Key factors influencing short implant success

Aim This systematic article reviews the literature on the confounding parameters that affect short implant survival in order to establish specific surgical and prosthetic protocols that create an optimal biomechanical scenario and ensure implant longevity. Materials and methods The available literature was screened for randomized clinical trials and prospective cohort and retrospective studies, published up to February 20, 2020, on the prognosis of short-length implants placed in posterior jaws. Studies evaluating the 5-year clinical performance of short dental implants (5 mm or 6 mm) in fixed rehabilitations of partially edentulous posterior jaws were included. Results Eleven studies were selected after assessment of inclusion and exclusion criteria, of which 8 were RCTs, 2 were prospective studies, and 1 was a retrospective study. After 5 years in function, 22 short (12 in maxilla and 10 in mandible) and 10 standard (2 in maxilla and 8 in mandible) implants were lost, resulting in high survival rates independent of implant length or location. More biological complications were found in standard implants especially those placed in augmented posterior mandibles (135 complications compared to 48 in short mandibular implants). Splinted prostheses were associated with less technical complications (15 out of 53 complications affecting short implants). Conclusion The findings of this review showed that, when used correctly, short implants achieve predictable and promising long-term outcomes, provided they are placed following a comprehensive surgical and prosthetic protocol, based on the different biomechanical parameters essential to optimize long-term prognosis. Clinical significance The use of short implants in clinical practice has considerably increased in a wide variety of cases, given that they offer several advantages for both patient and practitioner. Recent literature shows that, when specific criteria are respected, new generations of short implants present high, long-term survival rates. This review is designed to provide a thorough understanding of the surgical and prosthetic protocols that create an optimal biomechanical scenario for short implants and improve their prognosis.