Cell adhesion evaluation of laser-sintered HAp and 45S5 bioactive glass coatings on micro-textured zirconia surfaces using MC3T3-E1 osteoblast-like cells.

Laser texturing is a technique that has been increasingly explored for the surface modification of several materials on different applications. Laser texturing can be combined with conventional coating techniques to functionalize surfaces with bioactive properties, stimulating cell differentiation and adhesion. This study focuses on the cell adhesion of laser-sintered coatings of hydroxyapatite (HAp) and 45S5 bioactive glass (45S5 BG) on zirconia textured surfaces using MC3T3-E1 cells. For this purpose, zirconia surfaces were micro-textured via laser and then coated with HAp and 45S5 BG glass via dip coating. Afterwards, the bioactive coatings were laser sintered, and a reference group of samples was conventionally sintering. The cell adhesion characterisation was achieved by cell viability performing live/dead analysis using fluorescence stains and by SEM observations for a qualitative analysis of cell adhesion. The in vitro results showed that a squared textured pattern with 100µm width grooves functionalized with a bioactive coating presented an increase of 90% of cell viability compared to flat surfaces after 48h of incubation. The functionalized laser sintered coatings do not present significant differences in cell viability when compared to conventionally sintered coatings. Therefore, the results reveal that laser sintering of HAp and 45S5 BG coatings is a fast and attractive coating technique.

Micro-CT based finite element modelling and experimental characterization of the compressive mechanical properties of 3-D zirconia scaffolds for bone tissue engineering.

The present study aims at developing a computational framework with experimental validation to determine the mechanical properties of zirconia foams for bone tissue engineering. A micro-CT based finite element model that allows characterizing the mechanical property of such cellular structures is developed. Micro-CT images are filtered to vanish noises and smooth boundaries before constructing 3D zirconia foams using an adaptive Body-Centered Cubic background lattice. In addition to micro-CT images, the local material property at the scaffold struts is measured using a micro-indentation test, which shows a considerable difference with that of common zirconia owing to the manufacturing process. The computational model also takes the plastic deformation of material into account employing the Voce law, a nonlinear isotropic hardening law, as well as Von-mises yield criterion. Zirconia foams with different pore sizes are manufactured using the replica method and their mechanical properties determined experimentally. Such experimental outcomes are to validate and demonstrate the capability of the developed model, which can be used for pre-operational evaluations and preclinical tests of zirconia scaffolds. The stress magnitude and distribution within the scaffold as well as plastic strains and flow stress of the zirconia scaffold are computed and analysed. Using the proposed approach, a deep insight into the association of macroscopic behaviour of the scaffold to microscopic features, e.g. strut waviness, Plateau border, thickness variation of cells, irregularity, microstructural variability, imperfections and strut's material property associated with to the manufacturing procedure, can be gained.

Y-TZP/porcelain graded dental restorations design for improved damping behavior - A study on damping capacity and dynamic Young's modulus.

The development of dental restorative materials that mimic tooth-like properties provided by graded structures, aesthetics and properties such as strength, damping capacity and the ability for a continuous remodeling according to the biomechanical solicitation is a great challenge. In this work, damping capacity and dynamic Young's modulus of Y-TZP/porcelain composites for all-ceramic dental restorations were studied. These mechanical properties were assessed by dynamic mechanical analyses (DMA) at frequencies of 1, 5 and 10 Hz, over a temperature ranging from 0 to 60 °C, simulating extreme conditions when a cold or hot drink is experienced. The results showed that porcelain and porcelain-matrix composites exhibited higher damping capacity while Y-TZP and Y-TZP-matrix composites presented higher dynamic Young's modulus. Furthermore, while damping capacity is strongly influenced by the temperature, no significant difference in dynamic Young's modulus was found. For both damping and modulus properties, no significant influence of frequency was found for the tested materials. Based on the obtained results and also on the known advantages of the graded Y-TZP/porcelain structures over traditional bi-layer solutions (e.g., improved bending strength, enhanced mechanical and thermal stress distribution), a novel design of all-ceramic restoration with damping capacity has been proposed at the end of this study. A positive impact on the long-term performance of these all-ceramic restorations may be expected.

Development of novel zirconia implant's materials gradated design with improved bioactive surface.

