[Sinus floor elevation and simultaneous dental implantation: A long term retrospective study of sinus bone gain].

OBJECTIVE: To evaluate the sinus bone gains after sinus floor elevation procedures with or without grafts when implants were placed simultaneously. METHODS: The research included 26 edentulous patients in the maxillary posterior region, who were divided into 2 different groups according to the sinus lift procedures employed: group of osteotome sinus floor elevation with bone grafts (group A) and group of osteotome sinus floor elevation without bone grafts (group B). The implants were placed simultaneously, and were followed for a period of 30-50 months after sinus floor elevation as routine and then were observed for sinus bone change. RESULTS: There were 27 implants (13 implants for group A and 14 implants for group B) and the following time was 40.23 (36.20, 48.07) months. The residual bone height (RBH) was (6.64+/-1.21) mm for group A and ( 6.96+/-1.36) mm for group B; the difference between the two groups was not statistically significant (P=0.459).The sinus bone gain (SBG) when followed was (2.20+/-1.71) mm for group A, and 1.77 (0.94, 2.05) mm for group B; the difference between the two groups was not statistically significant (P = 0.583). The quality of apical bone around implant apex was divided into 3 categories which were excellent, fine and fair.The quality of apical bone around implant apex was excellent and fine for 9 implants in group A and 8 implants in group B, and the difference between the two groups was not statistically significant (Fisher exact test, P=0.695).The implant apex when followed was (0.09+/-1.32) mm below the new sinus floor for group A and (0.03+/-0.91) mm for group B, and the difference between the two groups was not statistically significant (P = 0.898). The SBG for the total was 1.85 (1.10, 2.20) mm. The SBG was statistically significantly only related to the protrusion height of the implant apex (r=0.383, P=0.049). CONCLUSION: Sinus floor elevation procedures with or without grafts can all gain good results. The SBG is related to the protrusion height of the implant apex significantly.