This document provides an overview of investigations used in dental diagnosis. It begins by defining diagnosis and the role of laboratory investigations. It then classifies investigations based on where they are performed (chairside or laboratory), their specificity/sensitivity, the type of hospital laboratory service used, and frequency of dental use. The remainder of the document discusses various chairside and laboratory investigations in hematology, biochemistry, microbiology, and imaging that are used in dentistry.

2. CONTENTS
• INTRODUCTION
• NEED FOR INVESTIGATION
• CLASSIFICATION
• CHAIR SIDE INVESTIGATIONS
• LABORATORY INVESTIGATIONS
• MOLECULAR DIAGNOSIS
• RECENT TRENDS
• CONCLUSION
• REFRENCES

3. INTRODUCTION
• Diagnosis is defined as; correct determination,
discriminative estimation and logical appraisal of conditions
found during examination as evidenced by distinctive
marks, signs and characteristics of diseases.
-Glossary of Periodontal terms
• Laboratory studies are extension of physical examination in
which tissue, blood, urine or other specimen are obtained
from patients and subjected to microscopic, biochemical,
microbiological or immunological examination.
• Information obtained from these investigations help us in
identifying the nature of the disease and leads to a final
diagnosis.

4. • Evidence shows Case History and Clinical examination
usually reveal most if not all of clinically relevant data
• Hence there remains a need to confirm our clinical
impression
• Investigations supplement rather than replace other
methods for gathering information
• It is a known fact that with the help of certain
investigations, some underlying systemic conditions of
which the patients are unaware of, are often identified
in dental practice for the first time.

5. NEED FOR INVESTIGATION
• Confirming or rejecting clinical diagnosis
• Providing suitable guidelines in patient
management
• Providing prognostic information of
the diseases under consideration
• Detecting diseases through case-finding
screening methods
• Establishing normal baseline values before treatment
• Monitoring follow up therapy
• Providing information for Medico-Legal consultations

6. CLASSIFICATION
• Based on WHERE investigation is done.
Acts as precursor to
lab investigations
e.g. Electric pulp
testing, Radiographs
CHAIR SIDE
INVESTIGATION
Significantly higher
specificity and
sensitivity
e.g. Glycated
hemoglobin
estimation,
peripheral smear
histology
LABORATORY
INVESTIGATION

7. • Based on SPECIFITY/ SENSITIVITY
SCREENING
TEST
An ideal screening
test is 100%
sensitive
Useful in large
sample size
E.g. blood glucose
estimation for
screening diabetes
DIAGNOSTIC
TEST
An ideal diagnostic
test is 100%
specific
Useful in
symptomatic
individual to
establish diagnosis
E.g. Glycated
hemoglobin
estimation, OGTT

8. • Based on HOSPITAL LAB services
HEMATOLOGY MICROBIOLOGY BIOCHEMISTRY
IMMUNOLOGY HISTOPATHOLOGY CYTOPATHOLOGY

9. • Based on frequency of dental use
(by- Sonis, Fazio, Fang)
FREQUENTLY
USED
OCCASIONALLY
DONE
RARELY
ORDERED
* CBC- Hb, Hct,
Absolute and
differential WBC
* Bleeding studies
-BT,CT, PT, Aptt
* Peripheral Blood
Smear
* Random Blood
Glucose
* Tests for
disturbance
of bone – Ca, P,
ALP
* ESR
* Urinalysis
* Screening Test
for Syphilis
* Enzyme testing –
CPK, SGOT, SGPT,
LDH
* Bilirubin
Estimation
* Creatinine
Estimation
* Acid Phosphatase
* BUN

10. CHAIR SIDE
INVESTIGATION

11. CHAIR SIDE
INVESTIGATION
DENTAL
CARIES
PERIODONTAL
DISEASE
SALIVARY
GLAND
DISEASE
PULP
DISEASE
MUCOSAL
DISEASE
MALOCCLUSION
TMJ &
MUSCLES

12. PERIODONTAL DISEASES
PERIODONTAL PROBE
NON - PERIODONTAL PROBE
HALIMETER
CHAIRSIDE KITS
RADIOGRAPHS

13. PERIODONTAL PROBE
• Most widely used diagnostic tool.
• Probing depth is measured from the free
gingival margin to the depth of the probable
crevice.
• Longitudinal measurement of clinical
attchment loss (CAL) or probing depth is a
‘gold standard’ for recording changes in
periodontal status.

