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1.
Mar Pollut Bull ; 197: 115679, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37890314

RESUMO

The soundscape is an intrinsic property of an ecosystem and influences the species that live in it. Here, we examined for the first time the soundscape of a beach, one of the most dynamic ecosystems on Earth, where every year the loggerhead sea turtle Caretta caretta lays eggs. The aim of this work was to analyze the acoustic components (biophony, anthropophony and geophony) to which turtles embryos were exposed throughout the development and the post-hatching period. The acoustic monitoring was carried out on the volcanic island of Linosa (central Mediterranean Sea, Strait of Sicily), during the months of July and August 2022, close to two turtle nests. Results revealed that all the acoustic levels (octave bands from 4 Hz to 16 kHz, and total 1-24,000 Hz band) showed lower values in July, and during the night. Furthermore, above 1 kHz the levels decreased and had very little variability. Anthropogenic noise was the main component of the soundscape and consisted of marine and land traffic, that affected sound levels directly or via seismic tremors. When the beach was exposed to the breaking waves, the latters were the first contributor to the noise up to 1 kHz. The only recognized biophony was represented by the shearwater choruses in July (at the frequency band 700-1500 Hz), but they had a negligible weight on the soundscape. Finally, human speech contributed to the soundscape at higher frequencies (1-8 kHz). These outcomes show that the embryos and the post-hatching turtles are exposed to a high anthropogenic noise level, which the effects of are still unknown.


Assuntos
Ecossistema , Tartarugas , Animais , Humanos , Estações do Ano , Sicília , Mar Mediterrâneo
2.
MethodsX ; 9: 101717, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35620759

RESUMO

This study presents an approach developed to derive a Delayed-Multivariate Exposure-Response Model (D-MERF) useful to assess the short-term influence of temperature on mortality, accounting also for the effect of air pollution (O3 and PM10). By using Distributed, lag non-linear models (DLNM) we explain how city-specific exposure-response functions are derived for the municipality of Rome, which is taken as an example. The steps illustrated can be replicated to other cities while the statistical model presented here can be further extended to other exposure variables. We derive the mortality relative-risk (RR) curve averaged over the period 2004-2015, which accounts for city-specific climate and pollution conditions. Key aspects of customization are as follows: This study reports the steps followed to derive a combined, multivariate exposure-response model aimed at translating climatic and air pollution effects into mortality risk. Integration of climate and air pollution parameters to derive RR values. A specific interest is devoted to the investigation of delayed effects on mortality in the presence of different exposure factors.

3.
Sci Total Environ ; 830: 154680, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35314224

RESUMO

Heat and cold temperatures associated with exposure to poor air quality lead to increased mortality. Using a generalized linear model with Poisson regression for overdispersion, this study quantifies the natural-caused mortality burden attributable to heat/cold temperatures and PM10 and O3 air pollutants in Rome and Milan, the two most populated Italian cities. We calculate local-specific mortality relative risks (RRs) for the period 2004-2015 considering the overall population and the most vulnerable age category (≥85 years). Combining a regional climate model with a chemistry-transport model under future climate and air pollution scenarios (RCP2.6 and RCP8.5), we then project mortality to 2050. Results show that for historical mortality the burden is much larger for cold than for warm temperatures. RR peaks during wintertime in Milan and summertime in Rome, highlighting the relevance of accounting for the effects of air pollution besides that of climate, in particular PM10 for Milan and O3 for Rome. Overall, Milan reports higher RRs while, in both cities, the elderly appear more susceptible to heat/cold and air pollution events than the average population. Two counterbalancing effects shape mortality in the future: an increase associated with higher and more frequent warmer daily temperatures - especially in the case of climate inaction - and a decrease due to declining cold-mortality burden. The outcomes highlight the urgent need to adopt more stringent and integrated climate and air quality policies to reduce the temperature and air pollution combined effects on health.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Idoso , Idoso de 80 Anos ou mais , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Cidades , Mudança Climática , Humanos , Mortalidade , Cidade de Roma/epidemiologia
4.
J Biol Regul Homeost Agents ; 34(6 Suppl. 3): 37-45, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33412779

