Keratoameloblastoma of the lower jaw: A rare challenging entity.

Ameloblastoma is the second most common benign odontogenic tumor with various histopathologic features. Except for the unicystic type of ameloblastoma, the different microscopic patterns of this tumor show no significant correlation with long-term clinical behavior. During recent decades, additional challenging subtypes of ameloblastoma, including "Keratoameloblastoma" (KA), have been introduced in the literature. Here, we present a case of KA and discuss the important diagnostic microscopic features.

Family and Rehabilitation of Children with Cochlear Implant: A Qualitative Study.

AIM: This study was conducted to explain the role of families in rehabilitating children with cochlear implants based on the participants' experiences and perceptions. METHOD: This research is a qualitative study based on the method of contract content analysis, and it is conducted with semi-structured interviews to collect information in Iran in 2018-2019. The interview was conducted with 12 participants, including caregivers (child caregivers with a cochlear implant), and the process of data collection continued until saturation. Interviews were recorded and transcribed, and the data were analyzed using Gran Haim and Landman content analysis. This study was guided by consolidated criteria for reporting qualitative (COREQ). RESULTS: The results of the study were formed in the main class titled the family, the effective rehabilitation factor, and two sub-classes titled supportive family and continuing professional and non-professional rehabilitation. CONCLUSION: The findings of this study indicated that the rehabilitation process in these children will be incomplete without the presence and support of the family.

Estimation of long-term and short-term health effects attributed to PM2.5 standard pollutants in the air of Ardabil (using Air Q + model).

Clean air is considered as a basic need for human health. However, air pollution is a significant threat to health in developed and developing countries. The aim of this study was to estimate the health effects attributed to PM2.5 pollutants in the air of Ardabil in 2018 (using Air Q + model). Raw data related to particles were collected from the Department of Environment and processed in Excel software and converted into an input file of the Air Q + model, and in the final stage, by considering appropriate epidemiological parameters and combining these data with air quality data, it was possible to estimate the health effects of air pollution. The results showed that the average annual concentrations of PM2.5 and PM10 were 15.47 and 30.94 in the study year, respectively. The total number of deaths due to ALRI, COPD, lung cancer, IHD, and stroke deaths on average during the study period were estimated to be 73, 11, 7, 15, and 14 deaths, respectively, which include 14.62, 15.78, 4.9, 12.43, and 11.6% of deaths due to ALRI, COPD, lung cancer, IHD, and stroke deaths, respectively. In conditions of concentration above 5 µg/m3, attributed proportion, total number of attributed cases and number of attributed cases per 100,000 population (with moderate relative risk and confidence interval of 95%) for cardiovascular diseases have been estimated to be 0.95% 103 people and 42.19 people. Also, the attributed proportion, the total number of attributable cases, and the number of attributable cases per 100,000 population (with moderate relative risk and confidence of 95%) for the admission of respiratory diseases have been estimated at 97.1%, 68 persons and 3 persons, respectively. Our results suggest that particle exposure even at low concentrations is associated with an increased risk of overall mortality and specific cause mortality and hospital admissions for respiratory and cardiovascular diseases.

Bottom-up synthesis of graphene films hosting atom-thick molecular-sieving apertures.

Incorporation of a high density of molecular-sieving nanopores in the graphene lattice by the bottom-up synthesis is highly attractive for high-performance membranes. Herein, we achieve this by a controlled synthesis of nanocrystalline graphene where incomplete growth of a few nanometer-sized, misoriented grains generates molecular-sized pores in the lattice. The density of pores is comparable to that obtained by the state-of-the-art postsynthetic etching (1012 cm-2) and is up to two orders of magnitude higher than that of molecular-sieving intrinsic vacancy defects in single-layer graphene (SLG) prepared by chemical vapor deposition. The porous nanocrystalline graphene (PNG) films are synthesized by precipitation of C dissolved in the Ni matrix where the C concentration is regulated by controlled pyrolysis of precursors (polymers and/or sugar). The PNG film is made of few-layered graphene except near the grain edge where the grains taper down to a single layer and eventually terminate into vacancy defects at a node where three or more grains meet. This unique nanostructure is highly attractive for the membranes because the layered domains improve the mechanical robustness of the film while the atom-thick molecular-sized apertures allow the realization of large gas transport. The combination of gas permeance and gas pair selectivity is comparable to that from the nanoporous SLG membranes prepared by state-of-the-art postsynthetic lattice etching. Overall, the method reported here improves the scale-up potential of graphene membranes by cutting down the processing steps.

