Immunohistochemical analysis of growth factors in platelet-rich fibrin membranes.

The use of autogenous materials to promote tissue regeneration has guided the direction of modern dentistry, and platelet-rich fibrin (PRF) is a promising biomaterial for tissue engineering. This in vitro immunohistochemical study aimed to analyze the presence of factors of endothelial growth and cell differentiation in PRF membranes by using the CD31 (endothelial cells) and CD163 (monocytes) markers. Five men and 5 women, aged between 25 and 60 years and without systemic health problems, were enrolled in the study. Blood samples were collected, submitted to a centrifugation protocol, and fixed in 4% formaldehyde, and then immunohistochemical analysis was performed. The histologic analysis of the slides showed that the fibrin clot was formed by a dense fiber network and cells trapped in its structure. One sample was excluded from the markers testing due to poor quality. All 9 of the valid samples were positive for the CD31 and CD163 markers, with reactivity ranging from 5% to 30% and 10% to 40% of cells, respectively. The immunohistochemical analysis showed the presence of CD31 and CD163 in the PRF membranes, indicating the potential for vascular neoformation and the significant presence of monocytes, which play an important role in tissue remodeling via their differentiation into macrophages.

In-Block Lateralization as a New Technique for Mobilization of the Inferior Alveolar Nerve: A Technique Case Series.

The edentulous atrophic posterior mandible is often a great challenge for implant rehabilitation. Although a number of treatment options have been proposed, including the use of short implants and surgical grafting techniques, in cases of severe bone atrophy, techniques for mobilization of the inferior alveolar nerve (IAN) have been shown to be efficient, with good results. Four female patients underwent IAN lateralization for prosthetic rehabilitation of the posterior mandible from 2013 to 2019, with 3 years to 5 years and 3 months of follow-up. This case series describes a new technique for mobilization of the IAN, named in-block lateralization, to facilitate access to the IAN and to reduce nerve manipulation. The implant is immediately installed (allowing nerve lateralization in unitary spaces), and the original mandibular anatomy is restored with autogenous bone from the original bed during the same surgical procedure. When well indicated and well performed, this new approach provides better and easier visualization of the IAN and safer manipulation aiming to achieve good results for implant stability and minimal risk of neurosensory disturbances, allowing rehabilitation even in unitary spaces.