• Protein – albumin
• Glucose - no
• Ketone – no :
• Bilirubin - no
• Blood - no
• Nitrate - no
• Uribilinogen – small amts
• Special tests -

68. 3. Microscopic examination of centrifuged
sediment
• Cells
• Casts
• Bacteria
• Parasites & yeasts
• Spermatozoa
• Crystals
• Artifacts & contaminants

69. TYPE Presence in Possible causes of abnormal
normal urine amts of cells in urine
RBC’s 0-5 cells / hpf Inflammatory diseses
Acute glomerulonephritis
Hypertension, renal infarction,
trauma, stones, bleeding
diseases, Use of anti
coagulants
WBC’s 0-8 cells /hpf Polynephritis, cystitis,
urethritis, prostatitis,
Transplant rejection,
Sq epi cells Often present Vaginal contamination
Tumor cells Not often present Tumors of
Renal pelvis, Renal
parenchyma,
Ureters, Bladder

70. Casts
Urinary casts are tiny tube-shaped particles made up of white blood cells, red blood
cells, or kidney cells.
form in kidney structures called tubules. Casts are held together by a protein
released by the kidney.
Type Description causes
Hyaline casts Colourless,Transperent, Low RI Strenous ex, acute
glomerulonephritis, Acute
polynephritis, Malignant
hypertension, Chronic renal
disease
Red blood cells casts Red cells in hyaline matrix AGN, Lupus N, Collagen
Yellow orange colour disease, Renal infarction,
High - RI Malignant hypertension
Granular casts Opaque granules in matrix Nephrotic syn
Congestive heart failure, Acute/
chronic renal disease
Fatty casts Fat globules Nephrotic synd, DM, Mercury &
ethylene glycol poisioning
Epithelial cells Hayaline matrix Glomerulonephritis, Vascuclar
High -RI disease, Toxin, Virus

71. Red blood cell cast in urine
White blood cell cast in
urine
Urinary casts. (A) Hyaline cast
(200 X); (B) erythrocyte cast
(100 X); (C) leukocyte cast
(100 X); (D) granular cast (100
X)

72. • Crystals
Urinary crystals. (A) Calcium oxalate crystals; (B) uric acid
crystals (C) triple phosphate crystals with amorphous
phosphates ; (D) cystine crystals.

73. SALIVARY CHEMISTRY

74. Salivary analysis
• protective fluid - oral cavity
• Like - blood & urine- composition may alter indicating
presence of disease
• ‘lie-detection test’
• Surrogate markers - local & systemic diseases and
conditions.
• so-called ‘salivary biomarkers’

75. Application of salivary analysis
• Advancing technologies - sensitive enzyme-linked
immunosorbent assays
• helps saliva – analyzed- study microbes, chemicals and
immunological markers.

76. Advantages of salivary
analysis
• convenient, non-invasive & painless.
• more cost-effective - testing blood assessment
of biologically active compounds - cellular level
• blood analysis - done on compounds – protein –
bound.

77. Collection of saliva samples
• Sample expectorated whole saliva
• Mixture – major & minor salivary glands + gingival
crevicular fluid
• Collected - 1.5 to 2 hours : after meal / after overnight
fast

78. Resting flow rate - whole saliva : 0.3 to 0.4 ml/minute
flow stimulated by paraffin chewing : 1–2 ml/minute.
Unstimulated/resting
Stimulated saliva saliva
• stimulated prior collection • collected into graduated tube or
pre-weighed vial by passive
• achieved - chew on softened
drooling
paraffin wax / washed rubber • flow rate per unit time -
bands. measured.
• Topical application of 2% citric • cotton swabs,cotton rolls; gauze
acid - directly to the tongue or filter paper strips (non-
volumetric collection)
• aspirated directly - floor of
mouth - plastic pipette or into a
graduated tube

79. Diagnostic Applications of
Salivary
Analysis

81. 3. Infectious diseases

82. 4. Oncology
• Saliva - analyzed - presence tumor markers, mutated genes
• exfoliated cells - saliva - used :simple, non-invasive method for
obtaining DNA for gene analysis.
• diagnosis / detection - cancers distant oral cavity.
p53 levels of salivary antibodies to p53.
CA 125 Elevated – ovarian carcinomas
c-erbB-2 & Epidermal Elevated – breast cancers
growth factor
Albumin Stomatitis associated chemotherapy
Ingested nitrate salivary nitrate - indicative ingested nitrate
converted to nitrite and nitrosamine
contribute - development of oral and gastric carcinomas
Recurrent oral cancer Salivary concentrations - carbohydrate antigens (Cyfra
21-1, TPS and CA 125) : found to significantly increase

