Treatment of Medication-Related Osteonecrosis of the Jaws (MRONJ) with Topical Therapy Using Active Oxygen Gel.

Medication-related osteonecrosis of the jaw (MRONJ) can be a debilitating complication that can arise in patients who took or are taking antiresorptive (including bisphosphonates) or antiangiogenic agents, leading to visible bone or a fistula that continues for more than eight weeks, without any history of radiotherapy. This clinical case aimed to describe the treatment of MRONJ with topical active oxygen therapy using blue®m oral gel. A 63-year-old female patient that had been taking weekly sodium alendronate (70 mg) for four years by oral via, presented discomfort and implant movement in the #46 region, by that underwent surgical extraction of the implant. After three months the patient returned and was diagnosed with MRONJ. Initially, conventional therapies were performed, including surgical debridement and antibiotic therapy, but without success. The patient still had clinical signs of osteonecrosis six months after the implant extraction. The entire socket was then filled with blue®m oral gel by topical application. The patient was instructed to continue applying the gel to the region every 8 hours for 15 days. After this period, the patient returned, and it was observed that the wound was in the healing process, with the presence of epithelialized tissue and without bone exposure. The 2-year clinical follow-up showed the lesion had healed entirely, and a new implant was installed. After the osseointegration period, the final prosthesis was placed. The patient remains under clinical follow-up. Therefore, it can be concluded that the application of blue®m oral gel in this clinical case assisted in the recovery of the osteonecrosis lesion.

Nanoscale hybrid implant surfaces and Osterix-mediated osseointegration.

Endosseous implant surface topography directly affects adherent cell responses following implantation. The aim of this study was to examine the impact of nanoscale topographic modification of titanium implants on Osterix gene expression since this gene has been reported as key factor for bone formation. Titanium implants with smooth and nanoscale topographies were implanted in the femurs of Osterix-Cherry mice for 1-21 days. Implant integration was evaluated using scanning electron microscopy (SEM) to evaluate cell adhesion on implant surfaces, histology, and nanotomography (NanoCT) to observe and quantify the formed bone-to-implant interface, flow cytometry to quantify of Osterix expressing cells in adjacent tissues, and real-time PCR (qPCR) to quantify the osteoinductive and osteogenic gene expression of the implant-adherent cells. SEM revealed topography-dependent adhesion of cells at early timepoints. NanoCT demonstrated greater bone formation at nanoscale implants and interfacial osteogenesis was confirmed histologically at 7 and 14 days for both smooth and nanosurface implants. Flow cytometry revealed greater numbers of Osterix positive cells in femurs implanted with nanoscale versus smooth implants. Compared to smooth surface implants, nanoscale surface adherent cells expressed higher levels of Osterix (Osx), Alkaline phosphatase (Alp), Paired related homeobox (Prx1), Dentin matrix protein 1 (Dmp1), Bone sialoprotein (Bsp), and Osteocalcin (Ocn). In conclusion, nanoscale surface implants demonstrated greater bone formation associated with higher levels of Osterix expression over the 21-day healing period with direct evidence of surface-associated gene regulation involving a nanoscale-mediated osteoinductive pathway that utilizes Osterix to direct adherent cell osteoinduction.

Influence of Titanium Alloy Scaffolds on Enzymatic Defense against Oxidative Stress and Bone Marrow Cell Differentiation.

Studies have been directed towards the production of new titanium alloys, aiming for the replacement of Ti-6 Aluminium-4 Vanadium (TiAlV) alloy in the future. Many mechanisms related to biocompatibility and chemical characteristics have been studied in the field of implantology, but enzymatic defenses against oxidative stress remain underexplored. Bone marrow stromal cells have been explored as source of cells, which have the potential to differentiate into osteoblasts and therefore could be used as cells-based therapy. The objective of this study was to evaluate the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in porous scaffolds of Ti-6 Aluminium-4 Vanadium (TiAlV), Ti-35 Niobium (TiNb), and Ti-35 Niobium-7 Zirconium-5 Tantalum (TiNbZrTa) on mouse bone marrow stromal cells. Porous titanium alloy scaffolds were prepared by powder metallurgy. After 24 hours, cells plated on the scaffolds were analyzed by scanning electron microscopy (SEM). The antioxidant enzyme activity was measured 72 hours after cell plating. Quantitative real time PCR (qRT-PCR) was performed after 3, 7, and 14 days, and Runx2 (Runt-related transcription factor2) expression was evaluated. The SEM images showed the presence of interconnected pores and growth, adhesion, and cell spreading in the 3 scaffolds. Although differences were noted for SOD and CAT activity for all scaffolds analyzed, no statistical differences were observed (p > 0.05). The osteogenic gene Runx2 presented high expression levels for TiNbZrTa at day 7, compared to the control group (TiAlV day 3). At day 14, all scaffolds had more than 2-fold induction for Runx2 mRNA levels, with statistically significant differences compared to the control group. Even though we were not able to confirm statistically significant differences to justify the replacement of TiAlV regarding antioxidant enzymes, TiNbZrTa was able to induce faster bone formation at early time points, making it a good choice for biomedical and tissue bioengineering applications.

