1

SUBJECTIVE & OBJECTIVE METHODS OF CARIES

DETECTION

2CONTENTS

INTRODUCTION DIAGNOSTIC TOOLS

VISUAL EXAMINATION TACTILE BASED ON RADIOGRAPHS

Conventional – IOPAR & BitewingXeroradiographyDigital

FUTURE TRENDS IN RADIOGRAPHIC DIAGNOSIS OF DENTAL CARIES

CO

NTEN

TS

3BASED ON VISIBLE LIGHT

BASED ON ELECTRICAL CURRENT

ULTRASOUND

ENDOSCOPY /VIDEOSCOPE

DYES – Enamel & Dentin

CONCLUSION

REFERENCES

4

In Greek “ Dia” means thoroughly “Giagnoska” means to know

OBJECTIVES

To identify lesions which require surgical treatment

(restoration).

Identify lesions, which require non-surgical treatment.

Identify high-risk group.

INTRODUCTION

5PREREQUISITES:

Accurate Reproducible Sensitive Reliable Specific Cost effective Not transferring infection to other

areas

6Methods of caries detection

In vivo

1. Visual examination

2. Tactile examination

3. Radiographs –conventional , digital and xeroradiography

4. Fiber optic transillumination

5. Optical method – Fluorescence, light scattering

6. Electronic resistance measurements

7. Ultrasonic

8. Dyes

7 In Vitro

Single tooth measurement

1. Chemical analysis

2. Cross sectional microhardness testing

3. Polarized light microscopy

4. Traditional transverse microradiography

5. Microprobe analysis

Method of sequential measurements on tooth slab

6. Iodine absorbitometry

7. Longitudinal microradiography

8. Light scattering

9. Surface microhardness

The visual examination of caries • detection of white spot,• discoloration and •frank cavitation or suspicious pits and fissures.

Visual examination

White spot

Pits and fissures

Discoloration

9 AIDS:

Magnification loupes

Use of temporary elective tooth

separation.

10PROCEDURE:

For detailed examination, the teeth are cleaned & dried with compressed air & illuminated with adequate light source.

DISADVANTAGES:

Discoloration of pits & fissures may be mistaken for cariesNot reliable for detection of secondary caries or occult caries.

11CLINICAL SEVERITY INDEX SCORES

Ekstrand et al, 1998

SCOR

ES

CRITERIA

0No or slight change in enamel translucency after drying

(> 5 sec)

1Opacity or discoloration hardly visible on wet surface,

but distinctly visible after air drying (> 5s)

2Opacity or discoloration distinctly visible without air

drying

3

Localized enamel breakdown in opaque or discolored

enamel &/or grayish discoloration from the underlying

dentine

4Cavitations in opaque or discolored enamel exposing

dentine

12

During the past 10 years the role of explorers in caries detection has become a controversial issue.

PROBING (TACTILE EXAMINATION)

13 AIDS:

-Mouth mirror

For direct illumination

For indirect illumination

Self illuminating

-Explorers

Right angle probe {no.6}

Back action probe {no.17}

Shepherds crook {no23}

Cow horn with curved ends {no.2}

PROCEDURE:

Determining roughness or softness of the tooth with sharp explorer. Both penetration & resistance to removal of an explorer tip i.e. the catch is interpreted as evidence of demineralization.

14REVIEW OF LITERATURE:

•Black et al (1924) gave the concept of passing the explorer into pits & noting whether or not there is softening & whether the instrument catches at any point.

•Simon et al (1956) recognized marginal changes around a previously placed restoration.

•Gilmore et al (1982) showed that a susceptible site can be entered by the use of a small sharp explorer or if enamel is rough , decalcified or directly opens in dentin.

15•Marzouk et al (1985) showed that by pressing a sharp explorer tip into pit &fissure will cause it to penetrate the enamel & or dentinal caries cone making a definitive diagnosis of caries.

•Strudvent et al (1985) were of the view that defects are best detected when an explorer provides tug back or resistance to removal.

16DISADVANTAGES:

•Can produce traumatic defects in lesions arrested by plaque control alone.

•Does not improve accuracy of diagnosis.

•Inter-operative variables.

•May transfer cariogenic bacteria from one site to another.

•Study by Lussi (1991) has found that application of too much pressure on explorer does not increase the accuracy of caries detection.

Use of floss as an adjunct to tactile sensation

Pickard (1961)

the use of floss for detection of caries.

18 VISUAL TACTILE METHOD

EUROPEAN SYSTEM

Visual methodexamination

requires 10 minutes / subject.

