**8.1 Oral bacterial smears**

For examination of surface lesions or exudates from a fistula or cyst, a specimen is procured by the means of a sterile platinum wire or a sterile exploring point. A sample of deposit or plaque on a tooth is gathered by the platinum loop, by exploring point or by a pipette. Root canal specimens may be taken with a sterile point. The specimen is then smeared on a glass slide. It is allowed to dry in the air and is fixed on the slide by drawing it three times through a Bunsen flame, when it is ready to be stained. For the proper collection of specimens, the precautions are:


## **8.2 Examination of exudates from inflammatory lesions: gingival pockets**

Discharge from gingival abscess shows various types of pyogenic bacteria (*Staphylococcus*, *Streptococcus pyogenes* and pneumococcus species). Discharge from fistulae and gingival pockets may in addition show a large number of leukocytes. Appleton gives the following method of obtaining a specimen from the gingival pockets:


**55**

*Methods of Collection and Transport of Materials to Laboratory from Oral and Dental Tissue…*

pocket or draw a bit of the material into the capillary pipet.

a.Drying the canal with two or three sterile absorbent points.

covering. Make certain that the point is in the medium.

d.With a sterile flat platinum needle, collect material from the very depth of the

e.Examine the specimen on a slide or else inoculate a number of deep test tubes of semi-liquid medium as ascitic fluid or ordinary nutrient agar plus a piece of fresh, sterile rabbit kidney tissue. This is satisfactory for the cultivation of

b.Inserting a fresh sterile absorbent point and leaving it until the tip is moistened

c.Removing the point with cotton pliers and, with one hand, opening the test

d.Flaming the test tube lip, dropping the point into the tube, and plugging or

f. If the medium is clear after the incubation, it is assumed that there is no growth of organism although a smear may be taken as a check. If the medium is cloudy or a precipitate is seen, assume that infection is still present. In questionable

These are used if bacteremia or septicemia is suspected. *Streptococci*,

*Staphylococci* or *Pneumococci* may be found. In patients with multiple osteomyelitis, with extreme lesions in mandible, blood cultures showed that streptococcal septicemia was the cause. In chronic cases at least 15–30 cc. of blood should be taken for

In actinomycosis the discharge pressed out from the fistula contains the so-called sulfur granules. When soft, these granules can be pressed between two slides and examined without staining. The granules appear as rosette-like masses with dense centers and a network of mycelium. Bulbous clubs or rays extend from the periphery.

Where thrush is suspected, moist preparations may be used, placing scrapings from the suspected lesion directly on a microscopic slide. A 10% solution of potassium hydroxide is added, and the slide is heated slightly and inspected under the microscope. The slide is examined for the branching mycelia and for spores of

*DOI: http://dx.doi.org/10.5772/intechopen.92677*

many anaerobes [10, 11].

**8.3 Bacteriologic tests of pulp canals**

with the exudate (usually 1 min).

e.Incubating for 48 h.

**9. Blood cultures**

The technique for culture from pulp canals is:

tube of the medium held in the other hand.

cases a second culture is taken [10, 11].

the test; in acute cases, 5 cc. is sufficient.

**9.2 Examination for** *Candida albicans*

*Candida albicans* [11].

**9.1 Examination of exudates for actinomycosis**

