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Caries Diagnosis and Activity Tests
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Contents • • • • •
Introduction Definitions Diagnosis for caries Caries activity tests Conclusion
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Diagnosis of dental caries “The eyes do not see what the mind doesn't know” Diagnosis is to distinguish irregularities and other issues of concern based upon a patient’s examination and interview www.indiandentalacademy.com
Diagnosis: the art or act of distinguishing one disease from another Modern management of caries: based on 3 major components Prevention Control Treatment
A diagnostic method should allow for detection of the disease in the earliest stages and for all pathological changes attributed to the disease to be determined for demineralization and re mineralization. Slow progression of disease, hidden lesions www.indiandentalacademy.com
Objectives of diagnosis: Identifying lesions requiring surgical treatment Identifying lesions requiring non-surgical treatment Persons at high risk for developing caries
Thus diagnosis is done using: Clinical criteria Tools Newer refined diagnostic tools www.indiandentalacademy.com
The iceberg concept According to WHO the shape & depth of carious lesion can be scored D1 D2 D3 D4
www.indiandentalacademy.com Pitts (1997) – precision of caries diagnosis is illustrated as an iceberg.
• Methods employed for caries detection -capable of accurately capturing at any given point, the manifestation of caries process into dental hard tissues -should monitor definitive changes in manifestations -should differentiae the actual effects -lesion initiation -lesion behavior www.indiandentalacademy.com
Classification (based
on physical properties) Mansson et al
1. X-rays
- IOPA/Bitewings - Radio-visual graph - Digital image enhancement - Digital subtraction radiography - Tuned aperture computed radiography
2.visible light -optical caries monitor -quantitative fiber optic trans-illumination - quantitative light-induced fluorescence
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3. Laser light-laser fluorescence measurement (Diognodent) 4. Electric current -electric conductance measurement -electric impedance measurement
5. Ultrasound –ultrasound caries detector
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Diagnostic tools • Visual & tactile examination • Conventional Radiographs • Digital radiography • Trans-illumination • DIFOTI
• Electronic Conductance Measurement • Diagnodent • Quantitative light fluorescence • Dye Enhanced Laser Fluorescence • Near-IR light imaging • Caries detection dyes • Ultra sound • Video scope • Infrared thermograph
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Visual and Tactile Examination • Visual examination:Mouth mirror, probe(explorer), good light
• Every tooth is dried and examined • Tactile evidence: roughness or softness of the tooth with explorer. :penetration and resistance to removal of an explorer tip.
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Criteria used for visual examination • 0 - no caries • 1-white/brown opacity hardly visible on wet surface/distinctly visible on dry surface
• 2 –opacity visibly distinct with out air drying • 3 – localized enamel breakdown • 4 -cavitation www.indiandentalacademy.com
• Change in colour and translucency in enamel • Lesions that appear chalky white • Break in the enamel surface • Greyish discoloration adjacent to marginal ridge and restorations • Black discolorations(arrested caries) www.indiandentalacademy.com
Visual methods commonly used •
Method used most commonly can detect ( combination of light, mirror and probe) -non cavitated enamel lesions on the smooth and anterior proximal surfaces -clinically detected lesions limited to enamel -dentin lesions with cavitations on smooth surfaces -secondary lesions with cavitations -limitations: cant detect non cavitated lesions in dentin on posterior proximal surfaces www.indiandentalacademy.com
• American method:-softened enamel catches the
explorer tip and resists removal -allows the explorer to penetrate under mild pressure -no tooth drying
• European method:-no probe is used -tooth is dried and a through visual examination • Meticulous clinical visual method:-cleaning, drying, and flossing-to disclose more lesions
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Tooth Separation and Floss • The visual method with temporary Elective Tooth Separation
• The Visual Method with Temporary Elective Tooth Separation and Impression of the approximal lesion
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RADIOGRAPHY parallel Intra oral
• Techniques Extra oral
Bisecting angle
Parallel adv: long source to body distance :less magnification and distortion of images :less over lapping thus providing better interpretation www.indiandentalacademy.com
• Radiographic appearance of the caries: initial enamel- small radiolucent notch advanced lesions-diffuse triangle with base to surface of the tooth-in enamel -appears as triangle with base towards towards pulp
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• **only 40% of the proximal lesions in the outer half of dentin-actually cavitated • 1-4 yrs—progress through enamel • Identification of degree of mineralization in radiograph • Need for more accurate assessment of the speed of caries progress www.indiandentalacademy.com
