Recent advances in periodontal diagnosis

First generation:- Conventional probes.
Second generation:- Pressure controlled visual measurement recording probes
Third generation:-Pressure controlled electronic probes with direct computer data capture.
Fourth generation : Aim at recording sequential probing positions along the gingival sulcus.
Fifth generation : Ultrasonic device attached to the 4th generation probe.

1. R ecent advances in periodontal diagnosis 1

2. Perio Files

3. Diagnosis Art of distinguishing one disease from another and determination of nature, location and causes of a disease. Periodontal diagnosis “ Recognizing a departure from normal in the periodontium and distinguishing one disease from another. It must be based on compilation of information from the medical and dental history, from signs and symptoms of disease and from clinical and radiographic examination of the patient.” 3

4. NEED of periodontal diagnosIS Diagnosis of specific periodontal diseases. Identification of sites or subjects at an increased risk of experiencing the progression of periodontal destruction. Treatment planning Monitoring of therapy. 4

5. Conventional Diagnostic Aids Clinical diagnosis- Bleeding on probing Increased GCF Pocket depth Attachment level measurements Radiographic diagnosis - IOPA Bitewing Panoramic radiography Microbiological diagnosis – Culturing 5

6. Limitations of conventional techniques Conventional diagnostic techniques do not Differentiate sites with ongoing periodontal destruction (active sites) and inactive sites Differentiate disease is progressing or in remission Provide information on the patient’s susceptibility to disease 6

7. Limitations of conventional techniques Periodontal disease is site specific and has a multifactorial origin where periodontal pathogens, host response, genetic, systemic, and behavioral risk factors interplay to develop the disease Consideration should be given to include microbiologic, immunologic, systemic, genetic, and behavioral factors, in addition to the traditional clinical and radiographic parameters 7

8. Advances in 8

9. Advances in clinical diagnosis 9

10. Periodontal Probing Pocket probing is a crucial and mandatory procedure in diagnosing periodontitis and evaluating periodontal therapy. Reduction of pocket depth and gain of clinical attachment are the major clinical outcome measurements used to determine success of treatment 11

11. Limitations of conventional Probes: Lack of sensitivity and reproducibility of the measurements. Readings of clinical pocket depth obtained with the periodontal probe do not normally coincide with the histologic pocket depth, since the probe normally penetrates the coronal level of the junctional epithelium. T he precise location of the probe tip varies depending on the degree of inflammation of the underlying connective tissues. 12

12. The disparity between measurements also depends on the probing technique, probing force, size of the probe, angle of insertion of the probe, and precision of the probe calibration. All of these variables contribute to the large standard deviations (0.5 to 1.3 mm) in clinical probing results, which make detection of small changes difficult. 13

13. Generations of Periodontal probes 14 Type Characteristics First generation: Conventional/manual probes Usual clinical instrument: a thin tapering tine marked to be read in mm. Second generation: C onstant force probes/ Pressure sensitive probe. As above, but with an electronic cut-out when the appropriate force is reached . Force up to 30g means probe tip remains in the CEJ; force up to 50gm are necessary to diagnose osseous defects e.g . vine valley ; Vivacare TPS Third generation : Automated computerized probes When probe is pressure sensitive and a device is activated that reads the measurement accurately . e.g. Florida; Foster miller Fourth generation : Three-dimensional probes These are aimed at recording sequential probe positions along gingival sulcus Fifth generation : non-invasive three dimensional probes These will add ultrasound or another device to a fourth generation probe . Identify attachment level without penetrating it.

14. Periodontal probes First generation :- Conventional probes. Second generation :- Pressure controlled visual measurement recording probes Third generation :- Pressure controlled electronic probes with direct computer data capture. Fourth generation : Aim at recording sequential probing positions along the gingival sulcus. Fifth generation : Ultrasonic device attached to the 4 th generation probe .

15. First Generation Probes Are manual probes like William’s periodontal probe UNC 15 probe CPITN probe Michigan probe WHO probe Nabers probe 16

16. Williams probe has markings at 1, 2, 3, 5, 7, 8, 9, and 10 mm. Marquis probe or H u- friedy color coded probe is color coded by alternately colored or black and silver bands that mark 3, 6, 9, and 12 mm. Michigan O probe with W illiams markings has circumferential lines at 1 mm, 2 mm, 3 mm, 5 mm, 7 mm, 8 mm, 9 mm, and 10 mm. PCP12 probe with Marquis markings has alternating shades every 3 mm. CPITN probe has markings at 3.5, 5.5, 8.5, and 11.5mm. 17

17. Williams Graduated Periodontal Prob e Markings include 1,2,3,5,7,8,9 and 10 mm with 4mm and 6mm missing for ease in measuring.

18. Marquis Colour Coded Probe Calibrations are in 3mm sections. Markings are 3,6,9,12 mm

19. WHO probe It has 0.5 mm ball at the tip millimetre markings millimetre markings at 3.5/ 5.5/ 8.5/ 11.5 mm colour coding from 3.5 to 5.5 mm.

