Do you still get that bonus booklet when you visit the dentist? Does the health insurance company then check whether you visit once a year or even twice a year?

If you need a dental prosthesis one day, the bonus book will be looked after. If you cannot prove regular annual or two-year checkups, there is no additional bonus for dentures.

The idea behind Bonus string:

For each control investigation,
Dentist practicea stamp is obtained. If insured persons can prove stamps for five years, there is a higher grant – 70 instead of 60 percent from the health insurance fund for dental replacement treatment (crone, bridge, prosthesis).

and that can actually be worthwhile and if you would not need such a replacement…