Search

This report describes the restoration of the healed single implant in the posterior region by using a lithium disilicate crown supported by an Acuris abutment. The restored implants were placed in the premolar and molar region of both the mandible and the maxilla by using a 1-stage approach. The definitive Acuris abutment was placed after an implant healing period of at least 3 months. Definitive impressions were made at least 3 months after surgery. The precrystallized lithium disilicate crown was adapted to a laboratory abutment and evaluated. The crown was then crystallized, finished, colored, and cemented to the definitive abutment by using an adhesive resin cement. The definitive restoration engaged the abutment without the use of screws or cement. A single healed implant can be successfully restored by using a lithium disilicate restoration supported by an Acuris abutment.

To provide a 1-year assessment of friction-retention abutments (Acuris, Dentsply Sirona) used to retain a single lithium disilicate (LSA total of 522 implants were placed to treat single-tooth premolar and molar edentulous sites in the mandible or maxilla. Three types of implants were used. The tested abutments were connected 3 months after implant placement. A single pressed LSA total of 507 patients (284 women and 223 men) received a restoration (T0), and 504 of them reached the T2 1-year follow-up. One restoration fractured after 10 months in function. No statistically significant difference was assessed in the soft tissue measurements or in the measurements of the distance between the supporting implant platform and the bone peak. None of the restorations detached during the observation period.The friction retention abutment is a viable option to retain an implant-supported monolithic LS

Overweight and obesity have been shown to significantly affect brain structures and size. Obesity has been associated with cerebral atrophy, alteration of brain functions, including cognitive impairement, and psychiatric diseases such as depression. Given the importance of lipids in the structure of the brain, here, by using 47 mice fed a high fat diet (HFD) with 60% calories from fat (40% saturated fatty acids) and 20% calories from carbohydrates and age-matched control animals on a normal chow diet, we examined the effects of HFD and diet-induced obesity on the brain lipidome. Using a targeted liquid chromatography mass spectrometry analysis and a non-targeted mass spectrometry MALDI imaging approach, we show that the relative concentration of most lipids, in particular brain phospholipids, is modified by diet-induced obesity (+ 40%of body weight). Use of a non-targeted MALDI-MS imaging approach further allowed define cerebral regions of interest (ROI) involved in eating behavior and changes in their lipid profile. Principal component analysis (PCA) of the obese/chow lipidome revealed persistence of some of the changes in the brain lipidome of obese animals even after their switch to chow feeding and associated weight loss. Altogether, these data reveal that HFD feeding rapidly modifies the murine brain lipidome. Some of these HFD-induced changes persist even after weight loss, implying that some brain sequelae caused by diet-induced obesity are irreversible.

Systemic sclerosis (SSc) is a connective tissue disease secondary to three cardinal pathological features: immune-system alterations, diffuse microangiopathy, and fibrosis involving the skin and internal organs. The etiology of SSc remains quite obscure; it may encompass multiple host genetic and environmental -infectious/chemical-factors. The present review focused on the potential role of environmental agents in the etiopathogenesis of SSc based on epidemiological, clinical, and laboratory investigations previously published in the world literature. Among infectious agents, some viruses that may persist and reactivate in infected individuals, namely human cytomegalovirus (HCMV), human herpesvirus-6 (HHV-6), and parvovirus B19 (B19V), and retroviruses have been proposed as potential causative agents of SSc. These viruses share a number of biological activities and consequent pathological alterations, such as endothelial dysfunction and/or fibroblast activation. Moreover, the acute worsening of pre-existing interstitial lung involvement observed in SSc patients with symptomatic SARS-CoV-2 infection might suggest a potential role of this virus in the overall disease outcome. A variety of chemical/occupational agents might be regarded as putative etiological factors of SSc. In this setting, the SSc complicating silica dust exposure represents one of the most promising models of study. Considering the complexity of SSc pathogenesis, none of suggested causative factors may explain the appearance of the whole SSc; it is likely that the disease is the result of a multifactorial and multistep pathogenetic process. A variable combination of potential etiological factors may modulate the appearance of different clinical phenotypes detectable in individual scleroderma patients. The in-deep investigations on the SSc etiopathogenesis may provide useful insights in the broad field of human diseases characterized by diffuse microangiopathy or altered fibrogenesis.