RESUMO

The aim of the study was to evaluate implant treatment for partial edentulism in a population of controlled type I diabetic patients. The research hypothesis was that implant survival rate, prevalence of peri-implant tissue infection and marginal bone loss at 2 years follow-up would not differ from a non diabetic population. A total of 106 patients (47=women, 59=men, mean age 38.36 years) presented with partially edentulous jaws. All patients underwent a two stage implant surgery (105 maxillary, 100 mandibular). Diabetic type I patients (53) were scheduled in Group A, while 53 healthy patients formed the Control Group. Clinical and radiological controls were performed from baseline up to 24 months and implants survival rate, presence of peri-implant tissue infections and marginal bone loss were assessed in all ptients. Group A and Control Group were compared by analyzing data at implant level, through either an independent sample t-test, with respect to bone loss, or Fisher Exact tests, with respect to (a) peri-implant mucositis, (b) peri-implantitis, and (c) post-operative wound infection. At the 24-month follow-up, 5 and 3 implants failed in diabetic and non-diabetic patients, respectively. No statistically significant difference was found in implant survival rate between the two groups (Group A: 95.19%; Control Group: 97.03%). Moreover, no statistical significant differences were found in infections occurrence, nor in marginal bone loss. The preliminary results of this prospective study showed how implant treatment for partial edentulism may a be safe and predictable procedure for diabetic type I patients, provided controlled glycemic levels and regular professional oral hygiene sessions.


Assuntos
Perda do Osso Alveolar , Implantes Dentários , Diabetes Mellitus Tipo 1 , Adulto , Perda do Osso Alveolar/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Estudos Prospectivos , Taxa de Sobrevida , Resultado do Tratamento
5.
J Biol Regul Homeost Agents ; 34(6 Suppl. 3): 19-25, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33386053

RESUMO

The aim of this randomized clinical trial was to compare the outcome of immediate versus delayedloading protocol using a new conical connection implant in post-extractive sockets with 4-year followup. Patients requiring single-tooth extraction for root fractures or periodontal disease in the maxillary or mandibular anterior or premolar areas were selected for the present study. After extraction, implants were placed immediately in fresh sockets. After randomization process, in group A immediate loading was performed while in group B a delayed loading protocol was followed. In both groups mean marginal bone loss was measured through intraoral digital radiographs at 3, 6, 12, 24, 36 and 48 months from loading. After a 48-month follow-up period, a success and survival rate of 96.55% was found in both groups. At 48-month follow-up, for group A a mean marginal bone loss of 0.14 ± 0.15mm was found, while for group B a value of 0.12 ± 0.12 mm was measured. No statistically significant differences between groups were found at each time point (P>0.05). When used in post-extractive immediate and delayed loading implant rehabilitations, the new conical connection implant showed a predictable outcome at 48-month follow-up. However, further clinical studies are needed to evaluate soft tissues adaptation, patient satisfaction, and long-term follow-up.


Assuntos
Perda do Osso Alveolar , Alvéolo Dental , Perda do Osso Alveolar/diagnóstico por imagem , Estética , Estética Dentária , Seguimentos , Humanos , Estudos Longitudinais , Estudos Prospectivos , Extração Dentária , Alvéolo Dental/diagnóstico por imagem , Alvéolo Dental/cirurgia , Resultado do Tratamento
6.
Eur J Cancer ; 109: 137-153, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30721788

