## 2 Materials and Methods
### Clinical Protocol  
Each treated patient received a comprehensive evaluation of function and esthetic in order to re-establish correct tooth positions. Patients were included in this treatment protocol if they were fully edentulous or partially edentulous with terminal dentitions in one or both jaws. Moreover, the periodontal status was screened, and only patients with plaque scores (PS) < 25% and bleeding on probing (BoP) < 20% could receive the treatment. For edentulous patients, brand-new removable dentures were fabricated and worn by patients to re-establish function, aesthetic, and correct tooth positions until the patients felt comfortable with the new disposition. For terminal dentition patients, partial dentures were fabricated if stable teeth were present, otherwise extractions were performed and immediate dentures were fabricated. Diagnoses were made clinically and radiographically with preoperative panoramic radiographs and CBCT scans with radiographic templates  
From 2010 to 2015, implants were positioned free-hand using the radiographic templates to prepare implant recipient sites; from 2016 to the conclusion of the report, fully computer-guided surgery with static templates was used to place the implants. Platform-switched implants with round apexes (Bone Level Implant, [PERSON], Straumann AG, Basel, Switzerland) or tapered apexes (Bone Level Tapered Implant, Straumann) with a narrow neck diameter of 3.3 mm were used in the treated patients. A specific drill set was used to prepare each implant recipient site (Surgical Kit, Straumann). The sequence of the drills was carefully respected in order to underprepare the implant recipient site, enhancing primary stability. The first drill was a needle drill that had to create a hole in the cortical zone. Then, the pilot drill (2.2 \(\O\) mm) was used to create a pathway in the hole made by the needle drill. These two drills were used under copious irrigation at 800 rpm. The last drill was the 2.8 \(\O\) mm drill, which followed the pilot drill pathway. The drill was used without irrigation at 40 rpm in order to recover bone chips along the drill. Then, the profile drill (3.3 \(\O\) mm) was used only in the crestal zone to reduce stress on the cortical zone during implant positioning. The flaps were limited to the implant recipient zone and were not overextended in order to reduce the invasiveness. The insertion torque was confirmed with a torque wrench (Straumann AG). After implant placement, angulated or straight screw-retained abutments (SRA, Straumann) were positioned to enhance the parallelism between the tilted and vertical implants with titanium copings screwed onto them. The SRAs could correct the emergence profile from 0\({}^{\circ}\) to 30\({}^{\circ}\) with different gingival heights to create an appropriate transmucosal tunnel and an axial support for the occlusal load. Sutures were used if necessary and were made by polyglycolic acid (PGA). ChloroExidine (0.1%) was recommended for patients twice daily for one week for plaque control. For pain control, the patients were prescribed analgesics. The sutures were removed 14 days after surgery. The interim prostheses based on the prosthetic plans were milled from blocks of polymethyl methacrylate (PMMA, dima Mill temp, Kulzer) and merged with a self-curing resin (Enamel Plus, Micerium) to the titanium copings. The correct position of the interim prosthesis was determined by occlusal contacts with the opposite dentition. The interim prostheses had no cantilevers and were screwed to 15 Ncm onto the SRAs (Figures 4 and 5). Figure 4: Interim prosthesis without cantilevers. Occlusion was verified with 40 \(\upmu\)m articulating paper to avoid heavy contacts in order to uniformly distribute in centric occlusion and light lateral contacts. Patients were recalled 7 days after the surgery and every 15 days to check the occlusal contacts for the first 3 months. Moreover, maxillary occlusal nightguards were delivered to every patient to minimize the parafunction stress on the implants.