Caries diagnosis

CARIES DIAGNOSIS & VACCINE

1. DEPARTMENT OF ORAL PATHOLOGY Presented by, Dr.D.Venkatesh kumar 1 st yr pg Caries diagnosis & Caries vaccine

2. Contents INTRODUCTION DEFINTION IDEAL REQUIREMENTS HISTORY METHODS OF DIAGNOSING CARIES TRADTIONAL METHODS ADVANCED DIAGNOSTIC TESTS RECENT ADVANCES CONCLUSION REFERENCES

3. Introduction Dental caries - multi factorial disease of the calcified tissues of the teeth, characterized by demineralization of the inorganic portion and destruction of the organic substances of the tooth. progressive bacterial damage to teeth. one of the most common diseases - 95% of population & still a major cause of tooth loss.

4. DIAGNOSIS Diagnosis is the art or act of identifying a disease from its signs and symptoms. The word diagnosis (plural, diagnoses) - Greek ‘‘ dia ’’ meaning ‘‘thorough’’ and ‘‘gnosis’’ meaning ‘‘knowledge’’.

5. IDEAL REQUIREMENTS 1. Accurate. 2. Sensitive. 3. Specific. 4. Reproducible. 5. Reliable. 6. Not transfer S. Mutants from affected area to unaffected area 7. Cost effective

6. HISTORY OF PATIENT History Factors Risk Increasing (Observational) Age Childhood, Adolescence Senescence Gender Women at slightly greater risk Fluoride exposure No fluoride in public water supply Diet Sugar containing foods, sticky foods Smoking Risk increases General Health GIT disorders & H/O Radiation Medication reduce salivary flow

7. METHODS FOR DIAGNOSING CARIES   VISUAL EXAMINATION. TACTILE EVIDENCE OF CARIES-PROBING TOOTH SEPARATION. DENTAL FLOSS. RADIOGRAPHIC CONVENTIONAL XERORADIOGRAPHY MODIFIED RADIOGRAPHIC TECHNIQUES IOPA BITEWING

8. INTRAORAL CAMERA ELECTRIC RESISTANCE ( CONDUCTANCE) OPTICAL DETECTION DYES

9. RECENT ADVANCES TERAHERTZ IMAGING OPTICAL COHERENCE TOMOGRAPHY CARIE SCAN ULTRASONIC IMAGING

10. TRADITIONAL METHODS VISUAL EXAMINATION : E ncompasses – criteria - detection of white spot, discoloration and frank cavitation . Examiner detects caries - change in translucency of enamel. Clean, dry and well-illuminated field. ICDAS – INTERNATIONAL CARIES DETECTION AND ASSESSSMENT SYSTEM - improved version of visual methods.

11. DISADVANTAGES

12. T ACTILE EVIDENCE OF CARIES: EXPLORER Determining roughness or softness of tooth surface with a sharp explorer . Both penetration & resistance to removal of an explorer tip - evidence of demineralization The explorer can be of different varieties such as: Right angle probe Back action probe Shepherds crook Cow horn with curved ends

13. Probing - criticized & questioned May transmit cariogenic bacteria. May produce irreversible traumatic defects in potentially re- mineralizable enamel. Mechanical binding of an explorer tip in a fissure - other causes like: Shape of fissure. Sharpness of explorer Force of application Path of explorer placement

14. TOOTH SEPARATION Electively and temporarily separating approximal surfaces - examine them A djunct to C & R examination It has good potential in validating other diagnostic methods of detecting approximal lesions. The method requires a second brief visit after a period of 3-7 days . LIMITATIONS : Requires second visit Discomfort to patient.

15. DENTAL FLOSS Pickard(1961) - use of dental floss for detection of caries. If its shreads one can suspect a proximal cavity. Disadvantage - overhanging restorations- proximal side –same features.

16. RADIOGRAPHIC TECHNIQUES 2 dimensional picture of 3 dimensional object. Net mineral loss must exceed at least 40-60% - radio graphically visible. IOPA - primarily used for detecting changes around roots & in b/n teeth Paralleling technique is superior to bisecting technique Visualization of approx 3 teeth CONVENTIONAL RADIOGRAPHS

17. BITEWING To detect INCIPIENT CARIES AT CONTACT POINTS 8 teeth in one radiograph can be visualized Regarding… incipient carious lesions, cervical margins of restoration , alveolar crest height , pulp chambers.