20. Naber’s probe Curved working end. For furcation areas Markings at 3,6,9,12 mm

21. Plastic Probes For Implants Avoid scarring and permanent damage to implants

22. Second Generation Probes (pressure sensitive) Objective - to reduce measurement variation by standardizing probing force. Probes available : Gabathuler probe True pressure-sensitive probe ( vivacare ) Prockprobe PDT sensor probe Vine valley probe 23

23. True Pressure Sensitive (TPS) probe Introduced by Hunter in 1994 A disposable probing head and a hemispheric probe tip with a diameter of 0.5 mm. Controlled probing pressure of 20 gm These probes have a visual guide and a sliding scale where two indicator lines meet at a specified pressure. 24

24. 25 In 1977, A rmitage designed a pressure-sensitive probe holder to standardize the insertion pressure and determine how accurate probing pressure of 25 pounds affected the connective-tissue attachment.  In 1978, V ander V elden devised a pressure-sensitive probe with a cylinder and piston connected to an air-pressure system. Subsequently, it was modified with a displacement transducer for electronic pocket-depth reading.

25. Vine valley Probe Introduced by Polson et al in 1980 It is an electronic pressure sensitive probe that is not sensitive to lateral forces and not subjected to error due to gravity. It allows control of insertion pressure & permits the use of different types of probe tips. The pressure force varies with a range of sensitivity of 5-100gms 26

26. Third Generation Probes (Automated/computer linked electronic constant pressure) Probes with controlled probing force that are capable of automated computerized data recording Probes available: Florida probe Toronto probe Foster-miller probe Interprobe 27

27. Florida probe Designed by G ibbs et al (1988). Advantage : constant probing force Precise electronic measurements Computerised data capturing Complete sterilization Limitations Lack tactile sensitivity Fixed-force setting throughout the mouth irrespective of inflammation and also causing discomfort to patients. Underestimation of deep probing depths 28

28. Two versions of the F lorida probe® handpiece are available for the determination of relative attachment levels: the stent probe and the disk probe. Stent probe uses an acrylic stent as a reference. Disk probe has a small metal disk attached to the sleeve and uses the occlusal surface or incisal edge of a tooth as a reference. Measurements made electronically and transferred automatically to the computer when the foot switch is pressed. Constant probing force is provided by coil springs inside the probe hand piece and digital readout. 29

29. R elative clinical attachment level (CALs) over a time period can be recorded by this probe. But these reference points may change over a period of time due to restoration of tooth or distortion of stent. So, it is desirable to use cementoenamel junction (CEJ) to measure clinical attachment level (CAL) 30

30. FLORIDA PASHA PROBE It measures CALs by identifying CEJ. It has a modified sleeve with 0.125-mm edge to facilitate catch at CEJ. This edge is so small that it do not interfere with probing depth measurements. More studies are awaited using this probe. 31

31. Foster Miller probe Devised by J effcoat et al in 1986, this probe has controlled probing pressure Can automatically detect the position of the CEJ. Record the clinical attachment level automatically. Is the prototype of third-generation probes. 32

32. Toronto probe Mcculloch and B irek (1987) designed this probe in the university of toronto ( C anada). Uses the occlusal-incisal surface as a reference point to measure the clinical attachment level. The sulcus is probed with a 0.5-mm nickel-titanium wire that is extended under air pressure. 33

33. Interprobe Calibrated for a constant 0.3-n (1.26 N/mm2) probing force and uses a 0.55-mm-diameter plastic filament. It is based on fiber optic technology. The probe tip is attached to an optical encoder transducer element. A fiber bundle transmits light to the transducer and reflected light to a signal processor. Probing depth is computed by comparison of the reflected light signal with the reference obtained from the zero position. 34

34. Fourth Generation Probes (Ultrasonic ) Projects a very narrow beam of high-frequency (10-15 mhz ) ultrasonic waves into the gingival sulcus. Detects echoes of returning waves, which are reflected back from tissues. The focused ultrasonic beam is transmitted into the sulcus in the same orientation as a manual probe. Ultrasound probe tip is gently placed on the gingival margin until slight blanching occurs, then swept along the entire gingival area. 35

35. Advantages- Detects much smaller increments of anatomic change Earlier detection of tissue breakdown Additional histological information, such as tissue thickness and inflammation Permits earlier diagnosis and intervention Handpiece design is ergonomically modified 36

36. Fifth-Generation Probes  Despite all the advances in earlier generation probes, they remain invasive and, at times, their use can be painful to patients. With these earlier generation probes, the probe tip usually crosses the junctional epithelium. Fifth-generation probes are being devised to eliminate these disadvantages. Probes are being designed to be 3D and noninvasive: an ultrasound or other device is added to a fourth-generation probe Fifth-generation probes aim to identify the attachment level without penetrating it. 37

37. Ultrasonographic (US) probe 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. It was devised by Hinders and companion at the NASA L angley research center. This small intraoral probe has an ultrasound beam projection area close enough in size to the width of the periodontal ligament space to give the optimal coupling and small enough to inspect the area between the teeth, while still delivering sufficient signal strength and depth of penetration to image the periodontal ligament space. 38

38. 39 The Ultrasonic Periodontal Probe To probe structures ultrasonically, a narrow beam of ultrasonic energy is projected down between the tooth and bone from a transducer, which is scanned manually along the gingival margin.

