Transport mechanisms in Co-doped ZnO (ZCO) and H-irradiated ZCO polycrystalline thin films.

In the present study, the electrical resistivity (ρ) as a function of the temperature (T) has been measured in polycrystalline ZnO, Co-doped ZnO (ZCO) and H irradiated ZCO (HZCO) samples, in the 300-20 K range. The achieved results show impressive effects of Co doping and H irradiation on the ZnO transport properties. The Co dopant increases the ZnO resistivity at high T (HT), whereas it has an opposite effect at low T (LT). H balances the Co effects by neutralizing the ρ increase at HT and strengthening its decrease at LT. A careful analysis of the ρ data permits to identify two different thermally activated processes as those governing the charge transport in the three materials at HT and LT, respectively. The occurrence of such processes has been fully explained in terms of a previously proposed model based on an acceptor impurity band, induced by the formation of Co-oxygen vacancy complexes, as well as known effects produced by H on the ZnO properties. The same analysis shows that both Co and H reduce the effects of grain boundaries on the transport processes. The high conductivity of HZCO in the whole T-range and its low noise level resulting from electric noise spectroscopy make this material a very interesting one for technological applications.

Epidemiological characteristic of Orofacial clefts and its associated congenital anomalies: retrospective study.

BACKGROUND: To evaluate the relationship between gender, ethnicity/citizenship, clinical phenotype, total prevalence, and the various congenital malformations associated with oral clefts (OC) in Italy across the period 2001-2014. METHODS: A retrospective analysis (2001-2014) was conducted based on the National Congenital Malformation Registries network of Italy (Emilia-Romagna Registry of Birth Defects [IMER] and Registro Toscano Difetti Congeniti [RTDC]), which were analyzed to investigate time trends, geographical/ethnic clusters, topography, sex ratio, and associated congenital anomalies of OC phenotypes. RESULTS: Among 739 registered cases, 29.8% were syndromic or had multi-malformed associated anomalies, compared with 70.2% having isolated orofacial cleft. Cleft lip (CL) was observed in 22%, cleft palate (CP) in 40%, and cleft lip and palate (CLP) in 38% of live births, stillbirths, and terminations of pregnancy for fetal anomaly cases. Other associated conditions were major anomalies of cardiovascular defects (39%), followed by defects of the limbs (28%), neuroectodermal defects (23%), and urogenital malformations (10%). Male-to-female sex ratio was 1:1.14 in CP, 1.22:1 in CL, and 1.9:1 in CLP. Foreigners were represented by 29% from Southeast Asia, 25% from Balkans, 25% from North-Central Africa, 9% from the East, 7% from Western Europe, and 5% from South America. Total prevalence of OC cases ranged from 0.9 (RTDC) to 1.1 (IMER) of 1000 births. CONCLUSIONS: This retrospective study provides a population-based, clinical-epidemiological description of the orofacial cleft phenomenon. As a relatively frequent congenital malformation, its social and economic impact is worthy of further study. These abnormalities can cause significant problems that may be solved or minimized by early diagnosis and treatment.

Porphyromonas gingivalis in the tongue biofilm is associated with clinical outcome in rheumatoid arthritis patients.

Several studies have suggested a link between human microbiome and rheumatoid arthritis (RA) development. Porphyromonas gingivalis seems involved in RA initiation and progression, as supported by the high occurrence of periodontitis. In this case-control study, we analysed tongue P. gingivalis presence and quantification in a large healthy and RA cohort. We enrolled 143 RA patients [male/female (M/F) 32/111, mean ± standard deviation (s.d.), age 57·5 ± 19·8 years, mean ± s.d. disease duration 155·9 ± 114·7 months); 36 periodontitis patients (M/F 11/25, mean ± s.d., age 56 ± 9·9 years, mean ± s.d. disease duration 25·5 ± 20·9 months); and 57 patients (M/F 12/45, mean ± s.d., age 61·4 ± 10·9 years, mean ± s.d. disease duration 62·3 ± 66·9 months) with knee osteoarthritis or fibromyalgia. All subjects underwent a standard cytological swab to identify the rate of P. gingivalis/total bacteria by using quantitative real-time polymerase chain reaction. The prevalence of P. gingivalis resulted similarly in RA and periodontitis patients (48·9 versus 52·7%, P = not significant). Moreover, the prevalence of this pathogen was significantly higher in RA and periodontitis patients in comparison with control subjects (P = 0·01 and P = 0·003, respectively). We found a significant correlation between P. gingivalis rate in total bacteria genomes and disease activity score in 28 joints (DAS28) (erythrocyte sedimentation rate) (r = 0·4, P = 0·01). RA patients in remission showed a significantly lower prevalence of P. gingivalis in comparison with non-remission (P = 0·02). We demonstrated a significant association between the percentage of P. gingivalis on the total tongue biofilm and RA disease activity (DAS28), suggesting that the oral cavity microbiological status could play a role in the pathogenic mechanisms of inflammation, leading to more active disease.

