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Advanced Periodontal Diagnostic Techniques (As an adjunct to conventional techniques)

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Post on 15-Aug-2015



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  1. 1. Advanced Periodontal Diagnostic Techniques (As an adjunct to conventional techniques)
  2. 2. Contentof discussion Introduction Limitations of conventional periodontal diagnosis Advances in Clinical diagnosis Advances in Radiographic assessment Advances in Microbiologic analysis Advances in characterizing the Host response Conclusion and future scopes
  3. 3. Introduction Definition of DIAGNOSIS (Dx)* : Diagnosis is defined as; correct determination, discriminative estimation and logical appraisal of conditions found during examination as evidenced by distinctive marks, signs and characteristics of diseases *Glossary of Periodontal terms
  4. 4. Recognizing a departure from health in the periodontium and distinguishing one disease, disease categorization, or etiology from another, Based on information obtained from the medical and dental histories, clinical and radiographic examination of the patient, and laboratory findings. PeriodontalDx*:
  5. 5. Purposes of Periodontaldiagnostic procedures
  6. 6. According to Armitage GC(1996) Periodontal diagnostic procedures can potentially serve 5 separate, but related purposes: 1. Screening 2. Diagnosis of specific periodontal disease 3. Identification of sites or subjects at an increased risk of experiencing the progression of periodontal destruction 4. Treatment planning and 5. Monitoring of therapy.
  7. 7. Current conventional techniques Clinical diagnosis is made by measuring either clinical attachment loss (CAL) or radiographically by loss of alveolar bone This kind of evaluation identify and quantify current clinical signs of inflammation , Provides historical evidence of damage with its extent and severity
  8. 8. Limitations !!! Does not provide cause of the condition No info. on patients susceptibility to the disease Cannot identify sites with ongoing periodontal destruction or sites in remission Cannot differentiate whether response to therapy is positive or negative
  9. 9. Periodontal disease is localized and multifactorial Periodontal pathogens Host response behaviouralsystemic Genetic
  10. 10. Advanced periodontal diagnostic techniques Advances in Clinical diagnosis Advances in Radiographic Assessment Advances in Microbiologic Analysis Advances in Characterizing the Host Response
  11. 11. Advances in Clinical Diagnosis
  12. 12. 1. Gingival temperature Kung et al (1990) claim that thermal probes are sensitive diagnostic devices for measuring early inflammatory changes in gingival tissue. Subgingival temperature at diseased sites is increased as compared to normal healthy sites Commercially available system PerioTemp probe enables the calculation of temperature differential (with sensitivity of 0.10C) between the probed pocket and subgingival temperature
  13. 13. Possible explanation for temperature with increasing probing depth is an increase in cellular and molecular activity caused by increased periodontal inflammation Haffajee et al. (1992): found that elevated subgingival site temperature is related to attachment loss in shallow pockets and elevated proportions of Pg, Pi, Tf, Aa.
  14. 14. 2. Periodontal probing Most widely used diagnostic tool Probing depth is measured from the free gingival margin to the depth of the probeble crevice. Longitudinal measurement of CAL or probing depth is a gold standard for recording changes in periodontal status
  15. 15. Limitation of conventional probing Lack of sensitivity and reproducibility. Disparity between measurement depends on: probing technique, probing force, angle of insertion of probe, size of probe, precision of calibration, presence of inflammation. Readings of clinical pocket depth measured with probe does not coinside with the histologic pocket depth. All these variable contribute to the large standard deviations (0.5-1.3 mm) in clinical probing results
  16. 16. Classification of periodontal probes depending on generation 1.First generation probes: (conventional probes) Conventional manual probes that do not control probing force or pressure and that are not suited for automatic data collection. example: Williams periodontal probe CPITN probe UNC-15 probe Goldman Fox probe
  17. 17. 2.Second generation probes: (Constant force probes) Study done by Tupta et. Al (1994) has shown that force to probe pocket: 30g force to probe osseous defect: 50g Introduction of constant force or pressure sensitive probes allowed for improved standardization of probing. e.g.: Pressure sensitive probe Constant pressure probe Limitation: data readout and storage is inaccurate.