Rehabilitation of children with cochlear implant in Iran: A scoping review.

Background: Recovery of children does not appear on its own after cochlear implantation. Coherent, thoughtful, and comprehensive rehabilitation is needed to achieve complete success. The purpose of this study was to identify the types of rehabilitation interventions for children with cochlear implants that have been performed in Iran. Methods: A scoping review study was conducted. An electronic search was carried out both in English and Persian. In English, the following keywords were used: cochlear implantation, child, cochlear implants, auditory rehabilitation, deaf, hearing loss, comprehensive, interventions, rehabilitation, and telerehabilitation and a combination of them in ProQuest, PubMed, Science Direct, and Scopus databases, Web of Sciences, Medline and Embase. Persian electronic search was conducted in the Scientific Information Database (SID) of Jihad Daneshgahi, Iran Journals Database (MagIran), and Islamic World Science Citation Database (ISC). Searches were done using articles published until September 25, 2020, and a total of 902 articles were found, of which 14 were directly related to the purpose of the study. Interventional studies were included in the study, and the quality of studies was measured using the Structured Effectiveness Quality Evaluation Scale. Results: The results showed that using music and rehabilitation equipment, different methods of speech therapy and auditory training, story-based instruction, creative play, family-centered instruction, and occupational therapy are interventions in cochlear implant rehabilitation. Speech therapy accounts for 54% of the rehabilitation share. The mean number of rehabilitation sessions was 26. These interventions were all somehow effective in children with cochlear implantation; the longer the training duration, the better the results. Conclusion: The process of cochlear implant rehabilitation in children is multi-professional; auditory training and speech therapy possesses the highest share of rehabilitation. Therefore, it is recommended to develop speech therapy centers in Iran.

Coordination-Driven Monolayer-to-Bilayer Transition in Two-Dimensional Metal-Organic Networks.

We report on monolayer-to-bilayer transitions in 2D metal-organic networks (MONs) from amphiphiles supported at the water-air interface. Functionalized calix[4]arenes are assembled through the coordination of selected transition metal ions to yield monomolecular 2D crystalline layers. In the presence of Ni(II) ions, interfacial self-assembly and coordination yields stable monolayers. Cu(II) promotes 2D coordination of a monolayer which is then diffusively reorganizing, nucleates, and grows a progressive amount of second layer islands. Atomic force microscopic data of these layers after transfer onto solid substrates reveal crystalline packing geometries with submolecular resolution as they are varying in function of the building blocks and the kinetics of the assembly. We assign this monolayer-to-bilayer transition to a diffusive reorganization of the initial monolayers owing to chemical vacancies of the predominant coordination motif formed by Cu2+ ions. Our results introduce a new dimension into the controlled monolayer-to-multilayer architecturing of 2D metal-organic networks.

Effects of cold chemical (glutaraldehyde) versus autoclaving sterilization on the rate of coating loss of aesthetic archwires: A double-blind randomized clinical trial.