RESUMO

INTRODUCTION: Treatment of patients with metastatic melanoma is hampered by drug-resistance and often requires combination with radiotherapy as last-resort option. However, also after radiotherapy, clinical relapses are common. METHODS & RESULTS: Our preclinical models indicated a higher rate of tumour relapse when melanoma cells were first treated with BRAFV600E inhibition (BRAFi) followed by radiotherapy as compared to the reverse sequence. Accordingly, retrospective follow-up data from 65 stage-IV melanoma patients with irradiated melanoma brain metastases confirmed a shortened duration of local response of mitogen-activated protein kinase (MAPK)-inhibitor-pretreated compared with MAPK-inhibitor-naïve intracranial metastases. On the molecular level, we identified JARID1B/KDM5B as a cellular marker for cross-resistance between BRAFi and radiotherapy. JARID1Bhigh cells appeared more frequently under upfront BRAFi as compared with upfront radiation. JARID1B favours cell survival by transcriptional regulation of genes controlling cell cycle, DNA repair and cell death. CONCLUSION: The level of cross-resistance between combined MAPK inhibition and radiotherapy is dependent on the treatment sequence. JARID1B may represent a novel therapy-overarching resistance marker.


Assuntos
Neoplasias Encefálicas/terapia , Resistencia a Medicamentos Antineoplásicos , Melanoma/terapia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Tolerância a Radiação , Radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Apoptose , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/secundário , Ciclo Celular , Movimento Celular , Proliferação de Células , Quimiorradioterapia , Feminino , Seguimentos , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Melanoma/genética , Melanoma/patologia , Pessoa de Meia-Idade , Mutação , Prognóstico , Proteínas Proto-Oncogênicas B-raf/genética , Estudos Retrospectivos , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Sci Rep ; 6: 36376, 2016 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-27808239

RESUMO

Subaqueous, asymmetric sand waves are typically observed in marine channel/canyon systems, tidal environments, and continental slopes exposed to strong currents, where they are formed by current shear resulting from a dominant unidirectional flow. However, sand-wave fields may be readily observed in marine environments where no such current exists; the physical processes driving their formation are enigmatic or not well understood. We propose that internal solitary waves (ISWs) induced by tides can produce an effective, unidirectional boundary "current" that forms asymmetric sand waves. We test this idea by examining a sand-wave field off the Messina Strait, where we hypothesize that ISWs formed at the interface between intermediate and surface waters are refracted by topography. Hence, we argue that the deflected pattern (i.e., the depth-dependent orientation) of the sand-wave field is due to refraction of such ISWs. Combining field observations and numerical modelling, we show that ISWs can account for three key features: ISWs produce fluid velocities capable of mobilizing bottom sediments; the predicted refraction pattern resulting from the interaction of ISWs with bottom topography matches the observed deflection of the sand waves; and predicted migration rates of sand waves match empirical estimates. This work shows how ISWs may contribute to sculpting the structure of continental margins and it represents a promising link between the geological and oceanographic communities.

8.
BMC Med Inform Decis Mak ; 15 Suppl 3: S2, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26391336

RESUMO

BACKGROUND: Standing from a bed or chair may cause a significant lowering of blood pressure (ΔBP), which may have severe consequences such as, for example, falls in older subjects. The goal of this study was to develop a mathematical model to predict the ΔBP due to standing in healthy subjects, based on their Heart Rate Variability, recorded in the 5 minutes before standing. METHODS: Heart Rate Variability was extracted from an electrocardiogram, recorded from 10 healthy subjects during the 5 minutes before standing. The blood pressure value was measured before and after rising. A mathematical model aiming to predict ΔBP based on Heart Rate Variability measurements was developed using a robust multi-linear regression and was validated with the leave-one-subject-out cross-validation technique. RESULTS: The model predicted correctly the ΔBP in 80% of experiments, with an error below the measurement error of sphygmomanometer digital devices (± 4.5 mmHg), a false negative rate of 7.5% and a false positive rate of 10%. The magnitude of the ΔBP was associated with a depressed and less chaotic Heart Rate Variability pattern. CONCLUSIONS: The present study showes that blood pressure lowering due to standing can be predicted by monitoring the Heart Rate Variability in the 5 minutes before standing.