Purpose To evaluate the 2-year performance of definitive implant- or tooth-supported three-unit fixed dental prostheses made of zirconia-reinforced lithium silicate placed to restore premolars and molars in clinical cases of partial edentulism. Materials and methods All patients received a three-unit fixed restoration made of monolithic, hot-pressed, zirconia-reinforced lithium silicate glass-ceramic. The restoration was cemented to two natural teeth or attached to two 3.5- or 4.5-mm-diameter square threaded, grit-blasted, acid-etched integrated implants with a Morse taper connection. Peri-implant pocket depth and bone and soft tissue remodeling were recorded for 2 years at each follow-up visit. Esthetic, functional, and biologic United States Public Health Services (USPHS) parameters modified by the World Dental Federation study design were assessed yearly until the final follow-up appointment. At the time of placement of the definitive restorations and at the 2-year follow-up visit, the opposing dentitions were identified by type of restoration and supporting structures. Results A total of 100 patients were consecutively enrolled in the period between June 2016 and July 2017, and 50 patients each received an implant-supported restoration (Group A) or a tooth-supported restoration (Group B). One (2%) of the 50 implant-supported prostheses fractured after 21 months of function. None of the other prostheses failed or became loose or detached. No significant differences involving probing levels or bone and soft tissue remodeling were found between the follow-up times. No cases of inflammation or infection of the mucosal cuff around the neck of the implants were recorded. The most common issue occurred immediately after placement of the prosthesis, when 3 patients (6%) from Group A and 4 patients (8%) from Group B asked for a modification of tooth shade. Conclusion Implant-supported or tooth-supported three-unit fixed dental prostheses made of zirconia-reinforced lithium silicate can be used to successfully restore cases of posterior partial edentulism. The 2-year results of this report will be studied more in depth in ongoing long-term research.

Purpose To evaluate the performance of definitive, implant-supported, lithium disilicate fixed dental prostheses (LS2 FDPs) manufactured with a computer-assisted design/computer-assisted manufacturing (CAD/CAM) system. All patients received two-unit restorations placed in posterior regions, supported by osseointegrated implants with cone-in-cone connection abutments. Materials and methods Two implants (Ankylos) were placed into healed sites or fresh extraction sockets in the maxillary/mandibular posterior regions of partially edentulous patients. Definitive digital impressions were made 3 months after surgery. Twenty-four patients received fixed monolithic LS2 restorations manufactured with the CEREC system. All restorations were connected to the implants using cone-in-cone connection abutments. Peri-implant pocket depths were recorded for 2 years at each follow-up visit. Esthetic, functional, and biologic United States Public Health Services (USPHS) parameters modified by the FDI World Dental Federation study design were assessed yearly until the last follow-up appointment. The opposing dentitions were identified by type of restoration and supporting structures at the time of placement of the definitive restorations and at the 2-year follow-up visits. Results One patient (4.16%) moved to an unknown location during the study. A total of 23 FDPs (95.8%) supported by 46 implants reached the 2-year follow-up. None of the prostheses failed, or became loose or detached. No significant difference involving probing levels between the experimental times were found. Conclusions The results of this research indicated that the abutment-prostheses connection using a cone-in-cone approach was successful within the 2-year period of this study. None of the studied monolithic LS2 glass-ceramic prostheses milled using the CEREC CAD/CAM system fractured or became detached.

Objective This study evaluated Neem oil and Hypericum perforatum (Holoil®) for treatment of scleroderma skin ulcers related to calcinosis (SU-calc). Procedure: We retrospectively analyzed 21 consecutive systemic sclerosis (SSc) patients with a total of 33 SU-calcs treated daily with Holoil® cream compared with a control group of 20 patients with 26 SU-calcs. Holoil® was directly applied to skin lesions, while the control group received only standard medication. Results Application of Holoil® either resulted in crushing and complete resolution of calcium deposits or facilitated sharp excision of calcinosis during wound care sessions in 27/33 cases (81.8%). Complete healing of SU-calc occurred in 15/33 (45%) of cases within a time period of 40.1 ± 16.3 (mean ± SD) days, while 18/33 (55%) of lesions improved in terms of size, erythema, fibrin and calcium deposits. Patients reported a reduction of pain (mean numeric rating scale 7.3 ± 1.9 at baseline versus 2.9 ± 1.4 at follow-up) The control group had longer healing times and a higher percentage of infections. Conclusions The efficacy of local treatment with neem oil and Hypericum perforatum suggest that Holoil® could be a promising tool in the management of SSc SU-calc.

Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy, excessive extracellular matrix deposition, and fibrosis of the skin and internal organs. Several infectious agents, including human herpesvirus-6 (HHV-6), have been suggested as possible triggering factors, but a direct association is still missing. We characterized 26 SSc patients for the presence of HHV-6 in tissues and blood, the anti-HHV-6 response, HLA-G plasma levels, and KIR typing. Given the prominent role of endothelial cells (EC) in SSc pathogenesis, along with HHV-6 tropism for EC, we also investigated the expression of pro-fibrosis factors in HHV-6 infected EC. Results showed the presence of HHV-6A in skin biopsies, and an increased virus load was associated with disease severity and poor natural killer (NK) response against the virus, particularly in subjects exhibiting a KIR2 phenotype. HLA-G plasma levels were significantly higher in HHV-6A/B-KIR2 positive SSc patients and in vitro HHV-6A infection-induced pro-fibrosis factors expression in EC, supporting its role in the development of the fibrosing process. Our data suggest an association between virus infection/reactivation and disease, opening the way to future studies to understand the mechanisms by which HHV-6A might contribute to the multifactorial pathogenesis of SSc.

Background: Systemic Sclerosis (SSc) is a connective tissue disease, characterized by endothelial dysfunction and fibrosis, potentially affecting internal organs and reducing life expectancy. Digital ulcers (DUs), as well as hand and face skin thickening, are the hallmarks of the disease. These alterations lead to pain, functional impairment, aesthetic damages, and psychological distress. Autologous fat grafting (AFG) is a surgical technique used also to promote tissue regeneration. In the last decade, AFG has been successfully developed to treat clinical conditions characterized by skin atrophy or fibrosis. AFG composition of multipotent cells, carrying angiogenic, and immunogenic properties, may be able to restore the damaged tissues. Objectives: Evaluate our experience with AFG to treat and prevent damage and disability due to DUs and SSc skin complications. Methods: We analyzed 25 SSc patients, extrapolated from a larger series of 45 subjects, complaining about mouth and/or hand impairment, due to skin involvement, and, in some cases, long-lasting DUs (M/F 6/19, mean age 55.69±9.25-SD-years, mean disease duration 184.68±121.09-SD-months, L/D cutaneous subsets 21/4). Surgical procedures consisted in the injection of centrifuged and purified autologous fat, harvested from hips or abdomen. 2ml of fat were grafted in each of the 8 sites around the mouth, while 0.5 or 1 ml around the neurovascular bundle at the base of each finger. The study included: preoperative data collection; 2 or 3 surgical sessions at a distance of 6 months one from the other; data collection at 3 months after each surgical session; data collection at 3 and 6 months of follow up-FU after the last surgical procedure. Data collection consisted of clinic-serological SSc features and clinimetric measures about hand and mouth, if present DUs were assessed as well. Furthermore, patients were asked to fill in questionnaires in order to express their level of satisfaction with hand and mouth functionality. Results: Overall 63 surgical procedures were performed. After 1 to 3 procedures, patients reported an improvement of perioral skin tension (p=0.0238) and a reduced dry mouth feeling (p=0.0269). Similarly, patients stated an improvement of hands tension (p=0.0037). Furthermore, we observed a complete healing of DUs in 8/9 patients (p=0.0297). These positive clinical changes were mirrored by a subjective amelioration. In particular, pain decreased, evaluated by short-form McGill Pain Questionnaire (SF-MPQ), scrutinizing sensory (p=0.3340) and affective (p=0.2234) descriptors. The perception of disability improved too, showing an amelioration trend in Health Assessment Questionnaire-HAQ (p=0.4301) and Mouth Handicap in Systemic Sclerosis scale-MHISS- (p=0.9775). Conclusion: Our results confirm the potential efficacy of AFG to treat SSc skin complications and DUs. We reported an almost complete healing of DUs and a promising improvement of skin thickness and hardness both at hands and mouth, with good safety profiles. These clinical results were reflected by the subjective improvement of patients’ well-being. Population enlargement and extended FU is ongoing to identify more responsive SSc subsets. Long term results with soft tissue biopsies will give us further data to finally evaluate the efficacy of this approach that aims to improve the care and quality of life of our SSc patients. Disclosure of Interests: None declared