In vitro osteogenesis process induced by hybrid nanohydroxyapatite/graphene nanoribbons composites.

Carbon nanotubes combine high bend and mechanical strength, which is advantageous for many structural and biomedical purposes. Recently, some biomaterials, based on carbon nanostructures and nanohydroxyapatite (nHAp), have been investigated as bone substitutes in order to improve regeneration. The aim of this study was to access the expression of some RNA transcripts (involved in the process of osteoblast differentiation) by mesenchymal stem cells cultured over different nanocomposite surfaces. A multi-walled carbon nanotube (MWCNT) was firstly grown using chemical vapor deposition and then exfoliated using chemical and oxygen plasma treatments to obtain graphene nanoribbons (GNR). The hybrid composites nHAp/GNR were prepared using the wet method assisted by ultrasound irradiation with different amounts of GNR (1.0, 2.0 and 3.0 wt %). Five groups were tested in cell cultures. Group 1: synthesized nHAp; Group 2: synthesized GNR; Group 3: nHAp and 1.0% of GNR; Group 4: nHAp and 2.0% of GNR and group 5: nHAp and 3.0% of GNR. Real time reverse transcription polymerase chain reactions were performed, and all data was submitted to Kruskal Wallis and Dunn tests, at a significance level of 5%. As a result, three nanocomposites with different proportions of GNR were successfully produced. After cell culture, the expression of osteogenic genes demonstrated no significant differences among the groups and periods. However, bone morphogenetic protein II (BMP II), integrin binding sialoprotein (IBSP), and Osterix highest expressions were observed in the group containing 3.0% of GNR. In conclusion, our hybrid composites may be useful in bone interventions requiring mesenchymal stem cell differentiation into osteoblasts for healing.

Modulação da expressão de miRNAs na diferenciação de osteoblastos em nanosuperfícies / Modulation of miRNA expression in osteoblast differentiation in nanosurfaces

Proposição: Este estudo teve como objetivo avaliar a modulação dos miRNAs que afetam o potencial osteogênico de CTMs em diferentes topografias de superfície de discos de vidro. Material e Métodos: Células tronco mesenquimais humanas foram plaqueadas nas diferentes superfícies e comparadas após 3, 7 e 14 dias para atividade de fosfatase alcalina, expressão de genes (Osteocalcina, Osteopontina, Sialo Proteína Óssea, Osterix, Runx2, BMP2 e ALP) e expressão de miRNAs. Microscopia eletrônica de varredura das superfícies com células foram obtidas para avaliação de adesão celular. Resultados: Atividade de fosfatase alcalina nas diferentes superfícies foi significantemente maior na superfície com nanotopografia. Do mesmo modo, a expressão de genes relacionados com osteoblastos foi mais elevada na superfície nano. Com 14 dias foi observado um aumento de 3.5 e 9 vezes para os genes Runx2 e Osterix, respectivamente. O gene da BMP2 e ALP também apresentou um aumento de 4 e 7 vezes comparado ao controle. Utilizando a tecnologia de sequenciamento de RNA (RNA-Seq) onde todos os RNAs existentes foram sequenciados, um total de 123 miRNAs com diferença de expressão foram encontrados comparando a superfície controle (dia 7) com a superfície nano (dia 14). 48 miRNAs apresentaram uma redução na expressão e 75 apresentaram um aumento de expressão. Alguns destes apresentaram marcadores para genes osteogênicos já identificados, tais como hsa-miR-135b-5p marcador para OCN, BSP, Runx2, CO15A1 e OSX, hsa-miR-122-5p marcador para OPN, hsa-miR-196a-5p marcador para BMP4, hsa-miR-26b-5p marcador para BMP2 e hsa-miR-148b-3p marcador para OPN. Conclusão: As superfícies com nanotopografia tem o potencial de melhorar a resposta de osseointegração de maneira a reduzir o tempo de osseointegração e também aumentar a produção de tecido ósseo ao redor dos implantes favorecendo assim áreas de qualidade óssea baixa. A utilização de miRNAs para alterar a resposta de diferenciação pode também ajudar a controlar o processo de osseointegração(AU)

