Enhanced Delivery of Rose Bengal by Amino Acids Starvation and Exosomes Inhibition in Human Astrocytoma Cells to Potentiate Anticancer Photodynamic Therapy Effects.

Photodynamic therapy (PDT) is a promising anticancer strategy based on the light energy stimulation of photosensitizers (PS) molecules within a malignant cell. Among a multitude of recently challenged PS, Rose bengal (RB) has been already reported as an inducer of cytotoxicity in different tumor cells. However, RB displays a low penetration capability across cell membranes. We have therefore developed a short-term amino acids starvation protocol that significantly increases RB uptake in human astrocytoma cells compared to normal rat astrocytes. Following induced starvation uptake, RB is released outside cells by the exocytosis of extracellular vesicles (EVs). Thus, we have introduced a specific pharmacological treatment, based on the GW4869 exosomes inhibitor, to interfere with RB extracellular release. These combined treatments allow significantly reduced nanomolar amounts of administered RB and a decrease in the time interval required for PDT stimulation. The overall conditions affected astrocytoma viability through the activation of apoptotic pathways. In conclusion, we have developed for the first time a combined scheme to simultaneously increase the RB uptake in human astrocytoma cells, reduce the extracellular release of the drug by EVs, and improve the effectiveness of PDT-based treatments. Importantly, this strategy might be a valuable approach to efficiently deliver other PS or chemotherapeutic drugs in tumor cells.

Effect of Titanium Hardness on the Integrity and Stress Concentration of External Hexagon Dental Implants

ABSTRACT: The aim of this study was to evaluate the influence of overtorque on integrity, strength and stress on external hexagonal implants (EH), with two different grades (N=10): conventional (C), grade 4; and modified (M), grade 4 with thermal treatment. The dimensions of EH were 3.75 x 13 mm; the specimens were fixed and submitted to SEM analysis and image acquisition. The abutment was then retained with 70 N/cm, re-analyzed by SEM, and a second image was obtained. The images were analyzed by Image J software (1.44o- NIH, USA) for dimensional variations measurement on surface of the hexagonal area. The finite element method was applied with a similar compliance to calculate the resultant stress (MPa) during the torque. Results were statistically analyzed with t-student test (5 %). The dimensional accuracy of M (0.22 mm2) was statistically significant (p<0.05). Minimum principal stress and von-Mises stress of C (-19.95 MPa, -19.94 MPa), were lower than M values (-55.83 MPa, -55.96 MPa), respectively. However, the M group showed lower deformation than C group. Therefore, more rigid titanium alloy is a promising alternative to avoid plastic deformation of prosthetic connec tions even concentrating higher stress magnitude on its structure.

RESUMEN: El objetivo de este estudio fue evaluar la influencia del sobrepar en la integridad, la fuerza y la tensión en los implantes hexagonales externos (EH), con dos grados diferentes (N = 10): convencional (C), grado 4; y modificado (M), grado 4 con tratamiento térmico. Las dimensiones de EH eran 3,75 de diámetro x 13 mm de longitud; las muestras se fijaron y se sometieron a análisis SEM y adquisición de imágenes. A continuación, el pilar se retuvo con 70 N / cm, se volvió a analizar por SEM y se obtuvo una segunda imagen. Las imágenes se analizaron con el software Image J (1.44o-NIH, EE. UU.) Para medir las variaciones dimensionales en la superficie superior del área hexagonal, que fue causada por un par excesivo. El método de los elementos finitos se aplicó con un cumplimiento similar para calcular la tensión resultante (MPa) durante el par. Los resultados se analizaron estadísticamente con la prueba t-student (5 %). La precisión dimensional de M (0,22 mm2) fue estadísticamente significativa (p <0,05). La tensión principal mínima y la tensión de von-Mises de C (-19,95 MPa, -19,94 MPa), fueron inferiores a los valores de M (-55,83 MPa, -55,96 MPa), respectivamente. Sin embargo, el hexágono del grupo M mostró menor deformación que el grupo C. Por lo tanto, la aleación de titanio más rígida es una alternativa prometedora para evitar la deformación plástica de las conexiones protésicas incluso concentrando una mayor magnitud de tensión en su estructura.

Berberine Photo-Activation Potentiates Cytotoxicity in Human Astrocytoma Cells through Apoptosis Induction.