18. Problems encounter with radiographic methods Overlapping of proximal contacts . Gagging sensation False diagnosis due to overestimation- increase lesion depth - change -angulations. Radiolucency cannot be judged - because of caries / resorption Superficial demineralization - buccal & lingual surfaces - imaged - approximal caries. Cervical burnout may mimic cervical caries.

19. Radiographic interpretation of occlusal caries limitations 1. Caries in enamel - difficult - superimposition of enamel over the fissures. 2. Lesions involving buccal grooves of molars are superimposed over the occlusal area - simulate occlusal lesions . 3. A thin radiolucency appears at the DEJ in occlusal caries , which is missed -considering - normal difference of radiolucency in enamel & dentin.

20. Problems in diagnosis of secondary caries Lesions - occlusal surface, b/n restoration & tooth cannot be visualized until - advanced stage. It is often difficult to differentiate between secondary caries & caries which have been left during restoration (residual caries).

21. XERORADIOGRAPHy It is complete dry non chemical process Image is recorded on aluminium plate coated -layer of selenium particles. Selenium particles - uniform electrostatic charge & stored - conditioner. When X‑rays are passed – film selective discharge –Se particles. POSITIVE IMAGE LATENT IMAGE DEVELOPMENT C.F.Carlson 1937

22. XERORADIOGRAPHY Later the procedure, Al plate - cleaned and used again . Xeroradiography is twice as sensitive as conventional films and a phenomenon of 'Edge Enhancement' is possible with this technique. No dark room for developing. No special light source for view .

23. XERORADIOGRAPHY ADVANTAGES Edge enhancement Less radiation Economical DISADVANTAGES Electric charge-film – discomfort to patient Development- 15 min

24. REASON FOR ADVANCES Advantages of early caries detection : Opportunity to monitor caries progression by remineralization . Creates an opportunity for a preventive - outdated “Drill and Fill” approach. New diagnostic modalities allow early lesions of caries to be quantified.

25. Intra oral camera Camera placed inside oral cavity to display Intra oral images on a computer Improved visual access Improved lightening Improved magnification Demonstrate pt needs for treatment

26. MODIFIED RADIOGRAPHIC TECHNIQUES R/F recorded – digital image receptors & enhanced – computer processing. A digital image - image formed & represented by a spatially distributed set of discrete sensors & PIXELS . Receptors-highly sensitive sensors - less radiation exposure than film It is the Image that has been recorded with non-film receptor . DIGITAL ENHANCEMENT

27. Two types of non film receptors for recording digital images : Digital image receptor (DIR)- collects x- rays directly(DDI) Direct digital imaging Scanning device -forming digital images- radiograph (IDI) Indirect digital imaging

28. Direct receptors Direct receptors communicate - computer -electronic cable-transfers data -radiofrequency transmitter. charged couple device (CCD)-connected to computer. CCD is a semiconductor- metal oxides( silicon ) that is coated with x‑ray sensitive phosphorous. CCD is sensitive both to X-rays and visible light.

29. Indirect Receptors Photostimulable phosphor plates (PSP)

30. Advantages Darkroom is not required Instant image is viewed The quality of image is consistent Elimination of the hazards of film development Radiation dose is decreased Capability for teletransmission . DISADVANTAGES High cost of system life expectancy - not fixed Detection of occlusal caries: performed almost equally well. No value in detection of initial enamel lesions / proximal dentinal lesions

31. Made it possible to use automated procedures-overcome- shortcomings-human eye - caries detection. Softwares - developed for automated interpretation of digital radiographs. This technique is based on the “EXPERT SYSTEM” COMPUTER IMAGE ANALYSIS

32. Advantages provide sensitive and objective observation- small lesions possible to monitor the lesion Quantification of small lesions - possible DISADVANTAGES Always need-standardization of exposure geometry Sensitivity is higher but specificity is lesser Time consuming and less economical.

33. SUBTRACTION RADIOGRAPHY PRINCIPLE: Optimally, all unchanged anatomical background structures will cancel and unchanged areas will be displayed in a neutral grey shade in the subtraction image. Areas with mineral loss - darker shades of grey Structured noise is reduced - to increase the detectability of changes in the radiographic pattern.

