ADVANCED DIAGNOSTIC AIDS

CONTENTS Introduction Efficacy of diagnostic test Limitations of conventional methods Advances in Clinical diagnosis Advances in Radiographic assessment Advances in microbiologic analysis Advances in charaterizing the host response New innovations Conclusion References

INTRODUCTION Proper diagnosis Intelligent treatment

Diagnosis Involves Analysis of case history Evaluation of clinical signs and symptoms Results of tests (Probing, Mobility, Radiograph,

blood test, biopsies)

Diagnosis Determines Presence of disease Type of disease Underlying disease process

A “Diagnostic” refers to tools, procedures or technologies that are used in determination of diagnosis

used to: a) predisposing risk factors

b) identify early disease

c) specific type of disease

Kornman,2005

EFFICACY OF DIAGNOSTIC TEST

1. Gold standard2. Accuracy3. Sensitivity4. Specificity5. Positive predictive value6. Negative predictive value

CONVENTIONAL CLINICAL DIAGNOSTIC TOOLS

LIMITATIONS

Sites with ongoing periodontal destruction Cause Patient’s susceptibility to disease

whether disease is progressing?? remission?? response to periodontal therapy + /-

??

ADVANCES IN CLINICAL DIAGNOSIS

ADVANCES IN CLINICAL DIAGNOSIS

Periodontal probes Non-Periodontal probes - Calculus detection system - Periodontal Disease Evaluation System - Gingival Temperature - Tooth mobility

PERIODONTAL PROBES Orban as the “eye of the operator beneath the gingival

margin” Latin word “Probo”, which means “to test”. Gold standard Simonton (1925) and Box (1928) were among the first to

advocate the routine use of calibrated probes locate calculus, measure gingival recession, width of attached

gingiva and size of intraoral lesions, identify tooth and soft-tissue anomalies, locate and measure furcation involvements and determine mucogingival relationships and bleeding tendencies.

TYPES OF PROBE:

Pihlstrom (1992) classified probes into three generations.

In 2000, Watts extended this classification by adding fourth- and fifth-generation probes.

First-Generation (Conventional) Probes: conventional hand-held instruments. Probes do not control for probing pressure and are

not suited for automatic data collection.1. Willams’ Periodontal probe: 1936, Charles

H.M. Williams Prototype/benchmark

2. Community Periodontal Index of Treatment Need (CPITN):

Professor George S. Beagrie & Jukka Ainamo 1978

FDI World Dental Federation/WHO Joint Working Group

CPITN-E (epidemiologic) 3.5mm & 5.5mm CPITN-C (clinical) 3.5mm,5.5mm,8.5mm & 11.5mm 5gm wt, ball tip 0.5 mm

3. University of Michigan O probe: 3mm, 6mm & 8mm

4. University of North Carolina-15 (UNC-15):

5. Naber’s probe: Furcal areas

Second-Generation (Constant-Pressure) Probes:

Pressure sensitive , not exceed 0.2 N/mm2

(Waerhaug, 1952) True Pressure Sensitive (TPS) probe: Prototype , Hunter 1994 Disposable probing head 20 gm & 0.5mm dia

First true pressure-sensitive periodontal probe :

Gabathuler and Hassell (1971) periodontal probe & a small piezoelectric pressure

sensor which was attached to the non-probing end of the probe tip.

In 1977, Armitage : Simple pressure-sensitive periodontal probe holder :

To standardize the insertion pressure.

In 1978, van der Velden presented the "Pressure Probe", which allowed probing force to be adjusted.

Cylinder & a Piston connected to a variable air pressure system

The electronic pressure-sensitive probe, allowing for control of insertion pressure, was introduced by Polson in 1980.

Polson’s original design was modified: the probe is known as the Yeaple probe, which is used in studies of dentinal hypersensitivity (Kleinberg et al., 1994).

A simple, constant-force, periodontal probe was presented by Borsboom and co-workers (1981). Their instrument used a stainless steel spring to generate constant force.

Kalkwarf et al 1986: force upto 30 g Junctional epithelium 50 g periodontal osseous defects

Third-Generation (Automated) Probes: Controlled force application, automated

measurement and computerized data capture and storage

Foster-Miller probe (Foster-Miller Inc, Waltham, MA): prototype.

Jeffcoat et al. in 1986, capable of automated cemento-enamel junction

(CEJ) detection and direct measurement of attachment level with a high level of repeatability and accuracy.

