Your question is very appropriate I will try to answer it. Generally it is seen with the wisdom teeth removal a big space is created behind the second molar which takes long to get completely healed. Also often food gets stuck there which makes cleaning difficult. So ideally when wisdom tooth is removed the cavity created should be packed with collagen sponge which makes the healing much faster also if a lot if bone is removed while taking out the wisdom teeth the site has to be grafted. I hope I could address your query.

Gums may cover socket in a week or so but bone deposition takes 6-8 weeks to occur. It's a natural healing  process. Just take proper care of oral hygiene & well  nutritious diet.