this seminar covers laboratory investigations routinely done in periodontics. all the necessary routinely tests along with its interpretation

1. Laboratory
investigations
and
interpretations
Presented by DR.AISHVARYA HAJARE
1st year postgraduate
Department of periodontics
1

2. Contents
 Introduction
 Definition
 Need for investigations
 Classification
 Lab investigations frequently used
• Haematological Investigations
• Biochemistry Investigations
• Microbiological Investigations
• Immunological Investigations
• Histopathological and Cytopathological Investigations
 Conclusion
 References
2

3. Introduction
 Diagnosis, the identification of disease by careful investigation of
patient’s signs, symptoms and history.
 Data gathering is the first step in the diagnostic process and the
medical & dental history play an extremely important role in
collection of data.
 Laboratory tests can be used to screen for disease in asymptomatic
individuals to establish or exclude the presence of disease in
symptomatic patients and to assist the practitioner in the management
of patient.
3

4.  Laboratory studies are an extension of physical examination in which
tissue, blood, urine or other specimens are obtained from patients &
subjected to histological, bio-examination, microbiological or
immunological examination.
4

5. Important characteristics of a
laboratory test
Characteristic Description
Accuracy Assesses a value that is in accordance with
the actual or true quantity found in patient
Cost Expense can affect patient acceptance
Interfering factors Endogenous (e.g. abnormal physiologic states)
or exogenous (e.g. drug usage) elements that
can alter test results.
Morbidity Discomfort associated with the test can affect
patient compliance
Precision Reproducibilty of test 5

6. Sensitivity The probability that the patient has
positive test
Specificity The probability that healthy patient
has a negative test
Reference range The limits of test results values
found in 95% of population
Specimen collection Gathering a specimen from the
patient at the appropriate time
6
Marotti A. Laboratory testing of patients with systemic conditions in
periodontal practices Perio2000:2004;34:84-108

7. Classification
 Based on where investigation is done
7
Chair side investigations Laboratory investigations
Act as precursor to laboratory
investigations
Significantly higher in sensitivity
and specificity
e.g. toluidine blue for grading
dysplasia, electrical pulp testing
for pulp vitality
e.g. glycated heamoglobin level

8.  Based on sensitivity/specificity
8
Screening test Diagnostic test
An ideal screening test is 100%
sensitive.
An ideal diagnostic test is 100%
specific.
Useful in a large sample size at
risk, typically cheaper
Useful in symptomatic
individuals to establish
diagnosis or asymptomatic
individuals with positive
screening test, expensive
e.g. blood glucose estimation
for screening diabetes
e.g. glycated heamoglobin
estimation.

9.  Based on hospital lab services
 1. HAEMATOLOGY
 2. MICROBIOLOGY
 3. BIOCHEMISTRY
 4. IMMUNOLOGY
 5. HISTOPATHOLOGY
 6. CYTOPATHOLOGY
9

10. HAEMATOLOGY
 Deals with the investigations of abnormalities of blood cells their
precursors and of the haemostatic and clotting mechanisms.
10

11. MICROBIOLOGY
 In this discipline body fluids, mucosal surfaces and excised tissues are
examined by using microscopical, cultural & serological techniques .
 To detect & identify the causative microorganisms.
11

12. BIOCHEMISTRY
 Also called chemical pathology.
 Deals with investigations of the metabolic abnormalities of the body in
disease states.
 Investigations are carried out by assay of various normal & abnormal
compounds found in the body fluids.
12

13. IMMUNOLOGY
 Deals with the detection of abnormalities in the immune system.
 Primary role to identify a disease is by observing the presence of an
antibody in the patient that resulted from the infection.
 The semi- quantitative measure of the amount of antibody present in
serum is called titre.
13

14. HISTOPATHOLOGY
 Deals with the identification of structural changes in diseased tissues
through microscopic examination of appropriately stained tissues sections
obtained from biopsy procedures.
14

15. CYTOPATHOLOGY
 Scientific study of role of individual cells or cell types in disease.
 Clinician collects a sample of abnormal from lesional tissue scrapings or
by means of tissue aspiration
 Cells are then stained & studied under light microscopy.
15

