advanced periodontal diagnostic techniques (as an adjunct ......periodontal disease is...

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.

http://cden.tu.edu.iq/index.php


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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



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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



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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.



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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.



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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



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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



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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



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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).



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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:



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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.



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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



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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



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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



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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


advanced periodontal diagnostic techniques (as an adjunct ......periodontal disease is...

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