  18. 18. 3.Third generation probe:(Automated probes) Computer assisted direct data capture was an important step in reducing examiner bias and also allowed for generation of probe precision. (according to NIDCR criteria) e.g.: Toronto probe Florida probe, Interprobe, Foster Miller probe.
  19. 19. Florida probe Tip is 0.4mm Sleeve- edge provides reference to make measurements Coil Spring; provides constant probing force Computer for data storage.
  20. 20. FP Handpiece tip as it enters the sulcus Handpiece tip with constant force in use (tip at bottom of sulcus) and sleeve properly positioned at the top of the gingival margin allowing the computer to measure the difference.
  21. 21. Clark and Yang (1992): trained operators and performing the double pass method, the measurements taken with Florida probe system shows lower standard deviation than those obtained with conventional probing. Mean Standard Deviation for CAL of about 0.3mm, which is superior to an average of 0.82mm reported by Haffajee et al. For conventional probing. Limitations Lack of tactile sensitivity Fixed probing force Underestimation of deep periodontal pockets.
  22. 22. 4.Fourth generation probes: (Three dimensional probes) Currently under development, these are aimed at recording sequential probe positions along a gingival sulcus. An attempt to extend linear probing in a serial manner to take account of the continuous and three dimensional pocket that is being examined. 5.Fifth generation probe: (3D + Noninvasive) Basically these will add an ultrasound to a fourth generation probes. If the fourth generation can be made, it will aim in addition to identify the attachment level without penetrating it. e.g.: Ultra sonographic probe.
  23. 23. Advances in RadiographicAssessment
  24. 24. Dental Radiographs are traditional method to assess destruction of alveolar bone. Conventional radiographs are very specific but lack sensitivity Primary criterion for bone loss is the distance from CEJ to the alveolar crest and distance more than 2 mm is considered as the bone loss. But variability affecting conventional radiographic technique are, Variation in projection geometry Variation in contrast and density Masking by other anatomic structures.
  25. 25. 1. Digital radiography Capturing radiographic image using a sensor The first direct digital imaging system, RadioVisioGraphy (RVG), was invented by Dr. Frances Mouyens. Advantages 1. Elimination of chemical processing 2. Increased efficiency and speed of viewing 3. Diagnostic information can be enhanced 4. Computerized storage of radiographs 5. Reduced exposure to the radiation
  26. 26. 2. Subtraction radiography Subtraction radiography was introduced to dentistry in 1980 by Ruttimann, Webber et & Grondahl HG This is a technique by which images not of diagnostic value in a radiograph, are eliminated so that changes in the radiograph can be precisely detected Serial radiographs converted to digital images superimposed composite image Quantitative changes
  27. 27. This technique requires a paralleling technique to obtain a standardize geometry and accurate superimposable radiographs This technique facilitates both quantitative and qualitative visualization of even minor density changes in the bone Bone gain appears as light areas and bone loss appears as dark areas Rethman et al.(1985): increased detectability of small osseous lesions by substraction method compared with conventional radiography
  28. 28. Recent image subtraction:diagnostic subtraction radiography (DSR) Modification Use of a positioning device during film exposure Image analysis software system applies an algorithm to correct angular alignment discrepancies.
  29. 29. 3. Computer Assisted Densitometric Image Analysis (CADIA) Video camera measures the light transmitted through radiograph and the signals form the camera is converted to gray scale image. Advantage: Measures quantitative changes in bone density longitudinally. Higher sensitivity, reproducibility and accuracy as compared to DSR.
  30. 30. 4. Computed tomography (CT) In 1972, Godfrey Hounsfield announced the invention of a revolutionary imaging technique, which he referred to as computerized axial transverse scanning Fan shaped X-ray source is used The computed tomographic image is reconstructed by computer, which mathematically manipulates data obtained from multiple projections. Computed tomography is a specialized radiographic technique that allows visualization of planes or slices of interest
  31. 31. eliminates the super imposition of images of structures superficial or deep to the area of interest. Because of inherent high contrast resolution, differences may be distinguished between tissues that differ in physical density by less than 1%. 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. Advantages over conventional radiography
  32. 32. Axial CT Coronal CT Sagittal CT Multiplaner imaging
  33. 33. Application of CT Used when accurate information regarding the topography of osseous structure is needed Soft tissue contour and dimension To check continuity and density of the cortical plates vertical height of the residual alveolar ridges density of the medullary space and basilar bone when determining how much space is available above the mandibular canal or amount of bone below maxillary sinus to receive a dental implant or whether there is a space occupying lesion in the maxillofacial region.