14. CLASSIFICATION OF PERIODONTAL
PROBES
FIRST GENERATION
• Conventional manual probes that do not control
probing force or pressure
• Not suited for automatic data collection.

15. • SECOND GENERATION
-Study done by Tupta et. Al ,Hunter (1994) has shown that
-force to probe pocket: 30g
-force to probe osseous defect: 50g
-Introduction of constant force or pressure sensitive probe
allowed for improved standardization of probing.
e.g.: Pressure sensitive probe
Constant pressure probe

17. • THIRD GENERATION
(AUTOMATED PROBE)
• Computer assisted direct
data capture was an
important step in reducing
examiner bias and also
allowed for generation of
probe precision. (according
to NIDCR criteria)
• E.g. Toronto probe, Florida
probe, Interprobe, Foster
Miller probe

18. • FOURTH GENERATION
-Watts(2000)- Three dimensional probe
- Allows 3D measurement of pocket.
-But, Still under-development
• FIFTH GENERATION
-3D + Noninvasive
-Eliminates the disadvantages of earlier
generation probes
-The only 5th generation probe-
Ultra Sonographic (US) probe

19. 1.CALCULUS DETECTION
-A calculus detection system
DetecTar which employs
spectro-optical technology
that has been suggested as a
potential aid in detecting
subgingival calculus.
-Based on measurements of
resonance vibrations of
ultrasonic treatment or auto-
fluorescence induced by laser
irritation
NON-PERIODONTAL PROBES

20. 3. GINGIVAL TEMPERATURE
• Increased blood flow and a very
high metabolic rate
• Sensitive diagnostic devices for
measuring early inflammatory
changes in the gingival tissues
• PerioTemp probe (Abiodent)=
sensitivity of 0.1o C
• 2 light indicating diodes:
• Red-emitting diode- higher temp
• Green-emitting diode-lower temp
• Haffajee et. al., 1992- sites with
higher temperature have greater
than twice the risk of future
attachment loss

21. 4. TOOTH MOBILITY
• Periotest Probe is a
hand-held probe.
• Mobility is recorded in
Periotest units (PTU)
from 0 to 50.
• The instrument taps
each tooth with an
impeller 16 times and
measures the time
taken for the tooth to
return to its original
position.

22. HALIMETER
• These machine measure the
level of sulfide gas.
• But it has certain drawbacks
in clinical application, some
of the common sulfides
such as mercaptan is not
easily recorded and can be
misrepresented in the test
results.
• Halimeter is also very
sensitive to alcohol, so one
should avoid drinking
alcohol or using alcohol
containing mouthwashes
for atleast 12hrs prior to
being tested

23. CHAIR SIDE KITS
MICROBIOLOGICAL
BIOCHEMICAL
GENETIC

24. MicroBiological Kit
1. OMNIGENE
• These are DNA probe systems developed to detect
subgingival bacteria.
• Sample of subgingival plaque is obtained on a paper sample
and is placed in the container provided and assayed.
• Probes are available for
P.gingivalis, P.intermedia,
A.acinomycetemcomitans,
F.nucleatum, E.corrodens,
T.denticola, T.pectinovorum
and C.recta.
• Reports are available within few hours.

25. • 2.EVALUSITE
• Evalusite is a diagnostic kit that
is based on a novel membrane-
based enzyme immunoassay
• Detection of three putative
periodontopathogens: Aa, Pg
and Pi.
• A paper point subgingival
plaque sample is collected
and added to a sample tube.
The sample is placed within the
kit.
• Detection and differentiation of
the bacteria requires
approximately 5 min and the
results are interpreted visually

26. 3. PERIOSCAN
• It is a chair side test kit
system which is used for
bacterial trypsin-like
proteases
• It works by detecting the
activity of this enzyme
and it can be measured
with the hydrolysis of the
colourless substrate N-
benzoyl-dL arginine-2-
naphthylamide (BANA)

27. 4. Perio Diagnostics
• It is a real – time PCR for the quantitative
determination of the six most important marker
organisms of periodontitis and peri- implantitis and the
total bacterial load.
• The marker organisms are
Aacomitans, P. gingivalis,
T.forsythus, T.denticola,
F.nucleatum and P. intermedia.
• Results of chair side test kits are available in a short
time and produce visual results which can be shown to
the patient.