Assuntos
Pressão Sanguínea/fisiologia , Frequência Cardíaca/fisiologia , Hipotensão Ortostática , Modelos Teóricos , Adulto , Eletrocardiografia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Projetos Piloto , Adulto Jovem
9.
Oral Implantol (Rome) ; 7(3): 57-70, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25992260

RESUMO

PURPOSE: The aim of this paper was to describe the CEREC 3 chairside system, providing the clinicians a detailed analysis of the whole digital workflow. Benefits and limitations of this technology compared with the conventional prosthetic work-flow were also highlighted and discussed. MATERIALS AND METHODS: Clinical procedures (tooth preparation, impression taking, adhesive luting), operational components and their capabilities as well as restorative materials used with CEREC 3 chairside system were reported. RESULTS: The CEREC system has shown many positive aspects that make easier, faster and less expensive the prosthetic workflow. The operator-dependent errors are minimized compared to the conventional prosthetic protocol. Furthermore, a better acceptance level for the impression procedure has shown by the patients. The only drawback could be the subgingival placement of the margins compared with the supra/juxta gingival margins, since more time was required for the impression taking as well as the adhesive luting phase. The biocopy project seemed to be the best tool to obtain functionalized surfaces and keep unchanged gnathological data. Material selection was related to type of restoration. CONCLUSIONS: The evidence of our clinical practice suggests that CEREC 3 chairside system allows to produce highly aesthetic and reliable restorations in a single visit, while minimizing costs and patient discomfort during prosthetic treatment. However improvements in materials and technologies are needed in order to overcome the actual drawbacks.

10.
Int J Immunopathol Pharmacol ; 26(3): 825-31, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24067485

RESUMO

This study was designed as a retrospective analysis of clinical outcomes of cases of periimplantitis treated by mechanical debridement and the administration of antibiotics combined or not with the administration of either the proteolytic enzyme serratiopeptidase (SPEP) or non-steroidal anti-inflammatory drugs (NSAIDs). Clinical charts of 544 partially edentulous patients treated for periimplantitis between June 1996 and December 2010 were analyzed to obtain clinical data of the affected implants just before the beginning of treatment and 12 months later to evaluate the outcomes of combined mechanical antibiotic treatment alone or in combination with the co-administration of the anti-inflammatory SPEP or NSAIDs. The comparative analysis revealed that therapeutic outcomes were significantly different in the three groups. Failure rate in the group that received SPEP (6 percent) was significantly lower compared to the group that received NSAIDS (16.9 percent; P less than 0.01) and to the group that received no anti-inflammatory therapy (18.9 percent; P less than 0.01). Treatment including SPEP was associated with significantly better healing also when successful treatments alone were considered. The data reported in this paper strongly support the hypothesis that SPEP is a valid addition to protocols for the combined therapy of peri-implantitis. In fact, it allows to enhance success rates significantly and also favors better tissue repair around successfully treated implants as compared to other regimens.


Assuntos
Antibacterianos/uso terapêutico , Anti-Inflamatórios não Esteroides/efeitos adversos , Desbridamento , Peptídeo Hidrolases/uso terapêutico , Peri-Implantite/tratamento farmacológico , Peri-Implantite/cirurgia , Terapia Combinada , Quimioterapia Combinada , Humanos , Peri-Implantite/diagnóstico , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Cicatrização/efeitos dos fármacos
11.
Comput Math Methods Med ; 2012: 816481, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23243464