  34. 34. Disadvantages of Computed Tomography specialized equipment and setting. Radiologists and Technicians need to be knowledgeable of the anatomy, anatomic variants and pathology of the jaws higher radiation Metallic Restorations can cause ring artifacts that impair the diagnostic quality of the image
  35. 35. Cone-beam Computed Tomography Routine use of CT in dentistry is not accepted due to its cost, excessive radiation, and general practicality. In recent years, a new technology of cone-beam CT (CBCT) for acquiring 3D images of oral structures is now available to the dental clinics and hospitals. It is cheaper than CT, less bulky and generates low dosages of X- radiations. The innovative CBCT machine designed for head and neck imaging are comparable in size with an orthopantomogram.
  36. 36. Advantages It gives complete 3D reconstruction CBCT units reconstruct the projection data to provide interrelational images in three orthogonal planes (axial, sagittal, and coronal). Its beam collimation enables limitation of X-radiation to the area of interest. Patient radiation dose is five times lower than normal CT, as the exposure time is approximately 18 seconds, that is, one-seventh the amount compared with the conventional medical CT. Reduced image artefacts
  37. 37. Evaluation of the jaw bones which includes the following: Bony and soft tissue lesions Periodontal assessment Soft tissue CBCT for the measurement of gingival tissue and the dimensions of the dentogingival unit alveolar bone density measurement Temporomandibular joint evaluation and Implant placement and evaluation Whenever there is need for 3D reconstructions Indications of CBCT
  38. 38. Advances In MicrobiologicAnalysis
  39. 39. Uses of microbiologic analysis 1. support diagnosis of various Periodontal disease 2. Can tell about initiation & progression 3. To determine which periodontal sites are at high risk for active destruction 4. Can also be used to monitor Periodontal therapy
  40. 40. Advances In Microbiologic Analysis includes: 1. Immunohistodiagnostic methods 2. Enzymatic methods 3. Molecular biology techniques Neucleic acid probes Checkerboard DNA-DNA hybridization PCR
  41. 41. Sample collection It is a common need of all the microbiologic analysis to collect an appropriate subgingival plaque sample Mombelli et al. (2002) have shown that four individual subgingival specimens, each from the deepest periodontal pocket in each quadrant, should be pooled to be able to detect the highest amount of pathogens. Transport the specimen in a anaerobic environment
  42. 42. Immunodiagnostic methods Immunological assays use fluorescent conjugated antibodies that recognize specific bacterial antigens, and the identification of these specific antigen-antibody reactions allows the detection of target microorganisms. This reaction can be visualized using a variety of techniques and reactions: 1. Direct (DFA) and indirect (IFA) immunofluorescent assays 2. Flow cytometry 3. Enzyme-linked immunosorbent assay (ELISA) 4. Latex agglutination
  43. 43. 1. Immunofluorescent assays
  44. 44. IFA is used mainly to detect A.a and P.g Zambon et. al (1986) showed that IFA is comparable to bacterial culture in its ability to identify these pathogens Zambon et. al (1995) sensitivity of these assays ranges from 82%-100% for A.a. and 91%-100% for P.g Specificity values of 88%-92% and 87%-89% respectively
  45. 45. 2. 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 Limitation is sophistication and cost involved with this procedure
  46. 46. 3. ELISA
  47. 47. ELISA has been used primarily to detect serum antibodies to periodontal pathogens. In research studies to quantify specific pathogens in subgingival samples A novel chair side ELISA commercially known as Evalusite has been marketed in Europe and Canada for the chair side detection of 3 periodontal pathogens. Aa, Pg and Pi