OBJECTIVE: The effect of any sterilization methods (cold chemical, or hot) on film removal from coated archwires has not yet been investigated. Thus, we assessed it. MATERIALS AND METHODS: This double-blind randomized clinical trial was performed on 120 observations: 40 macroscopically intact coated archwires from 4 brands were purchased (n=10 archwires/brand). Five wires from each brand underwent cold and 5 underwent hot sterilization. Wires were applied in 40 non-extractions patients at alignment phase of treatment (one month). Afterwards, 3 inter-bracket segments from each wire were examined microscopically, and the percentage of coating loss was recorded for each segment. Coating losses of the 4 brands and 2 sterilization methods were compared using a two-way ANOVA and a Welch t-test (α=0.05). Surfaces were also evaluated using scanning electron microscopy. RESULTS: The mean surface coating loss of hot (autoclave) and cold (glutaraldehyde) sterilization methods was 25.6±28.7 and 28.1±30.8 percent respectively. The mean surface coating removal of the Ortho Organizers, American Orthodontics, SIA, and Gestenco brands were 24.1±28.4, 36.7±36.0, 23.0±24.4, and 23.6±28.0 percent, respectively. The two-way ANOVA indicated a lack of overall significant differences among wire brands (P=0.189) and between sterilization types (P=0.629). However, the interaction of sterilization and brands was significant (P=0.005). CONCLUSIONS: Within the limitations of this 1-month clinical trial limited to 4 coated NiTi archwire brands only, the average coating removal of examined brands might not differ much, amounting to about 26% within a month. Glutaraldehyde and autoclave sterilization might not affect the average speed of coating loss in all brands, although each sterilization method might be favourable for certain brands.

Effect of different surface treatment methods on the shear bond strength of orthodontic brackets to temporary crowns.

INTRODUCTION: The number of adult patients seeking orthodontic treatment has been consistently increasing. Since the placing of the final restoration must be postponed until the completion of the orthodontic treatment, provisional restoration is recommended for the duration of the orthodontic treatment. These surfaces have special chemical properties, which necessitate the orthodontists to prepare the bonding area with special measures. METHODS: Polycarbonate and polymethylmethacrylate (PMMA) crowns (n=80) were randomly subdivided into 4 groups. Conditioning methods were grinding, sandblasting, CO2 laser and methyl methacrylate application. Samples underwent SBS testing. A scanning electron microscope (SEM) analysis was carried out. The data was analysed with ANOVA, Student t-test and Post-hoc test. Adhesive remnant index (ARI) was analysed with Chi2 test. RESULTS: In all surface treatments, the mean Shear Bond Strength (SBS) of PMMA was significantly higher than that of polycarbonate (P<0.001). In the polycarbonate groups, there was a significant difference between the mean SBS of the four treatment methods (P<0.001). However, there were no significant differences in PMMA group (P=0.076). In both crown materials, the mode of the failure was adhesive type, regardless of the conditioning method (P>0.05). CONCLUSIONS: PMMAs rendered higher bond strength than polycarbonates. In PMMA, all the surface treatment methods resulted in acceptable bond strength. However, if bonding the brackets to polycarbonate crown is needed, other conditioning methods are preferred over CO2 laser.

Surface topography of plain nickel-titanium (NiTi), as-received aesthetic (coated) NiTi, and aesthetic NiTi archwires sterilized by autoclaving or glutaraldehyde immersion: A profilometry/SEM/AFM study.