Photodynamic therapy (PDT) has recently attracted interest as an innovative and adjuvant treatment for different cancers including malignant gliomas. Among these, Glioblastoma (GBM) is the most prevalent neoplasm in the central nervous system. Despite conventional therapeutic approaches that include surgical removal, radiation, and chemotherapy, GBM is characterized by an extremely poor prognosis and a high rate of recurrence. PDT is a physical process that induces tumor cell death through the genesis and accumulation of reactive oxygen species (ROS) produced by light energy interaction with a photosensitizing agent. In this contribution, we explored the potentiality of the plant alkaloid berberine (BBR) as a photosensitizing and cytotoxic agent coupled with a PDT scheme using a blue light source in human established astrocytoma cell lines. Our data mainly indicated for the combined BBR-PDT scheme a potent activation of the apoptosis pathway, through a massive ROS production, a great extent of mitochondria depolarization, and the sub-sequent activation of caspases. Altogether, these results demonstrated that BBR is an efficient photosensitizer agent and that its association with PDT may be a potential anticancer strategy for high malignant gliomas.

Remodelling of sinus bone grafts according to the distance from the native bone: A histomorphometric analysis.

OBJECTIVES: To evaluate graft remodelling according to the distance from the native bone in maxillary sinuses grafted with anorganic bovine bone (ABB). MATERIAL AND METHODS: Bilateral sinus grafting was performed in twenty patients with residual bone height <5 mm before implant placement. After 8 months, biopsy samples were harvested, and histomorphometric analysis was performed to examine bone formation according to the distance (in mm) from the native bone (sinus floor). In the grafted area, the percentages of new bone (NB), residual graft material (rABB), and soft tissue (ST) were evaluated. RESULTS: A total of 103 biopsy samples were evaluated, and the percentages of NB, rABB, and ST were 31.62 ± 9.85%, 18.94 ± 7.88%, and 49.41 ± 9.52%, respectively, in the 1st mm; 27.15 ± 9.83%, 23.33 ± 9.45%, and 49.53 ± 11.73%, respectively, in the 2nd mm; 23.61 ± 13.02%, 21.35 ± 11.08%, and 55.03 ± 16.14%, respectively, in the 3rd mm; and 21.67 ± 12.29%, 19.67 ± 10.28%, and 58.66 ± 12.46%, respectively, in the 4th mm. The 1st millimetre of the grafted area (closer to the native bone) presented a larger amount of NB than the other portions of the grafted areas and a smaller amount of rABB than the 2nd mm of the grafted area (p < .05). The amount of ST was larger in the 3rd and 4th mm of the grafted area than in the first 2 millimetres (p < .05). CONCLUSION: The distance from the native bone influences bone formation following maxillary sinus augmentation.

Development of Artificial Plasma Membranes Derived Nanovesicles Suitable for Drugs Encapsulation.

Extracellular vesicles (EVs) are considered as promising nanoparticle theranostic tools in many pathological contexts. The increasing clinical employment of therapeutic nanoparticles is contributing to the development of a new research area related to the design of artificial EVs. To this aim, different approaches have been described to develop mimetic biologically functional nanovescicles. In this paper, we suggest a simplified procedure to generate plasma membrane-derived nanovesicles with the possibility to efficiently encapsulate different drugs during their spontaneously assembly. After physical and molecular characterization by Tunable Resistive Pulse Sensing (TRPS) technology, transmission electron microscopy, and flow cytometry, as a proof of principle, we have loaded into mimetic EVs the isoquinoline alkaloid Berberine chloride and the chemotherapy compounds Temozolomide or Givinostat. We demonstrated the fully functionality of these nanoparticles in drug encapsulation and cell delivery, showing, in particular, a similar cytotoxic effect of direct cell culture administration of the anticancer drugs. In conclusion, we have documented the possibility to easily generate scalable nanovesicles with specific therapeutic cargo modifications useful in different drug delivery contexts.

The Search for Molecular Markers in a Gene-Orphan Case Study of a Pediatric Spinal Cord Pilocytic Astrocytoma.

