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Lec. 2 5th year Dr. Suha Aswad Dahash
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Advanced Periodontal Diagnostic Techniques
(As an adjunct to conventional techniques)
Periodontal Dx :
Recognizing a departure from health in the periodontium and
distinguishing one disease based on information obtained from the medical
and dental histories, clinical and radiographic examination of the patient,
and laboratory findings.
Current conventional techniques
Clinical diagnosis is made by measuring either clinical attachment loss
(CAL) or radiographically by loss of alveolar bone.
• This kind of evaluation identify and quantify current clinical signs
of inflammation.
• Provides historical evidence of damage with its extent and severity.
Limitations !!!
1. Does not provide cause of the condition.
2. No info. on patient’s susceptibility to the disease.
3. Cannot identify sites with ongoing periodontal destruction or sites
in remission.
4. Cannot differentiate whether response to therapy is positive or
negative.
Lec. 2 5th year Dr. Suha Aswad Dahash
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Periodontal disease is multifactorial
Advanced periodontal diagnostic techniques:
1. Advances in Clinical Diagnosis.
2. Advances in Radiographic Assessment.
3. Advances in Microbiologic Analysis.
4. Advances in characterizing the Host response.
Advances in Clinical Diagnosis:
1. Gingival temperature:
• Subgingival temperature at diseased sites is increased as
compared to normal healthy sites.
• Possible explanation for ↑ temperature with increasing probing
depth is an increase in cellular and molecular activity caused by
increased periodontal inflammation.
• Commercially available system PerioTemp probe enables the
calculation of temperature differential (with sensitivity of
0.10C) between the probed pocket and subgingival temperature
Periodontal
pathogens
Host
response
behaviouralsystemic
Genetic
Lec. 2 5th year Dr. Suha Aswad Dahash
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• Haffajee et al. (1992): found that elevated subgingival site
temperature is related to attachment loss in shallow pockets and
elevated proportions of Pg, Pi, Tf, Aa.
2. Periodontal probing
• Most widely used diagnostic tool
Probing depth is measured from the free gingival margin to the
depth of the crevice/pocket.
• Longitudinal measurement of CAL or probing depth is a ‘gold
standard’ for recording changes in periodontal status.
Limitation of conventional probing
Lack of sensitivity and reproducibility.
Disparity between measurement depends on:
Probing technique, probing force, angle of insertion of probe, size
of probe, precision of calibration, presence of inflammation.
All these variable contribute to the large standard deviations (0.5-
1.3 mm) in clinical probing results
Lec. 2 5th year Dr. Suha Aswad Dahash
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Classification of periodontal probes depending on
generation:
1. First generation probes: (conventional probes)
Conventional manual probes that do not control probing force or
pressure and that are not suited for automatic data collection.
Example:
• Williams periodontal probe
• CPITN probe
• UNC-15 probe
2. Second generation probes: (Constant force probes)
Introduction of constant force or pressure sensitive probes allowed
for improved standardization of probing.
e.g.: Pressure sensitive probe
Constant pressure probe
✓ force to probe pocket: 30g
✓ force to probe osseous defect: 50g
Limitation: data readout and storage is inaccurate.
3. Third generation probe:(Automated probes)
• Computer assisted direct data capture was an important step in
reducing examiner bias and also allowed for generation of probe
precision.
e.g.:
• Toronto probe.
• Florida probe.
• Foster Miller probe.
Lec. 2 5th year Dr. Suha Aswad Dahash
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Florida probe
• Tip is 0.4mm
• Sleeve- edge provides reference to make measurements.
• Coil spring; provides constant probing force.
• Computer for data storage.
Limitations
1. Lack of tactile sensitivity
2. Fixed probing force
3. Underestimation of deep periodontal pockets.
4. Fourth generation probes: (Three dimensional probes)
• Currently under development, these are aimed at recording
sequential probe positions along a gingival sulcus.
• An attempt to extend linear probing in a serial manner to take
account of the continuous and three dimensional pocket that is
being examined.
5. Fifth generation probe: (3D + Noninvasive)
• Basically these will add an ultrasound to a fourth generation
probes.
Lec. 2 5th year Dr. Suha Aswad Dahash
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• If the fourth generation can be made, it will aim in addition to
identify the attachment level without penetrating it.
• e.g.: Ultra sonographic probe.
Advances in Radiographic Assessment
Dental Radiographs are traditional method to assess destruction of
alveolar bone.
“Conventional radiographs are very specific but lack sensitivity”
• 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.
