IMMEDIATE FIXED REHABILITATION OF SEVERE MAXILLARY ATROPHY USING TILTED TRANS-SINUS IMPLANTS WITH OR WITHOUT SINUS BONE GRAFTING: FOURYEAR RESULTS FROM A RANDOMIZED CONTROLLED TRIAL
PURPOSE. The aim of this trial was to compare the clinical outcomes of tilted trans-sinus implants with or without simultaneous sinus lift for immediate full arch rehabilitation of severe maxillary atrophy.
MATERIALS AND METHODS. Thirty-two subjects were enrolled in this trial for an immediately loaded fixed restoration supported by four or six implants. They were randomized to receive at least one trans-sinus implant without simultaneous bone grafting (group 1, n = 16) or one trans-sinus implant with sinus lift bone grafting (group 2, n = 16). Primary outcomes considered were prosthesis and implant failures, while secondary outcomes were complications and peri-implant marginal bone level changes.
RESULTS. Forty-one trans-sinus implants (23 trans-sinus implants without simultaneous bone grafting and 18 trans-sinus implants with sinus lift), 23 conventional tilted implants and 84 axial implants were inserted. No drops-out occurred. Four years after loading, no prosthesis was lost. One trans-sinus implant failed in the sinus lift group, but there was no statistically significant difference in implant failure between the two groups at patient level (0.0% vs. 6.3%, difference 6.3 %; 95% CI -4.7, 17.3; P = 0.99). No conventional tilted implants or conventional straight implants were lost. Complications occurred in nine patients in the group without bone grafting versus ten patients in the sinus lift group. No statistically significant differences were found in this regard either between groups (patient level, 9/16 vs. 10/16, 56.2% vs. 62.5%, difference 6.3%; 95% CI: -12.9, 25.8; P = 0.99) or the four different centres (50% vs. 62.5% vs. 50% vs. 75%, P = 0.99). Similarly, there were no significant differences in peri-implant marginal bone level changes between either groups (P = 0.67; difference 0.25 mm; 95% CI -0.23, 0.63) or centres (P = 0.695). Considering only trans-sinus implants, no statistically significant difference between the two treatment strategies was observed in peri-implant bone loss (P = 0.55).
CONCLUSIONS. No statistically or clinically significant differences were observed in outcomes between tilted trans-sinus implants supporting cross-arch immediately loaded fixed prostheses in atrophic maxillae placed either without simultaneous bone- grafting or with sinus lift four years after loading. However, longer follow-ups on a larger sample are needed.