AMERICAN DENTAL

ASSOCIATION CRITERIA (USA)Visual tactile

3 min per subject

19

RECENT ADVANCES(Visual, tactile assessment)

CLINICAL SEVERITY INDEX

- Ekstrand et al, 1998

Scor

e

INTERNATIONAL CARIES

DETECTION & ASSESSMENT

SYSTEM (ICDAS)

- Ismail et al, 2007

No/slight change in enamel translucency

after drying (> 5 sec)0

No/slight change in enamel translucency after drying (> 5 sec)

Opacity/ discoloration hardly visible on

wet surface, but distinctly visible after air

drying (> 5s)

1 1st visual change in enamel

Opacity/discoloration visible without air

drying2 Distinct visual changes in enamel

Localized enamel breakdown in opaque/

discoloured enamel &/or greyish

discoloration from the underlying dentine

3Localized enamel breakdown in opaque/ discolored enamel

Cavitations in opaque or discoloured

enamel exposing dentine4

Underlying dark shadow from dentin

- 5 Distinct cavity with visible dentin

- 6Extensive Distinct cavity with visible dentin (>1/2 surface)

SCORE 1

SCORE 6SCORE 5SCORE 4

SCORE 2 SCORE 3

Description and clinical examples of each score of ICDAS

ADVANTAGES :

ICDAS has presented CONTENT VALIDITY

ICDAS has presented CRITERION VALIDITY

Significant correlation with lesion depth in the histologic examination has been shown.

–Braga et al, 2009

The specificity has been high, even when considering the non-cavitated threshold.

- Novaes et al , 2009

LIMITATIONS :

In primary teeth, ICDAS cannot distinguish accurately between lesions related to the outer or inner half of the enamel.

– Braga et al, 2009

Its sensitivity has been low for proximal caries in vivo

- Novaes et al 2009

ACTIVITY ASSESSMENT OF NONCAVITATED

AND CAVITATED CARIES LESIONS- Nyvad et al, 1998

ADVANTAGES :

This system has presented construct & predictive Validity concerning caries lesion activity status.

Worked well in assessing the depth of lesions on PRIMARY TEETH.

– Braga et al, 2009

SCORE

CATEGORY Description of scores in NYVAD’S SYSTEM

0 Sound Normal enamel translucency and texture

1 Active caries(intact surface)

Enamel surface whitish/yellowish, opaque with loss of luster; feels rough on explorer examination. Intact fissure morphology; lesion extending along the walls of the Fissure

2 Active caries(surface discontinuity)Active caries(cavity)

Same as 1.

Surface of cavity feels soft/ leathery on gentle probing.

4 Inactive caries(intact surface)

Enamel surface whitish/ brownish/black. Lesion extending along the walls of the fissure

5 Inactive caries(surface discontinuity)

Same as 4. Localized surface defect. No undermined enamel or softened floor detectable with the explorer

6 Inactive caries(cavity)

Surface of the cavity feels shiny and feels hard on gentle probing.

7 Filling (sound surface)

-

8 Filling 1 active caries

Cavitated/Non-Cavitated Lesion

9 Filling 1 inactive caries

Cavitated/Non-Cavitated Lesion

26

RADIOGRAPHS

Conventional – IOPAR & Bitewing

Xeroradiography

Digital :

1. Enhancement

2. Subtraction

3. Tuned Aperture Computed Tomography (TACT)

27I. CONVENTIONAL RADIOGRAPHY

IOPA radiographs

Bitewing radiographs

It involves two techniques:

28•Other techniques are:

- Occlusal radiograph - Panoramic radiograph

29

LIMITATIONS:

•Overlapping of approximal contacts.

•False diagnosis due to over estimation of lesion depth due to change in angulations

•Occlusal lesions, at times are imperceptible due to bulk of buccal & lingual cusps.

•Radiolucency can be due to resorption or other defects like wear etc.

30

• It gives 2 dimensional image of a 3 dimensional object.

• Superficial demineralization on buccal & lingual surfaces may be misinterpreted as a proximal lesion

• Fracture of one lingual cusp may also appear as radiolucent proximal caries.

• Tilted maxillary lateral too, gives carious appearance

• Cervical burn out also mimics cervical caries.

31CRITERIA FOR RADIOGRAPHIC ASSESSMENT

- Mejare et al, 1999R0 = no radiolucency

R1 = Radiolucency confined to outer half of enamel

R2 = Radiolucency in inner half of enamel + extending upto but not beyond DEJ.

