Uso de microvibración e inhibidores de la catepsina K en tratamientos de regeneración ósea dental / Use of micro-vibration and cathepsin K inhibitors in dental bone regeneration treatments

Introducción: el hueso está en remodelación constante para mantener la estructura del esqueleto, tener un ciclo de resorción por los osteoclastos y formación de hueso nuevo a cargo de los osteoblastos; el hueso también es susceptible a enfermedades sistémicas, traumas, edad y trastornos genéticos que afectarán el remodelado óseo, produciendo una pérdida masiva de masa ósea regulado por hormonas, citocinas, enzimas, etcétera. El objetivo es realizar una revisión sistemática de artículos que muestren cambio o alteración al utilizar tratamientos con microvibraciones y farmacológicos sobre la catepsina K en el hueso alveolar. Material y métodos: para realizar una comparación entre la efectividad del tratamiento a base de microvibraciones y con inhibidores de la catepsina K, se realizó una revisión sistemática en nueve bases de datos (Wiley Online Library, PubMed, Google Academic, Scopus, ScienceDirect, SciELO, Medline, EBSCO y Springer Link). La población de estudio fueron ratas y ratones. Resultados: en este estudio se incluyeron 20 artículos cuya investigación se realizó en estudios clínicos. En los resultados podemos observar cómo todos los tratamientos de alguna forma mejoran el proceso de remodelado óseo. Es difícil comparar cuál de los tratamientos dentro de cada grupo es mejor que otro, debido a que los resultados expresados son cualitativos. Conclusión: acorde a los resultados expresados se opta por realizar un tratamiento con microvibraciones debido a que el uso de inhibidores de la catepsina K aún no se encuentra completamente desarrollado y no se comprenden sus consecuencias debido a su manera sistémica de actuar (AU)

Introduction: the bone is in constant remodeling to maintain the skeletal structure, having a cycle of resorption by osteoclasts and formation of new bone by osteoblasts, the bone is also susceptible to systemic diseases, trauma, age and genetic disorders that affect bone remodeling, producing a massive loss of bone mass regulated by hormones, cytokines, enzymes, etcetera. The objective is to perform a systematic review of articles that show a change or alteration when using micro-vibration and pharmacological treatments on cathepsin K in the alveolar bone. Material and methods: in order to make a comparison between the effectiveness of micro-vibration and cathepsin K inhibitor treatments, a systemic review was carried out in nine databases (Wiley Online Library, PubMed, Google Academic, Scopus, ScienceDirect, SciELO, Medline, EBSCO and Springer Link). The study population was rats and mice. Results: this study included 20 articles whose research was carried out in clinical studies. In the results we can see how all the treatments in some way improve the bone remodeling process, it is difficult to compare which treatment within each group is better than the other, because the results expressed are qualitative. Conclusion: according to the results expressed, it is decided that it is better to perform a treatment with micro vibrations because the use of cathepsin K inhibitors are not yet fully developed and their consequences are not understood due to their systemic way of acting (AU)

Regeneração óssea guiada para aumento horizontal de rebordo utilizando fibrina rica em plaquetas associada a enxertos ósseos: revisão de literatura / Guided bone regenerationfor horizontal bone augmentation using platelet- rich fibrin associated with bone grafts: literature review

Objetivo: revisar a literatura sobre os diferentes tipos de derivados de plaquetas autólogas e o desempenho clínico do uso do sticky bone para aumento ósseo horizontal de rebordo. Materiais e métodos: Para realização dessa revisão foram realizadas buscas nas bases de dados PubMed, Google Scholar e Web of Science, utilizando os seguintes descritores: "platelet-rich fibrin" AND "sticky bone" OR "alveolar bone grafting" AND "sticky bone" OR "guided bone regeneration" AND "sticky bone" AND "alveolar ridge augmentation" OR "Alveolar ridge augmentation" AND "sticky bone". Foram incluídos artigos publicados em inglês, que abordavam conceitos relacionados aos agregados plaquetários e a regeneração óssea guiada para aumento ósseo horizontal de rebordo utilizando fibrina rica em plaquetas associada à enxertos ósseos (sticky bone). Resultados: Após avaliação dos estudos encontrados foram selecionados 11 artigos sobre o uso do sticky bone para aumento horizontal de rebordo. Para compor este trabalho foram selecionados também 14 estudos de revisão e artigos associados ao tema. Por ser de fácil aplicação e obtenção, muitos autores têm estudado as aplicações cirúrgicas do sticky bone e os resultados demonstram que o aumento horizontal do rebordo utilizando essa técnica pode ser realizado de forma previsível. Conclusão: apesar de haver estudos promissores sobre o uso do sticky bone, falta evidência na literatura sobre seu sucesso clínico. Assim, para compreender o potencial regenerativo desta técnica são necessários um maior número de estudos randomizados, com diferentes materiais de enxerto e protocolos padronizados de obtenção do sticky bone.(AU)