Objective This study evaluated Neem oil and Hypericum perforatum (Holoil®) for treatment of scleroderma skin ulcers related to calcinosis (SU-calc). Procedure: We retrospectively analyzed 21 consecutive systemic sclerosis (SSc) patients with a total of 33 SU-calcs treated daily with Holoil® cream compared with a control group of 20 patients with 26 SU-calcs. Holoil® was directly applied to skin lesions, while the control group received only standard medication. Results Application of Holoil® either resulted in crushing and complete resolution of calcium deposits or facilitated sharp excision of calcinosis during wound care sessions in 27/33 cases (81.8%). Complete healing of SU-calc occurred in 15/33 (45%) of cases within a time period of 40.1 ± 16.3 (mean ± SD) days, while 18/33 (55%) of lesions improved in terms of size, erythema, fibrin and calcium deposits. Patients reported a reduction of pain (mean numeric rating scale 7.3 ± 1.9 at baseline versus 2.9 ± 1.4 at follow-up) The control group had longer healing times and a higher percentage of infections. Conclusions The efficacy of local treatment with neem oil and Hypericum perforatum suggest that Holoil® could be a promising tool in the management of SSc SU-calc.

Parvovirus B19 (B19V) has been proposed as a triggering agent for some autoimmune diseases including systemic sclerosis (SSc). In this study, we investigated whether B19V infection in vitro differently activates inflammatory pathways, including those dependent on caspase-1 activation, in monocytes from patients with SSc and healthy controls. We showed that B19V can infect both THP-1 cells and primary monocytes but is not able to replicate in these cells. B19V infection increases the production of tumor necrosis factor-α and induces NLRP3-mediated caspase-1 activation in both THP-1 cells differentiated with phorbol 12-myristate 13-acetate and in monocytes from patients with SSc but not from healthy controls. B19V infection was sufficient for THP-1 to produce mature IL-1β. Monocytes from patients with SSc required an additional stimulus, here represented by lipopolysaccharides, to activate cytokine genes. Following B19V infection, however, lipopolysaccharide-activated monocytes from patients with SSc strongly increased the production of IL-1β and tumor necrosis factor-α. Altogether, these data suggest that viral components might potentiate the response to endogenous and/or exogenous toll-like receptor 4 ligands in monocytes from patients with SSc. The B19V-mediated activation of inflammatory pathways in monocytes might contribute to the disease progression and/or development of specific clinical phenotypes.

Purpose This study evaluated the retention strength of welding caps for Ankylos standard abutments using a pull-out test. Materials and methods Each sample consisted of an implant abutment and its welding cap. The tests were performed with a Zwick Roell testing machine with a 1-kN load cell. Results The retention strength of the welding caps increased with higher abutment diameters and higher head heights and was comparable or superior to the values reported in the literature for the temporary cements used in implant dentistry. Conclusion Welding caps provide a reliable connection between an abutment and a fixed prosthesis without the use of cement.