BACKGROUND AND AIM: Surface topography is a crucial factor in bracket sliding mechanics. Literature on surface roughness of aesthetic archwires is scarce, and there is no study on surface topography of such archwires affected by any sterilization methods. The aim of this study was to compare the surface topography of plain nickel-titanium (NiTi) versus as-received aesthetic coated NiTi wires versus aesthetic wires sterilized by autoclaving or glutaraldehyde immersion. MATERIALS AND METHODS: This in vitro study was performed on 80 atomic force microscopy (AFM) observations, 160 profilometry observations, and 40 scanning electron microscopy (SEM) images from rectangular wires of the brands 'American Orthodontics, Ortho Organizers, SIA, and Gestenco'. AFM consisted of 8 subgroups of NiTi orthodontic wires, consisting of 4 subgroups of 4 brands of coated orthodontic wires and 4 subgroups of 4 brands of uncoated wires from the same brands. Profilometry consisted of 16 subgroups of NiTi orthodontic wires, consisting of 4 subgroups of 4 brands of coated orthodontic wires and 12 subgroups of 4 brands of uncoated wires from the same brands (4 as-received wire subgroups, 4 autoclaved, and 4 cold-sterilized subgroups). Scanning electron microscopy (SEM) and AFM images were subjectively evaluated. AFM and profilometry data were analysed statistically (α=0.05). RESULTS: Overall, the difference between surface roughness parameters of coated versus uncoated archwires was not significant (P>0.05). However, surface roughness of brands differed significantly. Mann-Whitney did not show any significant differences between sterilized wires (both sterilization methods together as one group) and unsterilized wires (both unsterilized coated and uncoated as one group) (P>0.460). After excluding plain uncoated NiTi group, the coated wires in 3 sterilization groups (no sterilization, autoclaving, glutaraldehyde) were not significantly different in terms of average overall surface roughness (Ra) and maximum roughness depths (Rq) of different sterilization groups (P>0.1) but the average maximum peak to valley heights (Rz) values of 3 sterilization groups were significantly different (P=0.0415). Dunn test showed that among three post-hoc pairwise comparisons of Rz values, only the comparison of "no sterilization versus autoclaving" was significant (P<0.05) and the other two were non-significant. CONCLUSION: Coating might not affect the surface roughness considerably. Brands have different surface roughnesses. Autoclaving but not cold sterilization might affect the surface roughness of coated archwires.

Supramolecular architectures of molecularly thin yet robust free-standing layers.

Stable, single-nanometer thin, and free-standing two-dimensional layers with controlled molecular architectures are desired for several applications ranging from (opto-)electronic devices to nanoparticle and single-biomolecule characterization. It is, however, challenging to construct these stable single molecular layers via self-assembly, as the cohesion of those systems is ensured only by in-plane bonds. We herein demonstrate that relatively weak noncovalent bonds of limited directionality such as dipole-dipole (-CN⋅⋅⋅NC-) interactions act in a synergistic fashion to stabilize crystalline monomolecular layers of tetrafunctional calixarenes. The monolayers produced, demonstrated to be free-standing, display a well-defined atomic structure on the single-nanometer scale and are robust under a wide range of conditions including photon and electron radiation. This work opens up new avenues for the fabrication of robust, single-component, and free-standing layers via bottom-up self-assembly.

Effects of debonding of orthodontic brackets on topography and surface roughness of composite restorations.

BACKGROUND: To increase bond strength of brackets bonded to composite restorations, underlying composite restorations are usually roughened. This and subsequent bracket debonding might deteriorate smoothness of composite restoration, leading to clinical and aesthetic problems. Since this was not assessed before, this study was conducted. METHODS: Seventy intact human premolars were collected and filled with composite restorations. They were randomly divided into 3 groups: control (n=10), surface treatments before bracket bonding (bur, sandblasting, overall n=40), and surface roughening without bracket bonding (bur, sandblasting, overall n=20). The 40 specimens with bracket bonding steps were divided into two subgroups of with and without polishing after debonding of brackets (each n=10). After aging the composites in two steps and treating surfaces according to abovementioned protocols, their surface topographies were evaluated under stereomicroscopy (80×), scanning electron microscopy (using Zachrisson-Arthun index, at 500× and 1000× zooms), and by profilometry. Profilometry parameters and Zachrisson-Arthun index were statistically compared among different groups (α=0.05, 0.005). RESULTS: According to Kruskal-Wallis test, all profilometry parameters or the Zachrisson and Arthun index were significantly different between groups involving bracket debonding and control (P≤0.001). Three-way ANOVA indicated that bracket debonding, polishing after debonding, and surface treatments before bracket bonding had a significant effect on Ra and Rz (P≤0.05). Tukey post hoc test showed that bur and sandblasting methods were not significantly different (P>0.05). CONCLUSION: Bur-roughening or sandblasting of composite surface before bonding brackets can increase surface roughness, while polishing can reduce it back to control levels.