Purpose: This study aimed to evaluate the modulation of miRNAs that affect the osteogenic potential of MSCs in different surface topographies of glass disks. Material and Methods: Human mesenchymal stem cells (hMSCs) were plated on different surfaces of glass disks and compared at 3,7 and 14 days for alkaline phosphatase (ALP) activity, expression of genes (Osteocalcin, Osteopontin, Bone Sialo Protein, Osterix, Runx2, BMP2 and ALP) and expression of miRNAs. Scanning electron microscopy of surfaces with cells were obtained to analyse the attachment of cells. Results: ALP activity on different surfaces was significantly greater in the nanotopography surface. At day 14 there was a 3.5-fold and a 9-fold increase for Runx2 and Osterix gene, respectively. BMP2 and ALP also increased by 4- and 7-fold compared to control. Using RNA sequencing technology (RNA-Seq) a total of 123 miRNAs were found differently expressed comparing control (day 7) to nano surface (day 14). 48 miRNAs were downregulated and 75 were upregulated. Some of them regulated osteogenic genes such as hsa-miR-135b-5p that targets OCN, BSP, RUNX2, CO15A1 and OSX, hsamiR-122-5p wich targets OPN, hsa-miR-196a-5p targets BMP4, hsa-miR-26b-5p that targets BMP2 and hsa-miR-148b-3p that targets OPN. Conclusion: Surfaces with nanotopography have the potential to improve osseointegration response in order to reduce the time of osseointegration and also increase the production of bone tissue around the implants improving low bone quality areas. The use of miRNAs to affect differentiation response may also help control the osseointegration process(AU)

Influence of implant drill materials on wear, deformation, and roughness after repeated drilling and sterilization.

PURPOSE: The aim of this study was to evaluate deformation, roughness, and mass loss of stainless steel, diamond-like carbon (DLC)-coated and zirconia drills after multiple osteotomies with sterilization procedures. MATERIALS AND METHODS: Drilling procedures were performed using stainless steel (G1), DLC-coated (G2), and zirconia (G3) drills. All groups were divided in subgroups 1, 2, 3, 4, and 5, corresponded to drills used 0, 10, 20, 30, and 40 times, respectively. RESULTS: No significant differences in mass and roughness were detected among all groups and subgroups. In SEM images, all groups revealed signs of wear while coating delamination was detected in G2. Drills from G1 displayed more irregular surface, whereas cutting edges were more regular in G3. CONCLUSION: Zirconia drills presented more regular surfaces whereas stainless steel drills revealed more severe signs of wear. Further studies must be performed to evaluate the putative influence of these findings in heat generation.

Bone apposition and surface treatment in dental implants: histomorphometric pilot evaluation in rabbits

Introduction: The surface of dental implants is an important factor for osseointegration process and different methods of surface treatment have been described. Objective: To investigate the bone apposition in implant surface treated with sandblasting and acid-etching. Material and methods: Ten rabbits were selected and received one implant treated with method I in the left tibia and one implant treated with method II in the right tibia. Then, twenty implants were divided in two groups, according to methods of sandblasting and acid-etching (method I and method II). After 7, 14, 30, 45 and 60 days, tibias were retrieved and submitted to histotechnical procedures. The percentages of bone-implant contact (BIC) and bone area between threads (BABT) were determined throughout histomorphometric analysis and bone apposition was detected in implants of both groups. Results: In BABT measurements, an increase was observed after 45 and 60 days in the method II, compared to method I and no differences were found after 7, 14 and 30 days. In BIC measurements, an increase was detected with method II at 45 days when compared to method I. No differences between groups in BIC values were observed after 7, 14, 30 and 60 days. Conclusion: Our data demonstrated that implants treated with the method II presented increase in the contact between bone and implant after 45 days compared to method I. Moreover, with concern to bone area between threads, it was observed an increased in the method II after 45 and 60 days. However, both groups can be successfully used as a therapeutic strategy to rehabilitation of edentulous patients. Then, further experiments are needed to evaluate, in depth, the putative differential role of each surface treatment.