Additive manufacturing and biomimetic materials in oral and maxillofacial surgery: a topical overview.

Additive manufacturing (AM) is the term used for different and complex techniques to manufacture products with complex morphology, often referred to as "custom-made". The product is made without needing to melt the material into pre-formed molds, nor to remove it from an initial mass, as happens in subtractive processes. The additive methodology gives the AM enormous potential in the widest fields of application, from aerospace to biomedical, from dental to maxillofacial. This wide range of AM technologies can be applied to different types of polymeric materials such as plastics, resins and biopolymers that are processed to obtain optimal scaffolds. The most common synthetic and biocompatible polymeric materials for the production of biocompatible scaffolds are: polylactic acid (PLA), polycaprolactone acid (PLC) and polylactic-co-glycolic acid (PLGA); such materials interact effectively with cell behavior and tissue development. These materials are degradable in the physiological environment and the degradation products do not have harmful effects. In conclusion, new biomaterials are increasingly being studied as possible therapeutic remedies. Advances in tissue engineering are leading to the development of new scaffolds useful for bone regeneration and therefore potentially valid for applications in maxillofacial surgery.

Updates in regenerative medicine applied to dental sciences.

Mesenchymal stem cells (MSCs) are found in high concentrations in several tissues, such as umbilical cord, adipose tissue and dental tissue. Dental stem cells reside in many areas of the oral cavity. Thanks to their abilities, dental stem cells could be used to treat diseases and to understand the basic mechanisms of developmental pathologies. There are currently numerous ongoing clinical trials evaluating a broad spectrum of conditions and situations using different stem cell populations. However, stem cell studies are raising profound ethical questions that weigh on the world of scientific research. Stem cells are always a hot topic in the scientific community. Their use is related also to their banking, as cell manipulation is also often related to medical and ethical issues. Many biomedical studies aim to treat diseases that were previously considered incurable with MSCs. All this has created the need to quickly and safely storage stem cells, usually in a stem cell biobank (SCB). Regenerative medicine is the most important approach for achieving complete tissue regeneration using stem cells isolated from adult tissues, embryonic stem cells, but also through the application of induced pluripotent stem cells (iPSC). iPSCs are non-pluripotent cells that are engineered to acquire the ability to differentiate into all different types of cells. In conclusion, the daily use of stem cells in regenerative procedures is still far from being safe and predictable, especially because of the biomedical component, often requiring experienced biologists and complex technologies for cell manipulation and cell banking. .

Value and Anisotropy of the Electron and Hole Mass in Pure Wurtzite InP Nanowires.

The effective mass of electrons and holes in semiconductors is pivotal in determining the dynamics of carriers and their confinement energy in nanostructured materials. Surprisingly, this quantity is still unknown in wurtzite (WZ) nanowires (NWs) made of III-V compounds (e.g., GaAs, InAs, GaP, InP), where the WZ phase has no bulk counterpart. Here, we investigate the magneto-optical properties of InP WZ NWs grown by selective-area epitaxy that provides perfectly ordered NWs featuring high-crystalline quality. The combined analysis of the energy of free exciton states and impurity levels under magnetic field (B up to 29 T) allows us to disentangle the dynamics of oppositely charged carriers from the Coulomb interaction and thus to determine the values of the electron and hole effective mass. By application of B⃗ along different crystallographic directions, we also assess the dependence of the transport properties with respect to the NW growth axis (namely, the WZ c axis). The effective mass of electrons along c is me∥ = (0.078 ± 0.002) m0 (m0 is the electron mass in vacuum) and perpendicular to c is me⊥ = (0.093 ± 0.001) m0, resulting in a 20% mass anisotropy. Holes exhibit a much larger (∼320%) and opposite mass anisotropy with their effective mass along and perpendicular to c equal to mh∥ = (0.81 ± 0.18) m0 and mh⊥ = (0.250 ± 0.016) m0, respectively. While no full consensus is found with current theoretical results on WZ InP, our findings show trends remarkably similar to the experimental data available in WZ bulk materials, such as InN, GaN, and ZnO.

Long-Lived Hot Carriers in III-V Nanowires.