Human cytomegalovirus (HCMV) is a highly prevalent opportunistic agent in the world population, which persists as a latent virus after a primary infection. Besides the well-established role of this agent causing severe diseases in immunocompromised individuals, more recently, HCMV has been evoked as a possible factor contributing to the pathogenesis of autoimmune diseases such as systemic sclerosis (SSc). The interplay between HCMV and immune surveillance is supposed to become unbalanced in SSc patients with expanded anti-HCMV immune responses, which are likely involved in the exacerbation of inflammatory processes. In this study, blood samples from a cohort of SSc patients vs. healthy subjects were tested for anti-HCMV immune responses (IgM, IgG antibodies, and T cells to peptide pools spanning the most immunogenic HCMV proteins). Statistically significant increase of HCMV-specific CD8+ T cell responses in SSc patients vs. healthy subjects was observed. Moreover, significantly greater HCMV-specific CD8+ T cell responses were found in SSc patients with a longer disease duration and those with higher modified Rodnan skin scores. Given the known importance of T cells in the development of SSc and that this virus may contribute to chronic inflammatory diseases, these data support a relevant role of HCMV-specific CD8+ T cell responses in SSc pathogenesis.

Background Systemic sclerosis (SSc) is a chronic, multisystem connective tissue disease characterised by by immune dys-regulation, obliterative microvasculopathy and fibrosis. Endothelial dysfunction, immune system imbalance and fibroblast activation constitute the three major factors of the pathogenetic process. In this context, oxidative stress could play a significant role through direct damage of endothelial cells and the persistent activation of the immune system. 1,2 Objectives This study investigated the presence of advanced protein oxidation products (AOPP) in serum of patients with SSc and its correlation with disease’s features. Methods 50 patients with SSc (M:F 1:7, mean age 57.3±11.2 SD, mean duration of disease 10±9.1 SD years), were screened for AOPP in the serum, using the AOPP OxiSelect Kit of CELL BIOLABS (San Diego, Ca, USA). Among 50 SSc patients, 39 had limited cutaneous subset, while 11 had the diffuse one. Anamnestic and clinical data were collected for all SSc patients. As a control group 50 consecutive healthy subjects, sex and age matched, were recruited. Results We found serum levels of AOPP increased in the SSc group compared with the controls (p Conclusions Serum AOPP levels are significantly higher in patients with SSc than in controls. In addition, the correlations of AOPP with SSc diffuse cutaneous subset, digital ulcers, and pulmonary involvement (indicative of progressive disease and worse prognosis) suggest a possible role of this marker in the identification of the cases with worse clinical evolution. The data of this preliminary study should be confirmed on larger case series and analysed in prospective studies, in order to understand its eventual usefulness during the follow-up of SSc patients. References [1] Ferri C, Valentini G, Cozzi F, Sebastiani M, Michelassi C, La Montagna G, et al. Systemic Sclerosis: Demographic, Clinical, and Serologic Features and Survival in 1,012 Italian Patients. Medicine (Baltimore). 2002; 81:139–153 [2] Steen VD. The many faces of scleroderma. Rheum Dis Clin North Am. 2008; 34:1–15 Disclosure of Interest None declared

Background: Systemic sclerosis (SSc) is an autoimmune systemic disease characterized by diffuse fibrosis of skin and visceral organs due to different genetic, infectious, and/or environmental/occupational causative factors, including the inhalation of silica dust. Objectives: To investigate serum trace elements including silicon (s-Si) levels in SSc patients living in a restricted geographical area with high density of worksites with silica exposure hazard. Methods: This case-control study included 80 SSc patients (M:F 10:70; aged 58.4 ± 11.9SD years, mean disease duration 10.1 ± 7.8SD) and 50 age-/sex-matched healthy control subjects consecutively investigated at our University-based Rheumatology Unit. Patients and controls were evaluated for environmental/occupational exposure categories (structured questionnaire), morphological characterization of serum micro-/nanoparticles (Environmental Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy microanalysis), and quantitative assessment of trace elements (inductively coupled plasma atomic emission spectroscopy). Results: Among various categories, only occupational exposure to silica dust was recorded in a significant proportion of SSc patients compared to controls (55% vs. 11%; p

Fatigue behavior of the titanium bars is of utmost importance for the safe and reliable operation of dental implants and prosthetic constructions based on these implants. To date, however, only few data are available on the fatigue strength of dental prostheses made with electric resistance welding and laser welding techniques. This in-vitro study highlighted that although the joints made with the laser welding approach are credited of a superior tensile strength, joints made with electric resistance welding exhibited double the minimum fatigue strength with respect to the joints made with laser welding (120 vs 60 N).