RESUMO

PURPOSE: The analysis of the complex model of fiber post and ferrule is given and studied in this paper. A novel approach and a solution to the evaluation of stress of post and core system within the ferrule effect are proposed. METHODS: Sixty freshly extracted premolars were selected for the study. The following experimental groups were therefore defined (n = 10): (1) 5 mm, (2) 7 mm, (3) 9 mm, (4) ferrule-5 mm, (5) ferrule-7 mm, and (6) ferrule-9 mm. Preshaping drills (C) were used to prepare the root canals at 5, 7, and 9 mm in depth. In specimens of groups 3-6 a circumferential collar of tooth structure of 2 mm in height. Fluorocore 2 core build-up material (I) was used for fiber post luting. With the same material, a buildup of 2 mm in height was created. A controlled compressive load (crosshead speed: 0.75 mm/min) was applied by means of a stainless steel stylus (Ø 1 mm) at the coronal end of the post extruding out of the root. RESULTS: In all the tests the level of significance was set at P < 0.05 . Significantly higher fracture strengths were measured in the presence of a ferrule effect. In groups 1, 2, and 3 (ferrule group), the mean fracture values were, respectively, 163,8 N, 270,9 N, and 254,7 N. These data are higher and statistically significantly different when compared with the three groups 4, 5, and 6 (no-ferrule group), in which the values obtained were, respectively, 40,5 N, 41,7 N, and 44,9 N. CONCLUSION: The ferrule effect in the endodontically treated teeth positively affects the fracture strength of the fiber post. Conversely, post depth insertion did not affect the resistance to fracture.


Assuntos
Planejamento de Prótese Dentária/métodos , Falha de Restauração Dentária , Análise do Estresse Dentário/métodos , Técnica para Retentor Intrarradicular , Algoritmos , Simulação por Computador , Esmalte Dentário , Desenho de Equipamento , Humanos , Técnicas In Vitro , Teste de Materiais , Modelos Estatísticos , Risco , Temperatura , Fraturas dos Dentes/terapia , Dente não Vital
12.
Oral Implantol (Rome) ; 5(1): 11-20, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23285401

RESUMO

PURPOSE: The purpose of this study was to investigate, by finite element analysis (FEA) and fatigue analysis, the influence of different loading conditions on the stress distribution in a 3-unit implant-supported Y-TZP fixed partial denture (FPD). MATERIAL AND METHODS: A three-dimensional FEM model was developed. The materials used in this study were assumed to be linearly elastic, homogeneous and isotropic. 100 N and 300 N loads over a 0,5 mm(2) areas with different angles (0°, 15° and 35°) and locations were applied on the prosthesis and the distribution of equivalent von Mises stress was investigated. A fatigue analysis was carried out too. RESULTS: Maximum stresses were found at the connector region of the framework when the intermediate element is loaded (100 N load pattern: 32,9 MPa, 33 MPa and 51,8 MPa; 300 N load pattern: 98,6 MPa, 102,8 MPa and 155,7 MPa, respectively with 0°, 15° and 35° of inclination). Results confirmed the vulnerability of both connector areas even if just one pillar was loaded with an increase in stress when angle of load inclination is larger. The cyclic fatigue evaluation indicates a strong propensity for fatigue behavior, presenting a considerable range of loading conditions. No fracture fatigue occurred with a 100 N force. A 300 N force applied to the pontic produces no fatigue problems because the load is equally shared by whole system. A 300 N force applied to one of the two pillars, or to both implants generates fatigue problems. CONCLUSION: F.E.M. analysis of a 3-unit implant-supported Y-TZPFPD, give accurate information about loading conditions for clinical success over time. Fatigue analysis results show structural reliability of the Y-TZP as framework material for 3-unit posterior FPDs.