  48. 48. 4. Latex agglutination Test +ve
  49. 49. merits Quantitative estimate of target species Not requiring stringent sampling and transport methodology Higher sensitivity and specificity than bacterial culturing for A.a, P.g and T.f. demerits Limited to the number of antibodies tested Not amenable for antibiotic susceptibility Lack the evidence of well- controlled clinical studies
  50. 50. Enzymatic Methods Tf, Pg, Td, and Capnocytophaga species share common enzymatic profile- a trypsin like enzyme. N-benzoyl-d L-arginine- 2-naphthylamide Trypsin like enzyme BANA hydrolysis -naphthylamide (chromophore)
  51. 51. PERIOSCAN uses this reaction for the identification of this bacterial profile in plaque isolates Loesh et al. (1986) detection of these pariodontal pathogens by BANA reaction serves as a marker of disease activity He also showed that shallow pockets exhibited 10% positive BANA reaction, whereas deep pockets (7mm) exhibited 80%-90% +ve BANA reaction Beck et al. (1995) used BANA test as a risk indicator for periodontal attachment loss
  52. 52. Disadvantage of BANA May be positive in clinically healthy site Can not detect sites undergoing periodontal destruction Limited organisms detected So that, negative results does not rule out the presence of other important periodontal pathogens.
  53. 53. Molecular Biology Techniques The principles of molecular biology technique reside in the analysis of DNA, RNA and the structure and function of proteins Diagnostic assays require specific DNA fragment that recognize complementary-specific DNA sequences from target microorganisms This technology requires bacterial DNA extracted from the plaque sample and amplification of the specific DNA sequence of the target pathogen
  54. 54. 1. Nucleic acid probes A probe is a known, single stranded nucleic acid molecule (DNA or RNA) from a specific pathogen synthesized and labeled with a enzyme of a radio isotope Hybridization: Pairing of complimentary strands of DNA to produce a double stranded DNA. Probe DNA B.DNA Hybridization
  55. 55. DMDx and Omnigene are commercially available genomic probes for the detection of Aa, Pg, Pi and Td. Van Steenberghe et al. (1999) reported a sensitivity of 96% and specificity of 86% for Aa., and 60% and 82% respectively for Pg in pure lab isolates. In clinical specimens, both sensitivity and specificity were reduced significantly, suggestive of cross reactivity with non target bacteria in plaque sample because of the presence of homologues sequences between different bacterial species
  56. 56. 2. Checkerboard DNA-DNA hybridization technology Developed by Socransky in 1994 40 bacterial species can be detected using whole genomic digoxigenin-labeled DNA probes. Applicable for epidemiologic research and ecological studies
  57. 57. 3. Polymerase chain reaction (PCR) Repeated cycles of oligonucleotide (primer)directed DNA synthesis of target sequences are carried out in vitro. The PCR method is considered the fastest and most sensitive method available for detecting the presence of bacterial DNA sequences A modification of the original PCR technology, "real- time" PCR, permits not only detection of specific microorganisms in plaque, but also its quantification.
  58. 58. Advantages 1. High detection limit. As less as 5- 10 cells can be amplified and detected. 2. Less cross reactivity under optimal conditions 3. Many species can be detected simultaneously Disadvantage 1. Small quantity needed for reaction may not contain the necessary target DNA 2. Plaque may contain enzymes which may inhibit these reactions.
