Your husband should be seeing the dentist regularly and speaking directly to the hygienist. Periodonitis is primarily caused by bacteria under the gum tissue and the way to combat this is to reduce the amount of bacteria in the mouth. Other factors thay cause periodontitis are systemic; like diabetes, auto immune diseases, and obesity (to name a few). He may need more frequent visits and/or a series of appointments for a deeper cleaning, but without knowing the extent of the disease or the risk factors involved, I cannot say for sure. The hygienist can also prescibe a mouthrinse called Chlorhexadine which kills bacteria for short term use, if necessary.
Diligent home care is essential to stopping the progress of periodonitis. Brushing two times a day (electric toothbrushes are best), for at least two minutes, and flossing daily is crucial. If chlorhexadine is not being used, Listerine or Crest Pro Health mouthwash are over the counter options as well.
Your husband's best course is to speak to the dentist and hygienist. There is no cure for periodontitis, but it can be managed with regular visits and good home care.
Good luck and work on the home care!!!! It is essential.
T., RDH
PS: Xylitol is a great product for reducing cavities, it kills the bacteria that causes them. However, it does not help with periodontal disease, they are caused by different bacteria. Just a little info for everyone.