• But variability affecting conventional radiographic technique are:
1. Variation in projection geometry.
2. Variation in contrast and density.
3. Masking by other anatomic structures.
1-Digital radiography
Capturing radiographic image using a sensor
Advantages
a. Elimination of chemical processing.
b. Increased efficiency and speed of viewing.
c. Diagnostic information can be enhanced.
d. Computerized storage of radiographs.
e. Reduced exposure to the radiation.
2-Subtraction radiography
This is a technique by which images not of diagnostic value in a
radiograph, are eliminated so that changes in the radiograph can be
Lec. 2 5th year Dr. Suha Aswad Dahash
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precisely detected.
• This technique facilitates both quantitative and qualitative
visualization of even minor density changes in the bone.
• Bone gain appears as light areas and bone loss appears as dark
areas.
3-Computer Assisted Densitometric Image Analysis (CADIA)
• Video camera measures the light transmitted through radiograph
and the signals form the camera is converted to gray scale image.
Advantage:
a. Measures quantitative changes in bone density.
b. Higher sensitivity, reproducibility and accuracy as compared to
c. Subtraction radiography.
4- Computed tomography (CT)
Computed tomography is a specialized radiographic technique that allows
visualization of planes or slices of interest
Serialradiographs
converted to digital images
superimposedComposite
imageQuantitative
changes
Lec. 2 5th year Dr. Suha Aswad Dahash
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Advantages over conventional radiography
Eliminates the super imposition of images of structures superficial or
deep to the area of interest.
Because of inherent high contrast resolution, differences may be
distinguished between tissues that differ in physical density by less than
1%.
Multiple scans of a patient may be viewed as images in the axial,
coronal, or sagittal planes depending on the diagnostic task, referred to as
multiplanar imaging.
Application of CT
Lec. 2 5th year Dr. Suha Aswad Dahash
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a. Used when accurate information regarding the topography of
osseous structure is needed.
b. Soft tissue contour and dimension.
c. To check continuity and density of the cortical plates.
d. Vertical height of the residual alveolar ridges.
e. Density of the medullary space and basilar bone.
f. When determining how much space is available above the
mandibular canal or amount of bone below maxillary sinus to
receive a dental implant, or
g. Whether there is a space occupying lesion in the maxillofacial
region.
Disadvantages of Computed Tomography
a. Specialized equipment and setting.
b. Radiologists and Technicians need to be knowledgeable of
the anatomy, anatomic variants and pathology of the jaws
c. Higher radiation.
d. Metallic Restorations can cause ring artifacts that impair the
diagnostic quality of the image.
5- Cone-beam Computed Tomography
• Routine use of CT in dentistry is not accepted due to
its cost and excessive radiation.
• 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.
• It is cheaper than CT, less bulky and generates low
dosages of X-radiations.
• The innovative CBCT machine designed for head and
neck imaging are comparable in size with an
orthopantomogram.
Advantages
a. It gives complete 3D reconstruction.
b. CBCT units reconstruct the projection data to provide
interrelational images in three orthogonal planes
(axial, sagittal, and coronal).
Lec. 2 5th year Dr. Suha Aswad Dahash
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c. Its beam collimation enables limitation of X-radiation
to the area of interest.
d. Patient radiation dose is five times lower than normal
CT, as the exposure time is approximately 18 seconds,
that is, one-seventh the amount compared with the
conventional medical CT.
e. Reduced image artefacts.
Advances in Microbiologic Analysis
Uses of microbiologic analysis
1. Support diagnosis of various Periodontal disease.
2. Can tell about initiation & progression.
3. To determine which periodontal sites are at high risk for active
destruction.
4. Can also be used to monitor Periodontal therapy.
Advances In Microbiologic Analysis includes:
1. Immunohistodiagnostic methods.
2. Enzymatic methods.
3. Molecular biology techniques.
• Neucleic acid probes
• Checkerboard DNA-DNA hybridization
• PCR.
Sample collection
§ It is a common need of all the microbiologic analysis to collect
an appropriate subgingival plaque sample
1- Immunodiagnostic methods
• Immunological assays use fluorescent conjugated antibodies
that recognize specific bacterial antigens, and the
identification of these specific antigen-antibody reactions
allows the detection of target microorganisms.
• This reaction can be visualized using a variety of techniques
and reactions:
Lec. 2 5th year Dr. Suha Aswad Dahash
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1. Direct (DFA) and indirect (IFA) immunofluorescent assays
2. Flow cytometry.
3. Enzyme-linked immunosorbent assay (ELISA)
4. Latex agglutination.
1. Immunofluorescent assays
Immunofluorescent assays is used mainly to detect A.a and P.g
2-Flow cytometry
• Rapid identification.