Objective: to review the literature on the different types of autologous platelet derivatives and the clinical performance of using sticky bone for horizontal bone ridge augmentation. Materials and methods: In order to conduct this review, it was conducted searches in the PubMed, Google Scholar, and Web of Science databases using the following descriptors: "platelet-rich fibrin" AND "sticky bone" OR "alveolar bone grafting" AND "sticky bone" OR "guided bone regeneration" AND "sticky bone" AND "alveolar ridge augmentation" OR "Alveolar ridge augmentation" AND "sticky bone". It included articles published in English that addressed concepts related to platelet aggregates and guided bone regeneration for horizontal bone augmentation using platelet-rich fibrin associated with bone grafts (sticky bone). Results: After evaluating the studies found, were selected 11 articles on the use of sticky bone for horizontal ridge augmentation. To compose this work, 14 review studies and articles associated with the topic were also selected. Due to its ease of application and availability, many authors have explored the surgical applications of sticky bone, and the results indicate that horizontal ridge augmentation using this technique can be predictably performed. Conclusion: while there are promising studies on the use of sticky bone, the literature lacks evidence regarding its clinical success. Therefore, to fully understand the regenerative potential of this technique, further randomized studies are needed, involving different graft materials and standardized protocols for obtaining sticky bone.(AU)

Células madre en odontología: nuevas perspectivas / Stem cells in dentistry: new perspectives

En el campo de la odontología, prevalecen actualmente alternativas terapéuticas con una filosofía conservadora. Sin embargo, con el advenimiento de los tratamientos con células madre (CM), se amplían las posibilidades terapéuticas, que buscan la combinación y el equilibrio entre la intervención tradicional y las posibilidades de reposición de estructuras anatómicas dañadas, a través de la regeneración de tejidos utilizando células madre o sus derivados (AU)

In the dentistry field, therapeutic alternatives with a conservative philosophy currently prevail. However, with the advent of stem cell (SC) treatments, therapeutic possibilities are expanding, seeking a combination and balance between traditional intervention and the pos- sibility of replacing damaged anatomical structures through tissue regeneration, using stem cells or their derivatives (AU)

The influence of haematogenous bone marrow on the early osseointegration of a titanium implant which penetrates the endosteum / La influencia de la médula ósea hematógena en la osteointegración temprana de un implante de titanio que penetra en el endostio

SUMMARY: The utility of metallic bio-medical implants in osseous or dental affections is irrefutable. The paper aims to test the tolerance of the bone marrow to titanium implants. Titanium implants were inserted in the femur of 11-months old rabbits. The implants penetrated the endosteum, half of their length getting into the haematogenous bone marrow. Seven days after the insertion we collected bone fragments containing the implant. The CT exam revealed a significant decrease in the density of the bone at the interface with the implant and a more discrete one aloof from the insertion area. The histologic exam after 7 days revealed osseous reparatory processes only in the endosteal area from where it expanded on the surface of the implant which was inside the marrow. The presence and intensity of the osseous reparatory processes after only seven days post-implant demonstrates that the marrow actively participates in bone regeneration and implants osseointegration.