BACKGROUND/AIM: We herein presented a case of pediatric spinal cord pilocytic astrocytoma diagnosed on the basis of histopathological and clinical findings. MATERIALS AND METHODS: Given the paucity of data on genetic features for this tumor, we performed exome, array CGH and RNA sequencing analysis from nucleic acids isolated from a unique and not repeatable very small amount of a formalin-fixed, paraffin-embedded (FFPE) specimen. RESULTS: DNA mutation analysis, comparing tumor and normal lymphocyte peripheral DNA, evidenced few tumor-specific single nucleotide variants in DEFB119, MUC5B, NUDT1, LTBP3 and CPSF3L genes. Differently, tumor DNA was not characterized by for the main pilocytic astrocytoma gene variations, including BRAFV600E. An inframe trinucleotides insertion involving DLX6 or lnc DLX6-AS1 genes was scored in 44.9% of sequenced reads; the temporal profile of this variation on the expression of DLX-AS1 was investigated in patient's urine-derived exosomes, reporting no significant variation in the one-year molecular follow-up. Array CGH identified a tumor microdeletion at the 6q25.3 chromosomal region, spanning 1,01 Mb and comprising ZDHHC14, SNX9, TULP4 and SYTL3 genes. The expression of these genes did not change in urine-derived exosomes during the one-year investigation period. Finally, RNAseq did not reveal any of the common pilocytic BRAF-KIAA1549 genes fusion events. CONCLUSION: To our knowledge, the present report is one of the first described gene-orphan case studies of a pediatric spinal cord pilocytic astrocytoma.

Trehalose Modulates Autophagy Process to Counteract Gliadin Cytotoxicity in an In Vitro Celiac Disease Model.

Celiac disease (CD) is a chronic systemic autoimmune disorder that is triggered by the ingestion of gliadin peptides, the alcohol-soluble fraction of wheat gluten. These peptides, which play a key role in the immune response that underlies CD, spontaneously form aggregates and exert a direct toxic action on cells due to the increase in the reactive oxygen species (ROS) levels. Furthermore, peptic-tryptic digested gliadin peptides (PT-gliadin) lead to an impairment in the autophagy pathway in an in vitro model based on Caco-2 cells. Considering these premises, in this study we have analyzed different mTOR-independent inducers, reporting that the disaccharide trehalose, a mTOR-independent autophagy activator, rescued the autophagy flux in Caco-2 cells treated with digested gliadin, as well as improved cell viability. Moreover, trehalose administration to Caco-2 cells in presence of digested gliadin reduced the intracellular levels of these toxic peptides. Altogether, these results showed the beneficial effects of trehalose in a CD in vitro model as well as underlining autophagy as a molecular pathway whose modulation might be promising in counteracting PT-gliadin cytotoxicity.

Influence of residual bone height and sinus width on the outcome of maxillary sinus bone augmentation using anorganic bovine bone.

OBJECTIVE: To evaluate the influence of the posterior residual bone height and sinus width on the outcome of maxillary sinus bone augmentation using anorganic bovine bone. MATERIAL AND METHODS: Bilateral sinus bone augmentation was performed using anorganic bovine bone in 20 patients with residual bone height <2 mm in at least one site on each side. Trephine samples were removed at the implant insertion site 8 months after the grafting procedure, and histological and histomorphometric analyses were performed to examine the relative amount (%) of new bone, anorganic bovine bone, and soft tissue in the grafted area. Based on cone beam computed tomography evaluation, the sites of implant insertion were classified according to sinus width into narrow, average, and wide, and according to residual bone height into ≤2 and >2 mm. RESULTS: A total of 146 implants were installed and 103 biopsies were evaluated. New bone formation in sites classified as narrow (69 sites), average (19 sites), and wide (15 sites) was 28.5% ± 9.24, 28.9% ± 8.61, and 30.3% ± 7.80, respectively. The mean posterior maxillary residual bone height was 4.0 ± 2.43 mm, and 26 and 77 sites were classified as ≤2 and >2 mm, respectively. New bone formation was 26.2% ± 9.10 and 29.8% ± 8.67 for residual bone height ≤2 and >2 mm, respectively. The differences were non-significant. CONCLUSIONS: Within the limitations of the present study, posterior residual bone height and sinus width were not factors with influence on new bone formation in sinuses grafted exclusively with anorganic bovine bone after 8 months of healing.

The In Vitro Effects of Enzymatic Digested Gliadin on the Functionality of the Autophagy Process.