39. To probe structures ultrasonically, a narrow beam of ultrasonic energy is projected down between the tooth and bone from a transducer, which is scanned manually along the gingival margin. 40

40. The ultrasound transducer is mounted in probe-tip shell, which incorporates a slight flow of water to ensure good coupling of the ultrasonic energy to tissues. The couplet water can come either from a suspended intravenous-type sterile bag or plumbed from the dental-unit water source. The focused ultrasonic beam is transmitted into the pocket in the same orientation as the insertion of a manual probe Then, the probe is moved along the gingival margin, so the two-dimensional graphical output corresponds to the results a clinician gets from “walking the sulcus” with a manual probe. 41

41. However, ultrasound gives more information because secondary echoes are recorded from tissue features at various depths. It appears likely that the technique also will be able to provide information on the condition of the gingival tissue and the quality and extent of the epithelial attachment to the tooth surface. This may supply valuable data to aid the clinician in the diagnosis and treatment charting of these diseases 42

42. Calculus Detection   Calculus detection probes detect subgingival calculus by means of audio readings and are reported to increase chances of subgingival calculus detection.  Detectar (dentply)- has a lightweight, well-balanced handpiece, which can be autoclaved, and it produces an audible beep to signify calculus detection. This probe may augment standard methods of calculus detection. 44

43. Calculus Detection   Expensive and the handpiece is bulkier than a standard periodontal probe. As with many automated probes, there is potential for false positive and false negative readings. 45

44. Calculus Detection BY   TECHNOLOGY NAME OF DEVICE FIBROOPTIC ENDOSCOPY PERIOSCOPY SPECTRO-OPTICAL TECHNOLOGY DETECTAR AUTOFLUORESCENCE DIAGNODENT 46

45. Calculus Detection AND REMOVAL BY   TECHNOLOGY NAME OF DEVICE ULTRASOUND PERIOSCAN LASER AUTOFLUORESCENCE KEYLASER3 47

46. PerioTemp probe PerioTemp probe ( Abiodent ) detects pocket temperature differences of 0.1°C from a reference subgingival temperature. Individual temperature differences are compared with those expected for each tooth, and higher-temperature pockets are signaled with a red emitting diode. 49

47. Haffajee et al in 1992 used this probe to assess its predictability in identifying loss of attachment, concluding that sites with a red (higher) temperature indication had more than twice the risk for future attachment loss than did those with a green indication. Increase in number of micro organisms are found at these sites like Prevotella Intermedia, Porphyromonas gingivalis, Tannerella forsythia, Actinomyces actinomycetemcomitans. Possible explanation is that either micro organisms increase temperature by initiating inflammatory process or increased temperature provides environment favorable for their growth 50

48. However, the influence of pocket depth on temperature is still not clear, and further studies are needed to demonstrate the accuracy of this device and its utility in clinical diagnosis. 51

49. Diamond probe/ Perio 2000 system Diamond probe/ perio 2000 system reportedly detects periodontal disease during routine dental examinations by measuring relative sulfide concentrations as an indicator of gram-negative bacterial activity even before the gums are bleeding. Consists of a single-use disposable probe tip with microsensors connected to a main control unit. 53

50. Diamond probe/ Perio 2000 system It is a early warning system that can be used for early screening, to help selecting sites for localized treatment and for evaluation of patients on supportive periodontal therapy. 54

51. Periotest System Periotest System ( Schulte et al. 1992) Measure the tooth mobility and initial stability of implants The use of the periotest, a non-invasive, electronic device that provides an objective measurement of the reaction of the periodontium to a defined impact load. 56

52. Periotest System Electronically controlled tapping metallic rod in a handpiece is used 57

53. FUNCTIONS - Assessment of the osseointegration of dental implants Natural teeth: A ssessment of periodontopathies , occlusal load and control of the treatment’s progress The periotest’s scale ranges from -8 to +50. The lower the periotest value, the higher is the stability /damping effect of the test object (tooth or implant)

54. Assessment of the Osseointegration of dental implants

55. 60

56. Periotest scale FOR IMPLANT -8 to : Good osseointegration of implant and pressure can be applied +1 to +9 : Clinical examination required, pressure not yet to be applied on implant 10 to 50 : Osseointegration insufficient. Pressure not allowed to be applied on implant 61

57. Periotest scale for teeth -8 to +9 : Clinically firm teeth (normal tooth mobility) 10 to 19 : First distinguishable sign of movement (mobility-1) 20 to 29 : Crown deviates within 1 mm of its normal position (mobility-2) 30 to 50 : Mobility is readily observed (mobility-3) 62

58. Laser Vibrometer Method Dynamic loads are applied and measured on teeth, with a small hammer and a load cell. The consequent displacement of tooth is then measured with a laser doppler vibrometer Ratio between the maximum of the tooth displacement and the input force peak are considered as the mobility degree index. Disadvantage is its high cost 63

59. Resonance Frequency Analysis Developed by Meredith and his co workers 20 years back. This method evaluates the stiffness of the bone-implant interface by means of a signal transducer connected to a frequency response analyzer ( O sstell ; integration diagnostics, göteborg , sweden ). Osstell displays the peak of a frequency-amplitude plot. Resonance frequency of the transducer-implant unit is calculated. Implant stability quotient (ISQ) is displayed as a number between 1 and 100. 64

