2: Efficacy of Diagnostic Techniques for Periodontal Diseases Flashcards
How is periodontal disease currently diagnosed?
almost entirely on the basis of its clinical manifestations
What are the clinical manifestations of periodontal disease?
- gingival inflammation (redness, swelling, plaque index, gingival index)
- periodontal probing (PD, BOP, CAL)
- tooth mobility
- Furcation involvement
- radiographs (BW or PA) (bone changes - amount of bone loss)
What are the traditionally used diagnostic procedures for patients over 50?
periodontal examination and radiographs
What diagnostic techniques are not routinely used in clinical practice?
- microbiological testing
- assessment of host response
- genetic analysis
What are the limitations to probe penetration, CAL, and radiographic examination?
PP: lack of sensitivity and reproducibility
CAL: poor reliability and reproducibility
RE: limited sensitivity in small bone changes, no value in evaluating disease activity or progression
What is a hollow tapered tip that is filled with water for coupling of the ultrasonic beam into the tissues?
ultrasonic periodontal probing
T/F. Conventional radiographs are very sensitive but lack specificity.
False, Conventional radiographs are very SPECIFIC but lack SENSITIVITY.
Why has cone-beam computed tomography (CBCT) been introduced in periodontology?
for the detection of periodontal defects in in vitro settings
The ___ of a diagnostic test refers to the probability of the test being positive when the disease is truly present.
Sensitivity
A / A + B
The ___ of a diagnostic test refers to the probability of the test being negative when the disease is not present.
specificity
D / C + D
What is the gold standard for microbiological testing?
bacterial culturing
Bacterial culturing can assess for ___ susceptibility of microbes and can only grow ___ bacteria but some putative pathogens are ___ (need special nutrients to culture) and are difficult to culture.
antibiotic; live; fastidious
Bacterial culturing has low ___, needs sophisticated equipment and experienced personnel, and is relatively time consuming and expensive.
sensitivity
Direct microscopy includes ___-___and ___-___ microscopy.
dark-field; phase-contrast
Although direct microscopy allows one to identify ___ and ___ of bacterial in a plaque sample, most of the main putative perio pathogens are ___-___ so it is difficult to identify.
morphology; motility; non-motile
How does immunodiagnostic methods work?
It uses Ab that targets specific bacterial Ag
How are direct and indirect immunofluorescent (IFA) microscopic assays are able to identify pathogens?
plaque smear
IFA detects ___ and ___, is comparable to bacterial culture and does not require ___ bacterial cells.
Aa; Pg; viable
What prevents the wide use of cytofluorography (flow cytometry)?
complexity and cost
What is enzyme-linked immunosorbent assay used for?
to detect serum antibodies to periodontal pathogens
What immunodiagnositic method is based on the binding of protein to latex beads coated with species-specific antibody?
latex agglutination
Pg, Tf, and Aa possess in common a ___-like enzyme that hydrolyzes a substrate ___.
trypsin; N-benzoyl-DL-arginine-2-naphthylamide (BANA)
Chair-side enzmatic kit named ___ is not able to distinguish between individual bacteria and may be positive at clinically healthy sites.
Perioscan
T/F. A negative result does not rule out the presence of other important periodontal pathogens.
True.
What are some examples of molecular biology techniques?
nucleic acid probes
checkerboard DNA-DNA hybridization
PCR
Real-time PCR
What nucleic acid probe has high sensitivity and specificity?
16S rRNA
Which molecular technique can identify up to 40 oral bacterial species in a single test but has not be generalized for diagnositc purposes?
checkerboard DNA-DNA hybridization
PCR has high ___ and ___ for the identification of target pathogens but it is unable to quantify pathogens accurately in clinical samples.
sensitivity; specificity
What samples are taken to assess host responses?
saliva gingival crevicular fluid (GCF most common used) blood serum blood cells urine
What is used in the diagnosis of hypophopshatasia?
urine
What is one collecting if they place a paper strip within the crevice for 30 seconds and then measure the fluid volume with a Periotron?
collecting GCF
What are the intracellular destruction enzymes released from dead or dying PMN/Neutrophils from the periodontium?
aspartate amino-transferase (released during tissue destruction)
alkaline phosphatase (membrane-bound glycoprotein involved in maintenance of alveolar bone)
beta-glucuronidase (lysosomal enzyme degrades proteoglycans and ground substance)
elastase (proteolytic enzyme foudn in lysosomal granules of neutrophils)
What is associated with the activity of matrix metalloproteinases and produced by inflammatory, epithelial and connective tissue cells?
extracellular destruction enzymes
There is a marked elevation in ___ levels in GCF from sites with ___ gingival inflammation. There is an inability to discriminate between sites with severe inflammation with or without ___ loss.