R3 = Radiolucency in dentin, broken DEJ, but with no obvious spread in dentin

R4 = Radiolucency with obvious spread in outer half of dentin.

R5 = Radiolucency with obvious spread in inner half of dentin (> half way through to the pulp)

32FIVE POINT SCALE FOR OCCLUSAL CARIES BASED ON

VISUAL EXAMINATION + RADIOGRAPHS

-Espelidel et al, 1994

Grade 1: Non cavitated white spot / slightly discolored caries lesion in enamel not detected on the radiograph.

Grade 2: Some superficial cavitation in the fissure entrance, some non cavitated mineral loss in the surface of the enamel. Surrounding the fissure / and a caries lesion in enamel detected on the radiograph.

Grade 3: Moderate mineral loss with limited cavitation in the extreme of fissure / lesion in the outer third of dentin, detected on radiograph.

Grade 4: Considerable mineral loss with cavitation / or lesion into the middle third of the dentin, detected on the radiograph.

Grade 5: Advanced cavitation / or lesion into the inner thirds of dentin, detected on radiograph.

33(II) XERORADIOGRAPHY-Chester Carlson, 1937

•It is also called as EDGE ENHANCEMENT RADIOGRAPHY which means differentiating areas of different densities at the margins or edges.

•This technique simulates a Xerox machine.

•The image is recorded on an aluminium plate coated with a layer of selenium.

•These selenium particles are given a uniform electrostatic charge & are stored in a unit called conditioner.

34ADVANTAGES :

•The characteristic feature of this technique is to capture both

positive & negative prints.

•Better contrast

•It is twice as sensitive than D speed film but comparable to E

speed film.

•Edge Enhancement

•No need of any developer unit

35LIMITATIONS:

•The electric charge over the film causes discomfort to the patient as oral cavity provides humid environment which acts as medium for flow of current.

•Exposure time varies as exact thickness of plate is not

decided.

•Processing has to be completed in 15 minutes.

36(III) DIGITAL IMAGING

A digital imaging is an image formed and represented by a

spatially distributed in rows and columns known as pixels.

37•These are of 2 types:

Direct- the direct image receptor that collects the x-rays directly e.g. RVG

Indirect- E.g. Video camera is used for forming digital images of a radiograph.

38

•Digital image is a simple means where image is recorded in non film receptors.

•There are three types of digital detectors available, namely:

- Charged Couple Device (CCD)

- Complementary metal oxide semi conductor (CMOS)

- Phosphostimulable phosphorous plates

39

SYSTEM MANUFACTURER PROBE SIZE

R V G Trophy, Japan 19 x 28 mm

Flash dent Villa, Italy 20 x 24 mm

Sens-a-Ray Regan, Sweden 17 x 26 mm

Vixa Gendex, Italy 18 x 24 mm

Certain examples of Direct Digital Radiography include:

40

ADVANTAGES: •Dark room is not required•Image is viewed instantly •Image quality is consistent•Radiation dose is reduced•Elimination of the hazards of film development•Contrast can be enhanced 70% by digital mode•Digital method is 50% more sensitive in detecting occlusal caries

DISADVANTAGES :

•High cost of system•Life expectancy of CCD in not certain

41

It was shown that the resolution of digital image is lower than radiographs and the range of grey shades is limited to

256, whereas in a radiographic film, over one million shades of grey appear.

The diagnostic performance of unenhanced digital image does not exceed radiographs. Therefore, the contrast can

be digitally enhanced.

1) DIGITAL IMAGE ENHANCEMENT

422) DIGITAL SUBTRACTION RADIOGRAPHY

•Two standardized radiographs produced with identical exposure geometry are used.

•The first one is called reference image & the next ones are for comparison. The reference image is displayed on screen & the comparison images are super imposed on it.

•The difference between the original & the subsequent images shows dark bright areas.

- B.G.Zeides des Plantes, 1920s

43Nummikoski et al (1992) & Minah et al (1998) have regarded

it as a powerful tool in detecting primary & secondary caries.

ADVANTAGES :

•Detecting progress of re-mineralization & de-mineralization pattern.

•Alveolar bone height in periodontal diseases

•It is 90% accurate & can detect even up to 5% of mineral loss as compared to 30- 60% by conventional radiographs.

44•Minimal thickness - detected is 0.012 mm of bone.

•Overall density & contrast are good.

•By increasing spatial resolution the amount of detail displayed can be increased.

DISADVANTAGES :

•Correct projection geometry is mandatory.

45

This method contracts radiographic section through teeth.

