The main objective of the study is to assess the knowledge and practice of periodontal health, which will be done using a well constructed and validated questionnaire. Then periodontal health status of all participants will be assessed via clinical examination of certain teeth.

The primary outcome of the study is the knowledge of periodontal health.It will be assessed by 10 questions focusing on the basic knowledge of gingival appearance, causes and consequence of periodontal disease, impact of systemic disease on the progression of periodontal conditions, and prevention. Then, periodontal practice will be addressed via several questions that evaluate the self-care practices of tooth brushing, flossing, mouth rinsing in recent one year, scaling in recent five years, and how to alleviate gingival bleeding if there is.

Periodontal examination using the community periodontal index (CPI) will be done for all of the participants to assess the status of periodontal condition. The dentition will be divided into sextants and the highest code number corresponding to the worst periodontal condition around each of the 10 indexed teeth being recorded.

Inclusion Criteria:

1. Patients whose age is above 15 years old.
2. Patient consulting in the outpatient clinic
3. Provide informed consent.

Exclusion Criteria:

1. Patients having problem in opening their mouth or undergoing intermaxillary fixation where oral examination will not be possible.
2. Patients diagnosed with psychiatric problems or intoxicated with alcohol or drugs.

- Dental patients will be recruited in a consecutive manner from the outpatient Diagnostic center, Faculty of Dentistry, Cairo University.