 Short implants are an increasingly popular treatment option for single tooth loss, especially in the posterior upper jaw. Compared with standard implants, short implants could also offer high survival rates and fewer intraoperative complications. Nowadays, immediate functional loading has become a well-accepted treatment modality in the daily dental practice. Immediate loading following a procedure can reduce overall duration treatment and the number of surgical interventions required. However, few studies have examined the treatment outcomes of immediately functionally loaded short implants. To explore these outcomes, researchers compared the effects of immediate versus delayed functional loading of short implants for single tooth replacement in the posterior maxilla. Their findings could offer valuable guidance to dentists weighing different implantation options for patients. Over the course of five years, the team monitored 63 patients receiving a single tooth implant 48 underwent immediate functional loading, whereas 15 underwent loading three months after insertion. The endpoints examined included implant survival rate, bone loss, bleeding on probing, plaque accumulation, periodontal probing depth, and the oral health impact profile. Overall, short implants inserted through either modality yielded satisfactory clinical outcomes. All patients showed subjective improvements in their oral health impact profile score over the post-op period, with no significant differences between the immediate and delayed loading groups. The three cases of implant failure observed throughout the entire study occurred solely in the immediate loading group. And although bone loss was well below the 2 millimeter limit set by the 2007 PISA consensus, bone loss was significantly lower in the delayed loading group. Furthermore, bleeding on probing was generally higher in the immediate loading group and significantly higher in the second and third years following implantation. Similarly, plaque accumulation and periodontal probing depth were higher for the immediate loading group throughout the observation period, which might be attributed to the effect of placing a provisional implant immediately after surgery. This implant could promote the adhesion of harmful bacteria that compromise dental health to some degree. Further studies with a larger sample size are needed to clarify the potential risk and treatment guidelines associated with the loading concept of implant placement for single tooth loss in the posterior maxilla.