The slices can be viewed for presence of radiolucencies.

Slices can be brought together in 3-D computer model called a psedohologram.

TACT slices and pseudohologram adequately detect primary and secondary caries.

3) TUNED APERTURE COMPUTED TOMOGRAPHY (TACT)

46

Significant differences between film, digital radiography, TACT slices in the

detection of caries.

FILM DIGITAL TACT

47FUTURE TRENDS IN RADIOGRAPHIC

DIAGNOSIS OF DENTAL CARIES 

(A) Terahertz Imaging

(B) Multi-photon Imaging

(C) Optical coherence tomography

48(A) TERAHERTZ IMAGING

- Arnone et al (1980)

It uses waves with terahertz frequency (15 µm to 1 mm). This wavelength forms short enough to provide a reasonable resolution.

SOURCE OF TERAHERTZ RADIATION Photoconductive emitters of certain crystals (Zinc telluride) exposed to short pulses (<10-12) seconds of visible infra red light would emit electromagnetic waves with the frequency in the terahertz range.

49 ADVANTAGES:

- Low power used for imaging.

- Use of Non-ionizing radiation.

DISADVANTAGES :

1) Low spatial resolution due to long wave length of the

source.

2) Alterations in image interpretation since terahertz

waves are strongly absorbed by water, a potential

complication in the mouth.

50(B) MULTIPHOTON IMAGING

- Vinerot et al, 2010

ADVANTAGES :

• Non invasive method.

• Low average level of laser power. Therefore lower risk of

photo toxicity to the pulp.

• Longer incident wave

length results in increased

penetration.

• Can collect information

from caries lesion up to 500 µm.

51

DISADVANTAGES :

- The Micron assay involves movements required to produce

serial tomographic images over a period of 1 min or so is

well beyond the capabilities of most dentists.

- Currently the technique is performed only on extracted

teeth and large laser equipment is required.

52 (C) OPTICAL COHERENCE TOMOGRAPHY

(OCT) Developed for transparent

and semi transparent

structures.

Wave length of light 840-1310

nm with a depth of 0.6-2 mm

is used

53 PRINCIPLE:

Based on interference of light.

OCT uses Super Luminescent Diodes (SLD) as light

source. Which produces light with the broad range of

wave length.

ADVANTAGES:

Non-invasive diagnosis of secondary caries.

Development of prototype hand pieces for intra-oral OCT.

54BASED ON VISIBLE LIGHT

Optical caries monitor (OCM) FOTI and DIFOTI (Electro-Optical Sciences,

Irvington, N.Y.) QLF (Inspektor Pro, OMNII Oral Pharmaceuticals,

West Palm Beach, Fla.) DIAGNOdent (KaVo, Lake Zurich, Ill.; Midwest

Caries I.D., Dentsply, York, Penn), DELF(DYE-ENHANCED LASER FLUORESCENCE) Ultraviolet

55(I) OPTICAL CARIES MONITOR (OCM)

This comprises of

light source

measuring and reference units

a detection part.

The light is transported through a fiber bundle to the tip of

hand piece.

The tip is placed against the tooth surface and the

reflected light is collected by different fibers of the same

tip.

56 (II) FIBER OPTIC TRANSILLUMINATION

( FOTI )

-Friedman & Marcus (1970) PRINCIPLE:

There is different index of light transmission for decayed and

sound tooth. Tooth decay has a lower index of light

transmission than the sound tooth structure, an area of decay

shows up as a darkened

57METHOD:

A 150 watt halogen lamp and rheostat is used to produce a light of variable intensity. A fiber optic probe of 0.5 mm diameter is used to place in embrasure area. The marginal ridge is viewed from occlusal surface.

58ADVANTAGE :

No hazards , lesion not easily diagnosed by radiographs

can be diagnosed.

Initial results indicate that both specificity and sensitivity

are high.

DISADVANTAGE :

Subject to inter and intra observer variation. The major

problem remains low sensitivity.

59Digital imaging fiber-optic transillumination

(DIFOTI) Schneidermanalt et

al 1997 Visible light fiber-optic transillumination and digital CCD

camera.

60

Mini D cariesD-Carie Mini is a new caries detection portable device which is based on Fiber-optic principle.

It is easy to use and requires no calibration.

61(III) QUANTITATIVE LASER OR LIGHT INDUCED FLUORESCENCE

Sundstrom et al. (1981)•Normal Teeth fluoresce under UV light

-Benedict et al (1929)

•There is a difference in the Fluorescence of sound and caries

teeth.