Impact of technical factors on on the quality of radiographic image • Type of the film used • Density • Contrast • Dark room processing www.indiandentalacademy.com
• ADVANTAGES : – Discloses sites inaccessible to other methods – Detects at early , reversible stage – Depth of lesion can be evaluated and scored by index given by Grondahl et al (1977) – Permanent record – Non-invasive
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Limitations – 2D image of a 3D object – Standardization needed for accurate reproducibility – Does not distinguish between sound, subsurface & cavitated lesions – Subjective – Non cavitated lesions on root difficult to diagnose – Underestimation of demineralization – Proximal caries on the apical 3rd of the restoration may not be detected – Can’t detect buccal/lingual caries – Occlusal caries not seen until it reaches DEJ – Unavoidable hazard ofwww.indiandentalacademy.com ionizing radiation
Xero Radiography • Technique simulates that of photo-copying • Image recorded on aluminium plate with a layer of selenium particles • Xerographic films to record the images produced by Xrays • These are a given a uniform electrostatic charge • X-rays-passes through film-causes the discharge of particles producing a latent image-converted in a processing unit. www.indiandentalacademy.com
• Advantages –edge enhancement -less radiation -economical • Disadvantages –electrical charge may cause discomfort to patients -exposure time varies with thickness of film -process of development cannot be delayed more than 15min www.indiandentalacademy.com
Digital imaging • Principle: works on a CCD which is electronically connected to computer • Image is formed and represented by a spatially dist set of discrete sensors and pixels • CCD-4 major components -x-ray image detection -digitalization -image processing -image display
CCD-is a semi-conductor made of metal oxide silicon coated with x-ray sensitive photons www.indiandentalacademy.com
Charge-Coupled device:CCD Egs: Durr Vista Ray Trophy RVG, Sens-A-Ray, Visualix/Vixa
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• Adv -no dark room processing -greater exposure latitude -reduced radiation dose -capability of teletransmission -image manipulation -ability to enlarge specific area • Dis -adv-high cost of the system -life expectancy is not fixed
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Digora image plate system Direct digital system-1989 Radiographic information is captured on a phosphorous storage screen Components-read out device -image plate -computer
Process takes 30min Image enhancement is possible
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Computed image analysis • Trophy 97 system- AI system (Logicon caries detector) • Applications have been developed to support the interpretation of carious lesions • Assessment and recording of lesion size • Unique histologic database
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• Adv –sensitive and objective observation of smaller lesions -possible to monitor the lesions -quantification of small lesion is possible • Dis adv-need for standardization of exposure geometry -high sensitivity and low specificity -time consuming -expensive www.indiandentalacademy.com
Digital subtraction radiology • principle:Optimally, all unchanged anatomical background structures will cancel, and changed areas will be displayed in a neutral grey shade in the subtraction image. •
Areas with mineral loss appear in darker shades of grey, and areas of gain appear lighter than the background.
• Dis adv: -inability to produce the same geometry -density and contrast are not proper www.indiandentalacademy.com
Advantages -broader latitude of enhancement -reduced in radiation dosage
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Tuned aperture computed tomography • It constructs radiographic slices, cross sections, through teeth-viewed for radiolucencies • Images brought to a 3D image-pseudohologram
• Used in early caries and secondary caries detection www.indiandentalacademy.com
FIBRE OPTIC TRANSILLUMINATION • Principle: decayed matter scatter light more strongly-lower index of light transmission • Vaarkamp(1997)- early enamel caries • Verdonschot et al(1991)-useful for enamel caries • Compressed air used- better visualization • .
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• When light passed through teeth -healthy enamel allows light pass through where carious enamel don’t
• Used in the anterior and the premolar region • Used to detect-enamel crazing -cracks in the tooth
Disadvantages-high level of inter and intra examiner variability www.indiandentalacademy.com
DIFOTI(DCNA 2005) • Components: – 2 handpieces – Disposable mouth piece – Foot control for selecting the images – Computer
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• Mechanism: light propagates from optical fiber to the tooth surface-the area of demineralization scatter light and appear dark • This image is acquired through CCD camera-and the lesion can be monitered
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Correct placement of proximal mouthpiece.
