Adjunctive low-dose doxycycline therapy effect on clinical parameters and gingival crevicular fluid tissue plasminogen activator levels in chronic periodontitis

Abstract.Objective and design:??The present study examined effectiveness of low-dose doxycycline (LDD) in combination with nonsurgical therapy on gingival crevicular fluid (GCF) tissue plasminogen activator (t-PA) levels and clinical parameters in chronic periodontitis (CP) a over 12-month period.Methods:??GCF samples were collected, probing depth (PD), clinical attachment level (CAL), gingival index (GI) and plaque index were recorded at baseline, 3, 6, 9 and 12?months. CP patients (n?=?65) were randomized to LDD or placebo groups. LDD group received LDD (20?mg) b.i.d for 3-months plus and root planing (SRP), while placebo group was given placebo capsules b.i.d for 3-months plus SRP. GCF t-PA levels were determined by ELISA. Friedman, Wilcoxon and Mann-Whitney test was used for statistical analysis.Results:??Significant improvement was observed in all clinical parameters in both groups over 12-month period (p?<?0.01). LDD group had lower PD, CAL and GI scores than placebo group at 6, 9 and 12-months (p?<? 0.05). GCF t-PA levels reduced in both groups over 12-month period (p?< ?0.01). LDD group had lower GCF t-PA levels than placebo group at 6 and 9-months (p?<? 0.05).Conclusions:??These results provide additional information about usefulness of LDD therapy as an adjunct to nonsurgical therapy in long-term management of periodontitis.