•Loss of fluorescence is due to:

i. Light scattered and thus the absorption per unit volume is small.

ii. Light scattering in the lesion that prevents the light from reaching the

fluorescing dentin.

iii. Protenic chromophores are removed by caries process.

METHOD:

Blue-green visible light emitted from a argon ion laser of

wavelength 488 nm is used.

Demineralization appears as dark spots.

Clinical example of a lesion on the mesial surface of the canine associated with partial denture wear.

The QLF image showing enhanced contrast between sound and demineralized enamel.

63ADVANTAGES

Diagnosis of early lesion of enamel

High diagnostic validity

Detection of carious lesions in deciduous is more accurate than in permanent teeth.

DISADVANTAGES Cannot

differentiate between decay and hypoplasia

Poorer specificity

than the visual examination alone or radiographic examination alone.

Cannot discriminate between lesions restricted to the enamel and those extending into the dentine.

64(IV) DIAGNOdent Lucci et al (1998)

•A variant of QLF system, a DIAGNOdent was based on

research by Hibst and Gal.

•Light source – diode laser red light 655 nm.

65METHOD:

Comprises a pen like device with detachable tips of different diameter.

A reading is provided on a digital display accompanied by an audible tone.

The DIAGNOdent unit (KaVo)

Close-up of the tip and the knob for turning it around. LF device (DIAGNOdentpen) with

the tip for fluorescence measurements on approximal surfaces

Light direction of the tip of DIAGNOdent pen for approximal caries detection.

Guidelines for the clinical use of DIAGNOdent

Values Guidelines

0 to 13 No active care is advised (NCA)

14 to 20 Preventive care is advised (PCA )

21 to 30 (approx) Preventive or operative care is advised, depending on the patient's caries risk, the recall interval, etc (PCA or OCA)

Over 30 (approx) Operative (and preventive) care is advised . (OCA and PCA)

69Bader and ShugarS (2004) recently reviewed the literature

concerning studies of DIAGNOdent and concluded that

DIAGNOdent is more sensitive than conventional methods of

caries detection but that the risk of over diagnosis or false

positive raises concern that detection might imply diagnosis.

Attrill & Ashley (2001) compared the accuracy and repeatability of

three diagnostic systems (DIAGNOdent, visual and radiographic) for

occlusal caries diagnosis in primary molars. The DIAGNOdent was

the most accurate system tested for the detection of occlusal

dentine caries in primary molars.

.

70

DISADVANTAGES:

• It cannot differentiate between decay, hypoplasia, or

unusual anatomic features.

• It can’t differentiate between enamel & dentine caries.

• It can’t differentiate between active & inactive lesions.

• It can give false results due to stain, deposits or

calculus

71(V) DYE-ENHANCED LASER

LUORESCENCE•It had higher sensitivity than laser auto Fluorescence alone.

ADVANTAGES:

•It is convenient & fast method.

•Carious lesion can be detected with less than 1mm diameter

& depth of 5-10μ.

DYES USED ARE:

- Pyro methane 556

- Sodium Fluorescin

72 (VI) ULTRAVIOLET

UV light is used to increase the optical contrast between caries

region and surrounding sound teeth.

ADVANTAGE :

Sensitive than visual tactile method

DISADVANTAGE:

Specificity is a problem as it cannot detect between caries

lesion and developmental defect.

73 BASED ON ELECTRIC CURRENT

-Magitot et al (1878)

PRINCIPLE: It is based on the principle of electric conductance which is

measuring the electrical conductivity through the pores.

The electric conductance & tooth resistance are inversely

proportional.

The increased conductance &/or decreased resistance are

indicative of hypo- or demineralized surface.

74•Two techniques have been devised:

1. Electroconductivity measurements

(Electronic Caries Monitor, Lode Diagnostics,

Groningen, The Netherlands)

2. Impedance spectroscopy (CarieScan,

IDMoS, Dundee, Scotland)

75ELECTRONIC CARIES DETECTOR

•It is the instrument used to measure electric conductivity of

tooth.

•When potential of less than 1 volt is applied, the resistance

above 600,000 ohms -caries free tooth surface,

below 250,000 ohms - caries involving dentin are present.

• 0-9 scale indicating from sound to degree of

demineralization.

76ADVANTAGES:

•It is site & surface specific measurement.

•It is useful in detecting caries at pre-cavitation stage.

•Useful in monitoring progress of caries during caries control

program.

DISADVANTAGES:

•It can only recognize demineralization & not caries

specifically.