 Position the hand piece.
Image review
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ADVANTAGES Doesn’t need ionizing radiationInstant images for comparison to evaluate any changes Non invasive early caries ,hidden caries no film, film processing, mounting, and storage. Difoti more sensitive than conventional radiographs detect fractures, integrity of www.indiandentalacademy.com amalgam , composite restorations
 Caries beneath old amalgam restoration
Limitations: Cant determine the depth of lesion Learning curve required White spots can be mistaken for cavitations
www.indiandentalacademy.com Interproximal caries
Optical Caries Monitor • Consists of -light source -measuring and reference points -detection part • The scattering co-efficent values were corelated with histological lesion depth • Used for Quantification of caries lesions on smooth surfaces
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ELECTRICAL CONDUCTANCE (FIXED FREQUENCY) METHOD • 1st proposed by Magitot in1878 • 1st described by Pincus in 1951-became popular in 1980’s • Principle: sound enamel has high resistance to current flow -carious enamel-porous filled with saliva has low resistance and high conductance Conductance increases as lesion progress • Meters can be calibrated to depth and extent www.indiandentalacademy.com
• Circuit –cord attached to a probe which is placed on the tooth-PT holds it to complete the circuit • The electrical conductance between the fissure and area of high conductance are converted to ordinal scale • Examples – Vangaurd Electronic Caries Detector (Massachusetts manufacturing corp.) – Caries meter L (G-C international corp.)
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• Vangaurd – 0 to 9 • Indicators for Caries L meter are 4 coloured lights
(DCNA, 1999) – – – – – –
Green- No caries Yellow- Enamel Orange- Dentin caries Red - Pulpal involvement Recent systems Electronic caries meter/ Monitor (ECM- LODE, Netherlands) – Caries Meter L (Onuki Dental, Japan) – ECM II (LODE) –Min of 7.5 L/Min(air)
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Indications: –
Pit and fissure caries
–
Failure of fissure sealants
Drawbacks –
results vary due to size of tip used
–
Results depend on the type of current used
–
Teeth should be dry False + results:
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Immature teeth
–
Cracks in enamel www.indiandentalacademy.com
Optically based caries detection methods • Enamel fluorescence- Benedict 1928 • principle :Electrons of lower energy status are moved to a higher status-when they fall back to the orignial level-energy is emitted in the form of light. • Nature of fluorescence is dependent on the incident light -near UV—blue -blue green—yellow and green -red or near infrared—red www.indiandentalacademy.com
• Chromophores causing fluorescence(organic components) blue—Ditrosyine yellow—protenitic chromophores red—protoporphyrin(bacterial breakdown) • Demineralization of dentinal hard tissue(enamel, dentin) results in loss of autofluorescence
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Light interacts with dental hard tissues in following ways – 1. photon reflected by material 2. scattered several times in medium 3. transmitted right through medium 4. absorbed - transformed into heat 5. absorbed - fluorescence
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Mechanism for Loss of autofluorescence • The light scattering in the lesion causes the light path to be much shorter than in sound enamel • The light scattering in the lesion acts as a barrier for the excitation of light to reach dentin • change in the molecular environment of the chromophores • Proteinic chromophores are removed by the caries process. www.indiandentalacademy.com
Diagnodent device • Near-infrared fluorescence • Hibst and Gall (1998) – red light (638-655nm) induced fluorescence could differentiate bet sound and carious tooth tissue. • Kavo Diagnodent – based on studies by Hibst and Gall – laser-based instrument – detection, quantification of DC on smooth and occlusal surfaces www.indiandentalacademy.com
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• Light from Diode laser (wl=655nm). Light transmitted through descendant optic fibre to hand-held probe – bevelled tip with fibreoptic eye. • Organic, inorganic molecules absorb light – fl occurs within IR spectra. • Emitted light collected through tip, passed to photo-diode detector. Back-scattered, short WL ambient light absorbed by bandpass filter. www.indiandentalacademy.com