13.
Oral Implantol (Rome) ; 4(3-4): 23-33, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23277870

RESUMO

The prevalence of the elderly population, as well as life expectancy, increased in the final decades of the 20th century, as described in the World Health Organization 2004 Annual Report. The edentulous condition therefore has a negative impact on the oral health-related quality of life. Patients wearing complete dentures for many years infact, and especially in the mandible, are often unsatisfied because of the instability of the prosthesis during speaking and eating. To date dental implant treatment is well documented as a predictable treatment for partial or complete edentulism. On the other hand the rehabilitation of atrophied edentulous arches with endosseous implants (> 10 mm) in the posterior regions is often associated with anatomic problems such as bone resorption, poor bone quality, mandibular canal, and the presence of maxillary sinuses. Different procedures have been proposed to overcome these anatomic limitations. The use of tilted implants parallel to the anterior wall of the maxillary sinus or the mental foramen/inferior alveolar nerve has been proposed as a conservative solution for the treatment of the atrophic edentulous maxilla. Aim of this study was to describe, through a detailed literature review, the clinical and biomechanical rationale for tilting implants and to evaluate the long-term prognosis of immediately loaded full fixed prostheses for the treatment of edentulous patients (#35) with extreme bone atrophy rehabilited with both axial (#70) and tilted (#70) implants from 2008 to 2010. The results of the present study would suggest that this new surgical technique may reduce patient morbidity and extend the indications for immediate loading full fixed rehabilitations. This improves the predictability of treatment goal, allows for a better risk management, and provides more individual information for the patient. These are the most important aspects of this technology, which may contribute to establish higher-quality standards in implantology.

14.
Oral Implantol (Rome) ; 4(1-2): 4-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23285395

RESUMO

PURPOSE: A novel technique for transcrestal guided sinus lift elevation (TGSL), is described underlining the step by step surgical protocol. MATERIALS AND METHODS: TGSL modified osteotome technique was planned by the NobelProcera(®) Software Planning Programm (Nobel Guide, Nobel Biocare AB) and performed by stereolitographic template. The depth of the planned osteotomy was determined precisely via cross-sectional images of the elevation site to facilitate puncture of the bony sinus floor without risk of perforation of the adherent sinus membrane. A customized drilling-osteotome protocol is used to raise the Schneiderian membrane to the final implant length. RESULTS: The sinus membrane is successfully elevated in all sites without any iatrogenic perforation. CONCLUSIONS: The TGSL modified osteotome technique may provide a new option for minimally invasive transcrestal sinus surgery and may represent a safe method to increase bone volume in the atrophic posterior maxilla. The results of the present study would suggest that this new surgical technique may reduce patient morbidity and extend the indications for transcrestal maxillary sinus floor elevation.

15.
Oral Implantol (Rome) ; 3(3): 26-37, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23285387

RESUMO

PURPOSES: The aim of the study was to assess by means a 3D finite element linear and non-linear analysis mechanical interaction between an implant-supported crown and surrounding tissues. MATERIALS AND METHODS: A three-dimensional FEM model was developed. Four different material combinations for the abutment and the core were evaluated: Y-TZP - Y-TZP, Y-TZP - microhybrid composite, T - microhybrid composite; T and Y-TZP. 250 N and 450 N loads over a 0,5 mm(2) areas with different angles (0° and 45°) and locations were applied on the occlusal surface of the framework and the distribution of equivalent von Mises stress was investigated. Using the most critical scenario, the influence of the gradual failure of the cement layer, due to increasing load, on the bone -implant interface, were investigated. RESULTS: The worst physiological loading condition was the one associated with a horizontal component (45°, 250 N). The 0°, 450 N load (relating to accidental or pathological condition) induced stress concentrations in the cortical bone comparable with those obtained for the tilted load, but with a greater extension to the cancellous bone. Y-TZP prosthetic elements determined minimum values of stress, due to vertical loads at the interface, while the microhybrid composite ones determined minimum stresses due to horizontal loads. CONCLUSION: Different material combinations for the abutment and the core influenced weakly the stress state at bone-implant interface, with a dependency closely related to the loading mode. The implant - prostheses system stress distribution depended on material choice. Furthermore progressive 45° loads with the gradual failure of the cement layer did not influence Von Mises stresses at bone-implant-interface.

