may be caused due to poor oral hygiene
Increased salivary secretion ,especially mucous secretion can cause gingivitis
thro' plaque deposition.
I would advice to maintain oral hygiene well.
Use soft bristled toothbrush and clean your teeth involving all aspects.
mouthrinse to gargle.
Antisialogogues can be administered to reduce salivary flow.
Take a balanced diet and drink plenty of water.Hope this helps.