Adjunctive subantimicrobial dose doxycycline:: effect on clinical parameters and gingival crevicular fluid transforming growth factor-β1 levels in severe, generalized chronic periodontitis

Background: At present there is limited data concerning the efficacy of non-surgical periodontal therapy supplemented with subantimicrobial dose doxycycline (SDD) in the treatment of severe, generalized periodontitis. The purpose of the present study was to evaluate the effect of adjunctive SDD therapy on clinical periodontal parameters and gingival crevicular fluid (GCF) transforming growth factor-beta1 (TGF-beta(1)) levels in patients with severe, generalized chronic periodontitis over a 6-month period. Methods: Thirty-five patients with severe, generalized periodontitis and 11 periodontally healthy subjects were included in the present study. Patients received full-mouth supragingival debridment at baseline and randomized to take either SDD b.i.d. or placebo b.i.d. for 3 months. Patients received root planing and oral hygiene instruction once a week for four consecutive weeks. Clinical measurements including probing depth (PD), clinical attachment level, papilla bleeding index and plaque index and GCF sampling were performed at baseline, 3 and 6 months. The GCF TGF-beta(1) levels were analysed by enzyme-linked immunosorbent assay. Results: Thirteen patients in both study groups completed the 6-month trial. Following scaling and root planing (SRP) plus SDD and SRP plus placebo therapy significant improvements in clinical periodontal parameters of both groups were observed (p < 0.025). In the SDD group a significantly higher percentage (%73.4) of deep pockets resolved (PD reduction >= 3 mm from baseline) when compared with placebo group (%49.7) at 6 months (p < 0.05). At baseline there were no significant differences in GCF TGF-beta(1) levels between three groups. Both total amount and concentration of GCF TGF-beta(1) in SDD and placebo groups increased when compared with baseline at 3 months. However, only GCF TGF-beta(1) levels of SDD group was significantly higher than baseline (p < 0.025) and placebo group (p < 0.017) at 3 months. At 6 months GCF TGF-beta(1) levels of both groups were similar to baseline levels (p < 0.025). Conclusions: These data indicate that combination of SDD with non-surgical therapy improves clinical parameters of periodontal disease and increases GCF TGF-beta(1) levels together with a decrease in prevalence of residual pockets in patients with severe, generalized chronic periodontitis. Increased GCF TGF-beta(1) levels following SDD therapy might suggest a novell pleiotrophic mechanism for tetracyclines to inhibit connective tissue breakdown.