16.
Oral Implantol (Rome) ; 2(2): 14-27, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23285359

RESUMO

PURPOSE: The aim of this study was to evaluate, by finite element analysis (FEA), the influence of finish line on stress distribution and resistance to the loads of a ZrO(2) crown and porcelain in implant-supported. MATERIAL AND METHODS: The object of this analysis consisted of a fxture, an abutment, a passing screw, a layer of cement, a framework crown, a feldspatic porcelain veneering. The abutment's marginal design was used in 3 different types of preparation: feather edge, slight chamfer and 50°, each of them was of 1 mm depth over the entire circumference. The ZrO(2)Y-TZP coping was 0.6 mm thick. Two material matching for the abutment and the framework was used for the simulations: ZrO(2) framework and ZrO(2) abutment, ZrO(2) framework and T abutment. A 600 N axial force distributed over the entire surface of the crown was applied. The numerical simulations with finite elements were used to verify the different distribution of equivalent von Mises stress for three different geometries of abutment and framework. RESULTS: Slight chamfer on the matching ZrO(2) - ZrO(2) is the geometry with minimum equivalent stress of von Mises. Even for T abutment and ZrO(2) framework slight chamfer is the best configuration to minimize the localized stress. Geometry that has the highest average stress is one with abutment at 50°, we see a downward trend for all three configurations using only zirconium for both components. CONCLUSIONS: Finite element analysis. performed for the manifacturing of implant-supported crown, gives exact geometric guide lines about the choice of chamfer preparation, while the analysis of other marginal geometries suggests a possible improved behavior of the mating between ZrO(2) abutment and ZrO(2) coping. for three different geometries of the abutment and the coping.

17.
Oral Implantol (Rome) ; 2(3): 21-6, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23285365

RESUMO

INTRODUCTION.: The aim of this experimental study was to reduce the exothermic reaction during curing of the resins to cold. The significant exotherm generated by the reaction of polymerization of the resin curing involves many clinical complications including the high risk of necrosis against tooth. MATERIAL AND METHODS.: They were used four different types of self curing resins all based on methyl methacrylate, Jet Kit, Major Dentin, Dura Lay, Temporary Cold. The reaction of polymerization of the resins was done in Teflon pans and was monitored by a thermocouple which recorded the highest level reached by each temperature resin with and without additive. The polymerization reaction took place for each resin in the presence of an essential oil, the terpinolene, which acted as a "chain transfer" and different temperatures were recorded. RESULTS.: Resins Dura Lay and Jet kit showed a reduction of very high temperature in the presence of terpinolene, with a statistically significant difference compared to the same reaction without terpinolene Major resin dentin in the presence of the additive has reduced by 8.4°C peak temperature. Resin Temporary Cold has showed benefits with respect to peak temperature, but the reaction was much more 'consistent presence of the additive. DISCUSSION.: The system through which the chain transfer acts to lower the temperature of the reaction is that of chain transfer. Namely that interfere with the reaction of the polymer chains, by transferring these acrylic radicals are no longer active, ie, no longer able to bind to other monomer units, thus avoiding the excessive growth of macromolecules which are those that determine the temperature rise. This leads to the formation of more polymer chains with lower molecular weight.

