Clinical and microbiological effects of scaling and root planing, metronidazole and amoxicillin in the treatment of diabetic and non-diabetic subjects with periodontitis: A cohort study.

AIM: To evaluate if non-diabetic subjects with periodontitis respond better than subjects with type 2 diabetes to the treatment protocol of scaling and root planing (SRP), metronidazole (MTZ) and amoxicillin (AMX). MATERIAL AND METHODS: Diabetic and nondiabetic subjects with severe periodontitis received SRP + MTZ (400 mg/thrice a day [TID]) + AMX (500 mg/TID) for 14 days. Subgingival biofilm samples were analyzed by checkerboard DNA-DNA hybridization for 40 bacterial species. Subjects were monitored at baseline, 3, 6 and 12 months post-therapy. RESULTS: Twenty-nine type 2 diabetics and 29 non-diabetic subjects participated of this study. Of the non-diabetics and diabetics, 68.9% and 75.9%, respectively, reached the clinical endpoint for treatment (</=4 sites with probing depth [PD] >/=5 mm) at 1 year post-therapy (p > 0.05). The diabetic group presented lower mean clinical attachment gain from baseline to 1 year post-therapy and higher mean proportions of the red and orange complexes than the non-diabetic group (p < 0.05). CONCLUSIONS: Non-diabetic subjects with severe periodontitis did not respond better than type 2 diabetic subjects to the treatment protocol of SRP + MTZ + AMX, both in terms of achieving the clinical endpoint for treatment and of PD improvement. Diabetic subjects exhibited a slightly worse microbiological response and showed a healing process more associated with gingival recession than the non-diabetics.