Abstract
Here, we present two Persian 58- and 39-year-old females with an edentulous posterior maxilla in the first molar region and a minimum residual bone height (RBH) of 4 mm. Sinus floor elevation with crestal approach was considered. Platelet-rich fibrin (PRF) was utilized as a crucial safeguard during sinus floor elevation with the assistance of bone tap drills featuring round ends. The placement of cylindrical implants was carried out simultaneously. Before applying this technique "in vivo" on human subjects, the "ex vivo" efficacy of PRF-assisted crestal sinus floor elevation with bone tap drills was evaluated. It seems that PRF-assisted crestal sinus floor elevation with bone tap drills can be used as a simplified minimally invasive technique.