16. Haematological investigations
 The complete blood count :
1. White blood cell count
2. White blood cell types (WBC differential)
3. Red blood cell (RBC) count
4. Hematocrit ( packed cell volume, PCV)
5. Hemoglobin (Hgb)
6. Red blood cell indices {mean corpuscular volume (MCV), mean corpuscular
hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC)}
7. Platelet (thrombocyte) count
16

17. RBC
 EVALUATION OF RBC- total number of red blood cells
normal range : male- 4.7-6.1 million/µl
female -4.2-5.4 million/µl
17

18.  Interpretation :
 Increased levels with congenital heart disease, erthyocytosis,
haemoglobinopathies, polycythemia vera, pulmonary disease,
severe dehydration and severe chronic obstructive pulmonary
disease.
 Decreased levels with anemia, bone marrow failure, cirrhosis,
dietary deficiency, leukemia, lymphoma, multiple myeloma,
heamoglobinopathy, hemolytic anemia, hemorrhage, Hodgkin's
disease, pregnancy, prosthetic valves, renal disease, and
rheumatoid/collagen vascular disease.
18

19. Haemtocrit
 Haemtocrit – a rapid and indirect measurement of red blood cell
number and volume.
RANGE : male – 42-52%
female – 37-47%
19

20. HAEMOGLOBIN
 Hemoglobin measures the amount of the oxygen-carrying protein in the blood.
 Anemias are distinguish by reduced haemoglobin levels.
 Laboratory test to assess it are
 Ferritin
 Folic acid
 Haemocrit
 Haemoglobin
 Iron
 Schilling test
 Vitamin B 12
20

21.  Range :
Male- 14-18g/dl
Female- 12-16g/dl
21
Chronic obstructive
pulmonary disease,
congenital heart
disease,
erythrocytosis, severe
dehydration & severe
polycythemia vera
Anemia, bone
marrow failure,
cirrhosis, dietary
defiency, hodgkins
lymphoma,
pregnancy

22. Ferritin
 Ferritin is a sensitive test to determine iron defiency anemia.
 below 10mg/dl is diagnostic of iron defiency anemia.
22

23. Folic acid
 Folic acid – is used to ascertain if the patients have megaloblastic
anemia or to assess the nutritional status of alcoholics.
 Normal range:
 5-25ng/ml
23
Pernicious
anemia,
Recent massive
blood infusion
and
vegetarianism.
Chronic renal
failure, hemolytic
anemia, liver
disease,
megaloblastic
anemia,
malabsorption,
malignancy,
malnutrition and
pregnancy

24. Serum Iron and Total Iron Binding
Capacity
 Iron deficiency is usually detected on the basis of the amount of iron bound
to transferrin in the plasma(serum iron) and the total amount of iron that
can be bound to the plasma transferrin in vitro
 Normal values
 Serum iron –male- 80-180 µg/dl
female- 60-160µg/dl
 TIBC – 250 – 370 µg/dl
 Transferrin : male: 215-365 mg/dl
female: 250 – 380 mg/dl 24

25. Schilling Test
 It is a measure of the patient’s ability to absorb orally administered
radioactive Vit B12 (cobalamin).
 Patients with pernicious anaemia excrete less than 5% of orally
administered dose in comparison with 8-25% by normal individuals.
25

26. Mean Cell Volume(MCV):
 Ratio of Haematocrit to RBC count expressed in µm3.
 Describes volume of RBC range:
• Normal – 82-92/ µm3
• Normocytic anaemia – 82-92/ µm3
• Microcytic anaemia – 50-80/ µm3
• Macrocytic anaemia – 95-100/ µm3
26

27. Mean Cell Haemoglobin(MCH):
 Ratio of Hb to RBCs and is expressed in picograms
 It expresses the Hb component of each cell range:
• Normal – 27-31 pcg
• Normocytic anaemia – 25-30 pcg
• Microcytic anaemia - 15-25 pcg
• Macrocytic anaemia - 30-50 pcg
27

28. Mean Cell Haemoglobin
Concentration(MCHC):
 Ratio of Hb to Hct
 Value expressed as a percentage of volume of red blood cells.
 Measures Hb concentration in grams/100ml of packed
erythrocytes
 range:
• Normal – 32-36%
• Normocytic anaemia – 32-36%
• Microcytic anaemia - 25-30%
• Macrocytic anaemia - 32-36%
28