18.
Oral Implantol (Rome) ; 2(3): 11-20, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23285364

RESUMO

STATEMENT OF PROBLEM.: The CAD-CAM technology has been developed to design and manufacture prosthetic structures with constant quality characteristics; in fact procedures are codified, manageable and repeatable. PURPOSE.: The purpose of this in vitro study is to evaluate the internal and marginal gap of zirconia casts made with a new CAD-CAM systematic that use Dental Wings laser scanner and Yenamak milling machine. MATERIAL AND METHODS.: 6 analogs of solid abutments of Straumann implants were used, fixed in plexiglass bases. The samples were scanned by Dental Wings laser; the file obtained by scanning of each probe was sent to the Yenamak D40 milling machine, then the casts were sintered in Protherm furnace. Then 6 samples were cemented with resin luting agent capsules (Relyx Unicem, 3M ESPE). The samples were incorporated in transparent epoxy resin. After resin hardening, the cylinders obtained were cut with a microtomes. These slices thus obtained were then polished with a Polisher sander with alumina dust decreasing grain. Each section was observed and photographed in reflected light with the aid of an optic microscope type, first at low magnification and then at higher magnification. RESULTS.: The overall average fitting of copings on the abutments was 32,87 µ. No differences were found in marginal fit on buccal and lingual sides, it was easily predictable because of the standard form of the used stumps. The recorded values for the marginal fit were lower than those of axial walls. The accuracy of adaptation was always achieved within the limits of clinical acceptability. CONCLUSIONS.: Within the limitations of this study, the system evaluated represents a valuable alternative to conventional prosthetic rehabilitation techniques.

19.
G Ital Med Lav Ergon ; 29(3 Suppl): 385-6, 2007.
Artigo em Italiano | MEDLINE | ID: mdl-18409737

RESUMO

We have examined the claims for advance maternity leave or prolonged benefits for breastfeeding addressed to Occupational Health Unity of Local Health Service 11 by women at harmful works in the period 2002-2005. The most frequent occupations were: shoemaker (29%), service company's employee (7%), tanners (7%), leather industry's employee (6%) and food industry's employee (6%). The most important risk factors were: bound postures, manual load handling, chemical hazards and biological agents. The numbers of claims increased during the period of interest. In the work place often risks for pregnancy and breastfeeding are not correctly assessed and women workers are not informed on their rights. The Occupational Health Unity of Local Health Service 11 tried to correct the lack of information for workers, employers, workers' representatives in health and safety and enterprise's occupational health physician.


Assuntos
Aleitamento Materno , Exposição Ocupacional/prevenção & controle , Saúde Ocupacional , Feminino , Humanos , Gravidez , Setor Público , Fatores de Risco
20.
Ann Ist Super Sanita ; 34(1): 75-80, 1998.
Artigo em Italiano | MEDLINE | ID: mdl-9679343

RESUMO

We report the results obtained in 1992 concerning the determination of blood lead levels (PbB) in 1321 subjects of the general population living in ten villages/towns of the Florence district characterised by the presence of artistic ceramic factories. We reported also the PbB values found in 2330 adults, 280 children, 39 pregnant women and their correspondent umbilical cords, who were examined during the second biological monitoring campaign against the risk of lead intoxication according to the DPR 496/82. Median PbB values were 92.5 micrograms/l (range 15-520 micrograms/l) for males and 62.5 micrograms/l (range 11-343 micrograms/l) for females. The lower PbB median values were found in the district of Livorno (76.25 micrograms/l and 48.25 micrograms/l in males and females, respectively) and Arezzo (80.5 micrograms/l and 52 micrograms/l in males and females, respectively). In comparison with the results obtained for the general Italian population during the previous biological monitoring campaign carried out in 1985-86 we observed PbB median values about 40% lower for both males and females and PbB median values about 55% lower for children. A significant statistic correlation (r = 0.53) was found between PbB of pregnant women and their umbilical cords.


Assuntos
Exposição Ambiental , Chumbo/sangue , Adolescente , Adulto , Idoso , Poluentes Atmosféricos/efeitos adversos , Cerâmica , Criança , Monitoramento Ambiental , Monitoramento Epidemiológico , Feminino , Sangue Fetal/química , Humanos , Indústrias , Recém-Nascido , Itália/epidemiologia , Chumbo/efeitos adversos , Intoxicação por Chumbo/sangue , Intoxicação por Chumbo/epidemiologia , Intoxicação por Chumbo/prevenção & controle , Lipídeos/sangue , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Programas Nacionais de Saúde , Gravidez , Estudos de Amostragem , Emissões de Veículos , gama-Glutamiltransferase/sangue
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