In Vivo Biological Behavior of Polymer Scaffolds of Natural Origin in the Bone Repair Process.

Autologous bone grafts, used mainly in extensive bone loss, are considered the gold standard treatment in regenerative medicine, but still have limitations mainly in relation to the amount of bone available, donor area, morbidity and creation of additional surgical area. This fact encourages tissue engineering in relation to the need to develop new biomaterials, from sources other than the individual himself. Therefore, the present study aimed to investigate the effects of an elastin and collagen matrix on the bone repair process in critical size defects in rat calvaria. The animals (Wistar rats, n = 30) were submitted to a surgical procedure to create the bone defect and were divided into three groups: Control Group (CG, n = 10), defects filled with blood clot; E24/37 Group (E24/37, n = 10), defects filled with bovine elastin matrix hydrolyzed for 24 h at 37 °C and C24/25 Group (C24/25, n = 10), defects filled with porcine collagen matrix hydrolyzed for 24 h at 25 °C. Macroscopic and radiographic analyses demonstrated the absence of inflammatory signs and infection. Microtomographical 2D and 3D images showed centripetal bone growth and restricted margins of the bone defect. Histologically, the images confirmed the pattern of bone deposition at the margins of the remaining bone and without complete closure by bone tissue. In the morphometric analysis, the groups E24/37 and C24/25 (13.68 ± 1.44; 53.20 ± 4.47, respectively) showed statistically significant differences in relation to the CG (5.86 ± 2.87). It was concluded that the matrices used as scaffolds are biocompatible and increase the formation of new bone in a critical size defect, with greater formation in the polymer derived from the intestinal serous layer of porcine origin (C24/25).

Decellularized Bovine Skeletal Muscle Scaffolds: Structural Characterization and Preliminary Cytocompatibility Evaluation.

Skeletal muscle degeneration is responsible for major mobility complications, and this muscle type has little regenerative capacity. Several biomaterials have been proposed to induce muscle regeneration and function restoration. Decellularized scaffolds present biological properties that allow efficient cell culture, providing a suitable microenvironment for artificial construct development and being an alternative for in vitro muscle culture. For translational purposes, biomaterials derived from large animals are an interesting and unexplored source for muscle scaffold production. Therefore, this study aimed to produce and characterize bovine muscle scaffolds to be applied to muscle cell 3D cultures. Bovine muscle fragments were immersed in decellularizing solutions for 7 days. Decellularization efficiency, structure, composition, and three-dimensionality were evaluated. Bovine fetal myoblasts were cultured on the scaffolds for 10 days to attest cytocompatibility. Decellularization was confirmed by DAPI staining and DNA quantification. Histological and immunohistochemical analysis attested to the preservation of main ECM components. SEM analysis demonstrated that the 3D structure was maintained. In addition, after 10 days, fetal myoblasts were able to adhere and proliferate on the scaffolds, attesting to their cytocompatibility. These data, even preliminary, infer that generated bovine muscular scaffolds were well structured, with preserved composition and allowed cell culture. This study demonstrated that biomaterials derived from bovine muscle could be used in tissue engineering.

Application of Fibrin Associated with Photobiomodulation as a Promising Strategy to Improve Regeneration in Tissue Engineering: A Systematic Review.