• Signal processed and displayed as an integer bet 0 and 99. • To collect fl from max extension of carious lesions on occlusal surfaces – instrument to be tilted around measuring site – tip picks up fl from slopes of fissure walls. • Lussi et al (2001) – good to excellent sensitivity, excellent reproducibility www.indiandentalacademy.com
Mech of diagnodent device
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0 and 99 and adjustable sound Readings (Tam & McComb, J Can Dent Assoc, 2001): 5-25: initial lesions 25-35:early dentinal caries > 35: advanced dentinal caries
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Factors influencing the outcome of the measurements • Presence of plaque, calculus and/or staining on the tooth • the degree of dehydration of tooth surface • For measurements on occlusal surfaces, it is also of great importance that the tip is tilted forwards and back in the fissure for all surfaces to be scanned. www.indiandentalacademy.com
Advantages
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limitations –Not differentiate between decay , hypoplasia, or unusual anatomical form. – IMP: quantitative measurement – Better accuracy in detection of dentinal caries – Cant diff bet active and inactive lesions –Sensitive to stains, deposits , calculus. Tooth should be clean and dry – Accuracy affected by existing restoration or fissure sealants
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Kavo prophyflex
QUANTITATIVE LASER/LIGHT FLUORESCENCE Bejelkhagen & Sundstrom (1981) Mechanism argon laser-488 nm Xenon arc lamp – 370 nm
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Tooth appears yellowgreen Demineralized areasdark ADVANTAGES: Incipient lesions – 25 Οm De Josselin De Jong (1992)-determines amt of mineral loss Monitor changes in lesions Red fluorescenceplaque, leaky margins www.indiandentalacademy.com
FUTURE ASPECTS(DCNA 2005) – active lesions detected
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LIMITATIONS: On accessible smooth surfaces only Lesion depth of about 400 Âľm Cant discriminate between enamel & dentin lesions Not suitable for dentin demineralization Cant differentiate bet decay , hypoplasia Wet/dry state, presence of plaque, calculus ambient light, daylight or office light www.indiandentalacademy.com
Dye Enhanced laser fluorescence • Absorbing dye introduced-enhances the color contrast between diseased and healthy tooth • Dyes used:- procoin dyes—stains enamel lesions-irreversible-reacts with OH and NH2 - Calcein dyes ZL-22 penetrates micro pores, and areas of white spots • To enhance FOTI-10% brilliant blue • Other dyes- Fluorol 7Ga -pyrromethane 556 www.indiandentalacademy.com -sodium fluorescein
Dyes used for caries diagnosis • Dyes should be -safe for intra-oral use -stain the tissues that are diseased -should be easily removed • Dyes used for enamel- Procoin -calcein-reacts with calcium and bounds to the lesion -brilliant blue-used with FOTI www.indiandentalacademy.com
Vista red, Vistadental
• carious dentin-2 layers -outer layer soft and decalcified, cannot be remineralised -inner layer, hard ,can be remineralised
• Dyes used- 0.5% basic fuchsin in propylene glycol outer layer-denatured collagen is stained inner layer-not stained • Replaced by-Acid red -methylene blue www.indiandentalacademy.com
• Silver nitrate • Methyl red • Alizarin stain • Modified dye penetration Iodine penetration-measures enamel porosity of incipient caries lesions-Bharkos(1997) • KI-to effected enamel for specific time and excess is removed-remains is estimating indicating porosity or caries enamel www.indiandentalacademy.com
IMAGING WITH NEAR-INFRARED LIGHT (Daniel Fried, DCNA, 2005) PRINCIPLE : Enamel is highly transparent in the near infrared (NIR), demineralized areas appear dark due to attenuation DISADVANTAGES : FOTI, QLF, Diagnodent
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EQUIPMENT InGaAs focal plane array - operates from 1000-1600 nm Low cost CCD camera - 830 nm- not very high contrast as with 1310 nm
TWO SETUPS For interprox lesions For occlusal lesions
LIGHT SOURCES NIR laser diodes Tungsten-halogen lamps Superluminescent Diodes (SLD)uniform illumination, better images due to lack of laser speckles
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ADVANTAGES: Lesion more clearly seen than with bitewing Better image contrast at NIR wavelengths than by X rays Can differentiate from stains, pigmentation, fluorosis & demineralization Thickness of 6.75 mm Can examine defects, cracks in enamel www.indiandentalacademy.com
Can detect incipient lesions not seen in radiographs
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Detection of subsurface decay hidden under the enamel.
