Dr:.Jayalwmar TR~a€lef

IntroductionIt is an infectious microbial disease of the teeth that resultsin localized dissolution and destruction of the calcifiedtissues. It is the most prevalent chronic disease affectingthe human race. Once it occurs, its manifestations persistthroughout life even though the lesion is treated. Thereare practically no geographic areas in the world whoseinhabitants do not exhibit some evidence of dental caries.It affects persons of both sexes in all races, all social-economic straits and every age group. It usually beginssoon after the teeth erupt in the oral cavity. Persons whonever develop carious lesions are designated "caries free.No satisfactory explanation of their cario resistance hasbeen found.

Hundreds of dental research investigators for more thancenturies have studied various aspects of dental caries.Despite this extensive investigation, many aspects ofetiology are still under observation and efforts atpreventions have been partially successful.

Etiology Factors Of Dental Caries

Keys Diagram

Micro flora: Acidogenic bacteria that colonize thetooth surface.

Host: quantity and quality of saliva, the quality ofthe tooth, etc.

Diet: intake of fermentable carbohydrates,especially sucrose, but also starch

Time: Total exposure time to inorganic acidsproduced by the bacteria of the dental plaque.

Diagnosis Of Dental Caries

Methods of caries detection in vivo (clinically)

1. Visual examination

2. Tactile examination

3. Radiographs - conventional, digital andxeroradiography

4. Fibre optic transillumination

5. Optical methods - Fluorescence, light scattering

6. Electronic resistance measurements

7. Ultrasonics

8. Dyes

9. Visible luminescent spectroscopy

10. Optical caries monitor

11. Laser luminescence

12 Endoscopic methods

13. Diagnodent.

Modified Keys Diagram Invitro: (forresearchpurposes)

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1. Chemical analysis

2. Cross-sectional microhardness

3. Polarized light microscopy

4. Traditional transverse microradiography

5. Microphobe analysis

6. Iodine absorbitometry

7. Longitudinal microradiography

8. Surface micro hardness

electron hole pairs are formed. The electrical chargecreated is captured, amplified, converted, and displayedas an image.

Storage phosphor screen technology:

This screen contains embedded phosphorus crystals thatluminesce when stimulated by light at a specificwavelength. The energy released results in a latent imagethat is stored in the screen rather than on conventionalfilm.

Xeroradiography:

Xeroradiography is a technique that uses modifiedxerographic copying techniques to record imagesproduced by diagnostic x-rays. They have on additionalfeature called "edge enhancement" effect. Due to thesesmall structures and areas of subtle density differences aremade more visible. They contain uniformly chargedselenium plates.

Fibre optic transillumination:

It has been designed for the detection of approximalcaries. (Freidman and Marcus, 1970). The principle oftransillumination is that there is a different index of lighttransmission for decayed and sound tooth structure.Illumination is delivered by means offibre optics from thelight source to the tooth structure. The resultant changesin light distribution as the light traverses the tooth are thenrecorded as an image for analysis.

The use ofFOTI has been proved to be effective speciallywhen used in the anterior region. The usage in theposterior region is associated with some difficulty. It hasbeen thus advocated as an adjunct to visual andradiographic methods. Dyes have also been used forenhancement of visualization. Comparative studies ofFOTI have led to mixed results in caries diagnosis becauseof high level of intra and inter-examiner variability.

Quantitative light induced fluorescence:

Light scattering is a measure of the observed whiteness ofa carious lesion that can be correlated with the degree ofmineral loss (Angmar-Mansson et al., 1987) and that theremaining small mineral particles in the lesion areembedded in water than in mineral-rich sound enamel.No threshold for the detection of white spot lesions usinglight scattering techniques has been determined, butlesions with a depth of only 25!lm have been measured invitro. The restriction of light scattering for cariesdiagnosis to smooth surfaces constitutes a significantdrawback of this technique, although research iscontinuing to develop light-induced fluorescence todetect occlusal caries. (Angmar-Mansson et al., 1998).

Visual examination:

This is called the European system of examination ofdiagnosing caries and requires about 10 minutes persubject.

The visual examination of caries encompasses the use ofcriteria such as detection of white spot, discolouration andfrank cavitation. Visual examination on its own andwithout aids can be quite unreliable. An examiner detectscaries by observing the change in translucency of enamel.This is done by observing a clean, dry and well-illuminated field.

Tactile examination:

The explorer and the floss to certain extent have been usedfor the tactile examination ofthe tooth.

The explorer can be of different varieties such as

1. Right angle probe [No.6]

2. Back action probe [No. 17]

3. Shepherds crook [No.23]

4. Cow hom with curved ends [No.2]

Radiographs:

Though conventional radiographs [Bitewing and 10PA)are most frequently used for the detection of caries, theyare associated with many drawbacks.

1. It presents a 2-D image of a three-dimensionalobject.

2. It may cause overlapping of the teeth due to faultyangulations.

3. The use of bisecting technique sometimes may alsomiss the initial lesion.

4. Another aspect is that net mineral loss must exceed atleast 20-30% in order to be radiographically visible.

Direct digital radiography:

Currently, digital radiographic images may be obtained byvideo recording and digitization of a conventional filmradiograph or by direct digital radiography. The firstdigital dental radiograph introduced in dentistry is calledradiovisiography (RVG). According to Wenzel (1998),the sensitivities are relatively high for detection ofocclusal lesions into dentin with a false-positive fractiont05%to 10%.