28. Biochemical Test Kit
1. PERIOGARD
• -Test kit uses paper point GCF
samples and calorimetric
detection.
• -Used for detection of AST
(Aspartate Transaminase)
2. POCKET WATCH
• It is one of the simplest tests for
analysing Aspartate aminotransferase
at the chair side
• Pocket watch provides an index of
cell death

29. 3. PERIOCHECK
• This system detects the presence of neutral proteases such as
collagenase in GCF
• The presence of neutral proteases is implicated in collagen break
down, which is an important feature of periodontal disease
• The test shows predictive value for disease progression in a short-
term evaluation
4. PERIO 2000
• The Perio2000 system is designed to display the sulphide level
digitally.
• Various pathogenic microorganisms produce sulphates, leading to
elevated levels of volatile sulphide compounds (VSCs) .
• Since these VSCs can directly degrade periodontal structures so
they may aggravate periodontitis and their evaluation can indicate
the subgingival microbial load

30. GENETIC TEST KIT
1. PST® genetic susceptibility test
• Periodontal susceptibility test (PSTR) is the first
and only genetic test that analyses two
interleukins (IL-1α and IL-1β)genes for variations.
• The IL-1 genetic testing can be used to
differentiate between IL-1 genotypes associated
with diverse inflammatory responses to identify
subjects at risk for severe periodontal disease
even before the age of 60

31. RADIOGRAPHS
• Dental Radiographs are traditional method to assess
destruction of alveolar bone.
• Primary criterion for bone loss is the distance from
CEJ to the alveolar crest and distance more than 2
mm is considered as the bone loss
• Conventional radiographs are
very specific but lack sensitivity

32. Conventional Radiographs
1.Periapical
radiograph
2.Bitewing
radiograph
3.Panoramic
radiograph

33. Advanced Radiographs
DIGITAL RADIOGRAPHY
• Capturing radiographic image using a sensor
• The first direct digital imaging system, RadioVisioGraphy
(RVG), was invented by Dr. Frances Mouyens.
• Image property almost equal to
conventional radiographs
• 1/3rd to half reductions in
radiation dose
• Uses a Charge Couple Device
(CCD) which is placed intra
orally as traditional films ,images
appear on a computer screen
which can be printed or stored.

34. SUBSTRACTION RADIOGRAPHY
• Subtraction radiography was introduced to dentistry in 1980
by Ruttimann, Webber et & Grondahl HG
• This is a technique by which images not of diagnostic value in
a radiograph, are eliminated so that changes in the radiograph
can be precisely detected
• This technique facilitates both quantitative and qualitative
visualization of even minor density changes in the bone

35. DIAGNOSTIC SUBSTRACTION
RADIOGRAPHY.
Applies an
algorithm that
corrects for the
effects of angular
alignment
discrepancies
Specialized
software
designed for
digital image
subtraction
Use of a
positioning
device during
film exposure

36. Computer Assisted Densitometric Image Analysis
(CADIA)
• Video camera measures the light transmitted
through radiograph and the signals from the camera
is converted to gray scale image.
• Camera is interfaced with an image processor
• Measures quantitative changes in bone density
longitudinally.
• Higher sensitivity, reproducibility and accuracy as
compared to DSR.

37. Cone-beam Computed Tomography
• In recent years, a new
technology of cone-beam
CT (CBCT) for acquiring 3D
images of oral structures is
now available to the dental
clinics and hospitals.
• PRINCIPLE- A thin fan beam
of X-Rays rotates around the
patient to generate in one
resolution around thin axial slice
of the area of interest.
.

38. • Multiple overlapping axial
slices are obtained by
several revolution of the X-
ray beam until the whole
area of interest is covered.
• With the help of a computer
and sophisticated
Algorithms these slices are
then used to generate a
three dimensional digital
map of the jaw which help
in evaluation of the patient

39. LABORATORY
INVESTIGATIONS

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

41. 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
Congenital heart disease
Erthyocytosis,
Haemoglobinopathies,
Polycythemia vera
Severe dehydration
Severe COPD
Anemia,
Bone marrow failure,
Leukemia
Hemorrhage,
Hodgkin's disease,
Rheumatoid/collagen
vascular disease

42. HAEMOGLOBIN
• Hemoglobin measures the amount of the oxygen-carrying
protein in the blood.
• Range : Male- 14-18g/dl Female- 12-16g/dl
COPD Anemia,
Congenital heart disease Dietary deficiency
Erythrocytosis, Hodgkin lymphoma
Severe dehydration Pregnancy
Severe polycythemia vera Cirrhosis

43. 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

44. CAPILLARY FRAGILITY TEST
Rumpel-Leede Test(Tourniquet Test):
• Test of ability of the superficial capillaries of the skin.
• 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.
• Dental Application – screening test for scurvy.