BACKGROUND Mixed cryoglobulinemia (MC) is a rare multisystem disease whose aetiopathogenesis is not completely understood. Hepatitis C virus (HCV) infection may have a causative role, and genetic and/or environmental factors may also contribute. AIMS To investigate the presence and possible role of environmental agents in MC. METHODS We recruited 30 HCV-infected MC patients with different clinical manifestations and a control group of 30 healthy, sex-/age-matched volunteers. We collected serum samples from each patient and incubated at 4°C for 7 days to obtain cryoprecipitate samples. We used environmental scanning electron microscopy (ESEM) and energy dispersive X-ray spectroscopy microanalysis to verify the presence of microparticles (MPs) and nanoparticles (NPs) in serum and cryoprecipitate samples. We evaluated environmental exposure using a medical and occupational history questionnaire for each subject. RESULTS MC patients had a significantly higher risk of occupational exposure (OR 5.6; 95% CI 1.84-17.50) than controls. ESEM evaluation revealed a significantly higher concentration, expressed as number of positive spots (NS), of serum inorganic particles in MC patients compared with controls (mean NS 18, SD = 16 versus NS 5.4, SD = 5.1; P < 0.05). Cryoprecipitate samples of MC patients showed high concentrations of inorganic particles (mean NS 49, SD = 19). We found a strong correlation between NS and cryocrit (i.e. percentage of cryoprecipitate/total serum after centrifugation at 4°C) levels (P < 0.001). CONCLUSIONS In addition to HCV infection, MPs and NPs might play an important role in the aetiopathogenesis of MC.

The use of the conical coupling connection to support definitive restorations was evaluated in cases involving full acrylic resin or hybrid acrylic resin-composite prostheses. The aim of this study was to evaluate the performance of definitive fixed partial prostheses made with lithium disilicate and supported by coupling connection abutments and healed implants.The prostheses were placed in the posterior regions of partially edentulous patients; 65 patients received fixed lithium disilicate restorations splinted with conical coupling connections to two implants. Implants were placed into healed sites and fresh extraction sockets. The prostheses were placed after healing periods of 3 months: restorations were followed yearly for 3 years. At each follow-up visit, peri-implant bone levels and pocket depths were recorded. Esthetic, functional, and biologic United States Public Health Services (USPHS) parameters modified by the FDI World Dental Federation study design were assessed at the last follow-up appointments.Two prostheses (3.07%) fractured: one was related to framework design error; one was caused by a car accident. Three patients reported small chips: these restorations were immediately polished. No significant difference involving peri-implant bone and probing levels between the experimental times were found. None of the prostheses became loose.The results of this research indicated that abutment-prostheses coupling connections were successful within the timeframe of this study.

Control of heat dissipation and transmission to the peri-implant area during intra-oral welding is very important to limit potential damage to the surrounding tissue. The aim of this in vitro study was to assess, by means of thermal infrared imaging, the tissue temperature peaks associated with the thermal propagation pathway through the implants, the abutments and the walls of the slot of the scaffold, generated during the welding process, in three different implant systems. An in vitro polyurethane mandible model was prepared with a 7.0 mm v-shape slot. Effects on the maximum temperature by a single welding procedure were studied using different power supplies and abutments. A total of 36 welding procedures were tested on three different implant systems. The lowest peak temperature along the walls of the 7.0 mm v-shaped groove (31.6 ± 2 °C) was assessed in the specimens irrigated with sterile saline solution. The highest peak temperature (42.8 ± 2 °C) was assessed in the samples with a contemporaneous power overflow and premature pincers removal. The results of our study suggest that the procedures used until now appear to be effective to avoid thermal bone injuries. The peak tissue temperature of the in vitro model did not surpass the threshold limits above which tissue injury could occur.