Heat management mechanisms play a pivotal role in driving the design of nanowire (NW)-based devices. In particular, the rate at which charge carriers cool down after an external excitation is crucial for the efficiency of solar cells, lasers, and high-speed transistors. Here, we investigate the thermalization properties of photogenerated carriers by continuous-wave (cw) photoluminescence (PL) in InP and GaAs NWs. A quantitative analysis of the PL spectra recorded up to 310 K shows that carriers can thermalize at a temperature much higher than that of the lattice. We find that the mismatch between carrier and lattice temperature, ΔT, increases exponentially with lattice temperature and depends inversely on the NW diameter. ΔT is instead independent of other NW characteristics, such as crystal structure (wurtzite vs zincblende), chemical composition (InP vs GaAs), shape (tapered vs columnar NWs), and growth method (vapor-liquid-solid vs selective-area growth). Remarkably, carrier temperatures as high as 500 K are reached at the lattice temperature of 310 K in NWs with ∼70 nm diameter. While a population of nonequilibrium carriers, usually referred to as "hot carriers", is routinely generated by high-power laser pulses and detected by ultrafast spectroscopy, it is quite remarkable that it can be observed in cw PL measurements, when a steady-state population of carriers is established. Time-resolved PL measurements show that even in the thinnest NWs carriers have enough time (∼1 ns) after photoexcitation to interact with phonons and thus to release their excess energy. Nevertheless, the inability of carriers to reach a full thermal equilibrium with the lattice points to inhibited phonon emission primarily caused by the large surface-to-volume ratio of small diameter NWs.

Surgical management of impacted primary teeth: report of two cases.

AIM: Impaction of deciduous teeth is an uncommon event. The purpose of this report is to describe two unusual eruption failures of a second primary molar and their treatment management. CASE REPORT: The diagnostic and therapeutic protocol of two cases selected at the Unit of Paediatric Dentistry, Department of Oral and Maxillofacial Science, "Sapienza" University of Rome, Italy, are presented. In both cases, the second deciduous molar was impacted, while no mechanical obstacle like odontomas or supernumerary teeth were present. CONCLUSION: The two case reports presented in this work are of scientific relevance, due to the rarity of this type of pathology.

Efficacy of safety catheter devices in the prevention of occupational needlestick injuries: applied research in the Liguria Region (Italy).

Healthcare workers who use or may be exposed to needles are at risk of needlestick injuries, which can lead to serious infections by bloodborne pathogens. These injuries can be avoided by eliminating the unnecessary use of needles and using safety devices. The present study was aimed at evaluating the impact of a safety-engineered device, with passive fully automatic needlestick protection, on the rate of needlestick injuries among healthcare workers. The setting of the study was a network of five public healthcare institutions situated in a Northern Italian Region. Data on the type of device, the number of employees and the number of catheter devices used per year were collected through regular meetings with healthcare workers over a period of five years. The most notable result of this study was the huge risk reduction associated with safety devices. Indeed, the risk of needlestick injuries due to conventional devices was found to be 25-fold higher than that observed for safety devices. However, it is noteworthy that a considerable part of this excess can be explained by the different background number of devices used. Moreover, descriptive analysis suggested that individuals with a poor/moderate training level had a lower risk than those with good/high training, though the difference was not statistically significant. In conclusion, there is convincing evidence of a causal connection between the introduction of safety devices and the reduction in needlestick injuries. This consideration should prompt the introduction of safety devices into daily clinical practice.

The relationship between upper airways and craniofacial morphology studied in 3D. A CBCT study.

OBJECTIVES: To assess whether morphology and dimension of the upper airway differ between patients characterized by various craniofacial morphology. SETTING AND SAMPLE POPULATION: Ninety young adult patients from the Postgraduate Clinic, Section of Orthodontics, Department of Dentistry, Health, Aarhus University, Denmark, with no obvious signs of respiratory diseases and no previous adeno-tonsillectomy procedures. Thirty patients were characterized as Class I (-0.5 < ANB < 4.5), 30 as Class II (ANB > 4.5), and 30 as Class III (ANB < -0.5). MATERIAL AND METHODS: Cone-beam computed tomography (CBCT) scans obtained in a supine position for all patients. Cephalometric landmarks were identified in 3D. Sagittal and transversal dimensions, cross sections, and partial and total volumes of the upper airway were correlated with the cephalometric measurements in all three planes of space. The cross-sectional minimal area of the upper airway was assessed as well. RESULTS: No statistical significant relationships between dimension and morphology of upper airways and skeletal malocclusion were found. CONCLUSION: Differences in craniofacial morphology as identified by the sagittal jaw relationship were not correlated with variation in upper airway volumes. A clinical significant relation was detected between minimal area and total upper airway volume.

