Case–Control Study with a 6-Month Follow-Up to Compare the Effect of Nano-Hydrophilic and Moderately Rough Implant Surfaces in Association with Transcrestal Sinus Lift

Background: Wettability of dental implant surfaces is a key factor in the osteointegration process. This study aimed to evaluate the effect of a new hydrophilic surface on implant stability in posterior maxilla rehabilitations. Materials and Methods: A 6-month, single-center, parallel-group clinical trial following STROBE guidelines was reported. Implant Stability Quotient (ISQ) changes were compared between implants with a moderately rough surface (MultiNeO CS, Alpha-Bio Tec, Israel, Control Group–CG) and those with the same surface and, in addition, nano-scale roughness and hydrophilic properties (MultiNeO NH CS, Alpha-Bio Tec, Israel, Test Group–TG) placed using a crestal sinus lift technique. ISQ values at bucco-lingual (ISQBL) and mesio-distal (ISQMD) sides were measured at insertion (t0), 4 months (t4), and 6 months (t6). Repeated measures ANOVA (RMA) was performed for statistical evaluation. Results: The study included 35 participants (18 TG, 17 CG). Mean ISQBL0 was 69.45 (SD = 12.62), increasing to 71.72 (SD = 6.74) at t4 and 75.21 (SD = 4) at t6. ISQMD0 mean was 67.54 (SD = 12.54), rising to 72.32 (SD = 6.90) at t4 and 75.67 (SD = 4.60) at t6. No statistically significant differences were found between groups, though TG showed a significant increase in ISQBL at t6 vs. t4 and ISQMD at t6 vs. t0. One-way ANOVA revealed no significant variations between mean ISQ differences over time. Conclusion: Both groups exhibited an increasing ISQ trend, but no significant differences were observed between t4–t0 and t6–t4 periods. Further research is required to assess the impact of hydrophilia on early loading, osteointegration, and long-term outcomes.