  59. 59. Advancesin characterizingthe Hostresponse
  60. 60. Assessment of host response refers to the study of mediators by immunologic or biochemical methods, that are recognized as a part of individuals response to the periodontal infection. Mediators 1. specific Mediator antibody to a putative pathogen 2. less specific reaction the local release of the inflammatory mediators, host derived enzymes and tissue breakdown products
  61. 61. For that... Diagnostic tests have been developed that add measures of the inflammatory process to conventional clinical measures. Sources of the sample are: GCF, gingival crevicular cells, Saliva, Blood serum, blood cells and rarely urine. Most efforts to date have been based on use of components of GCF and to a lesser extent, saliva and blood
  62. 62. Assessment of Host response Inflammatory mediators and products Host derived enzymes Tissue breakdown products
  63. 63. 1. Inflammatory mediators and products Cytokines present in GCF and investigated as potential diagnostic markers are: TNF IL-1 IL-1 IL-6 IL-8 PGE2 (product of COX pathway) Cross sectional studies have shown Good correlation with disease status and severity but not disease progression In cases of untreated periodontitis concentration of PGE2 was found increased (showing active Periodontal destruction)
  64. 64. Host derived enzymes Breakdown of collagen occours by two different pathways: Intracellular 1. Aspartate amino transferases 2. Alkaline phosphatase 3. - Glucuronidase 4. Elastase Extracellular Matrix metalloproteinase's family (MMPs)
  65. 65. Tissue Breakdown Products Analysis of GCF obtained from sites with active periodontitis clearly shows elevated levels of Hydroxyproline from collagen breakdown and GAGs from matrix degradation Osteocalcin and type-1 collagen peptides- progression of alveolar bone loss
  66. 66. Conclusion
  67. 67. 1. This discussion directly translates into improved periodontal therapy by offering the clinician, the radiographic & laboratory measure of periodontal infection as an adjunct to traditional clinical indices of periodontal disease. 2. Future application of advanced diagnostic techniques will be of value in documenting disease activity and treatment options 3. But, despite excellent progress in diagnostic methodology,conventional efforts evaluating inflammation and past evidence of tissue breakdown remain the standard for disease evaluation
  68. 68. 4. There is still a lack of a proven gold standard of disease progression 5. After all these years of intensive research, we still lack a proven diagnostic test that has demonstrated high predictive value for disease progression, has a proven impact on disease incidence and prevalence, and is safe, and cost-effective. A tremendous amount of research is still required to explore the role of advancements in diagnostic aids as a possible medium for the future prediction and prevention of periodontal disease.
  69. 69. 1. Text book of Carranza's clinical periodontology, 2007, W.B. Saunders Co. 2. Armitage GC, Svanberg GK, Lde H: Microscopic evaluation of clinical measurements of connective tissue attachment levels. J Clin Periodontol 1977; 4:173. 3. Socransky SS, Haffajee AD, Smith C, Martin L, Haffajee JA, Uzel NG, Goodson JM. Use of checkerboard DNA-DNA hybridization to study complex microbial ecosystems. Oral Microbiol Immunol 2004;19:352-362 4. Clark WB, Yang MCK, Magnusson 1: Measuring clinical attachment: Reproducibility and relative measurements with an electronic probe. J Periodontol 1992; 63:831. 5. Goodson JM, Haffajee AD, Socransky SS: The relationship between attachment level loss and alveolar bone loss. J Clin Periodontol 1984; 11:348. 6. Grondahl HG, Grondahl K: Subtraction radiography for the diagnosis of periodontal bone lesions. Oral Surg 1983; 55:208. References:
  70. 70. 7. Haffajee AD, Socransky SS: Attachment level changes in destructive periodontal diseases. J Clin Periodontol 1986; 13:461. 8. Kung RT, Ochs B, Goodson JM: Temperature as a periodontal diagnostic. J Clin Periodontol 1990; 17:557. 9. Loesche WJ: The identification of bacteria associated with periodontal disease and dental caries by enzymatic methods. Oral Microbiol Immunol 1986; 1:65. 10. Mombelli A, Graf H: Depth force patterns in periodontal probing. J Clin Periodontol 1986; 13:126. 11. Page RC: Host response tests for diagnosing periodontal diseases. J Periodontol 1992; 63:356. 12. Papanou PN, Neiderud AM, Papadimitriou A, et al: Checkerboard assessments of Periodontal Microbiota and serum antibody responses: A case control study. J Periodontol 2000; 71:885. 13. Zambon JJ, Bochacki V, Genco RJ: Immunological assays for putative periodontal pathogens. Oral Microbiol Immunol 1986; 1:39. 14. Tupta-Veselicky L, Famili P, Ceravolo FJ et al: A clinical study of an electronic constant force periodontal probe. J Periodontol 1994; 65:616.