RESUMEN: La utilidad de los implantes biomédicos metálicos en afecciones óseas o dentales es irrefutable. El documento tiene como objetivo probar la tolerancia de la médula ósea a los implantes de titanio. Se insertaron implantes de titanio en el fémur de conejos de 11 meses. Los implantes penetraron en el endostio y la mitad de su longitud penetró en la médula ósea hematógena. Siete días después de la inserción, recolectamos fragmentos de hueso que contenían el implante. El examen de TC reveló una disminución significativa en la densidad del hueso en la interfaz con el implante y una más discreta alejada del área de inserción. El examen histológico a los 7 días reveló procesos de reparación ósea solo en el área endóstica desde donde se expandió en la superficie del implante que estaba dentro de la médula. La presencia e intensidad de los procesos de reparación ósea después de solo siete días del implante demuestra que la médula ósea participa activamente en la regeneración ósea y en la osteointegración de los implantes.

Immunomodulatory effects and mechanisms of distraction osteogenesis / 国际口腔科学杂志·英文版

Distraction osteogenesis (DO) is widely used for bone tissue engineering technology. Immune regulations play important roles in the process of DO like other bone regeneration mechanisms. Compared with others, the immune regulation processes of DO have their distinct features. In this review, we summarized the immune-related events including changes in and effects of immune cells, immune-related cytokines, and signaling pathways at different periods in the process of DO. We aim to elucidated our understanding and unknowns about the immunomodulatory role of DO. The goal of this is to use the known knowledge to further modify existing methods of DO, and to develop novel DO strategies in our unknown areas through more detailed studies of the work we have done.

Regenerating effect of hyaluronic acid on circumferential bone defects in wistar albino rats / Efecto regenerador del ácido hialurónico en defectos óseos circunferenciales en ratas albinas wistar

Objective: To determine the regenerating effect of hyaluronic acid on circumferential bone defects in albino Wistar rats. Material and Methods: An experimental type study was designed and carried out with 15 albino male Wistar rats, 4 months old and weighing between 250 and 350 grams. Two circumferential bone defects 3mm in diameter and 0.8mm deep were created in the calvaria of the parietal bone (on both sides of the midline). One defect was filled with a demineralized bone matrix (control group); while the other defect was filled with the combination of a demineralized bone matrix plus hyaluronic acid (experimental group). Five experimental rats were euthanized at 30, 60 and 90 days after surgery and they were histologically evaluated following the parameters proposed by Heiple. Results: The experimental group presented a better degree of bone regeneration at 30 and 60 postoperative days. Conclusion: Hyaluronic acid is effective in bone regeneration of circumferential bone defects.

Objetivo: Determinar el efecto regenerador del ácido hialurónico en defectos óseos circunferenciales en ratas albinas Wista. Material y Métodos: Se diseñó un estudio de tipo experimental y se trabajó con 15 ratas albinas Wistar (todas macho) de 4 meses de edad y con un peso entre 250 a 350 gr. Se crearon en todas 2 defectos óseos circunferenciales de 3mm de diámetro y 0.8 mm de profundidad en la calota del hueso parietal (a ambos lados de la línea media). Un defecto fue rellenado con una matriz ósea desmineralizada (grupo control); mientras que el otro defecto fue rellenado con la combinación de una matriz ósea desmineralizada más el ácido hialurónico (grupo experimental). Se realizó la eutanasia a 05 ratas de experimentación a los 30, 60 y 90 días postquirúrgicos y se evaluaron histológicamente siguiendo los parámetros propuestos por Heiple. Resultados: El grupo experimental presentó un mejor grado de regeneración ósea en los 30 y 60 días postoperatorios. Conclusiones: El ácido hialurónico es eficaz en la regeneración ósea de defectos óseos circunferenciales.

Biomodificación alveolar como un procedimiento indispensable previo a regeneración ósea guiada / Alveolar biomodification as an indispensable procedure before guided bone regeneration

ABSTRACT Introduction: The placement of dental implants is based on the creation of optimal conditions in the remnant bone. In some cases, it is indispensable to perform bone regeneration procedures and use barrier membranes to create such optimal conditions capable of favorably supporting the dental implant. Objective: Describe alternatives of barrier membranes in cases of guided bone regeneration. Case report: A female 53-year-old patient presents with a gingival fistula attached to tooth 14. Root fracture is diagnosed and extraction is conducted. Next, alveolar biomodification is performed to carry out guided bone regeneration and placement of a fibrin-rich plasma membrane. When healing is complete dental implants will be placed. Conclusions: The use of barrier membrane alternatives has shown to be effective in cases of guided bone regeneration(AU)