60. Dental Mobility Checker (DMC) Originally developed by A oki and H irakawa. Measures tooth mobility with an impact hammer method using transient impact force. Aoki and H irakawa successfully detected the level of tooth mobility by converting the integration (rigidity) of tooth and alveolar bone into acoustic signals. A microphone is used as receiver and response signal transferred from the microphone is processed by Fast Fourier T ransform (FFT) for conversion for analysis in the time axis. Hence, the duration of the first wave generated by impact is detected. 65

61. DMC uses a small impact hammer as an excitation device. It is easily used even in molar regions. DMC may provide quite stable measurement for osseointegrated implants. But application of a small force to an implant immediately after placement may jeopardize the process of osseointegration . 66

62. ELECTRONIC NOSE  A hand held device, being developed to rapidly classify the chemicals in unidentified vapor. Its application by scientists and personnel in the medical and dental field as well as it is hoped that this technology will be inexpensive, miniaturizable and adaptable to practically any odor detecting task. This device is based on sensor technology that can smell and produce unique fingerprints for distinct odors. Preliminary data indicates that this device has a potential to be used as a diagnostic tool to detect odors. 68

63. Gas Chromatography (GC) It could not measure sulphide compounds, that are the major cause of halitosis. So a system was developed as FPD (Flame Photometric detector system) 69

64. GC with FPD Can measure VSCs (Volatile Sulphur compounds like hydrogen sulphide, methyl mercaptan and methyl sulphide) Accurate enough and considered as Gold S tandard Expensive Need personnel with special training to operate them. The equipment is not portable and a significant amount of time is needed to make each breath measurement. 70

65. PORTABLE SIMPLE GCs Oral Chroma, Twin Breasor Portable simple GCs Easy to use Digital readout Can measure VSCs and can be used for research and clinical studies Results of both are comparable to Gas Chromatography 71

66. OTHER PORTABLE DEVICES Halicheck Portable Easy to use Digital readout and can measure VSCs comparable to GCs Can be used for clinical studies 72

67. OTHER PORTABLE DEVICES B/B Checker ® As a single unit, this device is capable of detecting several kinds of gases mixed with VSCs in addition to other odorous gases. But Sensitivity and specificity is only 50%. 73

68. ADVANCES IN OCCLUSAL ANALYSIS Articulating paper foils and ribbons have been used extensively in clinical practice as occlusal indicators. Their clinical implementation requires the operator’s subjective interpretation of the markings to decide which contacts are acceptable and which are premature. Presence of many similar-sized marks on neighboring teeth is purported to indicate equal occlusal contact intensity and evenness. 75

69. Research on articulating paper mark size has revealed that the size of an articulating paper mark does not describe occlusal forces- C arey et al (2007) As an alternative method to the operator’s subjective interpretation of articulating mark appearance, computerized occlusal analysis is available to the practitioner 76

70. T-SCAN In 2006, a USB plug-in recording handle and new generation of software were released as the t-scan occlusal analysis system. The system displays a recorded occlusal “force movie,” which illustrates the various occlusal pressures with colors during playback. The darker colors represent low occlusal pressures and the brighter colors indicate higher occlusal pressures. The t-scan system is a valuable tool that aids in the diagnostic process of analyzing a patient’s bite to show what is and what is not functioning properly. 77

71. Key Features The ultra-thin, reusable sensor, shaped to fit the dental arch, inserts into the sensor handle, which connects into the USB port of your existing PC, making it easy to move from one operatory to another. Evaluating occlusal forces is as simple as having a patient bite down on the sensor while the computer analyzes and displays timing and force data in vivid, full-color 3-D or 2-D graphics. 78

72. Key Benefits Improve clinical results Determine premature contacts Minimize destructive forces Provide instant documentation Use as a patient education tool to enhance comfort and increase case acceptance Save time by preventing remakes 79

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74. 81 3-dimensional dental patient is assembled from the data scanned from the casts of a patient’s dentition. This provides quantitative information that would aid in the assessment of his chewing function and in identifying the occlusal interferences. Further, the sequential comparison of these occlusal contacts enables the dentist to identify the changes in the patient’s occlusion as time elapses.  

75. Advances in radiographic diagnosis 82

76. Conventional Radiographs 2 types of views in conventional radiographs: IOPA radiographs OPG Traditional methods for assessing the destruction of alveolar bone associated with periodontal disease Information about past disease activity

77. Limitations of conventional radiography 2D representation of 3D structures. Superimposition of teeth and other anatomic structures. Only interproximal alveolar bone levels can be assessed with some level of certainty. Detection and quantitative assessment of 2-wall and 3-wall defects remains a challenge 84

78. Limitations of conventional radiography Needs of substantial amount of mineral loss (30%-50%) before bone resorption can be detected. Variation in projection geometry Variation in density and contrast during processing of films Very specific, but lack sensitivity. 85

