Bone Regeneration in Defects Created on Rat Calvaria Grafted with Porcine Xenograft and Synthetic Hydroxyapatite Reinforced with Titanium Particles—A Microscopic and Histological Study

(1) Background: Alveolar bone regeneration in dentistry has become important with the evolution of implantology. Biomaterials used for bone grafting are increasingly used to provide resistant bone support that is favorable for the insertion of dental implants. The aim of the study was to analyze the degree of biocompatibility and bone neoformation of two biomaterials compared to natural healing. (2) Methods: Bone defects of 3 mm diameter were created in the calvaria of 15 adult male Wistar rats. Three groups were created: group A, in which natural healing was achieved; group B, in which porcine xenograft was added; and group C, in which experimental synthetic bone based on hydroxyapatite reinforced with titanium particles was added. Samples were collected at 2 and 4 months postoperatively and analyzed microscopically and histologically. (3) Results: Data were obtained on the healing pattern of the created cavities, as well as the degree of their filling with newly formed bone tissue. Following the results obtained from the stereomicroscope analysis and histological analysis, statistically significant differences were observed between the two biomaterials regarding the time required for the transformation process of the graft particles into bone. Thus, the porcine xenograft was incorporated more quickly into the native bone, while the synthetic bone required a longer period of time. (4) Conclusions: The bone graft materials used acted as scaffolds for the newly formed bone, but each biomaterial required a different amount of time for the particles to be incorporated into the native bone.