RESUMEN Introducción: Para la colocación de implantes dentales se deben establecer condiciones óptimas de hueso remanente, por lo cual existen casos en los que se hace indispensable realizar procesos de regeneración ósea y la utilización de membranas de barrera para generar esas condiciones óptimas que puedan soportar favorablemente el implante dental. Objetivo: Describir alternativas de membranas de barrera en casos de regeneración ósea guiada. Reporte de caso: Paciente femenino de 53 años de edad que acude a consulta por presentar fístula en encía adherida de órgano dentario 14, se diagnostica como fractura radicular y se procede a la extracción, posteriormente se realiza una biomodificación del alveolo para realizar regeneración ósea guiada y colocación de membrana de plasma rica en fibrina, se espera cicatrización para la colocación de implantes dentales. Conclusiones: El uso de alternativas de membranas de barrera muestra resultados efectivos en casos de regeneración ósea guiada(AU)

Resultados de los concentrados plaquetarios en la regeneración ósea guiada / Results of platelet concentrates in guided bone regeneration

Los defectos óseos alrededor de los implantes dentales son considerados enfermedades que afectan el soporte y estabilidad del implante dental lo que limita la oseointegración. El tratamiento de estos defectos involucra procedimientos de regeneración ósea guiada que se define como la reproducción o reconstitución de una parte perdida o dañada del tejido óseo periimplantario con el fin de restaurar su arquitectura y función. El plasma rico en plaquetas y el plasma rico en fibrina son concentrados de plaquetas autólogos ampliamente usados en la regeneración periodontal y regeneración ósea guiada; sin embargo, sus resultados clínicos, histológicos y radiográficos son discutidos cuando se tratan defectos óseos alrededor de implantes dentales. En la presente revisión se realizó una búsqueda de la información mediante las bases de datos de diferentes buscadores (PubMed, SciELO, Redalyc y ScienceDirect) para encontrar artículos que traten sobre el uso de los concentrados plaquetarios (plasma rico en plaquetas y plasma rico en fibrina) en la terapia de la regeneración ósea guiada. Clínicamente, los concentrados plaquetarios otorgan resultados favorables en la reducción de la profundidad de sondaje y ganancia de nivel de inserción clínica en el tratamiento de defectos infraóseos periodontales. Histológicamente, los concentrados plaquetarios favorecen la neoformación ósea aumentando la velocidad de regeneración. Radiográficamente, los concentrados plaquetarios favorecen el aumento de densidad ósea, relleno óseo y tejido mineralizado. Con ello, se logra una reducción significativa del tamaño del defecto óseo(AU)

Bone defects around dental implants are considered to be diseases affecting the support and stability of the implant, thus limiting osseointegration. Treatment of these defects involves guided bone regeneration procedures, defined as the reproduction or reconstitution of a part lost or damaged of the peri-implant bone tissue with the purpose of restoring its architecture and function. Platelet-rich plasma and fibrin-rich plasma are autologous platelet concentrates widely used in guided bone regeneration and periodontal regeneration. However, their clinical, histological and radiographic results are debated when bone defects around dental implants are dealt with. The present review included a search for information in the databases of various search engines (PubMed, SciELO, Redalyc and ScienceDirect) to find papers about the use of platelet concentrates (platelet-rich plasma and fibrin-rich plasma) in guided bone regeneration therapy. Clinically, platelet concentrates yield favorable results in reducing probing depth and raising the level of clinical insertion in the treatment of periodontal intraosseous defects. Histologically, platelet concentrates enhance bone neoformation, speeding up regeneration. Radiographically, platelet concentrates lead to an increase in bone density, bone filler and mineralized tissue. A significant reduction is thus achieved in the size of the bone defect(AU)

