The treatment depends on the severity of the problem. The good news is that early stages of a gum disease like gingivitis is treatable and reversible, all you need is a good dental hygiene routine.
If plaque has hardened into tartar, and is below your gumline, you would need professional cleaning. Ideally your oral care expert would advise scaling and root planing (SRP). You can think of it as a deep clean procedure for your teeth, which helps fight the gum disease.
However, If the gum disease has been left neglected for some time, you might need other treatments to remove the damaged tissue or help reverse bone loss. In extreme cases, surgical or restorative interventions are a must.
The first step however is to get a thorough annual periodontal assessment and diagnosis. 'The right person to help with this is a periodontist - a dentist who specializes in preventing, diagnosing, and also treating gum disease.