29. Erythrocyte Sedimentation Rate(ESR
or Sed Rate):
 In certain febrile diseases as well as in others the amount of
circulating fibrinogen is increased
 The resultant increased viscosity of blood slows down the
sedimentation rate of erythrocytes
 ESR indicates the speed with which the erythrocytes settle in
uncoagulated blood
 Values:
• Men < 50 years - <15 mm/hr.
• Women < 50 years - <20 mm/hr.
• Men >50 years - <20 mm/hr.
• Women >50 years - <30 mm/hr.
29

30.  Interpretation:
30
Raised ESR Lowered ESR
TUBERCULOSIS POLYCYTHAEMIA
SABE SPHEROCYTOSIS
ACUTE MI SICKLE CELL ANEMIA
SEPTIC SHOCK CONGESTIVE HEART FAILURE
ANAEMIA NEW BORN INFANT

31. White Blood Cell Count: (WBC)
 The white blood cells or Leukocytes are classified as either
granulocytes or agranulocytes
 Normal range: 4500-11000 cells/mm3
 High values may be caused by leukaemia, polycythaemia or
infectious diseases
 Low values may be due to bone marrow depression, aplastic
anaemia, drug reactions and viral infections viz influenza
31

32. Differential White Blood Cell Count:
(DLC)
 Obtained from a peripheral blood smear
 The granular and nongranular leukocytes are counted and its values
are expressed as a percentage of Total WBC.
Neutrophils:
 Band neutrophils are immature while seg neutrophils are mature
 Normal Band value – 2-3% while normal seg value – 50-60%
 High Band value may indicate presence of an acute infection while
Low value may indicate bone marrow depression
 High Seg values may indicate AML, drug/poison intoxication while
Low value may indicate malignant neutropenia or aplastic anaemia
32

33. Basophils:
 Normal value – 0 – 1%
 High values uncommon; may indicate myeloproliferative disease
 Low values may indicate an oncoming anaphylactic reaction
Eosinophils:
 Normal value – 0 – 5%
 High values are mostly observed in allergies or parasitic infections
 Low values are mostly observed in aplastic anaemia and patients on
cortisone therapy
33

34. Lymphocytes:
 Normal value – 30 – 40%
 High values may indicate chronic/viral infections, lymphocytic
leukaemia
 Low values may indicate aplastic anaemia or myelogenous leukaemia
Monocytes:
 Normal value – 3 – 7%
 High values are seen in Monocytic leukaemia, Hodgkin’s disease, SABE
 Low values are mostly seen in aplastic anaemia
34

35. Bleeding time
 Measures the time for haemostatic plug formation
 Normal Bleeding time – 2-7 mins
 Any clotting factor deficiency or platelet abnormality will lead to increased BT.
 Prolonged in
• Thrombocytopenia
• Acute leukaemia
• Aplastic anaemia
• Liver diseases
• Von-Willebrand’s disease 35

36. Capillary fragility test
 Rumpel-Leede Test(Tourniquet Test):
 Test of ability of the superficial capillaries of the skin of the forearm and hand to
withstand an increased intraluminal pressure and a certain degree of hypoxia
 Done by occluding veins of the upper arm with a blood pressure cuff for 5 mins.
 Indicated in suspicions of bleeding abnormalities, petechiae in oral cavity and scurvy.
 It is a clinical diagnostic method to determine a patient's haemorrhagic tendency.
 Presence of >20 petechiae/sq. inch is considered abnormal
 Dental Application – screening test for scurvy.
36

37. Clotting Time
 Measures the time required for formation of first clot.
 Screening test for coagulation disorders
 Normal Clotting time –: 4-14 mins
37
Interpretation:
• Prolonged in disease affecting stage II & stage IV of haemostatsis
• Increased in cirrhosis, hemophilia A&B
• Factor XI deficiency
• Hypofibrinogenemia
• Heparin & dicumarol anticoagulant therapy