Zirconia implants are becoming a preference choice for different applications such as knee, dental, among others. In order to improve osseointegration, implant's surfaces are usually coated with bioactive materials like hydroxyapatite (HAp) and beta-tricalcium phosphate (ß-TCP) that are very similar to the calcium phosphates found in bones. However, due to the implantation process, these coatings can be detached from the zirconia surface, leading to implant premature failure. In this work, a new component materials design aiming to avoid this coating detachment problem is proposed. It is based on the use of a bioactive zirconia-calcium phosphate composite outer layer onto the zirconia bulk, where the zirconia bulk provides mechanical strength and the outer layer provides biological performance. In order to assess the potential of this new materials design, two types of bioactive zirconia outer composite layers (zirconia reinforced by 10 vol% of HAp and by 10 vol% of ß-TCP) were produced by press and sinter process and the gradated samples were fully characterized concerning materials, mechanical resistance, fatigue resistance, and biological performance, as measured by different approaches. Results showed that the novel component materials design and the manufacturing process proposed for producing the bioactive zirconia samples with outer composite layers on zirconia bulk substrates are a promising solution for implants, with improved biological performance without substantially compromising their overall mechanical and fatigue properties.

Sliding behavior of zirconia porous implant surfaces against bone.

Different zirconia porous layers were produced on zirconia dense zirconia substrates by slip casting using powder with different mean sizes: 40 µm (Z40), 70 µm (Z70), and 100 µm (Z100). The dynamic and static coefficients of friction against bovine femoral bone, mimicking the implantation process, were conducted using a ball-on-flat reciprocating sliding tribometer under 3 N of normal load. Additionally, the porous layers were assessed with regard to their low temperature degradation (aging). Results revealed that the porous layers were able to keep their integrity during the sliding testes against bone, with no zirconia particles being transferred to the bone. Results did not show significant differences (p > 0.05) in kinetic and static COF values for Z40, Z70, Z100, and GRAD specimens, ranging from 0.53 to 0.77 and 0.65 to 0.90, respectively. The aging tests revealed that all surfaces were prone to low temperature degradation (~49% of monoclinic content after 18 h). In conclusion, the cohesive integrity of the layers and relatively high COF observed reveled that zirconia porous layers may be considered for replacing the current implant surfaces, and are expected to improve their primary stability. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1113-1121, 2019.

Inhibition of multi-species oral biofilm by bromide doped bioactive glass.

Bioactive glass is an attractive biomaterial that has shown excellent osteogenic and angiogenic effects for oral bone repairing procedures. However, anti-biofilm potential related to such biomaterial has not been completely validated, mainly against multi-species biofilms involved in early tissue infections. The aim of the present study was to evaluate the anti-biofilm effect of 58 S bioactive glass embedding calcium bromide compounds at different concentrations. Bioactive glass free or containing 5, or 10 wt % CaBr2 was synthesized by alkali sol-gel method and then characterized by physco-chemical analyses and scanning electron microscopy (SEM). Then, samples were tested by microbiological assays using optical density, real time q-PCR, and SEM. Bioactive glass particles showed accurate chemical composition and an angular shape with a bimodal size distribution ranging from 0.6 to 110 µm. The mean particle size was around 29 µm. Anti-biofilm effect was recorded for 5 wt % CaBr2 -doped bioactive glass against S. mitis, V. parvula, P. gingivais, S. gordoni, A. viscosus, F, nucleatum, P. gingivais. F. nucleatum, and P. gingivalis. Such species are involved in the biofilm structure related to infections on hard and soft tissues in the oral cavity. The incorporation of calcium bromide into bioactive glass can be a strategy to enhance the anti-biofilm potential of bioactive glasses for bone healing and infection treatment. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1994-2003, 2017.

Anti-biofilm properties of bioactive glasses embedding organic active compounds.

Bioactive glasses (BGs) are promising materials for bone repair due to their desirable properties such as osteoconductivity, biodegradability, angiogenic potential, and antibacterial activity. Ionic dissolution products from bioactive glasses increase the medium pH inhibiting surrounding bacteria proliferation. The activity of BGs against biofilm formation has been enhanced by incorporating organic antibacterial compounds. The aim of this review was to summarize evidence in literature which assesses the efficacy of antibacterial and anti-biofilm compounds embedded in bioactive glasses to prevent peri-implant infection during bone healing. A PubMed bibliographical research was carried out including articles published in the last 20 years. Most previous studies evaluated antibacterial efficiency in planktonic cultures but did not investigate biofilm inhibition, underestimating biofilm clinical relevance. Multifactorial features such as biocompatibility of embedded compounds, receptor site characteristics, and drug delivery efficiency have been found to influence the bioactive glass capability of acting both as an anti-biofilm agent and as a bone repairing biomaterial. Accordingly, further in vitro and in vivo studies are required to select the most promising anti-biofilm agents which should be incorporated into bioactive glasses to counteract biofilm proliferation, without inducing toxic effects on human cells, and with the added functionality of promoting bone regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 672-679, 2017.