•Developmental defects also give similar effect.

•Enamel cracks may give false positive result.

77

(i)Van Guard Electronic Caries

Detector

•Massachusetts Manufacturing Corp. in 1980.

•The measure scale ranges from 0-9.

•The tooth is dried to prevent conductance.

78(ii) Caries Meter L

•It was given by GE International Corp., Belgium.

•It gives indication by glowing lights.

•There are 4 light sequences denoting caries:

Green - No caries

Yellow - Enamel caries

Orange - Dentine caries

Red - Pulp involvement

79BASED ON ULTRASOUND

MEASUREMENTS

•Ultrasound makes use of sound waves (by application of an

alternating voltage applied to a piezoelectric crystal) with a

frequency ranging from 1.6 to 10 MHz.

•Ultrasound interacts differently with different tissues.

80

METHOD:

To reach the target tissue, a coupling agent namely water/

glycerin is used. A flexible probe tip is fit into wedge shaped

inter proximal contours to conform to the shape of the

tooth.

DISADVANTAGE :

Useful only for superficial enamel lesions.

81 ENDOSCOPE/ VIDEOSCOPE A blue light (400-500 nm) is used to excite fluorescence within

the tooth.

ADVANTAGE: 5-10 fold magnification possible.

DISADVANTAGES:

- Requires meticulous drying and isolation.

- Takes 5-10 minutes compared to 3-5 minutes for conventional

technique.

Additionally a camera can be used to store the image.

82  DYE-PENENTRATION METHODS

Dyes can help visualize a subject from its routine

background or from objects that appears similar.

It gives qualitative as well as quantitative values.

For caries detection qualitative examination is done.

83 FOR ENAMEL CARIES:

- Procion: disadvantage - irreversible as dye reacts with nitrogen

and hydroxyl groups of enamel.

- Calcein : Complexes with calcium

- Fluorescent Dye: i) Brilliant blue ii) Zyglo ZX – 22

FOR DENTINAL CARIES:

- 0.5% basic fuschin in propylene glycol

- 1% acid red in propylene glycol

MODIFIED DYE PENETRATION METHOD – Iodine penetration

method for measuring enamel porosity of incipient carious region was

developed by Balnos et al (1977).

According to Fusayama et al. (1979), basic fuschin

stains the outer layer of carious dentine but not the inner.

This outer layer is infected, highly degraded and

unremineralizable and therefore must be removed prior to

restoration. In contrast the inner layer is not infected and

has been invaded only by bacterial products.

85

Fusayama & Terachima (1972) also separated lesions

into acute and chronic in terms of stainability. They

postulated that in an acute lesion, heavier staining

occurred because of the lower dentine hardness,

whereas in a chronic lesion, lighter staining is observed

because of the harder dentine in the level below.

86SUMMARY & CONCLUSION

“Inspite of all new discoveries there is a truth in the

past which is not and cannot be ignored or brushed aside”-Dr R.A.Millikan.

87Tandon S . Text Book Of Pedodontics. ; 2nd edition , Paras Medical Pub : 2008

Vimal K Sikri. Textbook of Operative dentistry .2nd ed Delhi, CBS publishers and distributors :2008.

Fejerskov . Dental caries disease & management ; 2nd edition, blackwell publication:2005

Soben Peter. Essentials of Preventive & Community Dentistry. 3nd edition, Arya Publishing house :2005

Pinkham . Pediatric Dentistry ; 4th Edition, 2005 .Mc Donald . Dentistry for Child & Adolescent ; 8th

Edition, Mosby pub. : 2005.Stewart R E . Pediatric Dentistry; 1st Edition, 1985.

REFERENCES

Newborn E. Cariology. 3rd ed. Chicago: Quintessence publishing co, Inc, 1989 Axelsson . Diagnosis of Caries .Quintessence Pub. Co., 2000.Nikiforuk G .Understanding Dental caries: Vol 1 , 1985.Hidden and incipient carious lesions : DCNA 2005 ; 49.Bo Krasse. Caries risk ;Quintessence publication: 1982.Ricketts DN, Kidd EA, Wilson RF. A re-evaluation of electrical resistance measurements for the diagnosis of occlusal caries. Br Dent J 1995; 178(1):11-17. Thomas CC. Caries detector dye is useful and in diagnosis of dental caries. Dental abstract 2000 vol 45(5) D C Attrill & P F Ashley .Occlusal caries detection in primary teeth: a comparison of DIAGNOdent with conventional methods British Dental Journal 2001; 190: 440 – 443.

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