Bone healing in titanium and zirconia implants surface: a pilot study on the rabbit tibia

Introduction: Zirconia has been considered an alternative material to titanium for implant manufacturing, however the mechanisms regarding to bone healing in presence of zirconia implants remains poorly known. Objective: The objective of the investigation was to evaluate the bone healing surrounding titanium and zirconia implants in rabbits after 7, 14, 30, 45 and 60 days of implant placement through histological evaluation. Material and methods: Fifteen rabbits were used in this study and randomly subdivided into 5 groups, according to experimental periods. Titanium and zirconia implants were inserted into the right and left tibia, respectively. After healing periods of 7, 14, 30, 45 and 60 days, animals were euthanatized, the implants were removed and the samples were submitted to histological procedures. Results: Our histological results demonstrated similar bone healing surrounding titanium and zirconia implants after 7, 14 and 30 days after implant placement. After 45 days, a trend towards to earlier bone maturation was detected, remaining after 60 days. Inflammatory infiltrate, bone resorption and foreign body reaction were not observed in any periods and groups evaluated. Conclusion: Our findings demonstrated that zirconia and titanium presented a similar pattern of bone healing.

Tilted implants and prototyping: a security option for improving the anchorage in atrophic maxilla.

Rehabilitating atrophic maxilla poses many challenges. Reconstructive techniques that require sinus grafting are viable and acceptable; however, these techniques also are considered to be expensive, invasive, and time-consuming. Tilted implants anchored in distal areas using available bone have been reported as a less invasive and highly predictable treatment option. This article presents a case involving implant anchorage via tilted implants as an alternative technique to bone grafting procedures.

Evaluation of deformation, mass loss, and roughness of different metal burs after osteotomy for osseointegrated implants.

PURPOSE: This study used bovine ribs to comparatively assess the deformation, roughness, and mass loss for 3 different types of surface treatments with burs, used in osteotomies, for the installation of osseointegrated implants. MATERIALS AND METHODS: The study used 25 bovine ribs and 3 types of helical burs (2.0 mm and 3.0 mm) for osteotomies during implant placement (a steel bur [G1], a bur with tungsten carbide film coating in a carbon matrix [G2], and a zirconia bur [G3]), which were subdivided into 5 subgroups: 1, 2, 3, 4, and 5, corresponding to 0, 10, 20, 30, and 40 perforations, respectively. The surface roughness (mean roughness [Ra], partial roughness, and maximum roughness) and mass (in grams) of all the burs were measured, and the burs were analyzed in a scanning electron microscope before and after use. Data were tabulated and statistically analyzed by use of the Kruskal-Wallis test, and when a statistically significant difference was found, the Dunn test was used. RESULTS: There was a loss of mass in all groups (G1, G2, and G3), and this loss was gradual, according to the number of perforations made (1, 2, 3, 4, and 5). However, this difference was not statistically significant (P < .05). Regarding the roughness, G3 presented an increase in Ra, partial roughness, and maximum roughness (P < .05) compared with G2 and an increase in Ra compared with G1. There was no statistically significant difference (P > .05) between G1 and G2. The scanning electron microscopy analysis found areas of deformation in all the 2.0-mm samples, with loss of substrates, and this characteristic was more frequent in G3. CONCLUSIONS: The 2.0-mm zirconia burs had a greater loss of substrates and abrasive wear in the cutting area. They also presented an increased roughness when compared with the steel and the tungsten carbide coating film in carbon matrix. There was no statistically significant difference (P < .05) between G1 and G2 in any mechanical test carried out.

Evaluation of satisfaction of patients rehabilitated with zygomatic fixtures.

PURPOSE: The aim of this study was to evaluate the satisfaction of patients rehabilitated with zygomatic fixtures and prosthesis with immediate loading. MATERIALS AND METHODS: The study selected patients who were rehabilitated with zygomatic implants at the clinic of the Latin American Institute for Dental Research and Education (ILAPEO. Curitiba-PR. Brasil) between 2005 and 2009. The patients were asked to answer a control-questionnaire during their follow-up visits. Data were collected regarding the level of patient satisfaction, reason for dissatisfaction, number of post-operative clinical sessions, and the type of complication. Sixteen patients were selected: 10 females and 6 males. RESULTS: Half of the patients were completely satisfied while the other half were satisfied with some complaints. The complaints were related to hygiene, esthetics, phonetics, and discomfort during chewing. Regarding the post-operative evaluation, 50% of the patients were attended due to the prosthesis (62.5%) and the implant (37.5%). CONCLUSIONS: The treatment with zygomatic fixtures is predictable and reliable. The patients were satisfied both with implants and prosthesis.