34. Structured noises are the images , which are not of diagnostic value and interfere in routine interpretation of radiographs. Disadvantages: Inability to produce correct projection geometry Improper density and contrast

35. CONE BEAM CT C hief limitation - conventional intra-oral radiographs - (2D) image- structure (3D). CBCT - three dimensional imaging(3D) system This method - constructs radiographic slices, cross- section through teeth

36. Slices - viewed for radiolucencies Specifically useful for the detection of RECURRENT CARIES. CBCT - utilizes least amount of radiation- cost effective for patients. Radiation dose = quarter panoramic image / five dental x rays- high-speed film.

37. OPTICAL DETECTION Principle : carious lesion - low index- light transmission, - appears- dark shadow. Evolved due -growing concerns about ionizing radiations Vaarkamp et al (1997): early enamel lesions can be detected. Fiberoptic - halogen lamp + rheostat ------> light of variable intensity FIBRE OPTIC TRANSILLUMINATION

38. For examination, tip - probe - Embrasure immediately beneath the contact point Shadow - beneath -marginal ridge may be evident - break - integrity -enamel This can detect Enamel– crazing, cracks in tooth.   Interproximal caries

39. ADVANTAGES No hazards of radiations Simple and comfortable- patients Lesions, which cannot be diagnosed R/F Not time consuming . DISADVANTAGES Permanent records - difficult to maintain Difficult to locate the probe in certain areas Only useful for approximal and occlusal lesions not quantitative – NOT useful - caries monitor over time High level of inter and intra examiner variability

40. DIGITAL IMAGING FIBER OPTIC TRANSILLUMINATION DIFOTI -overcome shortcomings of FOTI - FOTI - digital CCD camera. FOTI - proximal and occlusal caries DIFOTI - Both incipient & frank caries – all tooth surfaces It was developed by S chneiderman et al 1997

41. Mechanism: Light propagates -optical fiber - tooth . During Transillumination , - area of demineralization scatter light and incipient lesions appear darker - image. Image - digital electronic CCD camera - eliminate inter/intra examiner variability. Image - analyzed -computer. It can not only detect the early lesions but also monitor -progress of lesion.

42. Advantages Detect fractures, integrity - restorations Instant images – obtained Non invasive detects early & hidden caries No film, film processing LIMITATIONS It cannot indicate - depth of lesion penetration. Cannot be used to detect caries in subgingival area. Cannot image -tooth completely covered by restoration

43. QUANTITATIVE LASER OR LIGHT – INDUCED FLUORESCENCE Quantitative assessment of dental caries. 1st investigation- Bejelkhagen & Sundstrom (1981). In QLF method, tooth - irradiating - visible light - blue green region.

44. Tooth- fluorescent green - Demineralized - as dark spots. Fluorescent filtered images - CCD video camera. Data - collected, stored and analyzed by custom-made software. Clinical applications : clinical trials, patient education, and preventive clinical practice. Monitor demineralization of teeth. early secondary caries beneath restorations

45. Advantages: Limitations: Cannot discriminate b/n enamel lesions & dentin Cannot differentiate b/n decay, hypoplasia & unusual anatomical features Incipient lesions - detected. Sometimes red fluorescence- porphyrins - indicates presence of dental biofilm, or high caries activity Quantification – enamel lesions -depth -400 µm

46. LASER FLUORESCENCE METHOD Measures the fluorescence - tooth that is induced after light irradiation to discriminate between carious and sound enamel. DIAGNODENT: It is a portable diode laser device. It operates- infra red light from a diode laser light- transmitted - descendent optic fiber to a hand-held probe- surface of tooth

47. Emitted fluorescence measured- photo-diode detector. control unit displays digital representation - wavelength detected The signal is finally processed & display an integer b/n 0 and 99 and also acoustically.

48. If the reading is 21-100 - definite area of decay - require operative intervention. 5-25: initial lesions 25-35: early dentinal caries > 35: advanced dentinal caries Clinical applications: The device performs best on smooth surfaces and in occlusal pits and fissures

49. Advantages High reproducibility High sensitivity & specificity May detect lesions -not apparent on R/F Easy to use LIMITATIONS Can detect enamel demineralization but cannot differentiate b/n decay, hypoplasia, or unusual anatomical form Diode laser –cannot reach deep dentinal areas- differentiate b/n superficial & deep dentinal caries

50. DIAGNODENT PEN Improved version - diagnodent . It has improved tips (less prone to breakage) & new small tip for detection of interproximal caries. Better digital display and audible caries indicator are also included .

