## 3 Results  
The search strategy initially identified 419 articles for screening. After eliminating duplicates, this number was reduced to 293 articles. Upon screening based on title and abstract, only 10 articles remained for the subsequent stage of the process. Screening at the full-text level resulted in just three articles [36; 37; 38], one pilot randomized clinical trial [36], one prospective case series study [37], and one case series study [38] that fulfilled all eligibility criteria. The flowchart of the screening and selection process, according to the PRISMA guidelines, is presented in Figure 1. The primary characteristics of the included articles are summarized in Table 2.  
Across all the studies, there existed notable diversity in the types of 3D scaffolds employed, as outlined in Table 3. More specifically, one study [36] used a polycaprolactone scaffold, the second one [37] used a porous hydroxyapatite block scaffold, and the third [38] combined a porcine antigen-free cartilage scaffold with collagen-based antigen-free bovine filling material. [PERSON] et al. [38], in their case series study, examined the effectiveness of 3D scaffolds in sinus lift procedures. They reported that implant stability increased through the follow-up period, while only two implants were lost, one due to temporary prosthesis and one due to postsurgical infection. [PERSON] et al. [36], in their RCT study, tested the healing of fresh sockets with or without the use of polycaprolactone 3D scaffolds. No adjunct agent was applied in the test group, whereas the sockets of the control group were merely sutured in order to achieve primary closure directly after tooth extraction. They concluded that the sockets healed with 3D scaffolds showed less vertical resorption compared to the control group. Nevertheless, the horizontal resorption was more evident in the test \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Author (Year)** & **Study Design** & **Sample** & **Intervention** & **Follow Up** & **Outcome Criteria** & **Main Results** \\ \hline [PERSON] et al. & Case series & 18 patients & 3D scaffold for sinus augmentation and implant placement & 6 and 12 months & 6 and (T0), 6 months (T1), and 12 months (T2). & Implant stability was increased over time from day 1 to 12 months postsupically. \\ \hline [PERSON] et al. (2014) [36] & RCT & 13 patients & Test group: 3D scaffold for socket preservation & Bone resorption, implant stability via IgA, degree of radioactivity via RGS, bone regeneration via micro-CT, via micro-CT, based mainly mineralized bone formation. \\ \hline [PERSON] et al. (2014) [37] & Prospective study & 10 patients & 3D HA scaffolds and graft for ridge augmentation and implant placement & 12 months & Presence of pain, supuration, or evaluation. Histological and histological component & Scaffolds were of satisfactory size, shape, and appearance. Good match to the defect. Easy handling. Less surgery time. \\ \hline  & & (3D): three-dimensional; (RCT): randomized clinical trial; (HA): hydroxyapatite; (RFA): resonance frequency analysis; (RGS): radiopacity grading scale; (CT): computerized tomography; (sig. dif.): significant difference; (P): level of statistical significance. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Main characteristics of the included studies. Figure 1: Flowchart of the screening and selection process, according to the PRISMA guidelines. group combined with less implant stability. Albeit, the last data showed no statistically significant difference between the two groups. [PERSON] et al. 's prospective study [37] revealed that the use of 3D scaffolds contributed to good healing of bone defects following an 8-month period. In more detail, the histomorphometric measurements of bone cores after 8 months reported 34.9% (\(\pm\)4.2) new bone, 26.3% (\(\pm\)2.8) biomaterial, and 38.8% (\(\pm\)4.7) marrow spaces. A quality assessment of the included studies is presented in Tables 4 and 5 for the RCT study and the case series studies, respectively.