38. Prothrombin time
 Secondary stage of hemostatic mechanism comprises the intrinsic and
extrinsic cycle. (Factors I,II, V ,VII, X)
 International normalized ratio(INR) consideration.
 Normal time – 11-14 secs
 Measured against a Control PT in terms of INR
 INR = PTTest / PTNormal
 Normal INR = 1 ; Abnormal INR > 1.5
38
Increased PT
• Disseminated Intravascular Coagulation
• Patients on Warfarin Therapy
• Vit K deficiency
• Early & End stage Liver failure

39. Activated Partial Thromboplastin
Time (aPTT):
 Measured in seconds, time required for clot to form in sample of
oxaloacetate plasma, to which partial thromboplastin reagent &
calcium chloride is added.
 Performance indicator of both the intrinsic & common pathways
 Typical reference range – 30-40 secs
39
Increased aPTT seen in :
• Patients on Heparin Therapy
• Von – Willebrand’s disease
• Disseminated Intravascular Coagulation
• Early Stage Liver failure/ Wilson’s disease
• Haemophilia

40. 40

41. Serum chemistry
 Serum is that portion of blood remaining after whole blood has been
allowed to clot
 Responsible for fluid maintenance Intra and extra cellularly
 Responsible for the optimal osmotic gradient, nerve and muscle
function and hydration
41

42. Glucose estimation
 Fasting Blood Sugar(FBS): Normal values – 70-90
mg/100ml
 Random Blood Sugar(RBS): 110-130 mg/100ml
 Post Prandial Blood Sugar(PPBS): <140 mg/100ml
42
High values are seen in Diabetes mellitus, Cushing’s
disease, pheochromocytoma, in patients taking
corticosteroids
Low values seen in insulin secreting tumours, Addison’s,
Pituitary hypo function

43. Oral glucose tolerance test
 Used for the definitive diagnosis of diabetes mellitus and for
distinguishing diabetes from other causes of hyperglycaemia like
hyperthyroidism.
 Should be performed on only healthy ambulatory patients who are not
under any drugs which may interfere with glucose estimation.
 OGCT(challenge Test) is a short version of OGTT used in pregnant
women to check for Gestational Diabetes
43

44. 44

45. Glycated Haemoglobin(HbA1c)
 Hb becomes Glycated by ketoamine reactions between glucose and
other sugars.
 Once Hb is Glycated, it remains that way for a prolonged period(2-3
months)
 Hence it provides a definitive value of blood sugar control of 2-3
month duration
 The HbA1c fraction is abnormally elevated in diabetic patients with
chronic hyperglycaemia
 It is considered to be a better indicator for diabetic control
compared to blood glucose levels
49

46. 50

47. Serum Calcium, Phosphorus:
 Indicated on suspicion of Paget’s disease, fibrous dysplasia,
primary and secondary hyperparathyroidism, osteoporosis,
multiple myeloma or osteosarcoma
 The concn. Of Serum Ca varies inversely with serum P
• Normal level Serum Ca – 9.2-11 mg/dl
• Normal level Serum P – 3- 4.5 mg/dl
• At levels less than 7 mg/dl Serum Ca, signs of tetany may
appear
51

48. Serum Alkaline Phosphatase: (ALP)
 ALP produced in small amounts in the liver but most notably in
osteoblasts
 Normal values:
52
ADULT CHILD
King Armstrong Units 4-13 15 -30
Bodansky Units 1.5 - 4.5 5 - 14
International Units
(IU/l
30 -85

49. INTERPRETATION
53
HIGH LOW
Obstructive liver disease Hypophosphatasia
Paget’s disease of bone Osteoporosis
Osteomalacia Hypothyrodism
Rickets Aplastic anaemia
Sarcoidosis Chronic myeloid leukemia
Lymphoma Wilson’s disease

50. Serum Uric Acid
 End product of purine metabolism
 Normal values:
• Males : 2.1-7.8 mg/100ml
• Females : 2.0-6.4 mg/100ml
 Abnormally high uric acid level seen in Gout, Renal failure,
leukaemia, lymphoma, starvation , lead poisoning & cancer
chemotherapy
 Low values are rare
54

51. Serum Creatinine
 Metabolic product of dephosphorylation of creatinine phosphate
 Raised in late stage Renal disease
 Its analysis is preferred to Serum Urea analysis as dietary protein intake
and protein catabolism do not alter its levels in the body
 Levels > 15 mg/dL indicates impaired renal metabolism
55

