Ivoclar Vivadent CRT bacteria Instrucciones De Uso página 3

CRT ® bacteria
English
Instructions for Use
Description
CRT bacteria is used to determine the mutans streptococci
and lactobacilli count in saliva by means of selective
culture media.
Indication
• In vitro diagnostics
• Bright agar surface: determination of lactobacilli count
in saliva
• Blue agar surface: determination of mutans streptococci
count in saliva, or plaque
Contraindication
Do not use CRT bacteria during treatment with antibiotics.
After such treatment, at least two weeks should pass
before CRT bacteria is used. After the use of an
antibacterial mouthrinse, at least 12 hours should
pass before CRT bacteria is used.
Application
The test is professionally conducted by the dentist and
skilled personnel.
Step by step procedure
1. Have the patient stimulate salivation by chewing the
enclosed paraffin pellet.
2. Collect the saliva in a suitable container.
Tip: Take this opportunity to measure also the
salivation rate and the buffer capacity of saliva
with CRT buffer from Ivoclar Vivadent.
3. Remove the agar carrier from the test vial.
4. Place a NaHCO 3 -tablet at the bottom of the vial.
5. Carefully remove the protective foils from the two agar
surfaces. Do not touch the agar.
6. Thoroughly wet both agar surfaces with saliva,
using a pipette. Avoid scratching the agar surface.
Tip: Hold the agar carrier slightly oblique.
7. Allow excess saliva to drip off.
8. Slide the agar carrier back into the vial and close the
vial tightly.
9. Use a waterproof pen to note the name of the patient
and the date on the vial.
10. Place the test vial upright in the incubator, e.g.
Cultura/Ivoclar Vivadent, and incubate at 37 °C / 99 °F
for 48 hours.
11. After removal of the vial from the incubator, compare
the density of the mutans streptococci and lactobacilli
colonies with the corresponding evaluation pictures in
the enclosed model chart.
Tip: Hold the agar carrier slightly oblique under a light
source to facilitate the evaluation.
Modified procedures
A slight modification of the test procedure permits the
determination of the mutans streptococci count in plaque:
• Remove plaque with a fine brush.
• Apply plaque on the blue agar without scratching the
surface. Up to four samples may be applied on the same
carrier in a parallel pattern without any difficulty.
Note: Apply a small amount of water to the NaHCO
tablet in case not enough saliva drips onto the tablet.
The preparation of sampling and incubation are carried out
according to the step-by-step procedure described in these
Instructions. As far as the evaluation is concerned, this test
only determines whether or not mutans streptococci are
present.
Evaluation
Findings of 10 5 CFU or more of lactobacilli and mutans
streptococci per ml saliva indicate a high caries risk.
Note
Leaving the test vial in the incubator for an additional day
or two does not influence the number of CFUs.
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