Implant Outcomes in Crestal Versus Open Sinus Elevation: A Randomized Clinical Trial

Abstract

Purpose: This study aimed to evaluate clinical, radiographic, patient-centered, and patient- reported outcomes of dental implants placed with maxillary sinus bone augmentation using two different sinus floor elevation techniques in reduced residual bone height of four to seven millimeters.

Materials and methods: Thirty implants were placed in conjunction with raising thirty maxillary sinuses in seventeen patients with residual bone heights of four to seven millimeters determined to be primarily due to sinus pneumatization rather than post-extraction resorption, as evidenced by the pre-operative CBCT analysis and comparison to neighboring alveolar bone level heights, with either crestal (indirect/osteotome) or open (direct/lateral window) sinus augmentation using allograft material. Patients were randomly assigned to the test group (crestal technique) or the control group (open technique). A 12-month follow-up assessed dental implant stability through Resonance Frequency Analysis (RFA) and monitored plaque, bleeding indices, and peri-implant probing depths. Changes in vertical, crestal, and buccal bone around the implants were examined after surgery, at six and at 12 months using low-dose Cone Beam Computed Tomography (CBCT) with a fusion module. Additionally, relative radiographic bone density was evaluated utilizing specialized software at six, nine and 12 months. Finally, the patient-centered outcome of edema was objectively measured as well as subjectively reported by the patient.

Results: After 12 months of follow-up, no significant differences were observed between the groups regarding radiographic parameters. There were no statistically significant differences in ISQ scores or implant success/failure rates (p>0.05). Clinically, the test (crestal) group exhibited a lower bleeding index (BI) (p=0.027) and more favorable edema outcome scores, measured by both patient-centered and patient-reported methods, compared to the control group (p=0.016 and 0.003, respectively).

Conclusions: The crestal sinus lifting technique using osteotomes, performed simultaneously with implant placement and allogenic bone grafting, shows only superior clinical outcomes of BI, radiographic outcomes of buccal bone changes, and patient-centered and reported outcomes of edema compared to the open sinus lifting technique. Therefore, the findings suggest that, while the crestal approach demonstrates certain advantages, both techniques can be considered for managing crestal bone heights ranging from four to seven millimeters, providing surgeons with two viable options for dealing with such reduced bone heights. This clinical trial was registered on ClinicalTrials.gov (ID: NCT06265467).

Clinical relevance: The technique of choice where the maxillary sinus had pneumatized, especially in areas where the residual bone height ranges from four to seven millimeters, is debatable. Our study presents crestal sinus versus open sinus augmentation as a less invasive alternative that may provide similar results.

Keywords: Bone grafting; Crestal Sinus lift; Dental Implants; Fusion module; Maxillary sinus; Open Sinus lift; Patient- reported; Patient-centered; Resonance Frequency Analysis; Sinus elevation.