52. Blood Urea Nitrogen
 Formed by the deamination of amino acids in the liver
 Protein metabolism produces ammonia, a toxic substance that is
converted into urea.
 Normal values – 8 -18 mg/100ml
 High BUN readings are seen in acute or chronic renal failure,
congestive heart failure and urinary tract obstructions
56

53. Serum Bilirubin: (Brb)
 Bilirubin is a bile pigment derived from the breakdown of
Haemoglobin
 Normal value: 0.1 – 1.2 mg/100ml
 Levels beyond 3.0 mg/100ml may indicate jaundice
 High values may also indicate haemolytic anaemia, biliary
obstruction, hepatitis and Gilbert’s disease
57

54. Lactate dehydrogenase LDH,
Serum glutamic oxaloacetic
transaminase SGOT,
Serum glutamic pyruvic transaminase
SGPT
 These enzymes can be indicative of liver disease.
 However, these enzymes are also found in other body tissues such as
bone, heart, kidney, etc.
 Isoenzyme tests usually must be performed in order to isolate the
isoenzyme that is elevated and if the source is the liver.
58

55. LDH,SGOT,SGPT:
 Lactate dehydrogenase (LDH) is responsible for the oxidation of lactic
acid to pyruvic acid.
 Normal range: 71-207 IU/L
 Serum glutamic oxaloacetic transaminase SGOT(AST) is responsible
for conversion of amino acids to keto acids
 Normal range: 0-35 IU/L
 Serum glutamic pyruvic transaminase SGPT(ALT) is responsible for
diagnosis of liver functions more so than SGOT levels
 Normal range: 0-35 IU/L
59

56. Saliva Chemistry
 Salivary function studies include:
• Measurement of Na, K, Cl concentration in saliva
• Measurement of total salivary flow
• Rate of flow of saliva from orifices
• Rate of discharge of radio-opaque dye from salivary gland following
retrograde sialography
60

57.  Normal values for unstimulated saliva are
• K – 25 mEq/L
• Na - <10 mEq/L
• Cl - 15-18 mEq/L
 Increase in K or Na values may indicate generic inflammation or
sialodenosis
 Parotid flow rate and salivary concn of Na,K,Cl, salivary amylase &
protein increases
61

58. Microbiology
 Culture and sensitivity tests are used to isolate and identify causative micro
organisms of an infection
 May be obtained from blood or urine
 Particularly helpful in evaluating infections related to throat, sinuses, root
canals or bone.
 Sensitivity tests may also be ordered when patient relapses, the identification
of the organism is uncertain or the disease is severe
 Most common limitation is the delay in receiving the report
 Another problem is in-vitro testing may not necessarily predict the same result
as in-vivo testing
62

59. Histopathology &
Cytopathology
 Histopathology refers to the microscopic examination of tissue in
order to study the manifestations of the disease.
 Cytopathology refers to the scientific study of role of individual cells
or cell types in disease.
63

60. Tissue Biopsy:
 A biopsy is a controlled & deliberate removal of tissue from a living
organism for the purpose of microscopic examination
 Relatively simple procedure producing little discomfort when
compared to exodontia or periodontal surgery.
 Indications:
• When signs and symptoms of an observed tissue change do not
provide enough information to make a diagnosis
• When neoplasia is one of the differential diagnosis
• To confirm a clinical diagnosis
64

61.  Contraindications:
 The systemic health of the patient may contraindicate biopsy
completely or at least cause its postponement
 Site of the lesion may pose a risk to biopsy (for eg. Biopsy in richly
vascularized areas may pose a risk of haemorrhage)
 Cases of clinically obvious malignant neoplasm should be referred
directly to the appropriate specialist as biopsy would delay
definitive care rather than accelerate it
65

62. Tissue Biopsy:
 Avoidance of Delay for Biopsy:
• Rapid growth
• Absent local factors
• Fixed lymph node enlargement
• Root resorption with loosening of teeth
• History of malignancy
• Uses:
• Diagnosis
• Grading of tumours
• Metastatic lesions
• Recurrence
• Management Assessment
66

