This was a randomized, controlled, multicenter clinical trial to investigate whether the outcomes for chemically modified SLA implants in terms of change in crestal bone level from implant surgery to 6 months were non-inferior with early loading (25 ± 3 days) compared to conventional loading (13 ± 1 weeks). The difference in mean crestal bone level change between the early loading and conventional loading groups was 0.048 mm (95 % CI −0.227–0.322); non-inferiority of early loading was therefore confirmed within the parameters of the study. Therefore, null hypothesis was rejected.

Few randomized clinical trials are available showing the results of early loading with chemically modified SLA implants, and there are also relatively few prospective observational studies available [41, 42]. However, clinical studies have shown that successful osseointegration can be maintained and achieved for up to 3 years with these implants, with lower probing depth and clinical attachment level values compared to historical SLA controls [35, 43, 44]. Short implants with this surface have also shown high survival rates and good crestal bone levels after 2 years [37]. Early loading with SLA implants has been shown to be predictable, with excellent outcomes. Clinical data have shown that SLA implants can have very high success rates after 5 years following restoration after 6 weeks in type I to III bone and after 12 weeks in type IV bone, in both fully edentulous and partially edentulous patients and in both the mandible and maxilla [45–48], with stable crestal bone levels over 5 years [49]. Predictable early loading of SLA implants with maxillary full-arch prostheses [50] and mandibular overdentures [51] has also been observed.

The mean change in the bone level between baseline and 6 and 12 months of 0.561 and 0.760 mm, respectively, for early loading was similar to that found in other clinical studies of early loading with chemically modified SLA (SLActive®) implants. For example, a mean change in the bone level of 0.63 ± 0.95 mm from baseline to 12 months was observed with early loading of implants with the chemically modified SLA surface in the posterior maxilla and mandible in a large prospective multicenter study [36]; after 3 years, the mean change in crestal bone level was 0.88 ± 0.81 mm, indicating minimal further bone loss beyond 12 months [38]. An earlier study of early loading with implants with the SLA surface showed a mean bone loss of 0.52 ± 0.98 mm after 1 year, also in the posterior maxilla and mandible [52]. A three-arm study of early loading of SLA implants in the edentulous posterior maxilla and mandible and completely edentulous maxilla showed a mean marginal bone loss of 0.75 ± 1.3 mm after 1 year [53], while a study of SLA implants in the posterior mandible showed mean crestal bone loss values of 0.57 ± 0.49 and 0.72 ± 0.50 mm for early loading after 2 and 6 weeks, respectively, after 1 year [54].