Why does bleeding occur when brushing teeth after not brushing for a long time?

If you don't brush your teeth for a long time, bleeding while brushing may indicate inflammation. Ultrasonic vibration is used to remove dental calculus, plaque, and inflammatory granulation tissue around the gums, followed by local irrigation with alternating hydrogen peroxide and physiological saline. The main purpose of daily tooth brushing is to remove plaque and food debris. Prolonged lack of brushing leads to plaque accumulation, formation of dental calculus, irritation of the gums, and subsequently gum inflammation and redness.