## 4 Discussion  
This study aimed to evaluate the osteogenic potential, structural integrity, and biodegradability of a novel 3D printed resin membrane based on soybean oil for guided  
Figure 11: Photomicrographs at 100\(\times\) magnification illustrating bone formation originating from the walls of the critical-size bone defect, indicated by yellow arrows, and bone formation over the graft granules, represented by green arrows, in the positive control (PC) and positive test (PT) groups at 4 and 8 weeks. [PERSON]’s blue and alizarin red staining. Figure 10: Photomicrographs at 100\(\times\) magnification illustrating bone formation originating from the walls of the critical-size bone defect, indicated by yellow arrows, in the negative control (NC) and negative test (NT) groups at 4 and 8 weeks. Stained with [PERSON]’s blue and alizarin red. bone regeneration (GBR). We emphasize the critical role of adequate bone volume in the long-term survival of implants and the necessity of an approach that combines the advantages of both resorbable and non-resorbable membranes in GBR procedures to meet these demands. Regarding the null hypothesis of this study, which postulated that the 3D printed soybean oil-based resin membrane would not promote significant differences in bone regeneration compared to the control conditions, the results indicate that the null hypothesis was rejected. The use of the 3D membrane demonstrated a significant increase in bone volume and superior bone formation outcomes compared to the control groups. Furthermore, the histological analysis revealed a favorable regenerative response, corroborating the osteogenic potential of the membrane and validating its applicability in GBR procedures. Different types of membranes are employed to address the specific needs of bone defects, whether vertical or horizontal [25; 26]. To assess the efficacy of these materials and techniques, preclinical experimental models are essential, particularly critical-size defects in the calvaria of animals [27]. These defects have minimum dimensions that prevent spontaneous bone regeneration throughout the animal's lifetime [28]. Although the exact size remains debated, studies suggest diameters ranging from 4 mm to 8 mm [29]. In this study, a 7 mm defect was chosen based on previous research within this reference range [24]. In GBR, the use of bone substitute materials, such as autogenous, allogeneic, and xenogeneic grafts, is fundamental in creating a matrix that supports cellular colonization and mesenchymal cell differentiation into osteoblasts, thereby promoting bone formation [30]. Xenogeneic grafts are biocompatible and possess osteoconductive properties. Among them, GTO, the material selected for this study, stands out due to these characteristics and its slow resorption rate, as well as its angiogenic and osteogenic potential demonstrated by [PERSON] et al. [28]. In the present study, a comparative analysis between the NC and the PC groups revealed greater bone volume in the PC group, which received the graft, both at 4 weeks (0.54 \(\pm\) 0.21 vs. 0.24 \(\pm\) 0.13) and 8 weeks (0.62 \(\pm\) 0.35 vs. 0.46 \(\pm\) 0.17), demonstrating the material's efficacy in bone regeneration. Favorable clinical outcomes can be achieved when bone grafts are associated with membranes (barriers) to cover the bone defect [30]. Mechanical separation of the treated area prevents the invasion of undesirable tissues, thereby enhancing regeneration. In the present study, a comparison between the PC and the PT groups showed that using the AESO-based membrane resulted in increased bone volume and new bone formation at 4 weeks (4.48% \(\pm\) 1.56% vs. 5.68% \(\pm\) 2.02%) and 8 weeks (4.51% \(\pm\) 1.11% vs. 7.58% \(\pm\) 0.79%), demonstrating its efficacy in maintaining the graft. The combination of GTO\({}^{\textregistered}\) with the AESO-based membrane provided a favorable level of osteoconductivity and supported bone formation.