Treatment with subantimicrobial dose doxycycline improves the efficacy of scaling and root planing in patients with adult periodontitis

Background: In a previous study, subantimicrobial dose doxycycline (SDD) si gnificantly improved clinical parameters associated with periodontal health in patients with adult periodontitis (AP) when used as an adjunct to a mai ntenance schedule of supragingival scaling and dental prophylaxis. In this double-blind, placebo-controlled, parallel-group, multicenter study, the ef ficacy and safety of SDD were evaluated in conjunction with scaling and roo t planing (SRP) in patients with AP. Methods: Patients (n = 190) received SRP at the baseline visit and were ran domized to receive either SDD 20 mg bid or placebo bid for 9 months. Effica cy parameters included the per-patient mean changes in clinical attachment level (CAL) and probing depth (PD) from baseline, the per-patient percentag es of tooth sites with attachment loss (AL) greater than or equal to2 mm an d greater than or equal to3 mm from baseline, and the per-patient percentag e of tooth sites with bleeding on probing. Prior to analysis, tooth sites w ere stratified by the degree of disease severity evident at baseline. Results: In tooth sites with mild to moderate disease and severe disease (n = 183, intent-to-treat population), improvements in CAL and PD were signif icantly greater with adjunctive SDD than with adjunctive placebo at 3, 6, a nd 9 months (all P <0.05), In tooth sites with severe disease, the per-pati ent percentage of sites with AL <greater than or equal to>2 mm from baselin e to month 9 was significantly lower with adjunctive SDD than with adjuncti ve placebo (P<0.05). Improvements in clinical outcomes occurred without det rimental shifts in the normal periodontal flora or the acquisition of doxyc ycline resistance or multiantibiotic resistance. SDD was well tolerated, wi th a low incidence of discontinuations due to adverse events. Conclusions: The adjunctive use of SDD with SRP is more effective than SRP alone and may represent a new approach in the long-term management of AP.