A Two-Dimensional Polymer Synthesized at the Air/Water Interface.

A trifunctional, partially fluorinated anthracene-substituted triptycene monomer was spread at an air/water interface into a monolayer, which was transformed into a long-range-ordered 2D polymer by irradiation with a standard UV lamp. The polymer was analyzed by Brewster angle microscopy, scanning tunneling microscopy measurements, and non-contact atomic force microscopy, which confirmed the generation of a network structure with lattice parameters that are virtually identical to a structural model network based on X-ray diffractometry of a closely related 2D polymer. The nc-AFM images highlight the long-range order over areas of at least 300×300 nm2 . As required for a 2D polymer, the pore sizes are monodisperse, except for the regions where the network is somewhat stretched because it spans over protrusions. Together with a previous report on the nature of the cross-links in this network, the structural information provided herein leaves no doubt that a 2D polymer has been synthesized under ambient conditions at an air/water interface.

Porcelain color alteration after orthodontic bonding using three different surface preparation methods.

BACKGROUND: By increasing the number of adults seeking orthodontic treatment bonding orthodontic brackets to the surfaces other than intact enamel has become necessary. The purpose of this study was to evaluate the effect of three different surface preparation methods associated with orthodontic bonding on porcelain color alteration. MATERIALS AND METHODS: In this in vitro study forty-five porcelain discs (6- mm diameter, 2- mm thickness) were fabricated. The color of the specimens was evaluated by means of a Vita Easyshade. Commision Internationale de I'Eclairage (CIE) L* a* b* system was used for color measurement. Then, the specimens were randomly divided into three groups (n = 15) with respect to the surface preparation methods including a 9.6% hydrofluoric acid (HF) + silane, sandblasting, and sandblasting + 9.6% HF + silane. Metal orthodontic brackets were bonded. Samples were stored in 37° c water for 24 hours. Afterward, the brackets were debonded with a debonding plier and porcelain surfaces were polished with a tungsten-carbide bur. The color assessment was done, and ΔE values were measured. ΔE = 3.7 units were considered as an acceptability threshold. Data were analyzed with Paired t-test and one-way ANOVA. Level of significance was set at P < 0.05. RESULTS: Orthodontic bonding changed the color parameters significantly. Mean L*, a* and b* difference were 1.35 ± 2.41, 0.19 ± 0.80, 0.89 ± 1.27 units, respectively (P = 0.003 for L*, P < 0.001 for a* and b*). There was not any significant difference in ΔE units between the groups (P = 0.456). In all the groups the mean ΔE values were below 3.7 units and within the clinically acceptable limit. CONCLUSION: Orthodontic treatment changed the CIE color parameters of porcelain surface. However, the color alteration is below the clinically acceptable threshold. With regard to color alteration, there is no difference between different surface conditioning methods.

Effects of autoclaving versus cold chemical (glutaraldehyde) sterilization on load-deflection characteristics of aesthetic coated archwires.

