Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Double-blind, Randomized, Parallel, Placebo-active Controlled, Multi-center Phase II Clinical Trial to Investigate the Efficacy and Safety of YH14642 Following 12-week Oral Administration in Patients With Chronic Periodontal Disease
Brief Summary: This study is designed to evaluate the efficacy and the safety of YH14642 in Korea patients with chronic periodontitis, in order to investigate the recommended therapeutic dose.


Options:
A: Inclusion Criteria:

* 18 years of age and up
* clinical and radiographic signs of severe (CAL 5 mm or more) chronic periodontitis.
* at least 20 natural teeth in situ
* pocket probing depths (PPDs) of ≥ 5 mm at a minimum of eight tooth sites
* willingness to participate and to be available at all times required for participation
* over 30% of the teeth present must have a PPDs)≥ 4 mm and insertion loss ≥ 5 mm evaluated by an experienced periodontist
* informed consent signed by the patient

Exclusion Criteria:

* if they (or parents or siblings) show confirmed or assumed allergies or hyper-sensitive skin reactions against moxifloxacin, ciprofloxacin (or other quinolones as listed in the "summary of product characteristics, Version Juli 2005"), metronidazole (or other 5-nitroimidazoles and ingredients of Flagyl® 400mg as listed in the "summary of product characteristics, Version Juli 2007"), systemic diseases or conditions as listed in the above mentioned "summary of product characteristics"
* subjects who have undergone antibiotic therapy three months before the start of the study under interrogation
* have Down's syndrome
* known AIDS/HIV
* regularly take systemic medication affecting the periodontal conditions, e.g. phenytoin, nifedipine, and/or steroid drugs
* professional periodontal therapy during 6 months prior to baseline
* require antibiotic treatment for dental appointments
* are pregnant or breastfeeding
B: Inclusion Criteria:

* Females and males with advanced periodontal disease referred between November 2007 and January 2009.
* No diseases known to be associated with periodontal diseases, i.e. diabetes mellitus, rheumatoid arthritis, pregnancies.
* No continuous medication known to affect the severity or progression of periodontal diseases.
* No previous systematic periodontal treatment.
* More than 5 pockets 5mm \< PPD \< 9 mm after a 3 month hygiene phase - i.e. before inclusion into study.
* Oral hygiene; \< 5% of surfaces with plaque at inclusion time.
* Signing an informed consent.

Exclusion criteria:

* diseases known to be associated with periodontal diseases, i.e. diabetes mellitus, rheumatoid arthritis.
* pregnancy
* continuous medication known to affect the clinical expression of periodontal diseases
* subgingival microbiological diagnosis which reveals bacteria with reduced/no sensitivity to metronidazole
C: Inclusion Criteria:

* ≥35 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 6 months;
* antibiotic therapy in the previous 6 months;
* long-term intake of anti-inflammatory medications;
* need for antibiotic pre-medication for routine dental therapy;
* use of orthodontic appliances;
* extensive dental prosthetic rehabilitation;
* allergy to metronidazole and/or amoxicillin.
D: Inclusion Criteria:

* Subjects must be 20 years of age or older
* Have at least 18 natural teeth
* Four or more clinical attachment level(CAL) ≥ 3mm
* Four or more periodontal pockets with a probing depth (PD) ≥ 4mm
* Have Bleeding on probing
* Provide informed consent and willingness to cooperate with the study protocol

Exclusion Criteria:

* Forbidden History of Panax Notoginseng and Rehmanniae Radix Preparata
* Hypersensitivity of Doxycycline
* Hypersensitivity of Zea mays L. extract
* Critical diseases such as HIV previous three years
* Patients with mental retardation and dementia
* Systemic diseases such as diabetes and hypertension
* Patients who take Anticoagulants or Antiplatelet Agents
* Patients who have malignant tumor
* Smoker
* Continually use for 2weeks of phenytoin, calcium channel blocker, cyclosporin, coumarin, nonsteroidal anti-inflammatory drugs and aspirin use in the previous one month
* Patients who need malignant tumor
* Patients who received periodontal treatment within the last 6 months
* Pregnant or lactating females

Answer: D