JDIR Issue (Successful implant placement using a UV-treated implant in a site with recurrent oroantral fistula)

1. Purpose
To report the clinical outcome of implant placement using ultraviolet (UV) photofunctionalization in a surgically and biologically compromised site with recurrent oroantral fistula (OAF) after repeated failed closure surgeries.

2. Methods and Results
A 23-year-old female with chronic recurrent OAF at #16 underwent two previous closure surgeries with persistent infection and compromised bone quality. After resolution of sinusitis and confirmation of graft stability on CBCT, implant placement was planned. Prior to insertion, implant surface wettability was evaluated using a saline droplet contact angle test, followed by UV photofunctionalization to restore surface bioactivity. A crestal osteotome sinus lift was performed simultaneously. Implant stability was assessed using resonance frequency analysis (ISQ), and clinical and radiographic follow-up was conducted for 14 months. The initial ISQ at placement was 75. At 5 months, ISQ increased to 85–96 at the final impression stage. A zirconia screw-cement-retained prosthesis was delivered 6 months after placement. At 14 months after implant placement (8 months after loading), the implant remained functionally stable without recurrence of OAF or infection. Radiographs confirmed maintained bone levels and absence of sinus pathology.

3. Discussion
Implant placement in previously infected OAF sites presents biological challenges due to scar formation, reduced vascularity, and compromised bone quality. UV photofunctionalization removes hydrocarbon contamination and restores superhydrophilicity of titanium surfaces, enhancing early cellular attachment and osseointegration. In this case, the synergy between implant macrodesign and surface bioactivation contributed to favorable secondary stability in a high-risk anatomical condition. Limitations include the single-case design, relatively short follow-up, and absence of standardized quantitative criteria for UV application.

4. Conclusion
UV-treated implant placement demonstrated favorable osseointegration and stable functional recovery in a recurrent OAF site with prior surgical failures. Surface bioactivation through UV photofunctionalization may be a viable strategy to improve implant prognosis in biologically compromised maxillary sites.