Gliadin, the alcohol-soluble protein fraction of wheat, contains the factor toxic for celiac disease (CD), and its toxicity is not reduced by digestion with gastro-pancreatic enzymes. Importantly, it is proved that an innate immunity to gliadin plays a key role in the development of CD. The immune response induces epithelial stress and reprograms intraepithelial lymphocytes into natural killer (NK)-like cells, leading to enterocyte apoptosis and an increase in epithelium permeability. In this contribution, we have reported that in Caco-2 cells the administration of enzymatically digested gliadin (PT-gliadin) reduced significantly the expression of the autophagy-related marker LC3-II. Furthermore, electron and fluorescent microscope analysis suggested a compromised functionality of the autophagosome apparatus. The rescue of the dysregulated autophagy process, along with a reduction of PT-gliadin toxicity, was obtained with a starvation induction protocol and by 3-methyladenine administration, while rapamycin, a well-known autophagy inducer, did not produce a significant improvement in the clearance of extra- and intra-cellular fluorescent PT-gliadin amount. Altogether, our results highlighted the possible contribution of the autophagy process in the degradation and in the reduction of extra-cellular release of gliadin peptides and suggest novel molecular targets to counteract gliadin-induced toxicity in CD.

Effect of Maxillary Sinus Membrane Perforation on Implant Survival Rate: A Retrospective Study.

PURPOSE: The aim of this retrospective study was to evaluate implant survival rates (ISRs) for implants placed in grafted sinuses where a membrane perforation occurred during augmentation using exclusively anorganic bovine bone (ABB) by means of clinical and radiographic examinations. Histologic information of five biopsy specimens taken from large membrane perforations is also presented. MATERIALS AND METHODS: Consecutive patients who underwent sinus augmentation procedures at a private practice Dental Institute between 2004 and 2013 were collected from a computer database. The following profiles were selected for data analysis: computed tomography prior to treatment; perforated membrane information according to size: not perforated, small (≤ 5 mm), medium (> 5 and < 10 mm), or large (≥ 10 mm); sinuses grafted exclusively with ABB and lateral window covered with a collagen membrane (CM); and implant survival after at least 2 years of functional loading placed in augmented sinuses. Implants were considered survivals in the absence of infection, mobility, or pain. RESULTS: The sample in this retrospective study comprised 531 patients; 214 required bilateral sinus augmentation, and 317 required unilateral sinus augmentation (total = 745 sinuses). A total of 1,588 implants were placed. From 745 augmented sinuses, 237 (31.8%; 523 implants) were perforated during the procedure. Among these, 48 perforations were large (20.2%; 107 implants), 67 (28.3%; 150 implants) were medium, and 122 were small (51.5%; 266 implants). Of 523 implants placed in perforated sinuses, 15 were lost (ISR = 97.1%). Comparison of the ISRs for small (97.7%), medium (97.3%), and large (95.3%) perforations with 1,065 implants placed in nonperforated sinuses (ISR = 97.7%) was not statistically significant. The histomorphometric analysis of the five biopsy specimens showed 24.52% ± 6.99% of new bone, 24.32% ± 6.42% of marrow space, and 51.2% ± 3.75% of the remaining ABB. CONCLUSION: The difference in ISR for implants placed in perforated and nonperforated sinuses was not statistically significant. Within the limits of the histologic data, histomorphometric results with 24.52% ± 6.99% of new bone formation in sinuses with large perforations showed similar bone formation compatible with nonperforated sinuses described in the literature. The authors attributed the high ISR shown in perforated sinuses in this study to the proper management of the perforations.

Identification of Autophagy-Related Genes and Their Regulatory miRNAs Associated with Celiac Disease in Children.

Celiac disease (CD) is a severe genetic autoimmune disorder, affecting about one in 100 people, where the ingestion of gluten leads to damage in the small intestine. Diagnosing CD is quite complex and requires blood tests and intestinal biopsy examinations. Controversy exists regarding making the diagnosis without biopsy, due to the large spectrum of manifesting symptoms; furthermore, small-intestinal gastroscopy examinations have a relatively complex management in the pediatric population. To identify novel molecular markers useful to increase the sensitivity and specificity in the diagnosis of pediatric CD patients, the expression levels of two key autophagy executor genes (ATG7 and BECN1) and their regulatory validated miRNAs (miR-17 and miR-30a, respectively) were analyzed by relative quantitative real-time-PCR on a cohort of confirmed CD patients compared to age-related controls. Among the investigated targets, the non-parametric Mann-Whitney U test and ROC analysis indicated the highest significant association of BECN1 with CD status in the blood, while in intestinal biopsies, all of the investigated sequences were positively associated with CD diagnosis. Nomogram-based analysis showed nearly opposite expression trends in blood compared to intestine tissue, while hierarchical clustering dendrograms enabled identifying CD and control subgroups based on specific genes and miRNA expression signatures. Next, using an established in vitro approach, through digested gliadin administration in Caco-2 cells, we also highlighted that the modulation of miR-17 endogenous levels using enriched exosomes increased the intracellular autophagosome content, thereby altering the autophagic status. Altogether, these results highlighted novel molecular markers that might be useful to increase the accuracy in CD diagnosis and in molecular-based stratification of the patients, further reinforcing the functional involvement of the regulation of the autophagy process within a digestive and autoimmune-related disorder as CD.

