biological and chemical indicators of disease risk


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Preventive Dentistry
Third Year

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biological and chemical indicators of disease risk

  1. 1. Biological and Chemical g indicators of disease risk By y Dr Wael Mohamed Swelam 17 March 2009
  2. 2. Background: g • Oral tissue functions are controlled by different molecules/factors diff t l l /f t – Salivary flow rate – Salivary components modifying its pH (acidity/alkalinity) ( idit / lk li it ) – Microorganisms – Grenetic • Al oral tissue functions affect its Also, l i f i ff i environment – Temperature – Enzymes and immunokines So, they are considered indicators for health & disease 17 March 2009 Dr. Wael M Swelam 2
  3. 3. 17 March 2009 Dr. Wael M Swelam 3
  4. 4. Microbiological evaluation g 1. Dental plaque a. a Tools • Plastic toothpick/dental instrument • Pad of plastic test strip • Culture medium at 37˚C/48h • Microscope with 10X magnification b. Advantages  High specificity , based on microorganisms identified = tooth risk for caries c. Limitations Information can’t be generalized I f ti ’t b li d Doesn’t reflect the biological ecology of oral cavity Inconvenient to identify colonization of organisms y g from multiple sites 17 March 2009 Dr. Wael M Swelam 4
  5. 5. Microbiological evaluation g 2. Saliva microbiological culture a.Principle: • Saliva is the vehicle for microorganisms • "un-stimulated" or "stimulated" saliva unb.Precautions Careful C f l recording f all medications; contraindicated di for ll di ti t i di t d during Systemic antibiotic Transient antihistaminic T i t tihi t i i Avoid foods/drinks or disclosing tablets 4h before test Avoid dental prophylaxis before sample collection 17 March 2009 Dr. Wael M Swelam 5
  6. 6. Test for Unstimulated Saliva Materials needed: • Measure-cup (graduated test tube with conical base) • Funnel • A watch or timer h How to measure. 1) The person sits in an upright position with his head inclined forward so that the production of saliva is collected in the floor of the mouth and then flows out over the lip. 2) Saliva formed is let to drip into the measure-cup for 15 minutes. 3) The result of this collection is expressed as milliliters per minute. 17 March 2009 Dr. Wael M Swelam 6
  7. 7. Test for Stimulated Saliva Materials needed: p paraffin for chewing to stimulate saliva secretion g • A piece of p • Measure-cup (graduated test tube with conical base) • Funnel • A watch or timer How to measure. 1) The person chews a piece of paraffin until it becomes soft. Before the collection is started the first portion of saliva is swallowed. 2) Start timer and the chewing is continued for another 5 minutes (for subjects with high secretion rate, 3 minutes may be enough). 3) The saliva is spat out at short intervals in a measure-cup during the collection period. 4) The colleted saliva is then measured. The measurement should not include the foam which is formed during the collection. The result is expressed as mililiters per minute. 17 March 2009 Dr. Wael M Swelam 7
  8. 8. Salivary flow rate analysis y y Unstimulated Saliva (ml/minute) more than 0 25 th 0.25 0.1 - 0.25 less than 0.1 normal l low very low Stimulated Saliva (ml/minute) More than 1.0 Normal 0.7 1.0 07-10 Less than 0.7 17 March 2009 Low Very low Dr. Wael M Swelam 8
  9. 9. 2 Laboratory analysis of cultured saliva 2. Serially dilute the sample Culture samples on SB20 agar for streptococci ; in anaerobic environment; WHY? Culture samples on Rogosa agar for lactobacilli species Added bacitracin, antibiotic to the cultured samples, WHY? Keep samples in culture at 3 ˚C/ 8 37˚C/48h Count the colonies 17 March 2009 Dr. Wael M Swelam 9
  10. 10. 3. Side chair analysis of Salivary S Mutans a.Commercial set “Dentocult SM Strip mutans” is based on broth, Usage of selective culture broth and The adherence and growth of mutans streptococci bacteria on the test strip b. b Materials needed :  Mitis salivarius broth for culture,  Add 5µg bacitracin tablet; WHY?  Start saliva stimulation,  After 2 min. introduce the plastic strip provided in the kit in-between the lips p  Rotate it to collect sample, remove & attach to the cap  Close Cap onto the vial and keep for 48h/37˚C 17 March 2009 Dr. Wael M Swelam 10
  11. 11. Caries risk category High Moderate Low 17 March 2009 Mutans streptococci (CFU/ml) ≥5.5 ≥5 5 ×105 ≥1 ×105 ~ <5.5×105 <1 ×105 1 10 Dr. Wael M Swelam 11
  12. 12. Analysis of Salivary pH as indicator for its buffering capacity a. a Principle: • Salivary buffering capacity is pH dependent • Salivary pH is directly related to • Acidogenicity of microenvironment • Sucrose challenge in the diet Dentobuff® Strip System Materials needed: Dentobuff® Strip, a kit which includes p • Paraffin tablet for chewing to stimulate saliva secretion • A test strip containing acid and ph-indicator • A standard color chart • A disposable p p p pipette • A cup or tube • A timer How to measure. 1) Saliva is collected in the same way as described in Tests for Stimulated Saliva. Usually buffer capacity is taken simultaneously with secretion rate 2) The pipette is used and one droplet of this stimulated saliva is placed on a small test pad of a test strip strip. 3) Wait exactly 5 minutes, as color will change with time, for the reaction of saliva and indicator.
