PROF AFSHAN BEY CHAIRMAN - PowerPoint Presentation

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PROF AFSHAN BEYCHAIRMANDEPT OF PERIODONTICS

ADVANCES IN

PERIODONTAL

DIAGNOSIS

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INTRODUCTION

Diagnosis is the corner stone in the practice of healing art. The practice of

periodontics

requires excellence in diagnostic skills.

Dictionary defines diagnosis as “art of identifying disease from its signs / symptoms”.

A clinician may afford to be unaware of change in the concept of a certain treatment technique, but cannot be weak clinically in the science of diagnosis.

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ADVANCES IN DIAGNOSTIC METHODS

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New clinical methods of diagnosis

Advances in measurement of periodontal attachment loss

The

main objective of periodontal

diagnosis is

to detect changes in

periodontal attachment

level

.

Traditional periodontal diagnosis methods are not precisely accurate and only allow retrospective diagnosis of attachment

loss.

The traditional

methods of

recording this are the use of

manual probing

with a graduated periodontal

probe and

radiographic examination to detect

bone loss.

However, the accuracy of probing is

affected by

a number of factors including the

position and

angulation of the probe, the

probing pressure

and the inflammatory state of

the tissues

.

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If probing measurements are to be used sequentially

to detect progressive loss

of attachment

these factors need to

be controlled

where possible and

the measurements

need to be made from a

fixed reproducible point.The ideal reference point is the cementoenamel junction (CEJ) but this is difficult to locate precisely because it usually lies subgingivally and it may be obscured by calculus or dental restorations. For these reasons other points such as the occlusal surface or a fixed point on a stent are often used in clinical research studies.

Advances in measurement of periodontal attachment loss

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Advances in probing

Because of the inaccuracy of manual

pocket probing

, the National Institute for

Dental Research

(NIDR) of the USA in

1979 requested

the development of more

sensitive method.They wanted: a precision of + 0.1 mm and a range of 10 mm a constant probing force measurement from a fixed reproducible pointguidance system to ensure reproducible pathwaynon-invasive proceduredigital output of data.

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Computer-linked electronic

constant pressure probes

currently available include:

• the

Florida probe

•

the

interprobe

• the Birek probe • the Jeffcoat probe

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Advances in probing

1. Florida probe system

This incorporates:

• constant probing force

• precise electronic measurement

• computer storage of data.

This

system eliminates errors of visual reading since the recorded measurements are sent to the associated computer's memory and is displayed on the screen. The system consists of a probe handpiece, a digital readout, a foot switch and a computer interface and computer. It has been found to be significantly superior to manual probing

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Advances in probing

Depending upon the type of fixed reference point, two models have been

developed-

Stent model

- has a 1mm metal collar that rests on a prepared ledge on a pre-fabricated

vacuoform

stent.

Disk model

- has a 11mm disk which rests on the occlusal surface or incisal edge of the tooth.The Florida probe can also read probing depths from the gingival margin using an interchangeable pocket depth handpiece.

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Advances in probing

Measurement of gingival temperature:

Instruments that measure the gingival temperature have been developed

.

A naturally occurring temperature gradient exists between maxillary and mandibular teeth, and between anterior and posterior quadrants

.

The Periotemp probe measures (Abiodent, Inc., Danvers, Mass) detects pocket temperature differences of 0.1˚C from a referenced subgingival temperature. Haffajee et al used this probe to assess its predictability in identifying loss of attachment, concluding that sites with red (higher) temperature indication had more than twice the risk for future attachment loss than did those with green indication..

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B. Advances In Radiographic Assessment

The tests for radiographic assessment can be divided

into

1.Those

that show the change over a period of time. They determine the present status of bone and hard

tissue.e.g

.,

Digital

radiography Subtraction radiography Computer Assisted Densitometric Image Analysis System (CADIA)2.Those that show the ongoing disease activity by determining the metabolic changes.e.g.,

Nuclear

medicine or

scintigraphy

.

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RADIOGRAPHS IN THE DIAGNOSIS OF

PERIODONTAL DISEASE

it is an adjunct to the clinical examination, not a substitute for it.

The radiograph reveals alterations in calcified tissue; it does not reveal current cellular activity but shows the effects of past cellular experience on the bone and roots.

