Prophylaxis (from the Greek phylassein, "be vigilant") is a collective term for all measures taken to prevent from the outset any impairments to health, their persistence, increase or reoccurrence. Chronologically, therefore, it mainly occurs prior to examinations for screening or early detection and minimally invasive treatment. Nowadays the modern terms prophylaxis and prevention are often used synonymously.

Prophylactic measures are classified according to various criteria:

Target group: They can be targeted at individual persons (individual prophylaxis), a specific population (group prophylaxis) or the entire population (collective prophylaxis). They are differentiated according to age group as infant-, child-, adolescent-, adult- and geno-prophylaxis and also according to the current physical status as pregnancy prophylaxis or handicapped prophylaxis.

Methods: Different types of methods can be used for prophylaxis, e.g. clarification about and application of behaviour patterns, mechanical and technical aids, preventive use of pharmacological and chemical active agents or vaccines.

Performed by: Measures can be performed by the person affected (oral self-care) or by other persons, mainly medical specialists (professional oral-care).

Disease pattern: Prophylaxis, which is completed on healthy patients (primary prophylaxis), should be differentiated from early detection of incipient disease processes (screening, secondary prophylaxis) and the prevention of relapses after completed treatment (tertiary prophylaxis). Primary-primary prophylaxis is used for pregnant women and is aimed at the unborn child.

Dental prophylaxis is mainly targeted towards caries prevention and periodontitis prophylaxis. One of the central objectives of dental prophylaxis is clarification about and implementation of measures for the control and regular removal of dental plaque (plaque control). It is mainly completed via domestic oral hygiene using aids for mechanical cleaning of occlusal, oral and buccal tooth surfaces (manual and electric toothbrushes, toothpastes), the interdental spaces (dental floss, interdental brushes, toothpicks). Bacterial reduction using disinfectant mouthwash (e.g. with chlorhexidine) can also be a sensible measure (chemoprophylaxis). The dentist can support prophylactic treatment by performing professional tooth cleaning.

Cleaning the tongue (tongue scraper) achieves halitosis prophylaxis.

Periodontal prophylactic measures include restricting or giving up the consumption of tobacco products, correct cessation of manifest diabetes and gingivitis prophylaxis.

Restriction or avoidance of drinks (soft drinks) or food (honey, sweets) with a high sugar content is an effective method of caries prevention. Sealing of caries-free fissures and pits by the dentist is also effective. Fluorides are also used for this purpose, e.g. collective prophylactic fluoridation of drinking water and salt, group and individual prophylactic measures using the application of fluoride gels and varnishes as well as by the use of fluoride toothpastes.

In the case of patients with serious pre-existing diseases or heart abnormalities, administration of antibiotics for endocarditis prophylaxis is required prior to invasive dental procedures.