Gingivitis is inflammation of gums. It is quite common in population. It may lead to a condition known as periodontitis which in turns leads to the loss of supporting elements of teeth. The main cause is plaque ֠bacteria and bio film which develops if oral hygiene is not good. Regular professional hygiene appointment does help in prevention of gingivitis.
Some times inspite of good hygiene there can be gingivitis and that may related to mucogingival condition - absence of functional tissue, high frenum and reduced available height between the cheek and gum margin (low vestibular height). Gingival enlargement also prevents proper hygiene which can be due to certain types of medication prescribed for high blood pressure, Epilepsy, and transplant patient.
All these conditions needs to be diagnosed should be treated in an appropriate ways.