National Institute for Dental and Craniofacial Research (NIDCR):

Gibbs et al. (1988) developed the Florida Probe® system (Florida Probe Corp, Gainesville, FL):

constant probing force, precise electronic measurement to 0.1 mm and computer storage of the data and sterilization of all system parts entering or close to the mouth

CAL- Fixed reference point occlusal surface of teeth- disk probe prefabricated stent- Stent probe

Florida PASHA Probe- Modified sleeve, tip edge 0.125 mm “catch” of the CEJ

Birek et al. (1981) and McCulloch et al. (1981) developed the Toronto Automated probe:

It used the occlusal/ incisal surface to measure relative clinical attachment levels.

Goodson and Kondon (1988) used fiber optic technology in their controlled-force Accutek probe.

The InterProbe™ (The Dental Probe Inc, Glen Allen, VA), also known as the Perio Probe, is a third-generation probe with a flexible probe tip, Jeffcoat 1991

Fourth generation probes: Three-dimensional (3D) probes. Currently under

development

Fifth-Generation Probes: 3D and non-invasive: an ultrasound or other device is added to

a fourth-generation probe. aim to identify the attachment level without penetrating it. The only fifth-generation probe available, the

Ultrasonographic (US) probe (Visual Programs, Inc, Glen Allen, VA), uses ultrasound waves to detect, image and map the upper boundary of the periodontal ligament and its variation over time as an indicator of the presence of periodontal disease.

Hinders &Companion at the NASA Langley Research Center.

NON-PERIODONTAL PROBES Calculus Detection Based on measurements of resonance vibrations of

ultrasonic treatment or autofluorescence induced by laser irritation.

Recently, a novel calculus detection system DetecTar (Ultradent, Salt Lake City, UT, USA) employing spectro-optical technology has been suggested as a potential aid in detecting subgingival calculus

Periodontal Disease Evaluation System The Diamond Probe/Perio 2000 System® is a dental

device designed to detect sulphide concentrations of various forms (S, HS, H2S and CH3SH) in gingival sulci

The system combines a conventional Michigan “O” style dental probe with a sulphide sensor, which measures periodontal probing depth, bleeding on probing and sulphide levels simultaneously

GINGIVAL TEMPERATURE Increased blood flow and a very high metabolic rate Kung et al 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

Diseased sites Posterior teeth Mandibular sites Temp increases with probing depth = Unknown Haffajee et. al., 1992 sites with higher temperature

have greater than twice the risk of future attachment loss Pathogens Increased temperature

Unclear

TOOTH MOBILITY Periotest Probe is a hand-held probe, Mobility is recorded in Periotest units (PTU) from 0 to

50. The instrument (BioResearch, Milwaukee, Wisconsin,

USA) taps each tooth with an impeller 16 times and measures the time taken for the tooth to return to its original position.

ADVANCES IN RADIOGRAPHIC ASSESSMENT

Destruction of alveolar bone Cannot accurately reflect bone morphology=

buccally/ lingually Interproximal bone levels Root length, root proximity, presence of periapical

lesions, estimates of remaining alveolar bone. More than 30% of bone mass lost Conventional radiographs are very specific but lack

sensitivity

Commonly used Bitewing Periapical Panoramic

Variations in projection geometry Variations in contrast & density caused by differences in

film processing, voltage, & exposure time & Masking of osseous changes by other anatomic structures

(2D mapping of 3D structures)

ADVANCES IN RADIOGRAPHIC ASSESSMENT

Digital radiography Digital subtraction radiography Computer-assisted densitometric image analysis system

(CADIA) Tuned aperture computed tomography (TACT) Computed tomography (CT) Cone-beam computed tomography (CBCT) Local computed tomography (LCT) Magnetic resonance imaging (MRI) Nuclear medicine bone scans Optical coherence tomography (OCT) Ultrasound imaging

DIGITAL RADIOGRAPHY

Advantages: The elimination of chemical processing. Shorter exposure-to-display time. 1/3rd to 1/2rd of dose reduction Computerized images which can be stored Selected region in the image can be enhanced for a

specific diagnostic task. The software offers a variety of measurement tools

Two digital radiography systems rely on the sensor – Direct method solid-state detectors which are based

either on charge-coupled device technology (CCD) or on complementary metal oxide semiconductor technology (CMOS)

key features is the immediate availability of the image Disadv: limited x-ray sensitive surface of the sensor thicker, rigid & cable attachment besides sterility issue.