63. 67
Excisional biopsy
Incisional biopsy
Punch biopsy

64. INTERPRETATION
 Gross and Histopathologic descriptions
 Gross description includes macroscopic features like colour , general
shape and metric dimensions
 Microscopic description includes the composition of the normal
tissues and any abnormal findings
 It can supplement the clinician’s understanding of the pathologist’s
diagnosis and may reveal the severity of some lesions.
 In addition, the microscopic description should indicate if the lesion
extends to the specimen margins, which in cases of excisional biopsy
may suggest the possibility of recurrence 68

65. Exfoliative Cytology
 Developed by Dr. George Papanicolaou who is also known as “Father of
cytology”
 In this, the surface of the lesion is either wiped with a sponge material or
scraped to make a smear.
 The appreciation of the fact that some cancer cells are so typical that they
can be recognized individually has allowed the development of this
diagnostic technique.
70

66. Fine Needle Aspiration
Cytology(FNAC):
 Microscopic examination of an aspirate obtained by inserting a
fine needle into a lesion.
 Painless and safe procedure for rapid diagnosis.
 Indications:
• Salivary gland pathology
• As a replacement for extensive biopsy
• Suspicious lymph nodes
• Recurrence
• Metastatic lesion
71

67. Immunology:
 Immunoassays are quick and accurate tests that
can be used on-site and in the laboratory to detect
specific molecules.
 Immunoassays rely on the ability of an antibody
to recognize and bind a specific macromolecule
in what might be a complex mixture of
macromolecules.
72

68. 1. ImmunoPrecipitation Assays:
 Detects Antibody in solution
 End point is visual flocculation of the antigen and the antibody in
suspension
2. Complement Fixation:
 Based on activation/fixation of complement following binding of
complement factors to Ag-Ab immune complexes
73

69. 3. Particle Agglutination:
 Relatively simple and fast
 Capable of detecting lower concentration of antibodies
 Designed to detect antibodies to viruses, subsequent to vaccination
 Utilizes Ag coated latex particles, coal particles
4. Enzyme Immuno Assay:
 Most sensitive
 Usually indirect assay that depends on the use of anti human IgG or
IgM Ab conjugate
 Antibody conjugate, if present is made to attach to enzyme which
catalyses conversion of substrate to a coloured product which is then
read by a spectrophotometer
74

70. 5. Radio Immuno Assay:
 Extremely sensitive and specific procedure
 Used to measure concentration of Ag in patient’s sera by using Ab
 To perform this, a known quantity of Ag is made Radioactive and is
made to compete with Ag in patient’s sera for Ab binding sites
 The radioactivity of free Ag remaining is measured using a Gamma
counter
75

71. ELISA: Enzyme-Linked Immunosorbent
Assay
 Is a test that uses antibodies and color change to identify a substance.
 Enzyme is used to detect the binding of Antibody – Antigen
 Enzyme converts colorless substrate into colored product, indicating the
presence of Antibody - Antigen complex
76

72. General Procedure:

73. Types of ELISA:
(on the basis of procedure)
Types
Non-
Competitive
Direct
Indirect
SandwichCompetitive
Multiple &
Portable

75. Competitive:
 Antibody coated microwell.
 Serum antigen & labeled antigen added together .... Competition
 Ab-Ag enzyme complex bound is inversely related to the conc. of
antigen present in sample.
 Increased serum antigen results in reduced binding of Ag-enzyme
conjugate with the antibody producing less enzyme activity & (yellow)
color formation.
 Used to determine small molecules like T₃ , T₄ & Progesterone.

76. Flow cytometry
 Used for rapid identification of oral bacteria that
involves labelling bacterial cells from a patient plaque
sample with both
 Species specific antibody
 fluorescein-conjugated antibody
 The suspension is then introduced in a flow
cytometer, which separates the bacterial cells into
an almost single cell suspension by means of a
laminar flow through a narrow tube.
81

77. 82

78. 83

79. Latex agglutination
 It is a simple immunologic assay based on the
binding of protein to latex.
 Latex beads are coated with the species-specific
antibody and when these beads come in contact
with the microbial cell surface antigens or antigen
extracts, cross linking occurs.
 Its agglutination or clumping is then visible usually
in 2 to 5 minutes.
84