AST; severe; attachment
T/F. ALP in GCF is higher in diseased then healthy sites
True.
Beta-glucuronidase is elevated from sites with ___ periodontal disease. It has high ___ and ___ when related to occurrence of clinical ___ loss. It is a good predictor for future ___ breakdown.
severe; sensitivity; specificity; attachment; periodontal
T/F. There is a negative correlation of elastase in GCF with clinical attachment loss.
False, There is a POSITIVE correlation of elastase in GCF with clinical attachment loss.
What is secreted by fibroblasts and macrophages that is responsible for remodeling and degradation of ECM components?
Matrix metalloproteinases (MMPs)
What is the level of MMPs in GCF if a patient is at significant risk for progression of periodontitis?
high
What happens to GCF MMP levels in response to treatment?
levels are reduced
Which MMPs are involved in the initial destruction of periodontal ECM?
MMP-2 (gelatinase A) MMP-9 (gelatinase B) MMP-8 (collagenase 2) MMP-13 (collagenase 3) MMP-3 (stromelysin-1)
What is the ECM of the periodontium composed of?
collagen
proteoglycan
non-collagen proteins
What tissue breakdown products are found in the GCF of sites with periodontitis?
hydroxyproline, glyconsaminoglycans, osteocalcin, type 1 collagen
Which cytokines are inflammatory mediators?
TNF-alpha IL-1alpha IL-1beta IL-6 IL-8 PGE2
T/F. Traditional immunoassays analyze only a single cytokine at a time.
True.
What assay uses color-coded beads and permits the simultaneous detection of up to 100 cytokines in a single well of a 96 well microplate?
bio-plex cytokine assay
In optical spectroscopy, infrared (IR) spectroscopy has vibrating ___ bonds of organic molecules absorb a characteristic wavelength of IR light. The ___ of the absorbed light can be used to establish a molecular fingerprint of a tissue or fluid.
covalent; spectrum
What does the wavelength of light absorbed by IR spectroscopy depend on?
- the nature of the covalent bond (C=0 or N-H)
- the type of vibration (binding and stretching)
- environment of the bond
IR spectoscopy can be used to characterize GCF from healthy, gingivitis, and periodontitis sites. What is its sensitvity and specificity?
both are high
T/F. IR spectroscopy of GCF is reagent free and requires only small sample volumes and minimal training for the operator.
True.
What type of spectroscopy measures oxygen saturation of the tissues?
near infrared (NIR) spectroscopy
The wavelength region ___ to ___ is dominated by the absorption from ___ hemoglobin (HbO2) and ___ hemoglobin (Hb).
500; 600; oxygenated; deozygenated
T/F. Tissue oxygenation at periodontitis sites significantly increases as compared to gingivitis and healthy control sites.
False, Tissue oxygenation at periodontitis sites significantly DECREASES as compared to gingivitis and healthy control sites.
Why test saliva?
- abundant fluid and easy to collect and store
2. highly enriched content of disease biomarkers (Sjogren’s syndrome and oral cancer)
What should be done to find out type and concentration of specific periodontal pathogens?
apply DNA PCR to identify specific periodontal pathogens
What could be done to test genetic susceptibility to periodontitis in individuals?
test genetic variation: over expression of IL-1a or IL-1b
T/F. Tests for periodontal disease identify general risk factors for the development of disease but fail to determine when periodontal destruction will occur.
True, they are not able to specifically predict periods of disease activity.
Salivary Occults Blood Test (SOBT) may offer a simple screening method for periodontal status when what is not possible?
when a through periodontal examination is not possible. It is not sufficiently specific to be a reasonable substitute fro a periodontal examination
How many proteins have been found in whole saliva?
2290
What may offer a cost-effective approach to screening of periodontal disease in large populations?
salivary proteome analysis
