Thoma et al. (2018) reported a mean marginal bone level change of −0.12 ± 0.54 in the 6‐mm group and −0.18 ± 0.96 in the group with longer implants, without a significant difference between the groups. Guljé et al. (2019) reported a mean marginal bone level change of −0.12 ± 0.36 mm and −0.14 ± 0.63 mm in the 6‐mm group and the 11‐mm group, respectively, without a significant difference between the groups. These bone level changes throughout 5 years of functioning were very limited. These results corroborate with the outcomes of the present study. Conical‐connection implants with platform‐switching between implant and abutment, together with an optimum surface roughness at the neck of the implant, appear to provide optimal conditions by which to maintain a stable peri‐implant marginal bone level (Cooper et al., 2019). Notwithstanding the much less bone‐to‐implant contact area of short implants, they are still able to withstand functional forces equally well as longer implants.

The presence of plaque is limited, but bleeding on probing is more commonly found at the 5‐year evaluation (Table 3). It must be said that there was no distinction in grades of bleeding; and that any isolated bleeding spot was counted as bleeding. Taking into account the low values of mean pocket probing depth in both groups, one could conclude that peri‐implant soft tissues are relatively healthy, probably due to the yearly oral hygiene regime patients were subjected to within the scope of this study. Prevalence of peri‐implantitis at time of the 5‐year follow‐up was 6% in the 6‐mm group and 7% in the 11‐mm group.