Clearance of a topically applied fluorescein gel from periodontal pockets

The clearance of a fluorescein gel applied with an irrigation technique in periodontal pockets was studied. In order to evaluate the time a drug remains in a periodontal pocket, the alteration in concentration of this drug in a given time period was investigated. After application of the gel in 4 pockets of 10 patients, samples were taken from 1 of the 4 pockets at 5, 10, 20 and 40 min. The results show that in the 1st phase, directly after application, most of the gel disappeared from the pocket, while in the 2nd phase, the fluorescein gel is washed out with a calculated 50% reduction time of 12.5 min. The rapid clearance of the gel observed after irrigation might provide a partial explanation of the minor effect of pocket irrigation on the subgingival microflora.