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:

* 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.
B: 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
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:

* 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

Answer: A