Indirect methods: (Digora System) uses a phosphor luminescence plate, which is a

flexible film-like radiation energy sensor placed intraorally and exposed to conventional X-ray tubes.

Adv: plate size and flexibility plates are then erased and can be reused.

Disadv: increased time and effort for scanning

DIGITAL SUBTRACTION RADIOGRAPHY

First demonstrated by Zeidses Des Plantes,1935 Principle: current image is superimposed on the

previous. Only the areas of change appear positive difference brighter negative difference darker

Baseline project geometry and image density must be reproduced

A high degree of correlation between changes in alveolar bone determined by SR & CAL changes in periodontal patients after therapy

Increased detectability of small osseous lesions. Disadv: identical projection alignment during

sequential radiograph Diagnostic subtraction radiography (DSR)

positioning device + specialized software

COMPUTER-ASSISTED DENSITOMETRIC IMAGE ANALYSIS SYSTEM

Video camera measures the light transmitted through a radiograph and the signals from the camera are converted into gray-scale images.

higher sensitivity and a high degree of reproducibility and accuracy.

TUNED APERTURE COMPUTED TOMOGRAPHY (TACT)

To assess tissues in three dimensions Based on the principle of tomosynthesis:

By shifting and combining a set of basis projections, arbitrary slices through the object can be brought into focus

Improves detection of defects around implants Tyndall et al., 2002 TACT is superior to conventional

radiography in detecting pericrestal bone gain

COMPUTED TOMOGRAPHY (CT)

In 1972, Godfrey Hounsfield The X-ray source travels helically around the patient

many times, emitting a narrow fan beam until the region of interest is covered.

The beam exiting the patient is captured in a digital sensor

Axial, coronal or sagittal planes This is referred to as multiplanar reformatted imaging

Indication for evaluating prospective implant sites for the amount & character of remaining alveolar bone.

Fuhrmann et. al., 1995 CT assessment of alveolar bone height and intrabony pocket is reasonably accurate

Dentascan:

CONE-BEAM COMPUTED TOMOGRAPHY (CBCT)

reduced dose of radiation

Drawbacks: increased effect of scatter radiation on image quality.

Scatter radiation reduces contrast and limits the imaging of soft tissues.

CBCT is mainly indicated for imaging hard tissues.

LOCAL COMPUTED TOMOGRAPHY (LCT)

A form of CBCT Uses a small field high resolution detector to

generate a limited high resolution 3D volume advantages of reduced patient dose and low cost Limited commercial availability

MAGNETIC RESONANCE IMAGING (MRI)

Non-ionizing radiation from the radiofrequency (RF) band

Soft tissues have a high water content, MRI provides excellent soft tissue contrast resolution

Adv: It offers the best resolution of tissues of low inherent

contrast. No ionizing radiation is involved Since the region of the body imaged is controlled

electronically, direct multiplanar imaging is possible without reorienting the patient.

Disadv: expensive, requires considerable scan time for high resolution images may be claustrophobic for the patient the potential of causing movement of ferromagnetic

metals in the vicinity of the imaging magnet Metals used in dentistry for restorations or orthodontics

will not move but may distort the image in their vicinity

NUCLEAR MEDICINE BONE SCANS

Radiolabeled pharmaceuticals that are specifically intended to image particular organs or detect specific disease processes.

assessing physiologic change in the absence of anatomic change.

technetium-labeled diphosphonate called 99m-Tc-methylene diphosphonate

To perform a bone scan, the radiopharmaceutical is injected intravenously. Following a period to allow for bony uptake of the

agent, uptake is either imaged using a gamma camera or measured using specially designed detectors for intraoral use.

Areas of active bone loss appear as hot spots in the image

Used : determine whether a patient has active sites of bone

loss and could benefit from an experimental treatment,

to determine whether a patient who is to undergo a bone marrow transplant has sites of active periodontal disease or occult disease that need immediate attention.

OPTICAL COHERENCE TOMOGRAPHY (OCT)

Biologic imaging system in 1991 by Huang et al high-resolution cross-sectional images of biologic structures

by scanning a lightly focused light beam across the tissue It uses broadband low-coherent Near-Infrared (NIR)

light sources Dental OCT images clearly depict anatomical structures

that are important in the diagnostic evaluation of both hard and soft oral tissue

Periodontal tissue contour, sulcular depth and connective tissue attachment

Active periodontal disease before significant alveolar bone loss occurs.

