The only objective way to know if you have had a thorough cleaning is to have plaque disclosure done. Plaque disclosure uses a special dye that only sticks to plaque (a sticky mass of bacteria known as biofilm).
Plaque is normally clear or tooth-coloured so it can be very difficult to see. The dye is dispensed in chewable tablets or as a gel that has to be painted on to the teeth, then rinsed with water to distribute it. This allows visualization of the plaque so that your dentist can clean more effectively. So perhaps this time, your teeth were cleaner and your dentist didn't need to spend as long cleaning your teeth.