Normal

Interdental

Septa

The

interdental septum normally presents a thin radiopaque border, adjacent to the periodontal ligament and at the crest, that is referred to as the lamina dura

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Prichard (1972) established the following four criteria to determine adequate angulation

of

periapical

radiographs:

1. The radiograph should show the tips of molar cusps with little or none of the

occlusal

surface showing.

2. Enamel caps and pulp chambers should be distinct.

3. Interproximal spaces should be open.4. Proximal contacts should not overlap unless teeth are out of line anatomically.

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Bone Destruction in Periodontal Disease

The earliest signs of periodontal disease must be detected clinically.

The radiographic image tends to show less severe bone loss than that actually present .The difference between the alveolar crest height and the radiographic appearance ranges from 0 to 1.6 mm, mostly accounted for by x-ray

angulation

.

Amount of Bone Loss- The amount of bone lost is estimated to be the difference between the physiologic bone level of the patient and the height of the remaining bone.

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Pattern of Bone Destruction- In periodontal disease, the

interdental

septa undergo changes that affect the lamina

dura

,

crestal

radiodensity

, size and shape of the medullary spaces, and height and contour of the bone. The interdental septa may be reduced in height, with the crest horizontal and perpendicular to the long axis of the adjacent teeth, or they may have angular or arcuate defects. The former condition is called horizontal bone loss, the latter angular or vertical bone loss

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HORIZONTAL BONE LOSS

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VERTICAL BONE LOSS

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Radiographic Changes in Periodontitis

Fuzziness and a break in the continuity of the lamina

dura

at the

mesial

or distal aspect of the crest of the

interdental

septum have been considered as the earliest radiographic changes in

periodontitisA wedge-shaped radiolucent area is formed at the mesial or distal aspect of the crest of the septal boneThe destructive process extends across the crest of the interdental septum and the height is reduced. Fingerlike radiolucent projections extend from the crest into the septumThe height of the interdental septum is progressively reduced by the extension of inflammation and the resorption of bone.

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A, Normal appearance of

interdental

septa. B, Fuzziness

and a break in the continuity of the lamina

dura

at the crest of the bone distal to the central incisor.

There are wedge-shaped radiolucent areas at the crests of the other

interdental

septa. C, Radiolucent projectionsfrom the crest into the interdental septum indicate extension of destructive processes. D, Severe bonel oss.

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Radiographic Appearance of Interdental Craters

Interdental

craters are seen as irregular areas of reduced

radiopacity

on the alveolar bone crests; they are generally not sharply demarcated from the rest of the bone, with which they blend gradually.

Radiographs do not accurately depict the morphology or depth of

interdental

craters, which sometimes appear as vertical defects.

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Radiographic Appearance of Furcation Involvements

Definitive diagnosis of

furcation

involvement is made by clinical examination, which includes careful probing with a specially designed probe (

Nabers

probe).

As a general rule, bone loss is always greater than it appears in the radiograph.

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Radiographic Appearance of the Periodontal Abscess

The typical radiographic appearance of the periodontal abscess is that of a discrete area of

radiolucency

along the lateral aspect of the root

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Radiographic Changes in Localized, Aggressive

Periodontitis

Bone loss may occur initially in the maxillary and

mandibular

incisor and/or first molar areas, usually bilaterally, and results in vertical,

arclike

destructive patterns

Loss of alveolar bone may become generalized as the disease progresses but remains less pronounced in the premolar areas.

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Radiographic Changes in Trauma from Occlusion

Trauma from occlusion can produce

radiographically

detectable changes in the lamina

dura

, morphology of the alveolar crest, width of the periodontal space, and density of the surrounding

cancellous

bone.

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Advances In Radiographic Assessment

DIGITAL RADIOGRAPHY

Developed by

Dr.Francis

Mouyen

in 1980’s.

Has 3 components : radio ,

visio & graphy component. The clinician can zoom in to different areas on the x-ray image, digitally enhance the image in order to better visualize certain anatomic structures, and in some cases, the image can even be colorized, a useful tool for patient education

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Advances In Radiographic Assessment

DIGITAL RADIOGRAPHY

:

It

allows the use of computerized images, which can be stored, manipulated, and corrected for underexposures and overexposures.