80. 85

81. Enzymatic methods (BANA)
 Tannerella forsythia , Porphyromonas gingivalis, Treponema
denticola and Capnocytophaga species share a common
enzymatic profile: all have a trypsin like enzyme.
 The activity of this enzyme can be measured with the hydrolysis
of the colourless substrate N-benzoyl-d L-arginine-2-
naphthylamide (BANA).
86

82.  The BANA-Zyme TM reagent strips are plastic cards to which
separate reagent containing matrices are affixed.
 The lower matrix is impregnated with BANA.
 Subgingival plaque samples were applied to the lower matrices.
The upper reagent matrix contains a chromogenic diazo reagent
(fast black K).
 Peptidase in certain anaerobic micro-organisms associated with
periodontal diseases can hydrolyze the peptide analog BANA.
 The upper reagent matrix, which reacts from BANA by
bacterial enzyme reacts with fast black K forming a permanent
blue color.
 The blue color of a positive or weak positive reaction appears in
the upper matrix and is permanent.
87

83. 88

84. 89

85. DNA PROBE
 DNA probe as a small piece of nucleic acid (typically single-stranded
DNA) that is used to detect complementary stretches of DNA.
 used in DNA or RNA samples to detect the presence of nucleotide
sequences (the DNA target) that are complementary to the sequence
in the probe.
90

86.  Comparison of the two methods revealed that the ELISA test identified P.
gingivalis and C. rectus significantly more often than the DNA probe
method and that T. denticola was detected more frequently with the DNA
probe.
91
W. Lee Melvin, Daniel A. Assad, Glenn A. Miller, Marlin E. Gher,Lloyd Simonson,
and Andrew K. York Comparison of DNA Probe and ELISA Microbial Analysis
Methods and Their Association With Adult Periodontitis J Periodontol
1994;65:576–582

87. Chair side diagnostic kits in
Periodontics
 Chairside periodontal kits provide immediate reports of the
microflora associated with the disease compared to cumbersome
and time-consuming traditional laboratory procedures.
1. Microbiological test kits
2. Biochemical test kits
3. Genetic kits.
92

88.  Microbial tests can also be used to monitor periodontal
therapy directed towards the suppression or eradication
of periodontopathogenic organisms.
93

89.  Omnigene
 These are DNA probe systems for a number of known
periodontopathogen subgingival bacteria.
 OmniGene Diagnostics, Inc. has applied the
principles of genetic engineering to develop species-
specific DNA probe tests for eight periodontal
pathogens
 Porphyromonas gingivalis,
 Prevotella intermedia,
 Aggregatibacter actinomycetemcomitans,
 Fusobacterium nucleatum,
 Eikenella corrodens,
 Campylobacter rectus, Bacteroides forsythus, and
Treponema denticola 94

90.  Evalusite (Kodak)
 It is a novel membrane immunoassay commercially available
in Europe and Canada for the Chairside detection of 3
periodontal pathogens.
 Membrane bound antibody in the well specific to
A.actinomycetemcomitans, P.gingivalis and P.intermedia
reacts with plaque sample.
95

91. PerioScan®
 Perioscan is a diagnostic test kit that utilizes the BANA (N-
benzoyl-DLarginine- 2 naphthylamide)-hydrolysis reaction,
developed to detect bacterial trypsin-like proteases in the dental
plaque.
 Which hydrolyzes the synthetic peptide benzoyl- DL-arginine-
naphthylamide or BANA.
96

92. Biochemical test kits
 Biochemical test kits used in periodontics analyze the
gingival crevicular fluid (GCF).
97

93.  Perio 2000
 The Diamond Probe/Perio 2000 System is a periodontal probe
that combines advanced ion selective electrode technology
with the standard "Michigan O" style probe.
 The sulfide sensor component in the system is used as an
adjunct to traditional diagnostic techniques in the evaluation of
periodontal diseases in adult patients.
98

94.  Prognos-Stik
 It detects elevated levels of MMPs in the gingival crevicular fluid
such as the elastases.
 The GCF is collected onto the filter paper strip impregnated with a
known amount of buffered elastase substrate labeled with a
fluorescent indicator.
 Soluble dye-labelled fragments of collagen are formed from the
reaction of neutral proteases with the gel and these diffuse onto the
sample strip turning the papers colour to blue.
99