84. HISTOPATHOLOGY, CYTOLOGY
AND
IMMUNOFLUORESCENT
STUDIES

85. • Study - microscopic anatomy of cells and tissues -
plants and animals.
• Performed by examining cells and tissues - sectioning
and staining
• Followed by examination - light microscope or electron
microscope

86. Commonly used methods
Exfoliative cytology :
• chair side
• Screening large areas, un limited repetition
• Early detection – maliganancy
• Lesions – herpes & candida – scrapping
• determining site of biopsy
Aspiration Cytology :
• Microinvasive procedure
Biopsy :
• gross & microscopic exam.
• Tissues of cells – removed living patients

87. BIOPSY
USES COMPLICATION
• Diagnosis of pathological • Hemorrhage
lesion • infection
• Grading of tumor • Poor wound healing
• Neoplastic & non neoplastic • Spread of tumor cells
lesions • Injury adjacent cells
• Metastatic lesions • Reaction - LA
• Evaluation of recurrence
• Therapeutic assessment
• Differentiation – Benign &
malignant

88. Immufluorescence studies
• Technique – antibodies or antigens are labeled with fluorescent
dyes
• Used - visualize - subcellular distribution of biomolecules.
• Immunofluorescent labeled tissue sections or cultures
• studied using a fluorescence microscope or by confocal microscopy
• Three types of fluorescent antibody
• Procedure - direct immunofluorescence, indirect
immunofluorescence

89. Direct immunofluorescence
technique
Indirect Immunofluorescence technique
• Auto antibodies bound to patient’s • detecting antibodies circulating -
tissue blood.
• Can be detected. • monkeys esophagus - patient’s
• Frozen section - patient’s tissue • serum is added.
• Antihuman antibodies tagged with • excess serum - washed away.
fluorescein dye is added. • Antihuman antibodies tagged -
• Excess suspension - washed fluorescein dye added.
away. • washed
• Section is viewed under • viewed under microscope (UV)
microscope (uv light).

91. ASPIRATE
DISEASE Aspirate
OKC Thick , cheesy ,yellow granular fluid
Keratin dough like consistency
Ameloblastoma Clear brownish yellow colour fluid
Odontogenic cyst Straw colored fluid : + cholesterol
crystals
Sebaceous cyst Sebum – homogeneous & yellowish
cheesy sub
Thyroglossal duct cyst Dark amber col.
Hemangioma, varicosities, hematoma Blue blood
Aneurysm & arteriovenous fistula Brighter red blood
Actinomycosis Pus with yellow granule - sulphur

92. Features Disease
Ruston bodies Dentigerous cyst
Reed sternberg cell Hodgkins disease
Saw tooth appearance Lichen planus
Picket fence / tombstone Primodial cyst
Lipschtz bodies Herpes simplex inf
Antischkow cell Apthous ulcer, sickle cell, megaloblastic and fe def
anemia
Liesegang ring CEOT
Cart wheel / checker board MM
app
Lava flowing around boulder Dentin Dysplasia
Honey comb/ swiss cheese Adenoid cystic carcinoma of salivary gland
pattern
Cell in cells Hereditary benign intraepithelial keratosis

93. SKIN LESIONS :
LP Saw tooth rete pegs
Pemphigus Tzank cells’
Pemphigoid Sub epithelial vesicles - acantholysis
CYSTS
OKC Tomb stone basal cells & satellite cysts
DENTIGEROUS CYST Cholesterol clefts
INFECTIONS
TB Langhans gaint cells & epitheloid cells
ACTINOMYCOSIS Col of fungus- ray fungs
BONE LESIONS
FD Trabaculae- chinese lettern pattern
PAGETS DISEASE Jig saw puzzle/ mosaic pattern
BENIGN & MALIGNANT TUMORS
SCC Multiple keratin pearl formation
Fibrosarcoma Cells – herring bone pattern

94. MICROBIOLOGY

95. • Study - microscopic organisms
• Microbiology is a broad term which
includes virology, mycology, parasitology, bacteriology,
immunology and other branches.