There

is a one-third to half reduction in radiation dose obtained with digital radiographs compared with conventional radiographs.

Digital

radiography may yield equal image properties when compared with conventional radiographs, but through digital storage and processing, diagnostic information can be enhanced.

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Advances In Radiographic Assessment

 

Subtraction radiography:

This technique relies on the conversion of serial radiographs into digital images. Changes in the density and volume of bone can be detected as lighter areas (bone gain) or dark areas (bone loss). Quantitative changes in comparison with the baseline images can be detected using an algorithm for gray-scale levels. This is accomplished using a computer

( Computer Assisted Subtraction Radiography).

This technique shows

A high degree of correlation between changes in alveolar bone determined by subtraction

radiography.Increased detectability of small osseus lesions compared with conventional radiographs.

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Advances In Radiographic Assessment

Digital subtraction radiography

is a method for detecting changes in radiographic

density.It

can detect even 5% of the mineral loss of bone.

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Advances In Radiographic Assessment

Subtraction

radiography

facilitates both qualitative and quantitative visualization of even minor density changes in bone by removing the unchanged anatomic structures from the image

.

Hauffman

et al

detected significant changes of crestal bone height of 0.87mm. Jeffcott et al showed a strong relationship between periodontal attachment loss using sequential measurements made with an automated probe and bone loss detected with subtraction radiography.

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Advances In Radiographic Assessment

CADIA:

A video camera measures the light transmitted through a radiograph , and the signals from the camera are converted into gray scale images. The camera is interfaced with an image processor and computer that allows the storage and mathematical manipulation of images.

CADIA appears to offer an objective method for following alveolar bone density changes quantitatively over time, and when compared with

digital

subtraction radiography, it has shown a high degree of sensitivity and a high degree of reproducibility and accuracy.

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Advances In Radiographic Assessment

Nuclear medicine or

scintigraphy

:

Nuclear medicine is a branch of

medicine

and medical imaging that uses the nuclear properties of matter in diagnosis and therapy. Many procedures in nuclear medicine use radionuclides, or

pharmaceuticals

that have been labelled with radionuclides (radiopharmaceuticals). In diagnosis, radioactive substances are administered to patients and the radiation emitted is measured. The majority of these diagnostic tests involve the formation of an image using a gamma camera. Imaging may also be referred to as radionuclide imaging or nuclear scintigraphy.

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Advances In Radiographic Assessment

Other diagnostic tests use probes to acquire measurements from parts of the body, or counters for the measurement of samples taken from the patient. In therapy, radionuclides are administered to treat disease or provide palliative pain relief. For example,

administration of Iodine-131

is often used for the treatment of thyrotoxicosis and thyroid cancer.

Nuclear medicine differ from most other imaging modalities in that the tests primarily show the physiological function of the system being investigated as opposed to the anatomy.

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B. ADVANCES IN MICROBIOLOGIC ANALYSIS

Bacterial culturing:

Historically, culture methods have been widely used in studies aimed at

characterising

the composition of

subgingival

micro biota and are still considered the reference method (“gold

standard”) when determining the performance of new microbial diagnostic tests.

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ADVANCES IN MICROBIOLOGIC ANALYSIS

D

rawbacks of

Bacterial

culturing

Culture

method can only grow live bacteria; therefore, strict sampling and transport conditions are essential

.

Some of the putative pathogens, such as Treponema species are fastidious and difficult to culture. The sensitivity of culture methods is rather low, since the detection limits for selective and non selective media average 103 to 104 bacteria, and thus low numbers of a specific pathogen in a pocket are undetected. The most important drawback, however, is that culture requires sophisticated equipments and experienced personnel and is relatively time consuming and expensive.

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ADVANCES IN MICROBIOLOGIC ANALYSIS

DIRECT MICROSCOPY

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ADVANCES IN MICROBIOLOGIC ANALYSIS

IMMUNODIAGNOSTIC METHODS:

Immunologic assays employ antibodies that recognise specific bacterial antigens to detect target microorganisms. This reaction can be revealed using a variety of procedures, including

direct

and indirect

immunofluorescent

assays,

flow

cytometry, enzyme linked immunosorbent assay, membrane assay, and latex agglutination.

