[Bleeding on probing.  Significance--consequences]. 
Bleeding on probing is one of the techniques for evaluation of the periodontal pocket tissues condition.  Bleeding, leading sign of inflammation inside the connective tissue, is a critical factor for pocket depth measurements, and with other variable factors prevents making reproducible measurements.  With the concept of periodontal disease with asynchronous bursts of activity and period of remission, has appeared the necessity to determine and even to predict the presence of destructive activity just as it occurs in a particular site in order to set up a selective therapy.  Many authors investigated for a correlation between destructive activity and bleeding on probing.  At the present time, the development of manual or electronic probes provides a useful diagnostic aid for the clinician in daily practice as well as the researcher in longitudinal studies.