Salt water gargle. Hexidine is it ok!

Sir recently I went for a 2 time  root canal 1 time I have done my root canal nears 2 months ago I have an infection but in infection they completed my root canal 2 time I again consult a dentist they told me it not done in proper way so they show me my infection is speard in my teeth root so they removed the root by doing minor surgery on 15 days ago now my infection is gone and stop  but my concern is that how much time It will take to regrow bone of my teeth root and plz tell me for healing a gums they done a stitches in my gum that time but now the stitches is removed I have some stitches mark. In gum will it gone back after healing how much time It will take and regrow back my natural gums will I do salt water rinse every days 2 time in a day  and 1 time can I use mouth wash like hexidine is it OK