Assessment of the half-life of cationic periodontal pocket irrigation

BACKGROUND: The concentration and persisting time of antimicrobial agents in the periodontal pockets are important factors for their antimicrobial efficacy. Increased clearance time in the periodontal pocket is a significant criterion for the selection of intrapocket irrigants. The aim of this study was to estimate the clearance time of a cationic agent from the periodontal pocket. METHODS: Thallium-201(Tl-201) was chosen as a tracer to simulate the clearance of cationic substance because of its electrical activity. Twenty patients with periodontitis and probing depths 6 to 9 mm were included in this study. In each patient, 3 Mega Becquerel (MBq) of Tl-201 were inserted into the periodontal pocket. Dynamic imaging was performed and clearance of radioactivity was measured. RESULTS: Clearance of radioactivity was 67.1 ± 16.9, 83.1 ± 13.9, 90.4 ± 10.4, 93.39 ± 8.0% at 30, 60, 90 and 120 min, respectively. Half-life of wash-out was determined as 20.3 ± 10.2 min. CONCLUSION: The results of this study demonstrate that the half-life of the cationic solution applied subgingivally was approximately 20 min and labelling of oral irrigants with radiotracers may be used to determine their clearance in further research.