• Principle is labelling bacterial cells with both species-specific
antibody and a second fluorescein-conjugated antibody.
• This suspension is introduced into flowcytometer, which separates
bacterial cells into an almost single cell suspension.
Limitation is sophistication and cost involved with this procedure.
3. ELISA
A novel chair side ELISA commercially known as “Evalusite” has been
marketed in Europe and Canada for the chair side detection of 3
periodontal pathogens: Aa, Pg and Pi.
Lec. 2 5th year Dr. Suha Aswad Dahash
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4. Latex agglutination
2. Enzymatic methods
PERIOSCAN uses this reaction for the identification of this
bacterial profile in plaque isolates
▪ Tf, Pg, Td, and Capnocytophaga species share common enzymatic
profile- a trypsin like enzyme.
Latex beads coated with species specific AB
When beads come in contact with specific species in sample they bind and agglutination occurs
Clumping of beads is visible, usually in 2-5 min
Lec. 2 5th year Dr. Suha Aswad Dahash
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3-Molecular Biology Techniques
• The principles of molecular biology technique reside in the
analysis of DNA, RNA and the structure and function of proteins.
• Diagnostic assays require specific DNA fragment that recognize
complementary-specific DNA sequences from target
microorganisms.
• This technology requires bacterial DNA extracted from the plaque
sample and amplification of the specific DNA sequence of the
target pathogen.
1. Nucleic acid probes
A probe is a known, single stranded nucleic acid molecule (DNA or
RNA) from a specific pathogen synthesized and labelled with an enzyme
of a radio isotope
Hybridization: Pairing of complimentary strands of DNA to produce a
double stranded DNA.
2. Checkerboard DNA-DNA hybridization technology
40 bacterial species can be detected using whole genomic digoxigenin-
labeled DNA probes.
• Applicable for epidemiologic research and ecological studies.
3. Polymerase chain reaction (PCR)
• Repeated cycles of oligonucleotide (primer)–directed DNA
synthesis of “target sequences” are carried out in vitro.
Trypsin
like
enzyme
BANA
β-naphthylamide
(chromophore)N-benzoyl-d L-
arginine-
2-naphthylamide
Lec. 2 5th year Dr. Suha Aswad Dahash
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• The PCR method is considered the fastest and most sensitive
method available for detecting the presence of bacterial DNA
sequences
• A modification of the original PCR technology, "realtime“ PCR,
permits not only detection of specific microorganisms in plaque,
but also its quantification.
Advances in characterizing the Host response
Assessment of host response refers to the study of mediators by
immunologic or biochemical methods, that are recognized as a part
of individual’s response to the periodontal infection.
Mediators
1. Specific Mediator
Antibody to a putative pathogen
2. Less specific reaction
▪ The local release of the inflammatory mediators, host derived
enzymes and tissue breakdown products
Sources of the sample are:
▪ GCF, gingival crevicular cells, Saliva, Blood serum, blood cells
and rarely urine.
▪ Most efforts to date have been based on use of components of GCF
and to a lesser extent, saliva and blood
Inflammatory mediators and products:
➢ Cytokines present in GCF and investigated as potential diagnostic
markers are:
• TNF a
• IL-1a
• IL-1ß
• IL-6
• IL-8
Lec. 2 5th year Dr. Suha Aswad Dahash
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➢ Prostaglandins e.g. PGE2
Host derived enzymes
Intracellular
1. Aspartate amino transferases.
2. Alkaline phosphatase.
3. Elastase
Extracellular
Matrix metalloproteinases (MMPs)
Tissue breakdown products
Analysis of GCF from sites with active periodontitis clearly shows
elevated levels of Hydroxyproline from collagen breakdown.
Osteocalcin and type-1 collagen peptides- progression of alveolar
bone loss.
Conclusions:
1. Future application of advanced diagnostic techniques will be of
value in documenting disease activity and treatment options.
2. Despite excellent progress in diagnostic methodology, convential
methods remain the standard for disease evaluation.
References:
• Carranza’s Clinical Periodontology 12th edition.
• Clark WB,Yang MCK,Magnusson 1:Measuring clinical attachment:
Reproducibility and relative measurements with an electronic probe
J Periodontol 1992; 63:831
• Grondahl HG,Grondahl K:Subtraction radiography for the diagnosis
of periodontal bone lesions.Oral Surg1983;55:208