Gingivitis and parodontitis are inflammatory parodontal diseases. The primary cause is bacterial plaque, whose formation may be intensified by other factors (secondary causes).

1. Local factors
   
   • Plaque
   • Caries
   • Mouth breathing
   • Reduced salivation,
   • Dental malpositions as plaque retention sites,
   • Overlapping crown rims as plaque retention sites,
   • Errors in filling design as plaque retention sites,
   • Anatomical characteristics complicating oral hygiene,
   • Smoking

2. Functional causes:
   
   • Occlusional and articulation dysfunctions, which may lead to incorrect dental stress

3. Internal factors 
   
   • Metabolic disorders, e.g., diabetes mellitus, allergies, smoking, malnutrition, blood diseases, diseases of the immune system, stress, hormonal changes.