Bioceramic cement in the filling of bone defects in rats

Abstract Purpose To evaluate PBS®MCIMMO cement in the filling of bone defects. Methods Thirty-six adult male Wistar rats were divided into three groups of twelve individuals each (group 1, group 2 and group 3). In all groups, a bone failure in the femur was induced, 2.0 mm wide and 7.0 mm deep. In group 1, the PBS®MCIMMO cement was applied to the bone defect produced and a titanium implant (CONNECTION®) 1.5 mm thick and 6 mm long was installed. In group 2, only the PBS® CIMMO cement was installed. In group 3, only bone failure was performed. Kruskal Wallis tests were performed to compare the mean area among the three groups. Results In all comparisons, significance was observed for group 2 (p = 0.0014-0.0026). Conclusion The PBS®CIMMO cement induced bone neoformation, and integration between the newly formed bone, cement, and implant was observed.

Effect of stem cells combined with a polymer/ceramic membrane on osteoporotic bone repair

Abstract Cell therapy associated with guided bone regeneration (GBR) can be used to treat bone defects under challenging conditions such as osteoporosis. This study aimed to evaluate the effect of mesenchymal stem cells (MSCs) in combination with a poly(vinylidene-trifluoroethylene)/barium titanate (PVDF-TrFE/BT) membrane on bone repair in osteoporotic rats. Osteoporosis was induced in female rats by bilateral removal of the ovaries (OVX) or sham surgery (SHAM), and the osteoporotic condition was characterized after 5 months by microtomographic and morphometric analyses. Calvarial defects were created in osteoporotic rats that immediately received the PVDF-TrFE/BT membrane. After 2 weeks, bone marrow-derived MSCs from healthy rats, characterized by the expression of surface markers using flow cytometry, or phosphate-buffered saline (PBS) (Control) were injected into the defects and bone formation was evaluated 4 weeks post-injection by microtomographic, morphometric, and histological analyses. A reduction in the amount of bone tissue in the femurs of OVX compared with SHAM rats confirmed the osteoporotic condition of the experimental model. More bone formation was observed when the defects were injected with MSCs compared to that with PBS. The modification that we are proposing in this study for the classical GBR approach where cells are locally injected after a membrane implantation may be a promising therapeutic strategy to increase bone formation under osteoporotic condition.

The influence of Aloe vera with mesenchymal stem cells from dental pulp on bone regeneration: characterization and treatment of non-critical defects of the tibia in rats

Abstract Objective This study aimed to evaluate the inflammatory effect and bone formation in sterile surgical failures after implantation of a collagen sponge with mesenchymal stem cells from human dental pulp (hDPSCs) and Aloe vera. Material and Methods Rattus norvegicus (n=75) were divided into five experimental groups according to treatment: G1) control (blood clot); G2) Hemospon®; G3) Hemospon® in a culture medium enriched with 8% Aloe vera; G4) Hemospon® in a culture medium containing hDPSCs and G5) Hemospon® in a culture medium enriched with 8% Aloe vera and hDPSCs. On days 7, 15 and 30, the animals were euthanized, and the tibia was dissected for histological, immunohistochemistry and immunofluorescence analyses. The results were analyzed using nonparametric Kruskal-Wallis test and Dunn's post-test. Results On days 7 and 15, the groups with Aloe vera had less average acute inflammatory infiltrate compared to the control group and the group with Hemospon® (p<0.05). No statistically significant difference was found between the groups regarding bone formation at the three experimental points in time. Osteopontin expression corroborated the intensity of bone formation. Fluorescence microscopy revealed positive labeling with Q-Tracker® in hDPSCs before transplantation and tissue repair. Conclusion The results suggest that the combination of Hemospon®, Aloe vera and hDPSCs is a form of clinical treatment for the repair of non-critical bone defects that reduces the inflammatory cascade's effects.