3D imaging of periodontal soft tissues and bone

ULTRASOUND IMAGING Ultrasonics is a branch of acoustics concerned with sound

vibrations in frequency ranges above audible level. Ultrasound imaging, or ultrasound scanning or sonography,

is a method of obtaining images from inside the human body through the use of high frequency sound waves.

Non-invasive periodontal assessment tool 1 to 20 megahertz Spranger (1971) who tried to determine the height of the

alveolar crest

Adv: ultrasound imaging can visualize periodontal and

oral tissues in vivo or ex vivo without the need for complicated processing, fixing or staining.

It is fast, easy and a reproducible technique. non-invasive nature of the imaging the avoidance of ionising radiation,

ADVANCES IN MICROBIOLOGIC ANALYSIS

Diagnostic microbiology- involves the study of specimens taken from patients suspected of having infection

More than 300 species isolated from different individuals

40 species from a single site

Microbiological tests are useful..

1) To identify putative pathogens and supporting the diagnosis of various forms of periodontal disease

2) To serve as indicators of disease initiation and progression and healing

3) To determine which periodontal sites are at higher risk for active destruction

4) To monitor periodontal therapy5) To aid in treatment planning of patients with

aggressive or non responding periodontitis by helping the doctor in selection of adjunctive antimicrobial therapy

ADVANCES IN MICROBIOLOGIC ANALYSIS

Bacterial culturing Direct Microscopy-dark-field or phase-contrast

microscopy Immunodiagnostic methods Enzymatic methods Diagnostic analysis based on Molecular Biology

techniques

ADVANCES IN CHARACTERIZING THE HOST RESPONSE

Diagnostic tests have been developed that add measures of the inflammatory process to conventional clinical measures.

Information on the destructive process Current activity of the disease Rate of disease progression Patterns of destruction Extent & severity of future breakdown Response to therapy

Assessment of the host response refers to the study of mediators, by immunologic or biochemical methods, that are recognized as part of the individual’s response to the periodontal infection

Inflammatory mediators & products Host-Derived Enzymes Tissue Breakdown products

NEW INNOVATIONS

Proteome analysis Genetic analysis

Proteome analysis: Salivary proteome: using both two-dimensional gel electrophoresis ⁄

mass spectrometry and ‘shotgun’ proteomics approaches

Hu et al. (2005) identified 309 distinct proteins in human whole saliva

NIDCR support salivary proteome projects, 1,166 salivary proteins

3 key features of pathogenic processes in periodontal disease - inflammation, collagen degradation and bone turnover.

GCF Proteomes: The composition of GCF greatly varies between

health and periodontal disease. Bostanci et al. (2010) performed analysis of the from

healthy and periodontally diseased sites 154 proteins of human, bacterial and viral origin

were identified in the 40 GCF samples obtained from the 10 subjects

The proportion of bacterial, viral and yeast protein was increased in disease compared to health

Genetic analysis: The etiology of periodontal disease is multifactorial and thus

influenced by genetics (i.e. the host) and the environment The periodontitis susceptibility trait test (Interleukin

Genetics, Waltham, Massachusetts) is the only genetic susceptibility test for severe periodontitis that is commercially available.

This system works by detection of two types of IL-1 genetic alleles, IL1A +4845 and IL1B +3954

CONCLUSION

After all these years of intensive research, we still lack a proven diagnostic test that has demonstrated high predictive value for disease progression, has an impact on disease incidence & prevalence, & is simple, safe & cost-effective….

Future application of advanced diagnostic techniques will be of value in documenting disease activity & treatment options.

REFERENCES

Newman MG, Takei HH, Klokkevold PR, Carranza FA. 10th edition. Carranza’s Clinical Periodontology. Saunders

Company 2006. 579-601. Ramachandra SS, Mehta DS, Sandesh N, Baliga V,

Amarnath J. Periodontal Probing Systems: A Review of Available Equipment. Dentistry India 2009; 3(3): 2-10.

Jeffcoat MK, Wang IC, Reddy MS. Radiographic diagnosis in periodontics. Periodontol 2000 1995; 7: 54-68.

Bostanci N, Heywood W, Mills K, Parkar M, Nibali L, Donos N. Application of label-free absolute quantitative proteomics in human gingival crevicular fluid by LC/MS E (gingival exudatome). J Proteome Res 2010; 9(5): 2191-2199.