96. Haematoxylin – Eosin Stain : Nuclei – blue black
Cytoplasm – Pink or varying grades
Collagen Fibers- Pink to red
Muscle fibers – deep pink to red
Fibrin – deep pink
Periodic Acid Solution / Periodic Acid schiff Carbohydrate – Magenta
Nucleus – Blue
Glycogen – Magenta
Carbol Fuschin & distilled water Gram + ve organisms : Violet (basophilic)
Gram –ve organisms : Pink Eosinophilic
Acid Fast stain ( Ziehl Neelsen’s stain) Mycobactterium tuberculi & Mycobacterium
leprae
{ red} tissue & other organisms – blue
Mycobacterium retains stain after decolorization – thick lipid mycolic acid

98. SEROLOGY AND
IMMUNOHISTOCHEMISTRY

100. METHODS OF DETECTION OF ANTIBODIES
1. Immuno-precipitation Assays
= detect antibodies in solution
= qualitative indication of the presence of
antibodies
= end-point is visual flocculation of the antigen and
antibody in suspension
2. Complement Fixation
= based on the activation or fixation of
complement following binding of complement
factors to Ag-Ab immune complexes

101. 3. Neutralization
= effectively of an organism or activity of toxin is neutralized by
specific antibody
= rarely used for diagnostic purposes
= mainly used to detect antibody formation after vaccination
4. Particle Agglutination
= relatively simple and fast
= capable of detecting lower concentration of antibodies
= designed to detect antibodies to viruses, subsequent to
interaction or vaccination
= utilize Ag coated latex particles, coal particles,
= direct and indirect methods

102. 5. Immunofluorescence
– requires use of microscope equipped provide ultraviolet
illumination or
– an instrument capable of irradiating the assay with UV light and
detecting resultant fluorescence with a fluorometer
6. Enzyme Immunoassay
– most sensitive
– usually indirect assay that depends on the use of an antihuman
IgG or IgM antibody conjugate
– antibody conjugate (if present) is made to attach to enzyme which
catalyzes conversion of substrate to a colored product which
will then be read with the use of a spectrophotometer
7. Radioimmunoassay
= high sensitivity

103. Tests for HIV
Laboratory diagnosis of HIV infection
❑ Detection of anti-HIV antibodies
❑ Detection of antigen
❑ Detection of viral nucleic acid
❑ Virus isolation.
Investigations for HIV non-specific tests
Lymphocytopenia below 2000 cu.mm
Decrease in CD4 count
Low t4:t8 ratio (t helper/t suppressor cell ratio) increase in
IgG and IgA.

104. Specific Tests
Primary tests
❑ EIA/ELISA
❑ Polymerase chain reaction
Confirmatory tests
❑ Western blot
❑ RIPA
❑ Immunofluorescence assay
❑ DNA/RNA amplification tests

105. PCR – Polymerase Chain Reaction –
• uses - amplify viral RNA from blood,
• detect even small amounts of virus in newly infected person.
• expensive, time consuming, and not readily available
RIPA –
• done when antibody levels are low or Western Blot results -
unclear
• expensive, difficult to perform, and not often used.
Immunofluorescence Assay –
• Confirmatory test used when Western Blot results are unclear.
• used instead of a Western Blot after an ELISA test.
DNA/RNA Amplification Tests –
• Tests similar to PCR
• used when the result of a western blot is unclear.

106. Radiological

107. • Radiographs – recomended for demonstrating varios
lesións

108. Region required Standard views Additional views
SKULL PA, Lateral skull SMV
FACIAL BONES OM,Lateral Red exposure SMV
PNS OM for max antrum Upper occlusal/lat
SMV.OPG,CT
Orthodontics OPG, Cephalometric
skull
Nasal bones OM – 30 ,Lateral,
MANDIBLE OPG Lat oblique, PA mandible
MAnd.Occlusal
TMJ Transcranial,Lat oblique, Transpharyngeal,Arthrog
OPG raphy, reberse townes,
Ct,,MRI

109. SPECIAL RADIOGRAPHIC TECNIQUES
• CT
• Digital Radiography
• Subtraction radiography
• Radionuclide imaging
• Sonography

110. Conclusion

111. THANK YOU

112. TESTS FOR SPECIFIC
DISEASES

113. Tests for Syphilis
• Diagnosis - achieved either by direct identification -
pathogen - serological findings & treponema pallidum

114. Serology
• confirmatory test - FTAABS - golden standard
• enzyme immunoassays, Western blot technique
• Serology in congenital syphilis: Finding specifi c IgM anti-
treponemal antibodies is helpful in diagnosing congenital infection
• If titers > in infant then mother