Please select the eligibility criteria that correspond to the clinical trial below.
Title: Impact of Different Dosages and Time of Administration of Metronidazole and Amoxicillin in the Treatment of Generalized Chronic Periodontitis: A Randomized Clinical Trial
Brief Summary: The aim of this study was to compare the clinical and microbiological outcomes of different dosages of metronidazole (MTZ) and of the duration of the systemic administration of MTZ and amoxicillin as adjunct to scaling and root planing (SRP) in the treatment of generalized chronic periodontitis (GChP).


Options:
A: Inclusion Criteria:

* The periodontal diagnosis of subjects with GAgP was established on the basis of clinical and radiographic criteria defined by the 1999 International World Workshop for a Classification of Periodontal Diseases and Conditions.
* Patients were included if they were between 18 and 35 years of age and otherwise healthy.

Exclusion Criteria:

* if the patients had any known systemic diseases or conditions that can/could influence the periodontal status (cancer, cardiovascular and respiratory diseases)
* history of hepatitis or HIV infection,
* immunosuppressive chemotherapy
* current pregnancy, planning a pregnancy or lactation
* requirement for antibiotic prophylaxis
* oral diseases other than GAgP, ongoing orthodontic therapy
* a history of antibiotic therapy or periodontal treatment within the preceding six months.
* Subjects were excluded if they had known allergies to quinolones or penicillin or metronidazole
* Not willing to participate to the study.
* Not accept to sign written informed consent
B: Inclusion Criteria:

* ≥30 years of age;
* at least 15 teeth (excluding third molars and teeth with advanced decay indicated for extraction)
* a minimum of 6 teeth with at least one site each with probing depth (PD) and clinical \* attachment level (CAL) ≥5 mm;
* at least 30% of the sites with PD and CAL ≥4 mm and bleeding on probing (BOP).

Exclusion Criteria:

* pregnancy
* breastfeeding
* current smoking and former smoking within the past 5 years;
* systemic diseases that could affect the progression of periodontitis (e.g. diabetes, immunological disorders, osteoporosis);
* scaling and root planing an in the previous 12 months;
* antibiotic therapy in the previous 6 months;
* long-term intake of anti-inflammatory medications;
* need for antibiotic pre-medication for routine dental therapy;
* allergy to metronidazole and/or amoxicillin.
C: Inclusion Criteria:

* diagnosis of Generalized Aggressive Periodontitis
* presence of ≥20 teeth
* presence of ≥ 6 sites presenting probing depth (PD) ≥5mm with bleeding on probing (BOP) and ≥2 sites with PD ≥7mm (including incisors and first molars, in addition to two other non-contiguous teeth between them)
* good general health
* \<35 years of age
* agree to participate in the study and sign a written consent

Exclusion Criteria:

* pregnant or lactating
* suffering from any other systemic disease (e.g. cardiovascular, diabetes, blood dyscrasias, immunodeficiency, etc) which could alter the course of periodontal disease
* received antimicrobials in the previous 6 months
* taking long-term anti-inflammatory drugs
* received a course of periodontal treatment within the last 12 months
* smoked
D: Inclusion Criteria:

* under 30 years old and systemically healthy, with at least 20 teeth present. Be willing to participate in the study which is corroborated by signing the informed consent form.

Commit to attend post-therapeutic controls and stop drinking alcohol during the time of ingestion of antibiotics.

Exclusion Criteria:

* Subjects in whom are contraindicated or with hypersensitivity to quinolones - Subjects who have undergone periodontal, surgical or mechanical antibiotic therapy six months before the start of the study according to interrogation.

Women in pregnancy or lactation, corroborated with previous medical history and medical consultation.

Answer: B