If you have a mix of natural teeth and dental implants, you will want to see your dentist at least twice a year for a cleaning and check up. If you have active or past gum (periodontal) disease, your dentist may want to see you more frequently. You should also brush your teeth and dental implant at least twice a day and floss them at least once a day.
If you do not have any of your own teeth and only have dental implants, you should still follow the advice above. Some people who have demonstrated very good home oral hygiene may be instructed to only see the dental office once a year for an evaluation. Dental implants don't decay, but they are still affected if bone around them is lost so it is important to keep them clean and to keep the gums around them healthy by brushing and flossing properly around them.