**8.3 Bacteriologic tests of pulp canals**

*Oral and Maxillofacial Surgery*

**8.1 Oral bacterial smears**

inoculation of appropriate media [8].

**8. Oral bacteriologic examination**

c.At the laboratory, using the sterile tissue grinders, the specimen is ground into suspension, which is left to settle. The supernatant fluid is then used for the

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:

culture specimen is taken; just dry the site with sterile gauze.

tions and the other under anaerobic conditions.

to saturate the swab with the transport media.

of organisms and alteration of flora [9].

a.Isolate the area with sterile cotton rolls.

a.Do not use antiseptic or disinfectants for cleaning the site from which the

b.The sterile swab moistened with sterile saline should be introduced into the wound or lesion and removed without touching the adjacent tissues.

c.The sterile swab should be immediately put into the sterile test tube and the part of the swab handle touched by the fingers and hand in grasping should be broken off and discarded. Some commercials have plastic cap that covers the end of the swab handle and also serves as a cap for the test tube. Two cultures should be taken from each site so that one can be grown under aerobic condi-

d.The cover of the test tube should then be screwed on tightly and the tube titled

e. Sterile swabs in empty tubes. These are not to be used as they may cause death

**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

b.Stroke the gingival wall of the pocket to milk out the grosser quantity of micro-

c.Paint the gingival margin with tincture of iodine 1 part, acetone 1.5 parts and

organisms. With a sterile cotton pledget, wipe away the exudates.

**54**

the gingival pockets:

glycerin 0.5 part.

The technique for culture from pulp canals is:

