Loading... Please wait...Whether you use an "old school" toothbrush or the next generation Diamond Ultrasonic Toothbrush - toothbrush heads need to be replaced at least every 3 months. Your Diamond toothbrush heads provide 30,000 strokes per minute! As durable as these brush heads are they still need to be replaced in order to experience the full benefits of your Diamond Ultrasonic Toothbrush.