Prenatal alcohol exposure reduces mandibular calcium and phosphorus concentrations in newborn rats.

Previous studies suggest that prenatal alcohol exposure affects fetal bone development, including bone quality. This study evaluated the chemical composition of mandibles from newborn rats after maternal 20% alcohol consumption before and throughout gestation. Nine rats were initially distributed into three groups: an Alcohol group, Pair-fed group, and Control group. The groups were fed prespecified diets for 8 weeks before and the 3 weeks during pregnancy. At age 5 days, eight newborns from each group were euthanized (total, n = 24). Using energy dispersive spectrometry, we evaluated samples of mandibles from newborns to identify changes in bone mineralization, specifically Ca and P concentrations. Ca and P concentrations were lower in the Alcohol group than in the Control and Pair-fed groups (P = 0.003 and P = 0.001, respectively). In summary, alcohol exposure before and throughout gestation reduces mandibular Ca and P concentrations in newborn rats. (J Oral Sci 58, 439-444, 2016).

Influence of post-etching surface treatment and thermo-mechanical cycling on fracture strength of ceramics.

BACKGROUNG: The aim of this study was to evaluate fracture strength of lithium disilicate-based ceramic crowns submitted to neutralization of hydrofluoric acid (HF) precipitates associated with ultrasonic bath and to thermo-mechanical cycling. METHODS: Eighty human molars received conventional full crown preparation after being included in polyurethane standard to simulate periodontal ligament. After scanning, the ceramic blocks were machined using CAD/CAM system to obtain the crowns. The crowns were distributed according to surface treatment: S and S-C; HF and silane; SNU and SNU-C; HF neutralization of HF precipitates, ultrasonic bath and silane. The crowns were cemented with dual cure resin cement and the specimens in Groups S-C and SNU-C were submitted to thermo-mechanical cycling (5/55 °C/60 s while 1.2 million mechanical cycles of 4 Hz/100 N). The samples were submitted to compressive test. Analysis of fractures was performed macroscopically (Burke method) and using Scanning Electron Microscope. The data of fracture strength were analyzed using the two-way ANOVA. RESULTS: No statistical difference among the groups was found (p-value = 0,799). Most failures were associated with the remaining tooth fracture and the fracture origin was located on the cementation surface. CONCLUSIONS: Postetching cleaning protocols do not improve the fracture strength of ceramics crowns. Thermo-mechanical aging did not weakened the ceramic crown.

Improving gingival smile by means of guided bone regeneration principles.

OBJECTIVE: This study evaluated the effectiveness of guided bone regeneration (GBR) carried out with xenogenic bone substitute (Bio-OssTM) and collagen resorbable membrane (Bio-GideTM) to improve gingival smile (GS) in patients with excessive vertical maxillary growth (EVMG). METHODS: Twelve healthy women aged between 20 and 49 years old (mean age of 26 years), with 5 mm or more of gingival exposure during fully posed smile (FPS) due to EVMG, were included. Baseline digital photographs were taken with standardized head position at rest and FPS. In eight out of 12 cases, crown lengthening procedure was indicated and the initial incision was made 2 to 4 mm from the gingival margin. In four cases, with no indication for crown lengthening procedure, a sulcular incision was performed. GBR was performed in all cases, using micro screws and/or titanium mesh associated with Bio-OssTM and Bio-GideTM. After 10 days, sutures were removed. Recall appointments were scheduled at 1, 6, and 12 months when standardized photographs were again taken. ImageToolTM software was used to measure the gingival exposure (GE) during FPS from the standardized close-up smile photographs at baseline and 12 months. RESULTS: GE mean at baseline was 275.44 mm2. After 12 months, patients who undergone exclusively GBR procedure, presented GE reduction of 40.7%, ∆ = 112.01 mm2 (statistically significant, p = 0.12), and patients who had crown lengthening associated with the graft had a reduction of 60%, ∆ = 167.01 mm2. CONCLUSION: Our results using GBR to improve GS in cases of EVMG showed an exceptionally high patient acceptance and satisfaction. One-year follow-up confirmed stable results.

