BACKGROUND: Maxillary sinus grafting is considered the most common surgical technique to secure a sufficient bone height for placing dental implants. It is carried out either by making a bony window in the lateral wall of the maxillary sinus (the external procedure) or through the alveolar entrance technique by using alveolar osteotomes (the internal procedure), depending on the quality and quantity of the remaining bone. OBJECTIVES: The aim of the present study was to compare radiologically the amount of bone gain (an increase in bone dimensions) and bone reduction (the loss of the graft volume) obtained by using tricalcium phosphate (TCP) and calcium sulfate (CS) grafts mixed with advanced platelet-rich fibrin (A-PRF). MATERIAL AND METHODS: Nine patients (18 maxillary sinuses) participated in this study, all of whom had bilateral edentulism involving the premolar/molar areas and a bone height of 0.5-5 mm between the sinus floor and the alveolar ridge. Two biomaterials were used in the sinus augmentation procedures. Each patient underwent a bilateral maxillary sinus lift with the use of different bone graft materials - with CS mixed with A-PRF used on one side, and TCP mixed with A-PRF on the other side. The grafting site was selected randomly. Afterward, bone gain and bone reduction were evaluated at the grafting site by using cone-beam computed tomography (CBCT). RESULTS: The mean bone gain on the side treated with TCP mixed with A-PRF was 7.532 ±1.150 mm, and on the side treated with CS mixed with A-PRF side it was 7.961 ±2.781 mm. The comparison of bone gain and bone reduction between the 2 groups showed no statistically significant differences at a 6-month follow-up. CONCLUSIONS: Using CS or TCP mixed with A-PRF was beneficial and safe in the two-stage maxillary sinus lifting procedure. A sufficient amount of bone was obtained for dental implantation.