You have been treated according to the new Guided Biofilm Therapy (GBT) protocol with new technical equipment (devices from EMS, Nyon, Switzerland, with AIRFLOW® and PIEZON® PS technology - Ultrasound) in association with regular preventive care for your recalls. The devices and the GBT protocol have been developed to make the prevention session as effective, comfortable and gentle as possible.We are interested in understanding your first-hand experience of this treatment. Please take a moment to fill out the anonymous questionnaire as well as you can: Please mark on the scale from 1 to 5, with 1 being the lowest and 5 the highest score.