Magneto-optical properties of wurtzite-phase InP nanowires.

The possibility to grow in zincblende (ZB) and/or wurtzite (WZ) crystal phase widens the potential applications of semiconductor nanowires (NWs). This is particularly true in technologically relevant III-V compounds, such as GaAs, InAs, and InP, for which WZ is not available in bulk form. The WZ band structure of many III-V NWs has been widely studied. Yet, transport (that is, carrier effective mass) and spin (that is, carrier g-factor) properties are almost experimentally unknown. We address these issues in a well-characterized material: WZ indium phosphide. The value and anisotropy of the reduced mass (µ exc) and g-factor (g exc) of the band gap exciton are determined by photoluminescence measurements under intense magnetic fields (B, up to 28 T) applied along different crystallographic directions. µ exc is 14% greater in WZ NWs than in a ZB bulk reference and it is 6% greater in a plane containing the WZ c axis than in a plane orthogonal to c. The Zeeman splitting is markedly anisotropic with g exc = |ge| = 1.4 for B⊥c (where ge is the electron g-factor) and g exc = |ge - gh,//| = 3.5 for B//c (where gh,// is the hole g-factor). A noticeable B-induced circular dichroism of the emitted photons is found only for B//c, as expected in WZ-phase materials.

Dental unit water treatment with hydrogen peroxide and monovalent silver ions artificially contaminated with freshly isolated pathogens.

BACKGROUND: Dental unit water (DUW) could be contaminated by human pathogens coming from biological fluids penetrated during patient treatment and by opportunistic pathogens detached from aquatic biofilm. These microorganisms could be spread to following patients. We tested the disinfectant activity of hydrogen peroxide and monovalent silver ions (H(2)O(2)-Ag(+)) into DUW artificially contaminated with freshly isolated pathogens. METHODS: The tested microorganisms were Staphylococcus aureus, Enterococcus faecalis, Candida albicans, Pseudomonas aeruginosa, Legionella pneumophila, Mycobacterium chelonae, non-pathogenic Bacillus clausii spores. Bacterial suspensions were inoculated into the waterlines of pre-sterilized dental turbines. The test-turbines were connected to DUW and contaminated water was treated for 10 minutes with H(2)O(2)-Ag(+)-based disinfectant (H(2)O(2) 3% v/v, Ag(+) 0.001% w/v). The control-turbines were left untreated. Turbines were washed with sterile hard water used to assess the residual bacterial loads (expressed in colony forming units -cfu). Each strain was tested five times and the mean log loads were assessed. Following the European Standardization Committee, the disinfectant activity was evaluated as mean log load reduction, that is, the difference between the mean log load detected on the control-turbines and the mean log load detected on the test-turbines. RESULTS: Mean bacterial loads detected on the control-turbines ranged between 105-107 cfu. The mean log load reductions resulted 7.5 log cfu for S. aureus, E. faecalis, P. aeruginosa, 6.3 for C. albicans, 5.4 for L. pneumophila, 5.3 for M. chelonae, 2.9 for B. clausii spores. CONCLUSIONS: DUW disinfection with H(2)O(2)-Ag(+) could help minimize the risk that planktonic pathogens are spread to patients during dental treatment.

The growth of Streptococcus mutans in different milks for infant feeding.

After birth various bacterial species, mainly streptococci, colonize the oral cavity and are frequently isolated from carious lesions in children. Previous studies suggest that an earlier colonization of a child's mouth by cariogenic organisms might be related to a higher risk of caries. The aim of this study is to assess the influence of different milks for infant feeding on the growth of Streptococcus mutans (SM) colonies. Three human milk samples from three different mothers and five infant formulas were tested. To prepare the bacterial inoculum, SM was grown in Brain Heart Infusion broth for 18 hours at 37°C in microaerophilic atmosphere. The growth of SM was determined immediately after the inoculation of milks (T0) and after 24 hours (T24) of incubation. After 24 hours of incubation (ΔT= CFUs/ml at T24 – CFUs/ml at T0) the bacterial growth changes were different among milks. Among the complementary milks tested, ΔT of formulas supplemented with Lactobacillus reuteri and with Bifidobacterium lactis was lower than those of non-supplemented formula. In conclusion, on the basis of the reduced SM growth in milks supplemented with probiotics, we may speculate that these formulas have a preventive effect on the development of caries in children.