  13. 13. Salivary p analysis result y pH y Compare the color of the test pad with the standard color chart. This color indicator reflects the pH on the strip. Final ph value 6.0 or more 4.5 - 5.5 4.0 4 0 or less 17 March 2009 Buffer capacity High Medium Low Dr. Wael M Swelam 13
  14. 14. Summery of saliva testing 17 March 2009 Dr. Wael M Swelam 14
  15. 15. 17 March 2009 Dr. Wael M Swelam 15
  16. 16. A. Analysis of subgingival plaque Precautions Careful recording for all medications; contraindicated during Antimicrobial including systemic antibiotic Removal of heavy deposits of supragingival plaque Transient antihistaminic 1. Direct examination using microscope; have limited value only to assess motile spirochetes 2. Culture organism and perform sensitivity test; sample preservation is critical for experimental success 3. PCR / DNA probes 4. 4 Perioscan “office based test indicate the presence of pathogens (T denticola B office-based test” (T. denticola, B. forsythus, & porphyromonas gingivalis) capable to hydrolyze BANA enzyme 17 March 2009 Dr. Wael M Swelam 16
  17. 17. Analysis of subgingival Temperature a.Principle: • Inflammation is usually related to increase in organ temperature; WHY? b Tools: using either infrared thermometer OR periotemp b.Tools: c. Protocol: Apply the tip similar to periodontal probe calibration First ll t th Fi t collect the normal healthy core temp, then measure the l h lth t th th subgignival temp The instrument uses light indicator system (Normal=green, Slightly elevated=yellow, and Elevated=red) 17 March 2009 Dr. Wael M Swelam 17
  18. 18. Objective: PST “Commercial” test to check two j interleukin-1 genes closely correlated to advanced periodontal diseases Tools & Procedure: – Collect finger stick blood sample – DNAase-free blotting paper – PCR technique to evaluate gene polymorphism 17 March 2009 Dr. Wael M Swelam 18
  19. 19. Background: 1) 2) 3) Inflammation of the gingiva, usually referred to as gingivitis, arises in the region of the crevicular epithelium well before any inflammation is clinically visible y Vasculature of gingival tissues provide a vehicle for entire immune process to occur in response to a bacterial challenge in subgingival environment GCF is a serous transudate a) b) In healthy condition it provide homeostasis maintenance mechanism It change into inflammatory exudate during inflammation to deliver immune cells and inflammatory exudate to local environment Objective: Immunologic analysis (Antigens, Antibodies, and Mediators) will be a measure of changes in host response to periodontitis 17 March 2009 Dr. Wael M Swelam 19
  20. 20. Tools: 1) M k Markers against; i t l ki 1β i t l ki 6 i t interleukin-1β, interleukin-6, interleukin-8, tumor necrosis factor-α 2) Enzymatic activity; neutral proteases, lactate y g ,β g , dehydrogenases, β-glucouronidase, and alkaline phosphatase Precautions: a) Moisture control b) Careful removal of existing debris Procedure: 1. Insert filter paper strip into gingival sulcus 2. Leave it in place till it appear saturated 3. Remove it and measure collected volume in periotron 4. ELISA to analyze markers and antibodies l k d b d 17 March 2009 Dr. Wael M Swelam 20
  21. 21. 17 March 2009 Dr. Wael M Swelam 21
  22. 22. Background: 1) 2) 3) 91% Diagnosis of Oral cancer is dependent on clinical exam, brush biopsy, toluidine blue, and biopsy Cancer cells change the body metabolism which can be traced metabolism, by its products in body fluids including saliva Saliva screening for oral cancer was +ve for a) b) c) d) e) ) HIV IL-1β, IL-8, Spermidine acetyltransferase, Ornithin decarboxylase O i hi d b l Tools: Oral Fluid Nano-Sensor Test (OFNASET) 17 March 2009 Dr. Wael M Swelam 22
  23. 23. OFNASET Automated, Integrated eicroelectromechanical system that g y will enable simultaneous and rapid detection of Multiple salivary protein, and Nucleic acid targets 17 March 2009 Dr. Wael M Swelam 23
  24. 24. • Microfluidic chip “using a detection system based on up-converting p p g phosphor technology” has been p gy developed to detect HIV, • TB assay to detect antibodies in saliva, • M l i test will identify nucleic acid as well as antigens Malaria ill id if l i id ll i 17 March 2009 Dr. Wael M Swelam 24
  25. 25. Oral pathogens & their toxins can be transmitted through p g g blood to other organs 1) Cardiovascular diseases (CVD): a) B th CVD & periodontal di ) Both i d t l disease are i fl inflammatory di d t disorder b) The relationship is indirect rather than direct Test Total serum cholesterol Low-density lipoprotein cholesterol (LDL) High-density lipoprotein cholesterol (LDL) C-reactive protein 17 March 2009 Normal Increase risk of CVD <200mg/dl 200-239mg/dl, borderline high ≥240mg/dl, high <100mg/dl <100 /dl 100-129 mg/dl, above optimal 130-159mg/dl, borderline high g/ , g 160-189mg/dl, high ≥190mg/dl, very high ≥60mg/dl, high <40mg/dl, low 1.5-3.0mg/dl, moderate risk <1.0mg/dl >3mg/dl, high risk Dr. Wael M Swelam 25
  26. 26. 1) Diabetes mellitus: a) Oral infections trigger inflammatory mediators = increase insulin resistance b) Conversely, diabetes increases risk for p ) y periodontal disease as indicated by (Glycated hemoglobin) level Test T t Impaired Glucose Gl tolerance Normal N l Diabetes Di b t Casual blood glucose conc. < 100 mg/dl Fasting l F ti plasma glucose (FPG) l < 100 mg/dl /dl 100-125 100 125 mg/dl /dl ≥ 126 mg/dl /dl Oral glucose tolerance test (OGTT) < 140 mg/dl, high > 140- <200 mg/dl ≥ 200 mg/dl Clycated hemoglobin (A1C) 17 March 2009 ≥ 200 mg/dl <6.0 <6 0 mg/dl /dl Dr. Wael M Swelam 26