Your bone and gum tissue should fit snugly around your teeth like a turtleneck around your neck. When you have periodontal disease, this supporting tissue and bone is destroyed, forming "pockets" around the teeth.
Over time, these pockets become deeper, providing a larger space for bacteria to live. As bacteria develop around the teeth, they can accumulate and advance under the gum tissue. These deep pockets collect even more bacteria, resulting in further bone and tissue loss. Eventually, if too much bone is lost, the teeth will need to be removed.
Scaling and root planing is a careful cleaning of the root surfaces to remove dental plaque and calculus (tartar, dental stone) from deep periodontal pockets and to smooth the tooth root to remove bacterial toxins. The result from scaling and root planing reduces gum inflammation and provide the patients to clean and maintain their teeth better.
Most periodontists would agree that after scaling and root planing, many patients do not require any further active treatment. However, most of patients will require ongoing maintenance therapy to sustain health. In case you still have deep pockets after deep cleaning, gum surgery procedure would be recommended since you have pockets that are too deep to clean with daily at-home oral hygiene and a professional care routine.