The shape of an implant crown has a significant influence on how well it can be kept clean using home oral hygiene, and concave crown shapes appear to be easier to clean; it also seems that the underside of an implant crown in the molar area is easiest to access with dental floss.

Commonly used definitions for successful periodontal treatment are extremely difficult to achieve, but are nevertheless associated with a lower rate of tooth loss; however, the tooth loss rate in patients who regularly attend supportive periodontal treatment sessions is generally very low.

Biofilm accumulation is the main aetiological factor in the development of peri-implant diseases; plaque control and supportive implant therapy are therefore crucial in preventing peri-implant diseases.

In old age, tooth loss leads to significantly reduced social participation in society, while maintaining a minimum of 20 teeth has the opposite effect and leads to a significant improvement and therefore more frequent social participation.