Influence of the geometry of nanostructured hydroxyapatite and alginate composites in the initial phase of bone repair

Abstract Purpose: To analyze, histomorphologically, the influence of the geometry of nanostructured hydroxyapatite and alginate (HAn/Alg) composites in the initial phase of the bone repair. Methods: Fifteen rats were distributed to three groups: MiHA - bone defect filled with HAn/Alg microspheres; GrHA - bone defect filled with HAn/Alg granules; and DV - empty bone defect; evaluated after 15 days postoperatively. The experimental surgical model was the critical bone defect, ≅8.5 mm, in rat calvaria. After euthanasia the specimens were embedded in paraffin and stained with hematoxylin and eosin, picrosirius and Masson-Goldner's trichrome. Results: The histomorphologic analysis showed, in the MiHA, deposition of osteoid matrix within some microspheres and circumjacent to the others, near the bone edges. In GrHA, the deposition of this matrix was scarce inside and adjacent to the granules. In these two groups, chronic granulomatous inflammation was noted, more evident in GrHA. In the DV, it was observed bone neoformation restricted to the bone edges and formation of connective tissue with reduced thickness in relation to the bone edges, throughout the defect. Conclusion: The geometry of the biomaterials was determinant in the tissue response, since the microspheres showed more favorable to the bone regeneration in relation to the granules.

Osteosíntesis Bioreabsorbible Bioactivo (Hidroxiapatita/Poly L-lactido) en Osteotomía Le Fort I Segmentada / Bioresorbable Bioactive Osteosynthesys (Hidroxiapatite/Poly L-lactide) in Le Fort I Segmented Osteotomy

RESUMEN: El objetivo de este artículo es presentar un caso clínico con la utilización de un innovador sistema de osteosíntesis basado en la mezcla de hidroxiapatita (HA) y acido poliláctico (PLLA). La paciente fue admitida en el Hospital Abraham González Peña de Lautaro (Chile) debido a una deformidad facial que exigió realizar una cirugía ortognática monomaxilar para avance y aumento transversal del maxilar; se utilizaron placas de tipo L y tornillos de HA/PLLA de 5 mm para la fijación maxilar, realizando la cirugía sin complicaciones; el proceso técnico y alta hospitalaria se ejecutó de forma convencional. Se realizó un análisis de la literatura donde se analiza la versatilidad, la seguridad y la estabilidad de segmentos cuando se utiliza este innovador material y se concluye que este tipo de osteosíntesis es aplicable a cirugía maxilofacial, exigiendo una curva de aprendizaje por parte del cirujano, necesaria para obtener resultados adecuados.

ABSTRACT: The aim of this paper is to show a clinical case, where was used an innovative osteosynthesys system based on the mixture of hidroxiapatite (HA) and polilactic acid (PLLA). The patient was admitted into Abraham González Peña Hospital (Chile), showing a facial deformity to treat with monomaxillary orthognathic surgery for advance and transversal increase of the maxilla.; were used type L plates and 5 mm screws of HA/PLLA for the internal fixation, performing the surgery without complications; the technical process and the ALTA hospital was realized in a conventional strategy. Was realized a literature review showing the versatility, safe and stability of bone segment when used this innovative material and it´s concluded that this osteosynthesis system can be used normally in maxillofacial surgery; a learning curve to learn about this material is needed by surgeons.

Demineralized bone matrix and calcium-phosphate cement in bone regeneration in rats

Abstract Purpose: To compare bone regeneration in critical-sized defects in rat calvarium using demineralized bone matrix and calcium phosphate cement. Methods: Thirty Wistar rats were divided into 3 groups of 10 animals each. Two defects of 5-mm were made in the parietal bones of each animal. Group I had calcium phosphate cement placed in the experimental defect, Group II had filled with demineralized bone matrix and Group III had with the combination of the matrix and cement in equal parts. All animals had one defect left unfilled to serve as controls. Five animals in each group were sacrificed at 4 and 8 weeks. Histomorphometric analysis was used to quantify the amount of new bone within the defects. Results: The results showed that demineralized bone matrix-treated defects had significantly more new bone at 4 weeks compared to calcium phosphate cement-treated defects (p=0.03) and also had significantly more new bone at 8 weeks compared to unfilled defects (p=0.04). Conclusions: The demineralized bone matrix was superior to calcium phosphate cement in bone regeneration. It seems that calcium phosphate cement acted by inhibiting the osteogenesis when associated with a demineralized bone matrix and this combination should not be recommended.

