Objectives: The aim of the study was to compare CBCT (Cone Beam Computed Tomography)-derived radiographic hard tissue gain after hydraulic transcrestal sinus floor elevation performed with versus without cross-linked hyaluronic acid (HA) and to assess associated clinical, radiographic, and patient-reported outcomes. Materials and Methods: This single-center, prospective clinical study enrolled 58 patients with 2–6 mm residual bone height in the posterior maxilla, assigned in a non-randomized parallel-group design to HA (n = 29) or No Graft (n = 29). The primary endpoint was CBCT-based 3D CBCT-derived radiographic hard-tissue volume gain at 12 months; secondary endpoints included vertical bone gain, marginal bone loss (MBL) at 12 and 24 months, implant stability quotient (ISQ), implant survival/success, complications, and patient-reported outcomes (VAS pain, OHIP-14). Analyses used ANCOVA and appropriate comparative statistics. Results: At 12 months, mean CBCT-derived radiographic hard-tissue volume gain was higher with HA (1210 +/− 610 mm3) than with No Graft (858 +/− 605 mm3; adjusted difference +352 mm3, 95% CI: 140–564; p = 0.002). ISQ at 12 months was greater with HA (p = 0.028), while MBL at 12/24 months did not differ significantly. Twenty-four-month implant survival was 98.1% (HA) vs. 94.3% (No Graft; p = 0.041). Complication rates were low and comparable; VAS pain at 72 h was modestly lower with HA. Conclusions: In this non-randomized prospective clinical study, cross-linked hyaluronic acid was associated with greater CBCT-derived radiographic hard-tissue volume gain and vertical radiographic gain after hydraulic transcrestal sinus floor elevation compared with clot stabilization alone. Clinical outcomes were favorable in both groups during the 24-month observation period. These findings support the interpretation of cross-linked hyaluronic acid as a potential space-maintaining adjunct in posterior maxillary sites with limited residual bone height; however, because no histological or histomorphometric assessment was performed, they should not be interpreted as proof of vital mature bone regeneration or superior bone quality.
Marenzi et al. (Fri,) studied this question.