45. CLOTTING TIME
• Measures the time required for formation of first clot.
• Screening test for coagulation disorders
• Normal Clotting time –: 4-14 mins
Prolonged in disease affecting stage II & stage IV of haemostatsis
• Cirrhosis, Hemophilia A&B
• Factor XI deficiency
• Hypofibrinogenemia
• Heparin & dicumarol anticoagulant therapy

46. PROTHROMBIN TIME
• Time required for clotting of citrated plasma after addition of
calcium and tissue plasmin
• Normal time – 11-14 secs
• Measured against a Control PT in terms of INR
• INR = PT Test / PT Normal
• Normal INR = 1 ; Abnormal INR > 1.5

47. INR and its Significance

48. 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.

49. Glucose Estimation
• Fasting Blood Sugar(FBS): Normal values – 70-90mg/100ml
• Random Blood Sugar(RBS): 110-130mg/100ml
• Post Prandial Blood Sugar(PPBS): <140mg/100ml
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

50. Glycated Hemoglobin
• Hb becomes Glycated by ketoamine reactions between
glucose and other sugars.
• Once Hb is Glycated, it remains that way for a prolonged
period(2-3months)
• 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

52. 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

53. 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

54. General Procedure:-

55. 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
nucleotidesequences (the DNA target) that are
complementary to the sequence in the probe.

56. • .Comparison of the two methods revealed that the
ELISA test identified P.gingivalis and C. rectus
significantly more often than the DNA probemethod
and that T. denticola was detected more frequently
with the DNA probe
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

58. MOLECULAR DIAGNOSIS
Potential biomarkers of periodontitis in saliva
1. Markers of inflammation
• β-glucuronidase(GUS)- signals the influx of neutrophils
• C-reactive protein (CRP)-
• Interleukin-1 (IL-1) & interleukin-6 (IL-6),
• Macrophage inflammatory protein 1α (MIP-1α) and
• Tumour necrosis factor (TNF)
• A newly identified anti-inflammatory interleukin IL-35, is
secreted by regulatory T-cells and suppresses the
inflammatory response of immune cells.
Important role in the suppression of periodontal inflammation
and maintaining of periodontal health

59. 2. Markers of connective tissue breakdown
• α2-macroglobulin- Levels of α2-macroglobulin, which is
intended for the inactivation of different proteases including
metalloproteinases and collagenase.
• Matrix metalloproteinases (MMPs)- The most important
proteolytic enzymes are the matrix metalloproteinases MMP-
8 (collagenase-2) and MMP-9 (gelatinase), a significant
increase of which was confirmed in the saliva of patients with
periodontitis.
• Tissue inhibitors of metalloproteinases (TIMPs) and
• Alanine aminotransferase (ALT) levels.

60. 3. Markers of bone remodelling
• Alkaline phosphatase (ALP),
• C-terminal telopeptide (carboxy-terminal collagen
crosslinks or CTX)
• Receptor activator of nuclear factor kappa-B ligand
(receptor activator of NF-κB or RANKL)
• Osteoprotegerin (OPG).
 The main problem with these biomarkers lies in their
extremely low concentrations at the time of remission and
at the time of exacerbation of premature degradation in
saliva
 Salivary markers of alveolar bone remodelling (bone
resorption/ bone formation) are still not described as being
as good as other biomarkers

61. SALIVARY BIOMARKERS

62. GCF BIOMARKERS

64. GCF biomarkers in periodontal Disease
 Superoxide dismutase 1 (SOD1)-most important line of
antioxidant enzyme defense system against reactive oxygen
species (ROS)
• Apolipoprotein A-I (ApoA-I)- major protein component of high-
densitylipoprotein
• Dermcidin (DCD)-antimicrobial function (Zelko and
collaborators)
 Annexin-1
• Cystatin-B
• Defensins
• L-plastin- Actin-bundling protein, exclusively expressed in leukocytes
and plays a crucial role in immune-mediated events (Bostanci and
investigators)
Detected only in the healthy individuals

65. • Baliban et al. aiming to use biomarker combinations to predict
health or disease from GCF samples using high throughput
proteomic analysis
• G3P_HUMAN- (Glyceraldehyde 3-phosphate dehydrogenase)
is an enzyme that participates in glycolysis and serves to break
down glucose for energy and carbon molecules
• TYPH_HUMAN- (Thymidine phosphorylase) is an enzyme that
participates in purine metabolism pathway and pyrimidine
metabolism pathway and is only found in periodontally
healthy GCF samples
• KV101_HUMAN-(Ig kappa chain V-I region AG)- most of
periodontally healthy individuals and few of the periodontitis.