Improving gingival smile by means of guided bone regeneration principles

ABSTRACT Objective: This study evaluated the effectiveness of guided bone regeneration (GBR) carried out with xenogenic bone substitute (Bio-OssTM) and collagen resorbable membrane (Bio-GideTM) to improve gingival smile (GS) in patients with excessive vertical maxillary growth (EVMG). Methods: Twelve healthy women aged between 20 and 49 years old (mean age of 26 years), with 5 mm or more of gingival exposure during fully posed smile (FPS) due to EVMG, were included. Baseline digital photographs were taken with standardized head position at rest and FPS. In eight out of 12 cases, crown lengthening procedure was indicated and the initial incision was made 2 to 4 mm from the gingival margin. In four cases, with no indication for crown lengthening procedure, a sulcular incision was performed. GBR was performed in all cases, using micro screws and/or titanium mesh associated with Bio-OssTM and Bio-GideTM. After 10 days, sutures were removed. Recall appointments were scheduled at 1, 6, and 12 months when standardized photographs were again taken. ImageToolTM software was used to measure the gingival exposure (GE) during FPS from the standardized close-up smile photographs at baseline and 12 months. Results: GE mean at baseline was 275.44 mm2. After 12 months, patients who undergone exclusively GBR procedure, presented GE reduction of 40.7%, ∆ = 112.01 mm2 (statistically significant, p = 0.12), and patients who had crown lengthening associated with the graft had a reduction of 60%, ∆ = 167.01 mm2. Conclusion: Our results using GBR to improve GS in cases of EVMG showed an exceptionally high patient acceptance and satisfaction. One-year follow-up confirmed stable results.

RESUMO Objetivo: o presente estudo avaliou a eficácia da regeneração óssea guiada (ROG) usando enxerto ósseo xenógeno (Bio-Oss(r)) e membrana de colágeno reabsorvível (Bio-Gide(r)) para melhorar a estética do "sorriso gengival" (SG) em pacientes com crescimento maxilar vertical excessivo (CMVE). Métodos: foram incluídas 12 mulheres saudáveis com idades entre 20 e 49 anos (média = 26 anos) com 5mm ou mais de exposição gengival durante o sorriso amplo posado (SAP), em função de CMVE. Foram realizadas fotografias digitais padronizadas (FDP) em repouso e em SAP. Em 8 dos 12 casos, foi indicado o procedimento de aumento da coroa clínica, e a incisão inicial foi realizada de 2 a 4mm da margem gengival. Em 4 casos, para os quais não houve indicação de aumento da coroa clínica, foi realizada uma incisão intrassulcular. A ROG foi realizada, em todos os casos, utilizando-se mini-implantes e/ou malha de titânio, associados a Bio-Oss(r) e Bio-Gide(r). Após 10 dias, as suturas foram removidas. O programa ImageTool(r) foi utilizado para medir a "área gengival exposta" (AGE) durante o SAP, nas imagens padronizadas do sorriso, em close-up, ao início do estudo e após 12 meses. Resultados: a média da AGE no início do estudo foi de 275,44mm2. Após 12 meses, os pacientes submetidos exclusivamente ao procedimento de ROG apresentaram redução na AGE de 40,7%, Δ = 112,01mm2 (estatisticamente significativo, p = 0,12); já nos pacientes em que o aumento de coroa clínica foi associado ao enxerto, a redução foi de 60%, Δ = 167,01mm2. Conclusão: os resultados do uso da ROG para melhorar o SG em casos de CMVE demonstraram aceitação e satisfação extremamente elevadas por parte dos pacientes. O acompanhamento de 1 ano pós-tratamento confirmou a estabilidade dos resultados.