Action of a deproteinized xenogenic biomaterial in the process of bone repair in rats submitted to inhalation of cigarette smoke

Abstract Purpose: To investigate if the inorganic bovine bone matrix changes the bone formation in rats submitted to inhalation of cigarette smoke. Methods: Twenty Wistar rats were divided into two groups: Cigarette Clot Group (CCG), which in the inhalation chamber received the smoke of 10 cigarettes, 3 times a day, 10 minutes, for 30 days and had the surgical cavity filled by clot; Cigarette Biomaterial Group (CBG), submitted to the same inhalation technique but with the cavity filled by biomaterial. Results: In CCG there was a significant difference of new bone tissue in the analyzed periods (15 and 45 days), and in 15 days, there was 4.8 ± 0.42 of bone formed and 11.73 ± 0.59 (p <0.05) in 45 days. The CBG also showed a significant difference between the periods of 15 to 45 days, being respectively 6.16 ± 0.30 and 11.60 ± 0.61. However, when the groups were compared, within the same analyzed periods, a significant difference was observed only in the period of 15 days, with the new bone percentage being greater in the CBG. Conclusion: The bone matrix acted as an osteoinductive biomaterial, biocompatible and aided in the repair process, mainly in the initial period of recovery.

Systemic melatonin application increases bone formation in mandibular distraction osteogenesis

Abstract This study aimed to investigate the effects of different doses of systemic melatonin application on new bone formation during mandibular distraction osteogenesis (DO) in rats. Mandibular DO was performed on 30 adult female Sprague-Dawley rats, which were randomly divided into three groups: control group (CNT), melatonin dose 1 (MLT-D1), and melatonin dose 2 (MLT-D2). A five-day latent waiting period and a ten-day distraction phase followed the surgery. After the surgery, rats from the MLT-D1 and MLT-D2 groups received 25 and 50 mg/kg melatonin, respectively, at 7, 14, 21, 28, and 35 days. The animals were euthanised 28 days after distraction, i.e. at 43 days after surgery. Histological and histomorphometric analyses revealed that the distracted bone area was completely filled with new bone formation in all three groups. The MLT-D2 group exhibited the most new bone formation, followed by MLT-D1 and CNT. The melatonin groups had more osteoclasts than the CNT (p < 0.05). The number of osteoblasts was higher in the melatonin groups than in the CNT group, and the MLT-D2 had more osteoclasts than the MLT-D1 group (p < 0.05). Finally, the osteopontin (OPN) and vascular endothelial growth factor (VEGF) levels were higher in the melatonin groups than in the CNT group, and the MLT-D2 had higher OPN and VEGF levels than the MLT-D1 (p < 0.05). This study suggests that systemic melatonin application could increase new bone formation in DO.

Efficacy of stem cells on bone consolidation of distraction osteogenesis in animal models: a systematic review

Abstract Distraction osteogenesis (DO) relies on the recruitment and proliferation of mesenchymal stem cells (MSC) to the target site, where they differentiate into osteoblasts to promote bone formation. Nevertheless, MSC recruitment appears to be slow and limits bone formation in DO defects. Thus, this systematic review aims to evaluate the ability of locally applied MSC to enhance bone formation in DO preclinical models. Databases were searched for quantitative pre-clinical controlled studies that evaluated the effect of local administration of MSC on DO bone formation. Eligible studies were identified and data regarding study characteristics, outcome measures and quality were extracted. Nine studies met the inclusion criteria. Autogenous and xenogenous MSC were used to promote DO bone formation. These included bone marrow-derived MSC, adipose tissue-derived MSC and MSC derived from human exfoliated deciduous teeth. Meta-analysis was not possible due to heterogeneities in study designs. Local MSC implantation was not associated with adverse effects. In 4 out of the 5 studies, locally delivered undifferentiated bone-marrow MSC had a positive effect on DO bone formation. Few studies evaluated the therapeutic effects of MSC from other sources. The adjunct use of biologically active molecules or forced expression of key genes involved in osteogenesis further boosted the ability of bone-marrow MSC to promote DO bone formation. While risk of bias and heterogeneity limited the strength of this systematic review, our results suggest that the use of MSC is safe and may provide beneficial effects on DO bone formation.