INTRODUCTION: The effect of any sterilization methods (cold [chemical] or hot) on load-deflection characteristics of aesthetic coated archwires has not yet been investigated. Thus, we assessed it. METHODS: In this experimental in vitro study, 90-coated archwires from 3 brands were purchased. Ten wires from each brand (n=30) underwent cold and 10 underwent hot sterilization, while 10 left unsterilized as negative controls. Load-deflection curves were established for each wire (as five 0.2mm intervals between 1.0 and 1.8mm displacements), using a three-bracket test. After determining the plateau phase that was present in all wires, the averages of plateau phase pertaining to loading and unloading curves and their discrepancies (hysteresis) were calculated for each subgroup (n=10). Average plateau values were compared using two-way ANOVA, Tukey, and independent-samples t-test (α=0.05). RESULTS: Average loading and unloading values were 906.6±129.7 and 295.9±84.5g respectively (t-test P<0.0001). Comparing loading plateaus, ANOVA indicated significant difference among wire brands (P<0.0001) but not among sterilization types (P=0.4793). Comparing unloading plateaus, ANOVA showed significant differences among wire brands (P<0.0001) and sterilization types (P=0.0008). Tukey showed that only cold sterilization and negative control differed significantly (P<0.001); cold and hot sterilization methods, or control and autoclaving were not significantly different (P>0.05). Comparing hysteresis plateaus, ANOVA indicated difference among wire brands (P<0.0053) but not among sterilization types (P=0.9166). CONCLUSIONS: Cold sterilization might reduce unloading plateau of orthodontic wires, but sterilization in general might not affect loading or hysteresis plateaus. Different brands had different plateaus of loading, unloading and hysteresis.

Structural Characterization of a Covalent Monolayer Sheet Obtained by Two-Dimensional Polymerization at an Air/Water Interface.

This work describes a two-dimensional polymerization at an air/water interface and provides, for the first time, direct spectroscopic evidence for the kind of crosslinks formed and for the conversion reached in a covalently bonded monolayer sheet. This evidence was obtained through a combination of a variety of monolayer characterization techniques before and after transfer onto solid substrates, in particular by tip-enhanced Raman spectroscopy (TERS) and TERS mapping after transfer of both the monomer and polymer monolayer onto Au(111). This work is a major advance for the field of 2D polymers synthesized at the air/water interface as it, in principle, allows estimation of the crystallinity by percolation theory and the location of regions with defects.

Two-Dimensional Calix[4]arene-based Metal-Organic Coordination Networks of Tunable Crystallinity.

A flexible and versatile method to fabricate two-dimensional metal-organic coordination networks (MOCNs) by bottom-up self-assembly is described. 2D crystalline layers were formed at the air-water interface, coordinated by ions from the liquid phase, and transferred onto a solid substrate with their crystallinity preserved. By using an inherently three-dimensional amphiphile, namely 25,26,27,28-tetrapropoxycalix[4]arene-5,11,17,23-tetracarboxylic acid, and a copper metal node, large and monocrystalline dendritic MOCN domains were formed. The method described allows for the fabrication of monolayers of tunable crystallinity on liquid and solid substrates. It can be applied to a large range of differently functionalized organic building blocks, also beyond macrocycles, which can be interconnected by diverse metal nodes.

Sleep quality and associated factors among patients with chronic heart failure in Iran.

BACKGROUND: Sleep disorders are common among patients with chronic heart failure (HF), and it can have a significant effect on patients' daily activities as well as their health. The purpose of this study was to assess sleep quality and its predictors in Iranian patients with chronic HF. METHODS: This cross-sectional study was conducted on a sample of 200 patients with HF in two hospitals of Tehran University of Medical Sciences from June to November 2009. These patients completed a demographic questionnaire, and their sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). One-way analysis of variance (ANOVA), Kruskal-Wallis test, t-test and Linear regression were used for data analysis. RESULTS: Seventy-nine percent of patients (n = 158) reported poor sleep quality (PSQI > 5). The range of global PSQI scores was 3-20. Also, a significant relationship was found between PSQI scores and patients' age (p<0.004), gender (p< 0.042), educational level (p< 0.001), occupational status (p< 0.038), number of hospitalizations (p< 0.005), type of referral (p< 0.001), non-cardiac diseases (p< 0.001), diuretic use (p< 0.021) and left ventricular ejection fraction (p< 0.015). Three predictors were identified using regression analyses with stepwise methods, and included age, type of referral and educational level. CONCLUSION: The high prevalence of poor sleep quality highlighted the importance of sleep disorders in HF patients. There are many factors associated with sleep quality and sleep disorders that health providers should recognize for improved and effective management.