79. Some of these limitations can be overcome by Using Paralleling technique Use of individualized film holders 86

80. Advances In Radiographic Assessment Digital radiography Digital subtraction radiography Computer-assisted densitometric image analysis system(CADIA) Computed tomography(CT) Cone-beam computed tomography (CBCT) Magnetic resonance imaging (MRI) Nuclear medicine bone scans Ultrasound imaging

81. Digital radiography Advantages Elimination of chemical processing Computerized images that can be stored, manipulated and corrected for overexposures and underexposures. Shorter exposure-to-display time One third or one half reduction in radiation exposure Quality image processing The software offers a variety of measurement tools 89

82. Digital radiography Advantages Very helpful for patient education Due to above advantages, it is expected that it will soon replace conventional radiography. 90

83. Two technologies currently available S olid-state detectors (Direct method) Photostimulable phosphor (PSP) (Indirect method) Solid-state detectors are based either on Charge-coupled device technology (CCD) or Complementary metal oxide semiconductor technology (CMOS) 91

84. 92 a) Kodak Insight F-speed film b) PSP plate c) CCD sensor d) CMOS sensor

85. DIRECT METHOD Direct method uses a change-coupled device (CCD) as sensor ( detector ), placed in patient’s mouth & linked by wire to computer. On conventional radiation exposure, image appears instantly on computer screen.

86. Based on photostimulated phosphor system also called as storage phosphor. PSP plates are dimensionally comparable to films & are handled similarly. Exposed plates are placed on plate scanner and scanned by laser beam. I mage will appear on screen. INDIRECT METHOD

87. Digital Subtraction Radiography Based upon fact that when two images of the same object over a time period are registered and superimposed the image intensities of corresponding pixels are subtracted, a uniform difference image will be produced. It cancels out the complex anatomic background against which this change occurs. The conspicuousness of the change is greatly enhanced. Subtraction images allow detection of mineral changes at little as 5%. 96

88. Digital Subtraction Radiography Changes in volume and density of bone can be viewed as lighter areas (as bone gain) and dark areas (as bone loss) This technique requires paralleling technique to have standardized geometry and accurate superimposable radiograph. Small osseous changes can be detected by it. Grondahl et al in 1988 showed 0.49mm of compact bone changes with it, that was three times larger than that shown by conventional radiography. 97

89. Digital Subtraction Radiography This technique facilitate both qualitative and quantitative visualization of very small density changes in alveolar bone by removing unchanged anatomic structure This helps in detecting even small density changes and improves the sensitivity and accuracy of evaluation 98

90. DISADVANTAGE Identical projection of X rays are required, which is nearly impossible in clinical setting. 99

91. Diagnostic Subtraction Radiography (DSR) Combined the use of positioning device during film exposure with special software designed for image subtraction using computers in dental office. This software corrects the angular alignment discrepancies and provides some degree of flexibility as compared to conventional subtraction radiography. 100

92. 101 Technique of Digital Subtraction Radiography(DSR)

93. Computer-Assisted Densitometric Image Analysis (CADIA) A video camera measures light transmitted through radiograph, and signals from the camera are converted into gray-scale images. This camera is interfaced with an image processor and a computer that allows the storage and mathematical manipulation of images. Quantitative changes in alveolar bone density over a period of time can be assessed with higher sensitivity, reproducibility and accuracy. 103

94. Computed Tomography Use a rotating fan beam to image one slice of the patient at the time, generally in an axial orientation. Once the image volume has been generated, images slices can be reconstructed in various orientations through a process called multi-planar reformatting ( mpr ). 105

95. 106 Computed Tomography

96. Advantages Eliminates superimposition of images Assessment of alveolar bone height and intrabony pocket is reasonably accurate High contrast resolution. Multiple scans of a patient may be viewed as images in the axial, coronal, or sagittal planes depending on the diagnostic task, referred to as multiplanar imaging.

97. Cone-beam CT (CBCT) During rotation, multiple sequential planar projection images are acquired X-ray source & detector moves around the a rotation fulcrum fixed within the center of region of interest.

98. 3D reconstruction - in three orthogonal planes (axial, sagittal, and coronal). Low radiation dose Reduced image artefacts Onscreen measurements are free from distortion & magnification. Reduced size & cost around 1/4 th to 1/5 th of conventional CT. Advantages

99. Denta scan Dentascan is a software program developed to automatically reformat the oblique cross-sectional images. It permits visualization of the mandible and maxilla in three planes: axial, oblique sagittal (cross-sectional), and panoramic 112

100. Dentascan 1.Axial computed tomographic image with reference curve in a patient 2.Reconstructed panoramic view. 3. Reconstructed mandibular cross sections.