CCD Technology:

The CCD is usually made of a chip of pure covalentlybonded silicon atoms. When the chip is exposed to visiblelight or x-ray radiation, bonds are broken, and charged

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Diagnodent:

A new method of caries detection is diagnodentintroduced by KaVo, Germany in 1999, which is based onthe principle of fluorescence. It enables to recognize at anearly stage pathological changes that prove difficult oreven impossible to detect, initial lesions,demineralization, changes affecting the tooth enamel.The incidence of fissure, approximal and residual cariescan be identified. It is also useful in determining theamount of carious involvement / decalcification indifferent areas ofthe same tooth.

Manufactures selected cut-off points

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Electrical conductance measurements:

The idea of an electrical method of caries detection datesback to 1878 when it is believed to have first proposed byMagitot. The theory behind the use ofERM is that soundsurfaces should posses limited or no conductivity whereascarious or demineralized enamel s.hould have ameasurable conductivity that will increase with increasingdemineralization (Huysmans et al., 1997). At locationswhere the pore volume of the enamel is larger, theelectrical conductance increases considerably.

When a potential of less than one volt is applied, theresistance of above 6,00,000 ohms indicates that tooth iscaries free. A resistance below 2,50,000 ohms indicatesthat caries involving the dentin is present.

Visible luminescent spectroscopy:

The visible emission spectra and the fluorescent lifetimesfor decayed and non-decayed regions of teeth differ.Quasi-monochromatic light from a tungsten sourcedispersed with a grating monochromator was focussed onthe teeth. Although, how exactly it works is unknown, thisis a non-radiological, non-invasive clinical method todetect dental caries.

Optical caries monitor:

This is an instrument, which quantifies incipient smoothsurface lesions. It has been seen that in vitro lesions reflectmuch more light than sound enamel.

Endoscopic methods:

Endoscopic methods of caries detection are potentiallysensitive diagnostic tools, which involve the use ofendoscopic methods. These give a magnified image ofthecarious lesion to be viewed. Initial studies on the potential

benefits of endoscopic examination, either with whitelight (VMV) or with filtered fluorescen~e excited by ablue curing light (VFF) , have been performed byLongbottom and Pitts.

Ultrasonics:

Ultrasonics is the use of sound waves for detection andthis offers considerable potential as a diagnosticinstrument. Ultrasonic imaging was introduced by Ng etal. (1988) as a method for detecting early caries in smoothsurfaces.

With the use of this instrumentation, sonic velocity andspecific acoustic impedance can be determined for thedentin and enamel as well as for the soft tissue and bone.This method can be readily adapted to easily accessibleareas but not for interproximal surfaces. Its main use,therefore, has remained invitro testing studies".

Dyes:

Dyes can facilitate caries detection and visualization. Anabsorbing dye can be introduced into lesions, enhancingthe colour contrast between the lesions and thesurrounding tooth structures. Calcein, Procion, Zyglo ZL-22, are used in the detection of enamel caries and Fuschin,Acid red system,9-aminoacrdine( disinfectant used inpulp canal treatment, less toxic and high bactericidalactivity) and Povidine- Iodine detect dentinal caries.

Ultraviolet illumination:

Ultraviolet (UV) light has been used to increase theoptical contrast between the carious region and thesurrounding sound tissue. The natural fluorescence oftooth enamel, as seen under UV illumination, is decreasedin areas of less mineral content, such as in caries lesions,artificial demineralization, or development defects(Alfano and Yao, 1981). The caries lesion appears as adark spot against a fluorescent background.

Summary And ConclusionThe boundaries of caries diagnosis and caries interventionare changing .Dentist currently use visual, tactile andradiographic information to detect relatively advancedchanges in the dental hard tissues .the clinicalmanagement of dental caries has been primarily directedat the treatment of the consequences of the diseaseprocess by placing restoration and not at curing the��������

Using emerging technology, dentist will be able to detectincipient dental caries (demineralization ) at an earlierstage than the clinically visible white spot .Dental caries isa dynamic process ,which in its early stages is reversibleand even in its more advanced stages can be arrested:

The widespread use of fluorides has dramatically reducedthe prevalence of dental caries and the rate of progressionof the carious lesion. These changes permit dentist toadopt to more conservative management strategiesdirected at prevention and cure of dental caries.

References1) Cariology, 3rd edition ernest new bum. Dmd,phd2) Pickards manual of operative dentistry, 8th

edition3) Diagnosis and risk prediction of dental

caries, Per axelsson4) Risk markers for oral diseases, vol 1, dental

caries edited by n. W .johnson5) Essentials of dental caries, the disease and its

management

6) A colour atlas of operative dentistry.j r grundy7) A text book of oral pathology, 6th edition

william .g. Shafer.8) oral diseases. roderick a cawson, william h

binnie, andrew w barejohn right.9) Essentials of preventive and community dentistry

soben peter.10) Sturdevant's art and science ofoperative dentistry.

Fifth edition11) The dental clinics of north america, cariology

James12) Clinical trends in the diagnosis and the treatment of

dental caries. Steven steinberg dds

STATE AWARDS WON BY IDA-DAVANGERE BRANCHAT 39TH KARNATAKA IDA CONFERENCE HELD AT MYSORE

- Best local branch- Best local branch Secretary

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