Processing and strengthening of 58S bioactive glass-infiltrated titania scaffolds.

In this work, TiO2 ceramic scaffolds were fabricated by the replica method using polyurethane (PU) sponges. Suspensions with high solid content were used to achieve scaffolds with improved mechanical behavior. TiO2 ceramic suspensions were optimized by rheological studies using different additives. It was found that the composition with 0.5 wt % Darvan enhanced the covering of the sponge struts. PU sponges of 45 to 80 ppi (pore per inch) were well coated without clogging pores. A thermal treatment with varying holding times, temperatures and heating rates was adjusted. The influence of different pore sizes on mechanical strength was evaluated. It was possible to obtain TiO2 scaffolds with 90% porosity and high pore interconnectivity, having compressive strength exceeding 0.6 MPa. TiO2 scaffolds were filled up with a 58S bioactive glass suspension to impart bioactive character to the scaffolds. These hybrid structures presented mechanical strengthening of about 26-213% depending on their sponge porosity. The prediction for cells viability via zeta potential measures indicated that this hybrid material is very promising for scaffold application with -19 to -25 mV between pH of 7.35-7.45. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 590-600, 2017.

Dyadic dynamics of perceived social support in couples facing infertility.

STUDY QUESTION: Is perceived social support from partner, family, and friends associated with increased infertility-related stress? SUMMARY ANSWER: While men's perceived support did not seem to influence their partners' stress, women's perceptions of spousal and familial support can affect the way men deal with the challenge of infertility. WHAT IS KNOWN ALREADY: Previous studies showed that low levels of social support are associated with poor psychosocial adjustment and treatment termination in women and men. Studies examining the impact of social support using the couple as unit of analysis are lacking. STUDY DESIGN, SIZE, DURATION: A cross-sectional sample of 613 Portuguese patients participated in the research, online over a 3-month period, and in a public fertility clinic over 11 months. PARTICIPANTS/MATERIALS, SETTING, METHODS: The final sample comprised 213 married or cohabiting couples (191 from the fertility clinic) who were actively attempting to have a child, were seeking infertility treatment and had not undergone previous preimplantation genetic diagnosis. Perceived social support was assessed through the Multidimensional Scale of Perceived Social Support and infertility-related stress was assessed with the fertility problem inventory. Hypotheses were tested by applying the actor-partner interdependence model using structural equation modeling. MAIN RESULTS AND THE ROLE OF CHANCE: Couples had been living together for an average (±SD) of 6 ± 3.5 years, and attempting a pregnancy for 3.8 ± 2.6 years. Nearly half of the couples had undergone infertility treatment (41.3%). Infertility stress was found to be associated with low family support for women (ß = -0.27, P = .003), and low partner support for both men (ß = -0.29, P = .001) and women (ß = -0.45, P = .006). Both women and men's perceived friend support were not significantly related to male or female infertility stress. Men infertility stress was also associated with their partners low levels of partner (ß = -0.24, P = .049) and family support (ß = -0.23, P < .001). No significant partner effects were observed for women. Despite being related to actor effects alone (female partner and family support), the explained variance of the model in women's fertility stress was greater (R(2) = 21%) than that (R(2) = 15.6%) for the combined actor and partner effects in men's fertility stress (male partner support, female partner and family support). LIMITATIONS, REASONS FOR CAUTION: The study data are cross-sectional and the generalizability of results is limited by self-selection. The characteristics of non-participants in both the clinical and online samples were not available, the perception of infertility-specific supportive behaviors was not assessed and differential analyses according to infertility diagnosis were not included in this study. WIDER IMPLICATIONS OF THE FINDINGS: Our data underline the importance of partner support in alleviating the burden of infertility. Men may experience infertility indirectly through the impact that it has on their partners. Our findings reinforce the need to involve the male partner throughout the whole treatment process and for couple-based interventions when providing infertility counseling. Further prospective research should be aimed at investigating the male experience of infertility. STUDY FUNDING/COMPETING INTEREST: This research was supported by a PhD scholarship from the Portuguese Foundation for Science and Technology granted to M.M. (FCT, SFRH/BD/44232/2008). The authors have no conflicts of interest to declare.

Scalp tumour as a sign of systemic B-cell lymphoma.