101. It allows internal structures such as the inferior alveolar canal, incisive canal, and maxillary sinuses to be seen in cross section. Precise millimeter measurements of the height and width of the alveolar ridge can be obtained without the distortion typically seen with standard panoramic views. Buccolingual atrophy and contour irregularities are readily assessed, and the optimal site for implantation can be determined. 114

102. 3 roles in managing patients for dental implant : It preoperatively identifies patients who have insufficient bone for implantation, obviating the need to contend with this sometimes unanticipated condition during surgery. Alternative treatment plans can be made in advance. It identifies the optimum site for implantation by locating the exact position of the inferior alveolar canal and maxillary sinuses and the area of maximum bone height, width, and density. 115

103. It identifies implant sites in patients who, based on standard radiographs, were once considered to be inoperable because of insufficient bone. In addition to its use in implant surgery, D entascan is proving to have more expanded applications. It not only identifies ideal implant sites but also depicts various types of pathology such as periapical and periodontal disease, sinus disease, tumors, root resorption, and foreign bodies. 116

104. Magnetic Resonance Imaging [MRI] Uses non- ionizing radiation Unlike conventional radiographic techniques-hard tissues, bone and teeth are not strongly imaged. Strength -ability to image soft tissue. Uses powerful magnetic field, radio waves and computer Gives better soft tissue images than CT MR imaging is mainly used in the study of TMJ and the soft tissue lesion of gingiva and other oral structures.

105. Nuclear Medicine Bone Scans Branch of radiology that uses radiolabelled pharmaceuticals technetiun-99m that are specifically intended to image particular organs or detect specific disease processes. Detects changes in bone metabolism that may precede or accompany architectural changes. Bone scans are best used to determine whether a patient has active sites of bone loss and could benefit from an experimental treatment, or to determine whether a patient who is to undergo a bone marrow transplant has sites of active periodontal disease or occult disease that needs immediate attention.

106. ADVANCES IN MICROBIOLOGIC ANALYSIS 121

107. Advantages of Microbial testing Determination of bacteria associated with disease in certain individuals ⁄ sites Aids in selection of the most appropriate antibiotics Avoidance of arbitrary antibiotic prescription and possible increase in bacterial resistance Determination of bacterial elimination ⁄ reduction in number after treatment to correlate with disease progression ⁄ resolution Detection of the emergence of resistant strains post-therapy 122

108. Techniques for detection of microbes Culturing Phase contrast microscopy Immunologic assays DNA probes Enzyme tests Molecular microbial diagnosis 123

109. culturing Reference method (gold standard) Plaque samples are cultivated anaerobically and by using selective and non-selective media, together with several biochemical and physical tests, the different putative pathogens can be identified Advantages Identify microbes Obtain relative and absolute counts of the cultured species Characterize new species Determine antibiotic susceptibility of oral microbes and pathogenicity of individual species. 125

110. Shortcomings Can only grow viable bacteria Sensitivity low Detection limit- 10 3 -10 4 bacterial cells Requires specific laboratory equipment Time consuming Expensive 126

111. Direct Microscopy ( Darkfield Or Phase Contrast Microscopy) Alternative to culture methods Directly and rapidly assess the morphology and motility of bacteria in plaque sample. Used to indicate periodontal disease status and to structure maintenance programs

112. Phase and Dark-Field Microscopy For motile forms- spirochetes Main putative periodontopathogens , including A ctinomyces actinomycetemcomitans , P.gingivalis are nonmotile and therefore this technique is unable to identify these species. It is also unable to differentiate among the various species of T reponema . An unlikely candidate as a diagnostic test of destructive periodontal diseases 129

113. Immunologic Assays 131

114. Immunodiagnostic Methods Immunological assays employ antibodies that recognize specific bacterial antigens to detect target microorganisms. Direct and indirect immunofluorescent microscopy assays Latex agglutination Flow cytometry Enzyme –linked immunoabsorbent assay (ELISA) Membrane assay

115. IMMUNOFLUORESENCE Immunofluoresence (IFA) is a process in which dyes called fluorochromes are exposed to UV, violet, or blue light to make them fluorescence or emit visible light. Eg ; R hodine B or Fluorescein isothiocyanate (FITC) IFA is used mainly to detect Actinomyces Actinomycetemcomitans and P.gingivalis

116. Latex Agglutination Immunologic assay based on the bonding of protein to latex. 2 types: Indirect assay- Inhibition assay- Based on principle of inhibiting expected agglutination reaction between known antigen and known antibody as a result of competition

117. Flow cytometry Rapid identification Principle is labelling bacterial cells with both species-specific antibody and a second fluorescein- conjugated antibody This suspension is introduced into flowcytometer , which separates bacterial cells into an almost single cell suspension by means of a laminar flow through a narrow tube. After incubation passed through a focused laser beam. Limitation: sophistication and cost involved

118. ELISA Primarily used to detect serum antibodies to periodontal pathogens. Test involves linking of various label enzymes to either antigens or antibodies. 2 basic methods are used: Double antibody sandwich assay Indirect immunosorbent assay

119. Enzymatic Methods of Bacterial Identification- BANA TEST B. Forsythus , P. Gingivalis , T. Denticola , and capnocytophaga species - all have in common a trypsin like enzyme. The activity of this enzyme can be measured with the hydrolysis of the colorless substrate n-benzoyl-dl-arginine-2-naphthylamide ( bana ). When the hydrolysis takes place, it releases the chromophore ß- naphthylamide , which turns orange red when a drop of fast garnet is added to the solution. Diagnostic kits has been developed using this reaction for the identification of this bacteria profile in plaque isolates ( P erioscan ). 140

