On patients who were treated with surgical operation, blood-culture was done to isolate bacteria. In the cases, appearance of bacteriemie was discussed concernning to methods of surgical treatment, time gathered blood for culti-vation, and degree of the disease was judged clinically.
1) Appearance of bacteriemie could not be considered to have any correlation to methods of surgical treatment (in comparison with gingivectomy and flap operation).
2) Detection of bacteriemie was performed most effectively on the blood gathered at 5 minutes of 5 minutes after operation has started was 41.7% operation (41.7%). On the blood gathered immediately after operation tested cases of 25% were considered to have bacteriemie. At 15 minutes after operation, the lowest frequency for isolation of bacteria was obtained (15.2%). As a tendency, bacteriemie were observed frequently at early stage in the surgical treatments.
3) No correlation observed between defection of bacteriemie and state of pyorrhea alveolaris.
4) Most of isolated bacteria were identified as Streptococcus viridans, and others were determined as Staphylococcus.