An 86-year-old man presented with a painful reddish tumour on the scalp with a 3-month history, mental confusion with recent onset and lymphadenopathies. Histological examination of the lymph node and cutaneous lesion revealed a dense infiltrate of atypical and large B cells. There was no evidence of bone marrow invasion. According to REAL (Revised European-American Classification of Lymphoid Neoplasms), this lymphoma was considered as a diffuse large B-cell lymphoma with concurrent cutaneous and nodal involvement. Cerebral computerized tomography (CT) scan showed bone and dura mater invasion in the right parieto-occipital region with collapse of lateral ventricle. The patient was submitted to systemic chemotherapy with cyclophosphamide, vincristine and prednisolone (CVP). There was a good response with regression of the cutaneous lesion, but the patient died after the third cycle. We point out the unusual clinical presentation and aggressive behaviour of this lymphoma.

Tuberculosis in a child presenting as asymptomatic oropharyngeal and laryngeal lesions.

We describe an 11-year-old boy who had several, asymptomatic, erythematous papules in the oropharynx and larynx with recent onset, two cervical lymphadenopathies, and a painless, erythematous plaque on the right wrist with a 2.5-year history of slow growth. Histologic examination of the mucocutaneous lesions revealed a submucous infiltrate of lymphocytes and Langhans giant cells in the papules and granulomatous dermatitis in the plaque. The cervical lymph node was biopsied and on the surgical scar, an erythematous, nodular lesion developed. A biopsy specimen of this lesion showed tuberculoid granulomas with prominent caseation necrosis, and culture was positive for Mycobacterium tuberculosis. The Mantoux test was strongly positive with a vesicular response. A diagnosis of mucocutaneous lupus vulgaris and scrofuloderma secondary to cervical tuberculous lymphadenitis was made. Two months after initiation of antituberculosis therapy there was a complete resolution of mucous lesions and healing with atrophic scars on the neck and wrist. This is a rare presentation in the literature and reminds clinicians that tuberculosis should be kept in mind in the differential diagnosis of oral cavity lesions.

Dermatological and ophthalmological sequels in toxic epidermal necrolysis.

BACKGROUND: Toxic epidermal necrolysis (TEN) is a rare, drug-induced disease characterized by epidermal detachment and mucosal involvement. After an acute period, potentially disabling cutaneous and ocular sequels may appear. Although long-term complications are not rare, only few outcome studies are published. OBJECTIVE: To evaluate the incidence of dermatological and ophthalmological sequels following TEN, to describe its clinical aspects and correlation with acute involvement. PATIENTS AND METHODS: Eight patients surviving to TEN were submitted to dermatological and ophthalmological observation ranging from 0.5 to 8 years after hospitalization. Cutaneous and ocular involvement, during the acute phase, was retrospectively analysed. RESULTS: Dermatological sequels were observed in 6 patients (75%) corresponding to those with more extensive skin involvement in the acute phase. The most frequent complications were cutaneous dyschromia (62.5%) and nail dystrophies (37.5%). Six patients (75%) had ocular complications with tarsal conjunctiva keratinization in 5 (62.5%) and keratoconjunctivitis sicca in 4 of them (50%). Trichiasis, corneal neovascularization and symblepharon were observed in 1 case. There was no correlation between the severity of acute ocular involvement and long-term complications. CONCLUSION: Following TEN, most patients have dermatological and ophthalmological sequels that persist for several years.

Tufted hair folliculitis after scalp injury.

We describe the case of a 38-year-old epileptic man with tufted hair folliculitis. The condition started 5 years ago after a scalp laceration that had been sustained 3 months earlier during an epileptic crisis. There then appeared a circumscribed inflammatory bulging lesion (with exudation and crusts) that evolved to scarring alopecia with tufts of 20 to 30 apparently normal hair shafts. Results of bacteriologic examination of pus extruding from the dilated follicular ostia revealed Staphylococcus aureus. The cutaneous pathologic examination showed polymorphous inflammatory exudate in the upper and mid dermis, which was mostly perifollicular, and the presence of normal and independent follicles in the deep dermis, which, while ascending, converged to a common dilated follicular channel. The patient was treated successively with oral flucloxacillin, erythromycin, ciprofloxacin, and amoxicillin/clavulanic acid and with topical application of erythromycin, clindamycin, povidone iodine, and ketoconazole. Transient improvement was followed by recurrence and enlargement of the affected area.

Autoimmune progesterone urticaria.

Autoimmune progesterone dermatitis is a rare cutaneous disorder characterized by recurrent and cyclic skin eruption with variable morphology, occurring during the luteal phase. A case of autoimmune progesterone urticaria in a 47-year-old woman is reported. An intradermal progestin test revealed a strong reactivity against this hormone. Treatment with tamoxifen and leuprolide acetate induced only a partial remission of urticaria. Bilateral oophorectomy was performed with absolute clearing of cutaneous lesions.