## 2 Materials and Methods
### GBR Procedure  
Patients were assessed for eligibility for the study. A preoperative CBCT scan was obtained for each patient to quantify bone volume. Patients lacking sufficient bone volume for implant placement were informed about the study details and signed the research-informed consent form. Once eligibility was confirmed and informed consent was obtained, a thorough oral examination was conducted to assess overall health and identify any oral pathologies requiring treatment before guided bone regeneration (GBR) and implant rehabilitation. Ten days prior to GBR and implant placement, all patients underwent professional oral hygiene procedures, including debridement, as necessary. Failed teeth in the operative sites were extracted eight weeks before GBR and implant placement. Patients received 2 g of amoxicillin (Zimox, Pfizer, Rome, Italy) one hour before surgery, followedby 1 g twice daily for two weeks. In cases of penicillin allergy, 600 mg of clindamycin was administered with the same postoperative regimen. Immediately before surgery, patients rinsed with a 0.2% chlorhexidine solution (Curasept, Curaden Healthcare, Saronno, Italy) for one minute. The surgical procedure was performed under conscious sedation (Diazepam, Hoffmann-La Roche, Basel, Switzerland) and local anesthesia (Septanest with adrenaline 1/100,000, Septodont, Saint-Maur-des-Fosses, France). A mid-crestal incision (slightly bucally advanced) was made into the residual keratinized tissue using a no. 15 surgical blade, followed by two bilateral vertical incisions one or two teeth away. A full-thickness flap was elevated beyond the mucogingival junction, at least 5 mm beyond the bone defect, and the recipient site was thoroughly cleared of soft tissue remnants. Autogenous bone was harvested from the planned implant site or the mandibular retromolar region using a minimally invasive cortical bone harvester (Micross, Meta, Reggio Emilia, Italy). The bone defect was then filled with a 50:50 mixture of autogenous bone and heterologous bone substitute (natural equine bone granules, Bioactiva, Arcugnano, Italy), pre-treated with Vortex Plasma using the material holder. A plasma-treated, CAD/CAM-designed, titanium mesh (Exocad DentalCAD, Exocad, Darmstadt, Germany), customized based on the contralateral region's outline and shape (New Ancorvis Srl, Bargellino, Calderara di Reno, Italy), was then placed to cover and protect the grafted site. The customized titanium mesh was fixed with two to three pre-planned bone screws and covered with a plasma-treated pericardium membrane (Bioactiva, Arcugnano, Italy) (Figures 6 and 7). Tension-free flap closure was achieved using Vicryl 4.0 sutures. Postoperatively, patients received 80 mg of ketoprofen (Oki, Dompe, Milan, Italy) and 4 mg/day of betamethasone (Bentelan, Glaxo, Verona, Italy) for two days. They were instructed to rinse with 0.2% chlorhexidine (Curasept) three times daily for two weeks and consume only soft foods for 30 days. Sutures were removed after 14 to 21 days. Baseline periapical radiographs were taken at the end of the procedure, during reopening, at prosthesis delivery, and annually thereafter. The ACTILINK Reborn with Universal Vortex Holder (Plasmapp Co., Ltd., Republic of Korea) was used to treat all biomaterials, as previously reported [12]. Six months after GBR, implants were placed following the manufacturer's standard protocol. After flap elevation, implant sites were prepared using drills of increasing diameter, with bone quality subjectively categorized as hard, medium, or soft. The motor torque was set to 25 Ncm during implant insertion. Implants (Osstem TSIII SOI, Osstem Implant CO., LTD., Seoul, Republic of Korea) were placed in prosthetically planned positions. Since the implants had an activated surface, no additional Vortex Plasma treatment was performed. Implants were placed at crestal level or slightly below, either freehand or using a CAD/CAM surgical template. Four months post-implant placement, the implants were exposed, and soft tissue was managed as needed.