Desenvolvimento e caracterização de ligas de Co-Cr-Mo / Development and characterization of Co-Cr-Mo alloy

As ligas de Co-Cr têm o uso consagrado para reabilitação oral com prótesesdentárias. Os procedimentos reabilitadores orais por implantes osseointegrados destacaram novas necessidades biomecânicas e estruturais das ligas metálicas. O objetivo deste estudo foi desenvolver e caracterizar três ligas metálicas de CoCr-Moexperimentais, para aplicação odontológica. Foram confeccionadas ligas de Co-Cr-Mo, com percentuais crescentes de Mo (6, 7 e 8% - A, B e C,respectivamente), por duas técnicas de processamento: L2, fusão para acréscimo de Mo a uma liga comercial certificada (American Society for Testing and Materials, 1996) (L1); e L3, fusão dos metais Co, Cr e Mo, comercialmentepuros. As ligas em estudo foram caracterizadas microestruturalmente pormicroscopia eletrônica de varredura (MEV), espectroscopia de energiadispersiva (EDS), difração de raios X (DRX), fluorescência de raios X (XDR);fisicamente por microdureza, resistência à corrosão. Fibroblastos dérmicoshumanos foram utilizados para avaliar a citotoxicidade das ligas experimentaisapós 1, 4 e 7 dias de cultura celular. Organização citoesquelética, adesão,viabilidade, morfologia e diferenciação celular foram avaliados por microscopiade fluorescência, análise bioquímica e MEV. Os resultados obtidos permitiramconcluir que as ligas experimentais (L2A, L2B, L2C, L3A, L3B e L3C) apresentaram desempenho microsestrutural, mecânico e citotóxico superior à L1, sendo indicada para utilização biomédica e odontológica

In Dentistry, the Co-Cr alloys are general used for oral rehabilitation by dentalprosthesis. The oral rehabilitation procedures by osseointegrated implants point out to new metal alloys’ biomechanical and structural necessities. The aim ofthis study was develop and characterize three experimental Co-Cr-Mo alloys,for dental application. Three alloys will be made out with different Mo’spercentages by two processing techniques: L2, casting by addition of Mo to a certified commercial Co-Cr alloy (American Society for Testing and Materials, 1996) (L1); and L3, casting of purified commercial metals (Co, Cr, Mo). The experimental alloys were characterized by microstructure by digital optical microscopy, scanning electron microscopy, energy dispersive X-ray spectrometry, X-ray diffraction and X-ray fluorescence; and mechanically by microhardness and corrosion resistance. Human dermal fibroblasts were used to evaluate the biocompatibility of experimental Co-Cr alloys after 1, 4 and 7 days of culture. Cellular adhesion, proliferation, viability, cytoskeletal organization and morphology were investigated using fluorescence microscope,biochemical assay and SEM. Based on data was possible to concluded thatexperimental alloys (L2A, L2B, L2C, L3A, L3B e L3C) shown higherperformance for microstructure, mechanical and cytotoxic as L1 and they are recommend to biomedical and dentistry applications

Grafting the nasal cavity with 100% anorganic bovine bone: a clinical and histomorphometric pilot report.

PURPOSE: The aim of the present study was to evaluate bone formation and survival rates for implants after nasal cavity grafting using exclusively anorganic bovine bone (ABB) by means of clinical, radiographic, and histologic/histomorphometric examinations. MATERIALS AND METHODS: Twelve subjects with edentulous atrophic maxillae were screened for the study; four required bilateral and eight required unilateral nasal cavity grafting. A full-thickness flap was raised to determine the position for the nasal window between the anterior wall of the sinus and the lateral wall of the piriform aperture. A window, 5 to 6 mm wide and 10 to 13 mm high, was created. The window was infractured into the nasal cavity to allow the ABB to be pushed inside and was then covered with a collagen membrane. Cone beam computed tomography (CBCT) was performed before grafting (during screening), after grafting, and 6 months later. Eight months after grafting, from the 16 sites grafted, biopsy cores were taken from three patients using a 2.5-mm trephine and processed to evaluate the percentages of new bone, marrow space, and residual ABB. One screw-form implant was placed in each grafted site and loaded after 3 months. After at least 6 months of loading, the fixed prostheses were removed and all implants placed in grafted areas were tested for mobility. RESULTS: The 6-month CBCTs clearly showed the radiopaque material inside the nasal cavity. The histomorphometric measurements showed 33.34% new bone, 30.30% marrow space, and 36.52% remaining ABB. All implants were osseointegrated and free of pain, infection, and mobility. All implants remained stable at a mean of 13 months after loading (range, 6 to 24 months). CONCLUSIONS: The clinical, radiographic, and histomorphometric results showed that nasal cavity grafting with ABB can be an excellent alternative in patients with extensively atrophic maxillae.