Nielsen HB, Schou S, Bruun NH, Starch-Jensen T. Single-crown restorations supported by short implants (6 mm) compared with standard-length implants (13 mm) in conjunction with maxillary sinus floor augmentation: a randomized, controlled clinical trial. International journal of implant dentistry. 2021 jul. 16;7(1):66. doi: 10.1186/s40729-021-00348-5