Implant placement combined with internal sinus lift without graft material

Objectives: Numerous techniques for external and internal sinus lifts are combined with different types of bone grafts. Objective of this study was to investigate the short-term outcome of implants placed with simultaneous internal sinus lifts without using graft materials. Methods: Within a prospective clinical study a total of 169 implants were placed in 81 patients in posterior quadrants of the maxilla. Surgery was combined with internal sinus lifts without using any graft material in 92 implants, whereas 77 implants (without sinus lift) served as controls. All patients underwent perio-operative antibiotic medication. Implant failures were recorded after a minimal observation period of 9 months (mean: 1.72 years; maximum: 4.18 years). Furthermore, panorama X-rays taken 6 months after implant placement were evaluated for the presence or absence of bone gain at the apical aspect of the implants. Kaplan-Meier survival curves and Cox regression analysis were performed to estimate survival curves for the implants and to isolate risk factors for implant failures. Results: A total of 5 failures were recorded (experimental group: 4; control group: 1). The probability of survival was above 94% for both groups. Four failures were characterized by missing osseous integration occurring during the first 3 months after implant placement. The other implants could be used for prosthetic restoration. Comparing the experimental group and controls, Cox-regression analysis revealed no effect of sinus lift (p=0.513) or perforation of the Schneiderian membrane (p=0.226) on the probability of survival. Six months after implant placement, bone gain at the apical aspect of the implants was observed in 32 from a total of 92 implants. Conclusion: Implants placed in combination with internal sinus lifts without using graft material demonstrate promising short-term outcomes with a considerable proportion of implants with apical bone gain within the first 6 months.