Nanoparticles (NPs) are materials with one dimension in the range of 1-100 nm. The toxicity of NPs remains widely unknown and still poses concerns, due to the peculiar characteristics of materials in the nano-size range. We analyze the toxicity of seven NPs ((Fe2O3, Fe3O4, Sb2O3, Au, TiO2, Co, and Ag) on primary cultures of human hematopoietic progenitor cells from the bone marrow of healthy donors with CFU assays, and show that antimony oxide (Sb2O3) NPs and cobalt (Co) NPs have a toxic effect, while the other NPs have no effect at the tested concentrations (5, 25 and 100 microg/ml). While Co NPs suspension is toxic to both erythroid and granulocytic-monocytic precursors, Sb2O3 NPs at 5 microg/ml are specifically toxic to erythroid colony development, suggesting a highly selective type of toxicity. With liquid culture assays we show that Sb2O3 NPs impair the proliferation of erythroid progenitors, while no toxic effect is observed when Sb2O3 NPs are added during erythroid differentiation. CFU assays and liquid culture assays on seven human cell lines of hematopoietic origin (K562, HL-60, CEM, CEM-R, Thp-1, Jurkat, and Molt-4) show that, contrary to what observed on primary cultures of bone marrow progenitors, Sb2O3 NPs have no toxic effect on proliferation of any of the cell lines, raising concerns about the use of immortalized cell lines for nanotoxicology tests.

The electric resistance welding procedure is used to join a titanium bar with specific implant abutments in order to produce a framework directly in the oral cavity of the patient. This investigation studied the effects of the welding process on microstructure and hardness properties of commercially pure (CP2 and CP4) Ti components. Different welding powers and cooling procedures were applied to bars and abutments, normally used to produce the framework, in order to simulate the clinical intraoral welding procedure. The analyses highlighted that the joining process did not induce appreciable changes in the geometry of the abutments. However, because of unavoidable microstructural modifications in the welded zones, the hardness decreased to values lower than those of the unwelded CP2 and CP4 Ti grades, irrespective of the welding environments and parameters.

Metal-based nanoparticles (NPs), are currently used in many application fields including consumer products, pharmaceuticals, and biomedical treatments. In spite to their wide applications, an in-depth study of their potential toxic effects is still lacking. The aim of the present research was to investigate the potential initiator or promoter-like activity of different metallic NPs such as gold, iron, cobalt, and cerium using the Balb/3T3 two-stage transformation assay. The results indicated that all the selected metallic NPs, except for cobalt, when used as initiators did not induce any transformation in Balb/3T3 cell line. Moreover, Au and Fe3O4 NPs, when used in place of the tumor promoter treatment TPA, increased significantly the number of Foci/dish as compared to the MCA treatment alone. The number of Foci/dish was 2.6 for Au NPs and 2.13 for Fe3O4 ones, similar to those obtained by the positive control treatment (MCA + TPA), whereas 1.27 for MCA treatment alone. On the contrary, CeO2 NPs did not show any difference in the number of Foci/dish, as compared to MCA alone, but it decreased the number of foci by 65% in comparison to the positive control (MCA + TPA). As expected, cobalt NPs showed an increased cytotoxicity and only a few surviving cells were found at the time of analysis showing a number of Foci/dish of 0.13. For the first time, our data clearly showed that Au and Fe3O4 NPs act as promoters in the two stage transformational assay, suggesting the importance to fully investigate the NPs carcinogenic potential with different models. © 2014 Wiley Periodicals, Inc. Environ Toxicol, 2014.

The aim of this prospective study was to assess the suitability of immediate rehabilitation of the edentulous mandible using SynCone copings and the intraoral welding technique. Patients with an edentulous mandible were fitted with a removable restoration supported by an intraorally welded titanium bar. Copings were connected to their respective SynCone 5-degree abutments and then welded to a titanium bar using an intraoral welding unit. This framework was used to support the definitive restoration, which was delivered on the day of implant placement. Restoration success and survival, implant success, and biologic or technical complications were assessed immediately after surgery and at 6 and 12 months. Twenty-two patients were consecutively treated with 88 immediately loaded implants. No acrylic resin fractures or radiographically detectable alterations of the welded frameworks were present in the 22 restorations delivered. One implant (1.1%) failed 1 month after surgery; all remaining implants (98.9%) were clinically stable at the 12-month follow-up. Within its limitations, this pilot study demonstrated that it is possible to successfully rehabilitate the edentulous mandible on the day of surgery with a definitive restoration supported by an intraorally welded titanium framework and SynCone 5-degree abutments.