It is known that achievement of primary stability is one precondition for osseointegration and treatment success. There are few reports of immediate [14] and early (6 weeks) functional loading of short implants [28]. This is related to good bone quality, implant design or implant site preparation (e.g. under-drilling). However, under-drilling of the crestal aspect may lead to decreased bone-to-implant contact [29]. It is desirable to reduce the periimplant stress on the crestal bone while providing sufficient primary stability for all bone densities.

Therefore, optimisation of the macro- and microdesign of short dental implants to improve the success rate and long-term stability is preferable. In fact, elderly patients with general comorbidity should benefit from the overall short treatment time [28, 30]. As previously shown, the oral health-related quality of life is compromised during the healing period after implant insertion [31], especially when augmentation procedures are required [11]. For several reasons, the overall treatment time should be reduced in patients with atrophic alveolar ridges.

The purpose of the present study was to clinically analyse the feasibility and safety of a new short dental implant system with an expandable compressive design in the apical region. We hypothesised that the innovative expandable macrodesign of this implant provides a reliable implant success rate and ensures high implant stability in vivo.