Bioactive glass added to autogenous bone graft in maxillary sinus augmentation: a prospective histomorphometric, immunohistochemical, and bone graft resorption assessment

Abstract Objective The aim of this study was to compare the bone resorption rate, histomorphometry and immunohistochemical findings of bioactive glass (Biogran; Biomet, Warsaw, IN, USA) mixed with autogenous bone grafts (1:1) and autogenous bone graft isolate in maxillary sinus elevation surgery. Material and Methods A total of 9 maxillary sinuses were grafted with Biogran with autogenous bone graft (group 1) and 12 were mixed with autogenous bone graft (group 2). Postoperative cone beam computed tomography (CBCT) was used to measure the initial graft volume after 15 days (T1), and 6 months later, another CBCT scan was performed to evaluate the final graft volume (T2) and determine the graft resorption rate. The resorption outcomes were 37.9%±18.9% in group 1 and 45.7%±18.5% in group 2 (P=0.82). After 6 months, biopsies were obtained concurrent with the placement of dental implants; these implants were subjected to histomorphometric analysis and immunohistochemical analysis for tartrate-resistant acid phosphatase (TRAP). Results The average bone formation in group 1 was 36.6%±12.9 in the pristine bone region, 33.2%±13.3 in the intermediate region, and 45.8%±13.8 in the apical region; in group 2, the values were 34.4%±14.4, 35.0%±13.9, and 42.0%±16.6 of new bone formation in the pristine bone, intermediate, and apical regions, respectively. Immunostaining for TRAP showed poor clastic activity in both groups, which can indicate that those were in the remodeling phase. Conclusions The similarity between the groups in the formation and maintenance of the graft volume after 6 months suggests that the bioactive glass mixed with autogenous bone (1:1) can be used safely as a bone substitute for the maxillary sinus lift.

Effects of hyperbaric oxygen treatment on implant osseointegration in experimental diabetes mellitus

Abstract Objective To evaluate whether hyperbaric oxygen (HBO) treatment has a favorable effect on implant osseointegration in diabetic rabbits. Material and Methods An experimental diabetes model was induced in 32 New Zealand rabbits through IV injection of alloxan. After the state of diabetes had been confirmed, one dental implant was placed in the metaphysical region of each animal's tibia. After the implants' placements, the animals were divided into two groups. Half of the animals underwent HBO treatment, while the other group did not receive HBO treatment and served as the control group. The animals were euthanized at the 4th and 8th weeks. The osseointegration of the implants were compared by histomorphometry and resonance frequency analysis (RFA). Results The Bone Implant Contact (BIC) values were significantly higher in the HBO group than in the control group at the 4th week. There was no difference in the BIC values between the groups at the 8th week. There was no significant difference in the RFA scores between the groups both at the 4th and 8th weeks after the operation. Conclusion Histomorphometry findings suggest that HBO has positive effect on implant osseointegration in the early healing period in diabetic rabbits. However, implant stability is not affected by HBO treatment.

Bone repair access of BoneCeramic™ in 5-mm defects: study on rat calvaria

Abstract Objective: The aim of this study was to evaluate the osteoconductive potential of BoneCeramic™ on bone healing in rat calvaria 5-mm defects. Material and Methods: A 5-mm calvaria bone defect was induced in three groups and the defect was not filled with biomaterial [Clot Group (CG)], autogenous bone (AG), or Bone Ceramic Group (BCG). Animals were euthanized after 14 or 28 days and the bone tissue within the central area of the bone defect was evaluated. Results were compared using ANOVA and Tukey test (p<0.05). Immunohistochemistry was performed using primary antibodies against osteocalcin, RUNX-2, TRAP, VEGF proteins, and 3-dimensional images of the defects in μCT were obtained to calculate bone mineral density (BMD). Results: In BCG, the defect was completely filled with biomaterial and new bone formation, which was statistically superior to that in the GC group, at both time-points (p<0.001 for 14 days; p=0.002 for 28 days). TRAP protein showed weak, RUNX-2 showed a greater immunolabeling when compared with other groups, VEGF showed moderate immunostaining, while osteocalcin was present at all time-points analyzed. The μCT images showed filling defect by BCG (BMD= 1337 HU at 28 days). Conclusion: Therefore, the biomaterial tested was found to be favorable to fill bone defects for the reporting period analyzed.