120. Loesche et al (1986) proposed the use of this BANA reaction in subgingival plaque samples to detect the presence of any of these periodontal pathogens and thus serve as a marker of disease activity. He showed that shallow pockets exhibited only 10% positive BANA reactions, whereas deep pockets (7 mm) exhibited 80% to 90% positive BANA reactions. Beck et al (1995) used the BANA test as a risk indicator for periodontal attachment loss. 141

121. Limitations: It may be positive at clinically healthy sites and remains to be proven whether this test can detect sites undergoing periodontal destruction. Since it only detects a very limited number of pathogens, its negative result does not rule out the presence of other important periodontal pathogens. 142

122. DNA Probes DNA obtained from pure cultures are enzyme-digested. Specific fragments of single strands are then radiolabelled and serve as a "DNA library" for future tests. Plaque samples submitted for assay are enzymatically digested and their fragmented single strands are attached by chemical treatment to a nitrocellulose filter. Fragments are then exposed to labeled single strands from the DNA library. Attachment of complementary strands to each other Washing away unlinked fragments. 144

123. Linked strands attached to the filter are exposed to auto radiographic plates to determine the extent hybridization occurred 145

124. Commercial chairside diagnostic kits 146 Commercially available kit Bacteria identified DMDx Patho Tek (DNA) A.comitans,P.gingivalis , P.intermedia , T.forsythus,C.rectus , T.denticola , F.nucletum . Meridol DNA proe test 3/8 A.comitans , P.gingivalis , P.intermedia , T.denticola , T.forsythus . Microdent Test( DNA) A.comitans , P.gingivalis , P.intermedia , T.denticola , T.forsythus . Perio Bac Test(DNA) A.comitans , P.gingivalis , P.intermedia , T.denticola , T.forsythus Omnigene and BTD A.comitans , P.gingivalis , P.intermedia

125. When compared to culture they have a sensitivity of 96% & specificity of 86% for A. Actinomycetemcomitans & 60% & 82% for P.gingivalis . Not affected by transport conditions Do not require anaerobic conditions to be maintained Can be done in dead bacteria and they do not depend on bacterial viability Advantages :

126. Checkerboard DNA- DNA Hybridization Technology Uses whole genomic , digoxigenin - labelled DNA probes Advantages : To assess large no. Of plaque samples ( 40 oral species in single test) Epidemiological purpose Disadvantage: Sophisticate equipment Expertise

127. Checkerboard hybridization This method was introduced in 1994, enabled the hybridization of 45 DNA samples against 30 DNA probes (i.e. Up to 1,350 simultaneous hybridizations) on a single support membrane. Socransky et al developed this technique for the detection to evaluate levels of 40 bacterial species often found in the oral cavity. It is based upon similar principle of DNA probes but the assay uses whole genomic, digoxigenin –labelled DNA probes and facilitates rapid processing of large numbers of plaque samples with multiple hybridization for up to 40 oral species in as single test. 150

128. Polymerase Chain Reaction Technique allows large quantities of DNA to be obtained from variety of tissues or microorganisms. It can detect a single micro-organism & has therefore the highest sensitivity of any microbiological method. Real-time PCR - uses single copy of gene per cell to achieve good correlation between the fluorescent signal measured & the number of cells obtained.

129. ADVANCES IN CHARACTERIZING THE HOST RESPONSE- Diagnostic biomarkers 154

130. Requisites for a periodontal diagnostic marker It should be able to distinguish periodontally healthy sites from those sites affected by gingivitis and periodontitis. It should be able to differentiate between progressive and non-progressive lesions. It should indicate the presence of a disease process before extensive clinical damage has occurred. It should have high specificity and sensitivity. It should have ease of use either as a chair side procedure, a home screening device or test. It should be cost-effective. 155

131. Sources Potential sample sources include saliva, gingival crevicular fluid (GCF), gingival crevicular cells, blood serum, blood cells, and urine. Analysis of urine only for differential diagnosis of tooth loss related to hypophosphatasia in young children, in whom the presence of phosphoethanolamine in urine is diagnostic of the disease. Most efforts to date have been based on the use of components of GCF and, to a lesser extent, saliva and blood. 156

132. Potential marker sources of periodontal disease activity in GCF Host derived enzymes and their inhibitors- released from dead and dying cells of the periodontium; PMNs and other inflammatory cells, epithelial, and connective tissue cells at affected sites. Inflammatory mediators and host response modifiers- TNF- α, IL-1 α , IL-1ß, IL-6, and IL-8. Tissue breakdown products- hydroxyproline from collagen breakdown and glycosaminoglycans from matrix degradation. Other bone and connective tissue proteins, including osteocalcin and type 1 collagen peptides , have been correlated with the progression of alveolar bone loss. ICTP – specific marker of bone loss. 157

133. 158 GROUPS OF POTENTIAL MARKER SOURCES OF PERIODONTAL DISESE ACTIVITY IN GCF Microbial Plaque Endotoxins (lipopolysaccharide) Enzymes Metabolic end products Host Cells Leukocytic enzymes Lactoferrin Lysozyme Host Tissue Collagens Proteoglycans Matrix proteins Host Factors: Immune Response Immunoglobulins Complement Eicosanoids Cytokines

