Efficacy of short-term adjunctive subantimicrobial dose doxycycline in diabetic patients--randomized study.
OBJECTIVE
To investigate the effectiveness of short-term adjunctive subantimicrobial dose doxycycline (SDD) treatment in patients with diabetes mellitus type 2 and chronic periodontitis (CP).


METHODS
Thirty-four patients with CP and type 2 diabetes mellitus were included in the placebo-controlled, double-blind study. After scaling and root planing (SRP), patients were randomly assigned to two groups, receiving either SDD or placebo bid for 3 months. The probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), approximal plaque index, glycated hemoglobin (HbA1c) level were recorded and gingival crevicular fluid (GCF) samples were collected at baseline and after 3-month therapy for the estimation of matrix metalloproteinase-8 levels.


RESULTS
Clinical attachment level, PD, and BOP improved significantly in both groups after therapy (P < 0.05). The statistically significant difference between the two groups after the therapy was observed only in PD in tooth sites with initial PD ≥ 4 mm (SRP + placebo: 3.41 ± 0.6 mm vs SRP + SDD: 2.92 ± 0.5 mm, P < 0.05). GCF matrix metalloproteinase-8 levels were significantly reduced only in SRP + SDD group (P < 0.01). There were no changes in HbA1c levels after therapy.


CONCLUSION
The short-term administration of SDD gives significant benefit at tooth sites with moderate disease (PD ≥ 4 mm) when compared to SRP alone in patients with diabetes and CP.