Avaliação da deformação, perda de massa e rugosidade das fresas, após osteotomia para implantes osseointegrados, com diferentes tipos de metais / Evaluation of the deformation, loss of mass and rugosity of burs after dental implant osteotomy, with different types of covering

Objetivo: Avaliar comparativamente, em costela bovina, a deformação, a rugosidade e a perda de massa, de três diferentes tipos de tratamento de superfície de fresas, utilizadas em osteotomias, para instalação de implantes osseointegráveis. Materiais e método: Foram utilizadas 25 costelas bovinas e 3 tipos de fresas helicoidais de 2.0 mm e 3.0 mm para osteotomias para instalação de implantes (Fresa de aço (G1), Fresa com revestimento de filme de Carboneto de Tungstênio em Matriz de Carbono (G2) e Fresa de Zircônia (G3)), que foram subdivididas em 5 subgrupos: 1 – fresas sem uso e 2, 3, 4 e 5 correspondente ao número de perfurações 10, 20, 30 e 40, respectivamente. Todas as fresas foram submetidas a medidas de rugosidade (Ra, Rz e Rmáx), massa (gramas) e análise em microscópio eletrônico de varredura (MEV) antes e após uso. Os dados foram tabulados e submetidos a análise estatística através do Teste de Kruskal-Wallis e, quando encontrada diferença estatisticamente significante, ao Teste de Dunn. Resultados: Houve perda de massa em todos os grupos (G1, G2 e G3), sendo essa redução de forma gradual, conforme o número de perfurações realizadas (1, 2, 3, 4 e 5). Mas esta diferença não foi estatisticamente significante (P<0,05). Ao analisarmos os testes de rugosidade o G3 apresentou aumento de Ra, Rz e Rmáx (P<0,05) em relação ao G2. E um aumento de Ra em relação ao G1. Não houve diferença estatisticamente significante (P<0,05) entre G1 e G2. Na análise por microscopia eletrônica de varredura (MEV) foram observadas áreas de deformação em todas as amostras de 2.0 mm, com perda de substratos, sendo o G3 o que mais apresentou essas características. Conclusão: As fresas de Zircônia de 2.0 mm apresentaram maior perda de substratos e desgaste por abrasão, na região de corte. Apresentaram, também, um aumento de rugosidade em relação as de aço e as de revestimento de filme de Carboneto de Tungstênio em Matriz de Carbono (WC/C). Não houve diferença estatisticamente...

Purpose: Evaluate comparativily, in bovine ribs, the deformation, rugosity and loss of mass, in three different types of bur covering, used in dental implants osteotomy. Materials and methods: Twenty five (25) bovine ribs and three (3) types of helical burs of 2.0 mm and 3.0 mm for dental implant bed preparation had been used (Stell Bur (G1), Tungsten Carbid inCarbon Matriz Bur (G2) and Zirconia Bur (G3)), that they had been subdivided in five sub-groups: 1 – bur without use and 2, 3, 4 and 5 correspondent to the number of perfurations: 10, 20, 30 and 40, respectively. All burs had been measure in rugosity tests (Ra, Rz and Rmax), mass (gram) and scanning electron microscope (SEM) analisys before and after use. The data had been tabulated and submitted to statistical analysis through Kruskal-Wallis Test and, when significant statistical differnces were found, to Dunn Methods Test. Results: Loss of mass where found in all groups (G1, G2 and G3), being this reduction in gradual form as the number of carried through perfurations (1, 2, 3, 4 and 5). But this difference was not statistical significant (P<0,05). When analyzing the rugosity tests the G3 presented increase of Ra, Rz and Rmax (P<0,05) in relation to G2. And a increase of Ra in relation to G1. It did not have significany statistical difference (P<0,05) between G1 and G2. In the scanning electron microscope (SEM) analysis it was observed in all the 2.0 mm samples plastic deformation and drill wear, having been G3 what more it presented these characteristics. Conclusion: The 2.0 mm Zirconia burs had presented major consuming and drill wear in the cutting area. They had presented, also, an increase of rugosity related to G1 and G2. There was no significant statistical diferences between G1 and G2 in no carried through mechanical test