Fibrin, derived from proteins involved in blood clotting (fibrinogen and thrombin), is a biopolymer with different applications in the health area since it has hemostasis, biocompatible and three-dimensional physical structure properties, and can be used as scaffolds in tissue regeneration or drug delivery system for cells and/or growth factors. Fibrin alone or together with other biomaterials, has been indicated for use as a biological support to promote the regeneration of stem cells, bone, peripheral nerves, and other injured tissues. In its diversity of forms of application and constitution, there are platelet-rich fibrin (PRF), Leukocyte- and platelet-rich fibrin (L-PRF), fibrin glue or fibrin sealant, and hydrogels. In order to increase fibrin properties, adjuvant therapies can be combined to favor tissue repair, such as photobiomodulation (PBM), by low-level laser therapy (LLLT) or LEDs (Light Emitting Diode). Therefore, this systematic review aimed to evaluate the relationship between PBM and the use of fibrin compounds, referring to the results of previous studies published in PubMed/MEDLINE, Scopus and Web of Science databases. The descriptors "fibrin AND low-level laser therapy" and "fibrin AND photobiomodulation" were used, without restriction on publication time. The bibliographic search found 44 articles in PubMed/MEDLINE, of which 26 were excluded due to duplicity or being outside the eligibility criteria. We also found 40 articles in Web of Science and selected 1 article, 152 articles in Scopus and no article selected, totaling 19 articles for qualitative analysis. The fibrin type most used in combination with PBM was fibrin sealant, mainly heterologous, followed by PRF or L-PRF. In PBM, the gallium-aluminum-arsenide (GaAlAs) laser prevailed, with a wavelength of 830 nm, followed by 810 nm. Among the preclinical studies, the most researched association of fibrin and PBM was the use of fibrin sealants in bone or nerve injuries; in clinical studies, the association of PBM with medication-related treatments osteonecrosis of the jaw (MRONJ). Therefore, there is scientific evidence of the contribution of PBM on fibrin composites, constituting a supporting therapy that acts by stimulating cell activity, angiogenesis, osteoblast activation, axonal growth, anti-inflammatory and anti-edema action, increased collagen synthesis and its maturation, as well as biomolecules.

Reverse Cast Metallic Core Based on the Original Prosthetic Crown.

The dental crown can be restored using the root in clinical situations where the dental remnant allows adequate anchorage by the use of an intraradicular retainer. After endodontic treatment, reconstruction of the dental anatomy depends on correct planning and the type of restoration to be used. This requires reestablishment of form and function with creation of anchoring features, avoiding detachment and favoring the distribution of forces, thus preventing fracture of the remnant due to functional and parafunctional forces applied on the tooth. This paper reports the clinical case of a patient who sought dental care for a full metal-ceramic crown with a cast metallic core with reduced length that had been detached from tooth 24. After clinical and radiographic examination, root integrity was verified. The patient was offered reconstruction with a cast metallic core of satisfactory length, providing adequate retention and support, with reutilization of the original prosthetic crown, serving as a reverse template of the coronal portion of this new core, providing reduction in costs and operational time.

Reproduction of Esthetic Individuality in Upper Immediate Complete Denture / Reproducción de la Individualidad Estética en Prótesis Completa Inmediata Superior

ABSTRACT: Prosthodontics, in general, aims to rehabilitate the masticatory function of the patient, as well as the stomatognathic system, maintaining his or her individual facial characteristics. The immediate removable complete denture is placed immediately after extraction of the natural teeth and allows adaptation of the patient from the dentate state to the denture, until the definitive denture is placed. When an immediate complete denture is fabricated, esthetics plays a fundamental role and thus the assembly of artificial teeth can be performed maintaining the same position, alignment and arrangement of the remaining anterior teeth, providing a natural and esthetic appearance to the denture, thus the transition from the dentate to the edentulous state is less noticeable. This paper reports the case of a patient who needed oral rehabilitation with an immediate upper complete denture and presented favorable smile esthetics of the anterior teeth, which allowed the preservation of alignment, position and arrangement of natural teeth during the assembly of artificial teeth, maintaining and preserving the esthetic individuality and facial harmonization, meeting the patient's desire and expectations.

RESUMEN: La prostodoncia, en general, tiene como objetivo rehabilitar la función masticatoria del paciente, así como el sistema estomatognático, manteniendo sus características faciales individuales. La dentadura postiza completa removible se coloca inmediatamente después de la extracción de los dientes naturales y permite la adaptación del paciente del estado dentado a la dentadura, hasta que se coloque la dentadura definitiva. Cuando se fabrica una dentadura postiza completa inmediata, la estética juega un papel fundamental y, por lo tanto, el ensamblaje de dientes artificiales se puede realizar manteniendo la misma posición, alineación y disposición de los dientes anteriores restantes, proporcionando un aspecto natural y estético a la dentadura, por lo tanto, la transición desde el estado dentado hasta el estado desdentado es menos notable. Este artículo informa el caso de una paciente que necesitó rehabilitación oral con una dentadura postiza completa superior inmediata y presentó una estética de sonrisa favorable de los dientes anteriores, lo que permitió preservar la alineación, la posición y la disposición de los dientes naturales durante el ensamblaje de los dientes artificiales, manteniendo y preservando la individualidad estética y la armonización facial, satisfaciendo los deseos y expectativas del paciente.