The aim of the study was to compare the clinical effects of systemic use of doxycycline to amoxicillin plus metronidazole as adjunctive treatment in nonsurgical debridement of aggressive periodontitis (AgP). Twenty four patients with aggressive periodontitis were enrolled in this clinical study. They all received oral hygiene instruction and full-mouth nonsurgical debridement using manual instruments. The test group received as adjunctive antibiotic treatment 200 mg of doxycycline the first day followed by 100 mg per day during 14 days. The control group received 500 of amoxicillin and 250 of metronidazole, three times a day for 7 days.

This comparative clinical study was conducted in the department of Periodontology, Center for Dental Consultation and Treatment (CDCT), Rabat, Morocco.

Prior to participation, the purpose of the investigation was fully explained to all participants and written informed consent was obtained from all patients. The study protocol was approved by the biomedical ethical committee of University Mohammed V in Rabat, Morocco, and conducted according to the principles outlined in the Declaration of Helsinki on experimentation involving human subjects.

Patients : Twenty four subjects diagnosed with localized (LAgP) or generalized aggressive periodontitis (GAgP) (8 patients with LAgP and 16 with GAgP) were enrolled in the study. Patients were aged between 16 and 26 years and were from both genders (22 female and 2 male).The diagnosis was based on the classification of the American Academy of Periodontology (AAP).

Clinical variables were pocket depth, plaque index, gingival index

At the end of the debridement sessions, patients were assigned doxycycline or the amoxicillin plus metronidazole regardless the type of AgP. So that, experimental group of patients were administered 200 mg of doxycycline the first day followed by 100 mg per day for 14 days, and the control group were administered 250 mg of metronidazole and 500 mg of amoxicillin, three times a day for 7 days.

Data analysis The data were analyzed using the patient as a unit (subject based analysis). The statistical analysis was performed with a statistical program (SPSS Inc., Chicago, IL, USA). The improvement of periodontal status was evaluated by calculating, for each patient, the difference in Plaque Index (DIP), gingival index (DIG) and probing depth (DPD) ≥ 4mm, between baseline and 3 months post treatment. For each patient, the quantitative variables (PI, GI, and MPD) were expressed as medians and quartiles and were compared before and after treatment using the Wilcoxon test. Improved plaque index (DIP), gingival index (DIG), and probing depth (DPD ≥ 4mm) was compared between the two groups (doxycycline and amoxicillin plus metronidazole) using the Mann-Whitney test. A level P<0,05 was accepted for statistical significance.

Inclusion Criteria:

• subjects in good general health,
• presence of at least 20 teeth,
• no periodontal treatment performed during the previous 12 months,
• absence of antibiotic intake during six months before the study,
• and no known allergies to antibiotics used in the study

Exclusion Criteria:

• pregnancy,
• lactation,
• and smoking.