Please select the eligibility criteria that correspond to the clinical trial below.
Title: Adjunctive Antimicrobial Therapy of Periodontitis: Long-Term Effects on Disease Progression and Oral Microbiological Colonization
Brief Summary: The purpose of this study is to determine the size of the benefit of an adjunctive empiric antibiotic therapy compared to standard mechanical debridement and oral hygiene instructions in a representative sample of German periodontitis patients.


Options:
A: 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.
B: Inclusion Criteria:

* periodontal screening index (PSI) of IV in at least one sextant;
* range from 18 to 75 years of age;
* clinical and radiographic signs of moderate (clinical attachment loss \[CAL\] of 3 to 4 mm) to severe (CAL 5 mm or more) chronic or aggressive periodontitis;
* at least 10 natural teeth in situ;
* pocket probing depths (PPDs) of ≥ 6 mm at a minimum of four teeth;
* willingness to participate and to be available at all times required for participation;
* willingness to abstain from using antimicrobial mouth-rinses during the study except for those explicitly prescribed;
* informed consent signed by the patient;
* sufficient knowledge of German language.

Exclusion Criteria:

* if they (or parents or siblings) show confirmed or assumed allergies or hyper-sensitive skin reactions against amoxicillin (or other penicillins or other ingredients of Amoxicillin-ratiopharm® 500mg 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", or show confirmed lactose intolerance;
* 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 undergoing or require extensive dental or orthodontic treatment;
* are pregnant or breastfeeding;
* have rampant caries;
* any oral or extraoral piercing in or around the oral cavity with ornaments or accessory jewelry;
* are dental students or dental professionals;
* have participated in a clinical dental trial in the six months preceding the study;
* cognitive deficits.
C: Inclusion Criteria:

* \> 20 teeth
* \> 5% sites (approx. 8 sites) with pocket depth \> 4 mm and / or 5% sites with attachment level \> 4 mm and mean AL \< 4.5 mm and mean PD \< 3.9 mm (not including tooth brush abrasions).

Exclusion Criteria:

* \> 50% of sites with pocket depth or attachment level \> 4 mm
* Pregnancy or nursing
* Periodontal or antibiotic therapy in the previous 6 months
* Any systemic condition which might influence the course of periodontal disease or treatment (e.g. diabetes, AIDS)
* Any systemic condition which requires antibiotic coverage for routine periodontal procedures (e.g. heart conditions, joint replacements etc.)
* Liver disease
* Any known allergy to amoxicillin, metronidazole or doxycycline
* Lactose intolerance
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: B