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Endoscope /video scope • Based on fluorescence of blue light(400-500 nm) • Viewed with specific broadband gelatine filter- white spot lesions appear darker • White light-with out filter-white light endoscopy • Helps in detecting small carious lesions • Video camera mounted on custom-made metal mirror holder-Image of the enamel surface can be viewed on the screen—videoscope www.indiandentalacademy.com
• Advantages -provides a magnified image -clinically feasible • Disadvantages-requires drying and isolation of teeth -time consuming -expensive www.indiandentalacademy.com
Ultrasonic Imaging • Demineralization of enamel-ultrasound pulse echo technique • Definite correlation between mineral content of the body and relative amplitude changes • Used for imaging smooth surface caries • Ultrasonic probe sends longitudinal waves on to tooth surface and receiving the waves • White spots,initial enamel lesions-weak surface echo • Visibly cavitated lesions-high amplitude echo • Alternative to radiographs-proximal lesions www.indiandentalacademy.com
Infra Red Thermography (jou. of dental reas 2004)
• Principle:thermal radiation travels in form of waves and • • • •
is possible to measure changes in thermal energy when fluid is lost from the lesion by evaporation. Tech –Kaneko et al(1999) Proposed for determining the lesion activity rather than for detecting absence or presence of caries. This system—indium thermal sensors which can detect thermal changes in order of 0.02 Source to sensor distance is 20cm and time taken to capture data is 2min www.indiandentalacademy.com
• Limitations –not used intraorally because relation to variation to temp occurs due to resp and evaporation from other oral surfaces • Source to specimen distance not suitable for posterior teeth • Lesion staining may effect heat transfer between sound and carious tooth www.indiandentalacademy.com
OTHER MODALITIES • ACIST – alternating current impedance spectroscopy technique • EFF – Endoscopic Filtered fluorescence method • Magnetic resonance micro-imagery • UV illumination • Visible luminescent spectroscopy • Laser luminescence www.indiandentalacademy.com
Potential new diagnostic modalities (Hall and Girkin j of den res 2004)
• MULTI-PHOTON IMAGING • INFRARED FLUORESCENCE • OPTICAL COHERENCE TOMOGRAPHY • ULTRASOUND • TETRAHERTZ IMAGING www.indiandentalacademy.com
Differential Diagnosis • Cervical burnout • Wasting disease of teeth(attrition, abrasion) • Radiolucent restorations • Hypo plastic enamel • Internal resorbtion • External resorbtion • Match band effect www.indiandentalacademy.com
ABRASION RESTORATIVE MATERIAL www.indiandentalacademy.com
ATTRITION
CERVICAL BURNOUT www.indiandentalacademy.com
Caries Activity Tests • DEFINTION OF CARIES ACTIVITY (Messer, Aus Dent J, 2000)
“the rate at which dentition is destroyed by caries, represented by the sum of the new carious lesions and enlarged lesions per unit time”
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USES OF CARIES ACTIVITY TESTS: To determine the need and extent of preventive measures Indicator of patient cooperation Aid in timing of recalls Determine success of therapeutic measures Motivate and monitor the effect of education programs. To identify high risk groups/individuals Aid in determination of prognosis Precautionary signal to orthodontist www.indiandentalacademy.com
Guide to insertion of expensive restorations
REQUIREMENTS OF A CARIES ACTIVITY TEST (SNYDER) Have a sound theoretical basis Show max correlation with clinical status Be accurate Be simple Inexpensive Take little time Validity Reliability Feasibility
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VARIOUS CARIES ACTIVITY TESTS Lactobacillus colony count test Snyder test Reductase test Buffer capacity test Fosdick calcium dissolution test Dewar test S.mutans level in saliva test-screening tests Cariostat test Caries risk test
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LACTOBACILLUS COLONY COUNT TEST • Hadley - 1933 • number of bacteria in saliva by counting the number of colonies appearing on Tomato Peptone Agar or Rogosa Agar • METHOD – Saliva collected – 1:10 & 1:100 dilution made – Spread on agar plate(0.4 ml) – Incubated for 3-4 days at 37°C – Bacterial colonies counted-Quebec counter www.indiandentalacademy.com