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Immunofluorescent assays:-

Both direct and indirect IFA are able to identify and quantify the percentage of the pathogen using a direct plaque smear

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ADVANCES IN MICROBIOLOGIC ANALYSIS

Indirect

Immunofluorescent

assays:-

Zambon

et al has shown that this technique is comparable to bacterial culture in its ability to identify the pathogens in subgingival plaque samples. Comparative studies state that sensitivity of these tests ranges from 82%-100% for A. actinomycetemcomitans. And from 92%-100% for P.gingivalis.

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ADVANCES IN MICROBIOLOGIC ANALYSIS

Cytofluorography

or flow

cytometry

for the rapid identification of oral bacteria

:

involves labelling bacterial cells from a patient plaque sample with both species specific antibody and a second fluorescein conjugated antibody. The suspension is then introduced into the flowcytometer, which separates the bacterial cells into an almost single cell suspension by means of a laminar flow through a narrow tube. The sophistication and the cost involved in tis procedure preclude its wide use.

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ADVANCES IN MICROBIOLOGIC ANALYSIS

Enzyme linked

immunosorbent

assay

:

- Is similar in principle to other radioimmunoassay, but instead of the radioisotopes, an

enzymatically

derived color reaction is substituted as the label. The intensity of the color depends on the concentration of the antigen and is usually read

photometrically for optimal quantification. ELISA has been used primarily to detect serum antibodies to periodontal pathogens, although it has also been used in research studies to quantify specific pathogens in subgingival samples using specific monoclonal antibodies

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ADVANCES IN MICROBIOLOGIC ANALYSIS

.. A membrane assay has been adapted for chair side clinical diagnostic use. It involves a linkage between the antigen and a membrane bound antibody to form an

immunocomplex

that is later revealed through a colorimetric reaction.

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ADVANCES IN MICROBIOLOGIC ANALYSIS

Latex agglutination:-

Is a simple immunologic assay based on the binding of the protein to latex. Latex beads are coated with a 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 available in 2-5 minutes

.

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ADVANCES IN MICROBIOLOGIC ANALYSIS

There area two types of inhibition assay

Indirect assay:

It is the most common latex agglutination test. The antibody is bound to latex agglutination beads, and when it is mixed with bacterial suspension from plaque samples, agglutination is visible.

Inhibition assay:

It is based on the principle of inhibition of the expected agglutination reaction between known antigen and known antibody as a result of competition.

A membrane immunoassay has recently been marketed by the name of

Evalusite

. It involves the linkage between an antigen and a membrane bound antibody to form an immunocomplex that is later revealed by a colorimetric reaction. Evalusite has been designed to detect A. actinomycetemcomitans, P.gingivalis, P.intermedia.

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ADVANCES IN BIOCHEMICAL AND ENZYMATIC METHODS

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ADVANCES IN BIOCHEMICAL AND ENZYMATIC METHODS

Nucleic acid probes:

Deoxyribonucleic acid (DNA) probes entail single stranded segments of nucleic acid, labelled with an enzyme or radioisotope, that can locate and bind to their complementary nucleic acid sequences with low reactivity with non-target organisms. DNA probes may target whole genomic DNA or individual genes.

Probes targeting whole genomic probes has propensity for greater cross-reactivity, however specific genes such as 16s

rRNA

ribonucleic acid genes contain signature sequences limited to the organisms of the same species, and display little or no cross-reactivity.

The probes are able to detect as low as 10

2-104 bacteria, and the sensitivity and specificity are not affected by mixed bacteria present in plaque samples

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ADVANCES IN BIOCHEMICAL AND ENZYMATIC METHODS

Checkerboard DNA- DNA hybridisation technique:

 

Socransky

et al

developed this technique for the detection and levels of 40 bacterial species often found in the oral cavity. The assay uses whole

digoxigenin-labeled

DNA probes and facilitates rapid processing of large numbers of plaque samples with multiple hybridisation of for upto 40 oral species in a single test. This permits detection of 104 cells of each species. It is particularly applicable for epidemiologic research and ecologic studies because it does not require viable bacteria and allows for the assessment of large number of plaque samples and multiple species.