66. RECENT BIOMARKERS
 OBESITY RELATED
• Chemerin - an adipokine ; chronic periodontitis(CP) & DM
Pradeep et al,2015
• Leptin - The decreasing leptin level in GCF and gingival tissue was
associated with a deteriorated periodontal status, and smokers also
showed reduced GCF leptin levels in recent studies
 SYSTEMIC DISEASE RELATED
• Progranulin – CP & type 2 DM. Pradeep et al 2013
• Caspase 3 - GCF and the serum concentration of caspase-3 proportionally
increases with the progression of periodontal disease
Pradeep et al 2014
 IL-29 - antiviral IL-29 level was highest in GCF of aggressive
periodontitis patients while that of chronic periodontitis lying in
between.
Shivaprasad BM ,Pradeep AR 2013

67. 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.
Beáta Bolerázska Trends in Laboratory Diagnostic Methods In Periodontology
ACTA MEDICA (Hradec Králové) 2016; 59(1):3–9

68. • Optical coherence tomography (OCT) is a non-invasive method of
imaging dental microstructure which can potentially evaluate the health of
periodontal tissue.
• This method provides an ‘optical biopsy’ 2–3 mm in depth of tissue
• It uses broadband low coherent near-infrared (NIR) light sources that
provide considerable penetration into tissue without any known
detrimental biologic effect
• Periodontal tissue contour, sulcular
depth and connective tissue attachment
are visualised at high resolution
using this technology.
• Because OCT reveals microstructural detail
of the periodontal soft tissues, it can
potentially identify active periodontal
disease before significant
alveolar bone loss occurs

69. Optical Spectroscopy
Infrared Spectroscopy- The IR spectrum of gingival crevicular fluid
(GCF) is a rich source of information regarding the oral cavity and
associated inflammation.
• Analysis of the IR spectrum of GCF, unlike traditional biochemical
analyses, measures the total contents of GCF and may prove to be a
powerful diagnostic and prognostic tool in periodontal diseases
Near-infrared spectroscopy- Another novel non-invasive optical
modality currently under exploration for periodontal disease
diagnosis. This type of spectroscopy can be used to monitor
haemodynamic and oedema-based markers of soft tissues of the
oral cavity
• Monitoring the water bands in gingival tissues provides an index of
tissue hydration and thus any difference in intensity may represent
a simple indicator of inflammation at specific periodontal sites

70. CONCLUSION
• "Periodontal Diagnosis" is an important tag that a clinician
ties on the periodontal disease condition of the patient,
capturing all his past experience with the condition in
question.
• The entire constellation of signs and symptoms, along with a
detailed history is elicited, documented and interpreted to
reach at a diagnosis.
• Most often an accurate diagnosis is, the very first concrete
step towards the planning and execution of an appropriate
individualized treatment plan, contributing significantly
towards the success of the therapy
• As Periodontists, we should have a thorough knowledge about
different investigations pertaining to our field of study

71. REFERENCES
• Textbook of Periodontology, Carranza 11th Ed
• Bricker, Langlais, Miller ; Oral Diagnosis, Oral Medicine and
Treatment Planning ; 2nd edition
• Principles and Practice of Oral Medicine, Stephan S Sonis,
Fazio, Fang
• Stern.R. Karplis, Kinney, Glickman. Using International
normalized ratio to standardize prothrombin time
• Armitage GC, Jeffcoat MK, Chadwick DE: longitudinal
evaluation of elastase as a marker for the progression of
Periodontitis, J Periodontol 1994; 65:120

72. • Agrawal P, Sanikop S, Patil S. New developments in tools for
periodontal diagnosis. International dental journal. 2012
Apr;62(2):57-64.
• Ramachandra SS, Mehta DS, Nagarajappa Sandesh M, Vidya Baliga
M, Janardhan Amarnath M. Periodontal probing systems: a review
of available equipment. Periodontics. 2009 May;3(3).
• Pajnigara NG, Kolte AP, Kolte RA, Pajnigara NG. Chair side diagnostic
kits in periodontics. International Dental Journal of Students
Research. 2016 Apr;4:25-31
• 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