95.  PerioGard
 based on the detection of an enzyme called aspartate aminotransferase
(AST).
 This commercial test consists of a tray with two test wells for each
tooth, and appropriate reagent for conducting the test.
 The test involves collection of GCF with the filter paper strip which is
then placed in tromethamine hydrochloride buffer.
 A substrate reaction mixture containing 1-aspartic and α-keto-gluteric
acid is added to the sample and allowed to react for ten minutes.
 In the presence of AST, the Aspartate and α keto-gluteric acid are
catalyzed to oxaloacetate and glutamate.
100

96.  Periocheck
 Periocheck (Advanced Clinical Technologies Inc., Westwood, MA
02090, USA) is a rapid chairside test to detect the presence of
neutral proteases.
 Crevicular fluid is collected on filter paper strips and these are
placed on a collagen dye labelled gel matrix.
 Soluble dye-labelled fragments of collagen are formed from the
reaction of neutral proteases with the gel and these diffuse onto the
sample strip turning the papers colour to blue.
 The quantity and intensity of the colour reaction is compared to a
standard colour chart and is related to the level of neutral protease
activity originally present in the crevicular fluid sample
101

97.  PerioWatch
 developed as a simple method of analyzing Asparate amino Transferase
(AST).
 in the presence of pyridoxal phosphate, AST catalyzes the transfer of
an amino group from cysteinesulfinic acid, by a aketoglutaric acid to
yield β-sulfinyl pyruvate and glutamate.
 β-sulfinyl pyruvate rapidly decomposes and releases inorganic sulfite
which react with malachite green to convert from a green dye to
colourless form.
102

98.  Genetic test kits
 Various gene polymorphisms are considered to be risk factors
for the initiation or progression of periodontal disease.
 Identification of the genetic polymorphism is difficult but now
some chairside kits are available for its detection.
103

99.  PST Genetic Susceptibility Test
 Genetic Principals of the GenoType® PST®
 Two polymorphisms within the IL-1 gene cluster show a close
association with periodontitis:
1. Interleukin 1A gene, position -889
2. Interleukin 1B gene, position +3953
 Within both polymorphisms allele 1 harbors a cytidin (C), whereas
allele 2 carries a thymidin (T) at the respective position. In
particular, when both genes carry allele 2 a strong over-production of
the local inflammatory mediator, interleukin-1 will occur.
104

100.  The GenoType® PST® detects the corresponding allele
combination in patients allowing an evaluation of the individual
periodontitis risk and future strategies for therapy.
105

101. Recent trends in the diagnosis
of periodontal diseases
 Nano-biochips, which integrate various laboratory procedures in a
single cartridge (device), are currently considered to be the most
appropriate for type of diagnosis.
 A saliva sample (100–300 microlitres) or a drop of blood is
sufficient for the diagnosis.
 A network of liquid components ensures complete transfer and
processing of salivary samples for multiple analyses in order to
provide quantitative and qualitative information on the target
biomarkers of disease.
106
Beáta Bolerázska Trends in Laboratory Diagnostic Methods In Periodontology
ACTA MEDICA (Hradec Králové) 2016; 59(1):3–9

102. 107

103. Conclusion:
 Lab investigations have become an integral component of a complete
examination of the patient
 They confirm the authenticity of our clinical impression and also
provides a prognostic know how post treatment
 As Periodontists, we should have a thorough knowledge about different
investigations pertaining to our field of study
 We should also know how to correlate our history taking and clinical
examination so as to order for the most appropriate investigation
108

104. References :
 Angelo Mariotti Laboratory testing of patients with systemic
conditions in periodontal practice Perio 2000:2004;34:84-108
 Young DS,Bermes EW, Specimen collection and processing: sources
of biological variation
 Scully C, Wolff A. Oral Surgery in patients on anticoagulant therapy
 Stern.R. Karplis, Kinney, Glickman. Using International normalized
ratio to standardize prothrombin time
 W. Lee Melvin, Daniel A. Assad, Glenn A. Miller, Marlin E.
Gher,Lloyd Simonson, and Andrew K. York Comparison of DNA
Probe and ELISA Microbial Analysis Methods and Their Association
With Adult Periodontitis J Periodontol 1994;65:576–582
 Bricker, Langlais, Miller ; Oral Diagnosis, Oral Medicine and
Treatment Planning ; 2nd edition
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