134. HOST-DERIVED ENZYMES AND THEIR INHIBITORS IN GCF 160 Aspartate aminotransferase Alkaline phosphatase Acid phosphatase Β- Glucouronidase Elastase Elastase inhibitors α ₂ -Macroglobulin α ₁ - Proteinase inhibitor Cathepsins Cysteine proteinases (B,H,L) Serine proteinase (G) Cathepsin D Trypsin -like enzymes Immunoglobulin-degrading enzymes Glycosidases Dipeptidyl peptidases Non specific neutral proteinases Collagenases Gelatinases Tissue inhibitor of MMP-1 Stromyelysins Myeloperoxidases Lactate dehydrogenase Arylsulfatase Creatinine kinase β-N-acetyl- hexosaminidase

135. INFLAMMATORY MEDIATORS AND HOST RESPONSE MODIFIERS IN GCF 162 Cytokines Interleukin-1α Interleukin-1β Interleukin-1ra Interleukin-2 Interleukin-6 Interleukin-8 Tumor necrosis factor α Interferon α RANTES ( chemoattractant and activator of macrophages and lymphocytes) Prostaglandin E ₂ Leukotriene B ₄ Acute – phase proteins Autoantibodies - Anti- desmosomal antibody Antibacterial antibodies Plasminogen activator (PA) PA inhibitor-2 (PAI-2) Substance P Vasoactive intestinal peptide Neurokinin A Platelet-Activating Factor CD14 Cystatins Calgranulin A (MRP-8)

136. TISSUE BREAKDOWN IN GCF 164 Glycosaminoglycans Hyaluronic acid Chondroitin – 4 – sulfate Chondroitin – 6 – sulfate Dermatan sulfate Hydroxyproline Fibronectin fragments Connective tissue and bone proteins Osteonectin Osteocalcin Type I collagen peptides Osteopontin Laminin Calprotectin Hemoglobin β-chain peptides Pyridinoline crosslinks (ICTP)

137. BONE FORMATION MARKERS 165 Type I procollagen propeptide – proliferation C-terminal propeptide fragment (PICP) N -terminal propeptide fragment (PINP) Alkaline phosphatase – matrix formation Total alkaline phosphatase ( Al-p ) Bone alkaline phosphatase (Bal-p) Osteocalcin, bone Gla protein – mineralization (BGP) C-terminal fragment Mid-portion Intact

138. BONE RESORPTION MARKERS 166 Pyridinium cross-link Urine pyridinoline (PYP), deoxypyridinoline (DPD), HPLC method Urine free deoxypyridinoline ( fDPD ) 2. Pyridinium cross-link collagen peptide fragment Serum C-terminal telopeptide (ICTP) Urine C-terminal telopeptide (CTx, crosslaps®) Urine N-terminal telopeptide (NTx, osteomark®) 3. Tartrate -resistant acid phosphatase 4. Galactosyl hydroxylysine (GHYL) 5. Hydroxyproline 6. N-terminal osteocalcin fragment 7. Glycosaminoglycans (GAGs)

139. Chairside Diagnostic Kits

140. Advances in genetic diagnosis 168

141. Potential types of the patient’s and the benefits that may be derived from the decision to determine patient’s genotype Patients with early signs of periodontal disease. Patients who are resistant to accepting treatment recommendation. New periodontal patients, with family history of periodontal problems . Patients not responding to routine periodontal procedures. Biologic family members of genotype positive patients 169

142. PST GENETIC TEST PST® genetic susceptibility test-[periodontal susceptibility test, IL genetics inc. Waltham. Mass]- Kornman & Colleagues First genetic test that analyzes two IL-1 genes for variations that identify an individual’s predisposition for over expression of inflammation and risk for periodontal disease. Il-1 genetic susceptibility may not initiate or cause the disease but rather may lead to earlier or more severe disease. This test is not intended to and does not diagnose a specific disease. It can be used to differentiate certain IL-1 genotypes associated with varying inflammatory responses to identify individuals at risk for severe periodontal disease even before age 60. 170

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144. TREATMENT DECISIONS INFLUENCED BY GENETIC TESTING The finding that a patient is genotype- positive does not indicate that the patient will develop severe periodontitis. Papapanou et al (2001) reported that among healthy patients and patients with periodontitis, the percentage of genotype-positive patients was 41.7% and 45.2% respectively. In the study by K ornman and colleagues (1997)- 38 %of the patients with moderate periodontitis were genotype-positive. In addition, 33% of patients with severe periodontitis were genotype-negative. 172

145. Thus, detection of a positive genotype is not sufficient to initiate therapy, and the finding of a negative genotype is inadequate to conclude that the patient will not develop severe periodontitis. Even if the presence of specific genetic polymorphisms associated with an increased risk of developing periodontitis is identified, periodontitis will not develop if the bacterial pathogens do not overwhelm the host response. 173

146. ORAL RINSE TEST TO DIAGNOSE PERIODONTAL disease 174

147. Oral Rinse Test A simple and rapid method for the quantification of oral neutrophil levels in saliva. Is useful for examining the periodontal breakdown and the effectiveness of periodontal therapy. Utilizes a 30 second oral rinse that is collected from the patient. A biochemical agent is added that results in a colour change that reports the number of oral neutrophil present. 175

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