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No of colonies CFU/ML 0-1000
CARIES ACTIVITY Little or none
1000-5000
Slight
5000-10,000
Moderate
> 10,000
Marked
Advantages Disadvantages DENTOCULT-LB www.indiandentalacademy.com
SNYDER TEST • Principle:Measures the ability of microorganisms in saliva to form acids from carbohydrate • METHOD: – saliva sample is collected.(0.2cc pipetted in to media) – Incubated for 72 hrs at 37°C. – Media contains • Bactopeptone
20 gms
• Dextrose
20 gms
• Sodium chloride
5
• Agar
16
gms gms
• Bromocresolwww.indiandentalacademy.com green 0.02 gms
CARIES ACTIVITY
COLOR CHANGE FROM
BLUE/GREEN TO YELLOW High
24 hrs
Medium
48 hrs
Slight
72 hrs
Immune
no change>72 hrs
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Alban’s test • Modification of snyder test • Uses less agar i.e 5ml per tube • Saliva is directly drooled into tubes • Incubated for 4 days at 37deg C • Color change is noted from bluish green to yellow www.indiandentalacademy.com
REDUCTASE TEST • Measures the activity of the salivary enzyme reductase • Sample is mixed with an indicator ie diazoresorcinol • Changes in color measured after 30 secs & 15 mins www.indiandentalacademy.com
COLOR
TIME
SCORE
CARIES ACTIVITY
Blue
15 min
1
Non conducive
Orchid
15 min
2
Slightly conducive
Red
15 min
3
moderate conducive
Red
Immediately
4
Highly conducive
Pink or
Immediately
5
Extremely conducive
white www.indiandentalacademy.com
Buffer Capacity Test • Principle:amount of acid required to lower the ph of saliva to 5 • Method : 0.2cc of stimulated saliva is collected to 4ml of distilled water • HCL 0.5N is added and the amount of acid required to get the ph to 5 www.indiandentalacademy.com
final pH value
Buffer capacity
blue
6.0 or more
high
green
4.5 - 5.5
medium
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yellow
4.0 or less
low
SALIVARY FLOW RATE
more than 0.25
normal
0.1 - 0.25
low
www.indiandentalacademy.com less than 0.1 very low
FOSDICK CALCIUM DISSOLUTION TEST • 25 ml of gum stimulated saliva is collected • Placed in an 8 inch test tube with 0.1 gm of powdered human enamel • Tube shaken for 4 hrs, then again analyzed for calcium content • The amount of enamel dissolution increases as the caries activity increases • DEWARS TEST- www.indiandentalacademy.com pH is measured
MUTANS GROUP OF STREPTOCOCCI SCREENING TESTS • Plaque/toothpick method • Saliva/ tongue blade method • S. mutans adherence method • S. mutans dip-slide methods • S. mutans replicate technique www.indiandentalacademy.com
Plaque/toothpick method • Plaque samples placed in ringers solution • Samples are shaken until homogenized • Plaque suspensions streaked across a mitis salivarius agar plate containing sulphadimetine
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• Aerobic incubation at 37°C for 72 hrs, the cultures are examined under microscope GRADE
COLONIES/10 FIELDS
1
None
2
<8
3
≥8
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Saliva/tongue blade method •
Saliva/plaque samples obtained using tongue blades
•
Inoculated on M.S.B agar for 48 hrs at 37°C
•
Counts of more than 100 CFU are prop to greater than 106 colonies per ml of saliva by conventional methods
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S. mutans adherence method • Saliva inoculated in MSB broth for 24 hrs at 37°C • After growth, the supernatant removed • Cells adhering to the glass examined macroscopically SCORE
NO OF COLONIES
-
No growth expressed
+
Few deposits from 1-10
++
Scattered deposits of smaller size
+++
Numerous minute deposits & more than 20 large deposits (indicates > 105 CFU/ml) www.indiandentalacademy.com
CARIES RISK TEST(C.R.T) • Advocated as a new,quick and effective test • 2 components- CRT bacteria -CRT buffer • CRT bacteria-estimates the no: of cariogenic bacteria in pt’s saliva • CRT buffer- determines the buffer capacity of saliva www.indiandentalacademy.com
• CRT bacteria- two in one dip-in slide test which identifies counts of - streptococcus mutants -lactobacillus • Stimulated saliva is collected and applied to both slides of the dip-in—incubated for 48hrs at 37°C www.indiandentalacademy.com
• CRT buffer- available in the strip form • Change in colour to indicate the buffering capacity-High, Medium, or Low • Takes 5min
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conclusion
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