Er:YAG laser for brackets bonding: a SEM study after debonding.

BACKGROUND: The introduction of Er:YAG laser in dentistry for ablation of hard tissues advocated an alternative method of enamel etching for orthodontics purpose. MATERIALS AND METHODS: 55 extracted human third molars were inserted in acrylic resin blocks and divided into five groups of 11 teeth. Group 1 was treated with 37% orthophosphoric acid for 30 seconds. Group 2 was treated with laser irradiation (Er:YAG Fidelius III, Fotona, Slovenia) at 80 mJ and 4 Hz. Group 3 underwent laser treatment (80 mJ, 4 Hz), followed by 37% orthophosphoric acid for 30 seconds. The teeth in Group 4 were treated with laser at 40 mJ and 10 Hz. The teeth in Group 5 were treated with laser (40 mJ, 10 Hz), followed by 37% orthophosphoric acid for 30 seconds. The adhesive remnant index was determined after debonding. RESULTS: Kruskas-Wallis test showed that location parameters (median and mean) are significantly different between Groups 2 and 4 when compared with control group; on the contrary no significant difference was detected between Groups 3 and 5 with the controls. CONCLUSION: The use of Er:YAG laser alone, as in Groups 2 and 4, showed no significant advantages over phosphoric acid in the bonding procedure for orthodontics brackets.

Marsupialization of radicular cyst in a 9-year-old child: report of a case and review of the literature.

The following report describes the treatment of a 9-year-old child affected by a radicular cyst. The case was treated through the extraction of the impacted primary tooth followed by marsupialization. The residual cystic cavity was filled with a removable device in order to speed the healing process, facilitate the eruption of the permanent teeth and avoid orthodontic treatment. This technique is suitable as conservative treatment for patients affected by radicular cyst.

A new aid in temporomandibular joint disorders' therapy: the universal neuromuscular immediate relaxing appliance.

Among the various treatment options currently indicated to deal with temporomandibular joint disorders (TMD) an important role is played by occlusal devices, which can be used in an individualized or universal manner. A new universal occlusal appliance device was designed and patented at the Clinical Gnathology Service of the Sapienza University of Rome. To assess its validity and efficacy a preliminary study on a sample of 50 patients was carried out. Patients were selected from a cohort of 158 according to the RDC-TMD (SPEC) criteria and randomly assigned to two groups, the patient group (PG), treated with the device, and a control group (CG) without any treatment. The two groups were evaluated by comparing four VAS pain scores: muscular, migraine, cervical and temporomandibular joint (TMJ). On the whole, all VAS pain scores in the PG showed a marked and statistically significant improvement after treatment, decreasing to about 50-80 percent, while the control group remained stable. The best improvement was achieved in muscular pain. Age did not affect neither the initial scores, nor the pain response to the treatment. The pain scores tended to slightly increase with time of application (one, two or three months), but this trend was significant only for cervical pain. Overall the results are favourable to the application of this new occlusion device. However, the data should be considered preliminary and require further verification in time and on a higher sample of patients of both sexes.

Orofacial diseases in solid organ and hematopoietic stem cell transplant recipients.

OBJECTIVE: Solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients are at risk of several diseases, principally attributable to immunosuppression. This global overview of SOT/HSCT-associated orofacial diseases is aimed at providing a practical instrument for the oral healthcare management of SOT/HSCT recipients. METHODS: Literature search was made through MEDLINE. The associations between orofacial diseases and SOT/HSCT were assessed using observational studies and case series and were classified into 'association', 'no association', and 'unclear association'. RESULTS: Lip/oral cancers, drug-induced gingival overgrowth (DIGO), infections, including hairy leukoplakia and, less frequently, post-transplantation lymphoproliferative disorders (PTLDs) and oral lichenoid lesions of graft-versus-host disease (GVHD), were associated with SOT. Lip/oral cancers, GVHD, mucositis, DIGO, infections and, less frequently, PTLDs were associated with HSCT. Associations of orofacial granulomatosis-like lesions and oral mucosa-associated lymphoid tissue-type lymphoma with SOT, and of pyogenic granuloma and hairy leukoplakia with HSCT were unclear. Periodontal disease and dental caries were not associated with SOT/HSCT. For none of the local treatments was there a strong evidence of effectiveness. CONCLUSIONS: Solid organ transplant/HSCT recipients are at risk of orofacial diseases. Adequate management of these patients alleviates local symptoms responsible for impaired eating, helps prevent systemic and lethal complications, and helps where dental healthcare has been neglected.