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ADVANCES IN BIOCHEMICAL AND ENZYMATIC METHODS

Polymerase chain reaction (PCR):

PCR has emerged as the most powerful tool for the amplification of genes and their RNA transcripts. It was developed in 1985, and is used almost universally to study DNA and RNA obtained from a variety of tissue sources.

PCR begins with the isolation of DNA from a fresh tissue sample. By heating the complementary double strands, DNA splits into single stranded forms intended to act as the template dictating the nucleotide sequence in vitro.

Slide48

ADVANCES IN BIOCHEMICAL AND ENZYMATIC METHODS

The amplification is followed using a DNA polymerase that requires a primer, or known short

oligonucleotide

sequence corresponding to the border of the region that is amplified. A second primer, complementary the opposed chain, must be used to anneal or bind the template and flank the region of interest. This amplification can be performed several times.

In 1988, a

thermostable

DNA polymerase isolated from the organism

Thermus

aquaticus known as Taq-polymerase was developed. This has allowed the automatization of the reaction using specific appliances called thermocyclers.

Slide49

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ADVANCES IN BIOCHEMICAL AND ENZYMATIC METHODS

Enzymatic diagnostic assays

Microbial enzymatic tests were developed for rapid

chairside

diagnosis. The analysis of

crevicular

fluid is one possibility, because its components show the

etiopathogenical

phenomena produced in the periodontium, being considered as markers of the progression and severity of periodontal disease.BANA test: In 1992, Dr. Löesche introduced a chairside quick microbial-enzymatic test, BANA [N-benzoyl-DL-arginine- B-napthylamide ]. in order to assess the presence of some bacteria pathogen species in the subgingival plaque.TOPAS test: TOPAS (Toxicity Prescreening Assay)

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ADVANCES IN BIOCHEMICAL AND ENZYMATIC METHODS

The principle of BANA test is to detect the presence of three anaerobic bacteria associated with periodontal disease by the analysis of

subgingival

plaque. These three bacteria are:

Porphyromonas

gingivalis

, Treponema denticola, and Bacteroides forsythus. Socransky and Haffajee (1997) concluded that these three pathogens have a great prevalence in patients with periodontitis.

Slide52

The BANA positive bacterial species contain a certain enzyme that can hydrolyze the peptide impregnated on BANA strips. This peptide is N-

benzoyl

-DL-

arginine

-B-

napthylamide

(BANA). When samples containing any of the three bacteria are placed on a BANA impregnated test strip, a hydrolytic reaction gives the

stripa

distinctive blue color. The darker the blue, the more organisms are present.

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ADVANCES IN BIOCHEMICAL AND ENZYMATIC METHODS

TOPAS (Toxicity Prescreening Assay),detects the indirect presence of bacteria by two markers of gingival infection: bacterial toxins and bacterial proteins.

This test can be associated with the severity of inflammation and with the evolution of a destructive process, making the difference between an active and an inactive periodontal disease.

The principle of TOPAS test is the detection of the presence of actively growing and dividing anaerobic pathogens which results in increased levels of their toxic metabolites in the

crevicular

fluid.

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ADVANCES IN BIOCHEMICAL AND ENZYMATIC METHODS

This test includes two reagents, one for measuring the concentration of bacterial toxins and the second for measuring the level of total proteins in the

crevicular

fluid.

First the paper point is imbedded in

crevicular

fluid is introduced in the yellow cap vial. Here the reaction of the bacterial toxins from the

crevicular

fluid with certain chemical colorless reagents contained in the yellow cap vial takes place.The second step consists in measuring the level of total proteins (including antibodies, human serum\ albumin, aspartate aminotransferase, beta glucuronidase and bacterial proteins). The second reaction of TOPAS is based on the color change produced by adding the reagent from the blue cap vial.

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CONCLUSION

With the advancement in knowledge of the basic science, dental structures and wider intercommunication of clinical experience, periodontal conditions are understood and diagnosed better now compared to previous years. However conversely, increase in the knowledge of basic science has also highlighted the limitations of the various diagnostic method that are currently in use.

Slide56

Correct treatment begins with a correct diagnosis.