51. DYE PENETRATION METHOD :   In caries diagnosis, qualitative examination- prior requirement. observation of coloured dye signifies presence of caries. Dyes should fulfill the following criteria :

52. Dyes - carious enamel ' Procion ' dyes stain enamel - irreversible and acts as a fixative.  ' Calcein ' dye makes a complex with calcium- bound to the lesion. 'Brilliant blue‘- enhance the diagnostic quality of FOTI

53. Dyes - carious dentin carious dentin - two layers‑ outer layer-soft -cannot be remineralized & inner- hard & can be remineralized . 0.3% Basic Fuschin in propylene glycol – demineralized dentin which the collagen is stained- inner one remains unstained – outer dentin removed clinically. The staining by the dye is the result of denaturation of collagen .

54. Basic Fuschin dye – carcinogenic- replaced- acid red & methylene blue. Methylene blue is also slightly toxic so acid red is preferred. Acid red is specific and more reliable

55. MODIFIED DYE PENETRATION METHOD 'The Iodine penetration method' -enamel porosity -incipient caries- Bakhos et al. (1977). Potassium iodide - specific period of time - well‑defined area of enamel - excess is removed. The iodine, which remains in the micropores , is estimated and that indicates the permeability of enamel. 

56. TERAHERTZ IMAGING Terahertz pulse imaging (TPI) - new imaging technique Terahertz freq 10 12 HZ / wavelength of 30µm. Although, the TPI - new technique - imaging caries -a hope in future it could indicate caries in all areas of teeth For an image to be obtained by terahertz irradiation the object is placed in the path of the terahertz beam. RECENT ADVANCES

57. Also possible - record terahertz images - CCD detector . Longitudinal sections through 3 teeth have demonstrated increased terahertz absorption by early occlusal caries Work in progress to image intact teeth with early carious lesions.

58. Advantages : Disadvantages : TPI system uses only micro-watts - non-ionizing more safer than those employing X-rays Adverse thermal effects are unlike Relatively expensive Needs more researches to make it possible to be used in OC

59. OPTICAL COHERENCE TOMOGRAPHY (OCT) Method of measuring transparent and semitransparent structures Based on interference of light- & measures -light scattering OCT can be defined as optical infer metric technique to create cross sectional images of scattering media.

60. OPTICAL COHERENCE TOMOGRAPHY (OCT) OCT provides high resolution - imaging of incipient caries. With OCT, early lesions can be readily identified as regions of high light backscattering with depth into the enamel as compared to healthy sound enamel.

61. Clinical applications : Imaging - interproximal & occlusal caries Early root caries Advantages quantitatively monitor- mineral changes - lesion. Can determine depth of the lesion. Disadvantages Regions of high light backscattering - not related to caries development can lead to false positive results .

62. CARIESCAN Cariescan offerrs earliest possible detection of caries. Unique device provides accurate & repeatable data to monitor caries over time. Mechanism: It utilizes AC impedance spectroscopy (ACIST). The impedance- healthy tooth -very high due to relatively low ionic conduction.

63. As a tooth demineralizes – increase- larger pores. As lesion progresses, pores -connect & tooth becomes a mix of high & low conductive parts -impedance decreases. As the decay progresses, dentin involved- impedance falls further. As a result the sensitivity and specificity of the ACIST system in distinguishing these different stages is very high .

64. 0-100 scale 0-50 = low probability of caries 51-90 = medium probability of caries 91-100 = high probability of caries Used for the detection of EARLY AND HIDDEN LESIONS 92.5% accurate in detecting both sound and carious teeth, minimizing false positive or false negative results.

65. ADVANTAGES Highest proven accuracy of all caries detection methods No ionizing radiation risk Easy to record and compare progress CONTRAINDICATIONS : patients with cardiac pacemakers fitted. DISADVANTAGES : It cannot be used to assess: Secondary caries Integrity of a restoration Dental root caries It should not be used when tooth surfaces - plaque and or other debris.

66. ULTRASONIC IMAGING Introduced - detecting early carious lesions - smooth surfaces. PRINCIPLE : The demineralization of natural enamel is assessed by ultrasound pulse echo technique It is observed -definite correlation b/n mineral content of lesion & relative echo amplitude changes.

67. Ultrasonic probe - longitudinal waves - surface - tooth & also serves the function of receiving the Waves. Application: To find lesions on smooth surfaces & detecting RECURRENT CARIES Sound wave with frequency 1.6 to 10 MHz Initial white spot lesions ─ no or weak echo Cavitated lesions ─ echo with high amplitude To be continued………