1,148 research outputs found
Are the insertion torque value and implant stability quotient correlated, and if so, can insertion torque values predict secondary implant stability? A prospective parallel cohort study
No full textPurpose: Primary stability is the most important prognostic index for predicting osseointegration. It is generally thought that to achieve high primary stability, it is necessary to insert an implant with a high insertion torque (IT). To date, it has not yet been determined whether IT and implant stability quotient (ISQ) values are correlated. The primary aim of the study was to determine the correlation between IT and ISQ values at the time of implant insertion (T0); at 2 months, the time of healing (T1); and at 6 (T2) and 12 months (T3) after loading. The secondary aims were to determine the influence of different macroscopic implant designs and of a different insertion arch on this correlation; and to assess whether implants inserted with a high IT, that is, > 50 Ncm, had higher levels of implant stability at 2-, 6-, and 12-month follow-ups. Materials and methods: STROBE guidelines were followed. Partially or monoedentulous patients were randomly assigned to receive taper thread on straight-body implants with microthreads (group A) or without microthreads (group B). At implant insertion, IT and ISQ values were recorded. At 2-, 6-, and 12-month follow-ups, the ISQ values were recorded. A spring-style torque wrench was used to assess the IT. The Osstell device was used to determine the ISQ values. Descriptive statistics, Pearson correlation, and t test were used. P was set at ≤ .005. Results: Two hundred fifty subjects were assessed; 142 were included. Two hundred sixty-eight implants were inserted (group A, 137 implants; group B, 131 implants). No subject dropped out, and no implant failed. A statistically significant correlation between ISQ and IT was determined at the time of implant insertion (T0; P = .000). The implant morphology and arch did not influence the correlation. An IT > 50 did not determine a higher secondary stability. Conclusion: There is a strong correlation between IT and primary stability, but IT is not correlated with the secondary stability. A different implant macroscopic design and a different arch of insertion did not influence this correlation. Moreover, implants inserted with IT > 50 Ncm do not result in greater secondary stability
The survival of Morse cone–connection implants with platform switch
No full textPURPOSE:
The aim of this prospective clinical study was to evaluate the survival up to 5 years of Morse cone-connection implants with platform switch considering the influence of biologically relevant, anatomical, and stress-related variables. STROBE guidelines were followed.
MATERIALS AND METHODS:
Seven hundred forty-eight implants were inserted in 350 patients. Follow-up visits were scheduled at the time of stagetwo surgery (2 months later) and at 6, 12, 24, 36, and 60 months. All implants were initially loaded with a cemented provisional acrylic restoration. The definitive metal-ceramic restorations were cemented at the 6-month follow-up. Implant cumulative survival rates (CSRs) were calculated using life table actuarial method. Survival data were also analyzed by the log-rank test and Cox regression. The statistical analysis was conducted at the patient level. P ≤ .05 was considered as an indicator of statistical significance.
RESULTS:
During the follow-up (mean: 40 months; SD: 20.27), 28 patients were considered failed (8%). The CSR and its standard error (SE) was 92% ± 2.17%. Patients with implant-supported single crowns had a CSR of 90%, whereas those with implant-supported fixed dental prostheses had a CSR of 93%. The implant diameter (P = .0399) and implant length (P = .0441) were statistically significant. The probability of failure was almost 75% lower for patients with wide rather than standard implants, 91% lower for patients with long implants, and 69% lower for patients with standard implants compared with short implants.
CONCLUSION:
The use of Morse cone-connection implants with platform switch is a safe and reliable treatment method. Stress-related variables influence the risk of failure confirming the importance of biomechanical factors in the longevity of osseointegrated implants; thus, the clinician may obtain better results if attention is paid to these factors
Miniscrew-supported distal jet versus conventional distal jet appliance : a pilot study
No full textMaxillary molar distalization is the most frequently used nonextraction treatment in the correction of Class II malocclusion. The use of traditional intra-oral devices shows unreliable results. Nowadays the use of miniscrew-supported appliances helps prevent anchorage loss. The aim of this pilot study is to compare the amount of upper first molar distalization and the dentoalveolar side effects using traditional distal jet appliance and miniscrew-supported distal jet appliance. 20 patients were randomly assigned to receive a treatment with miniscrew-supported distal jet appliance (Group A) or with traditional distal jet appliance (Group B). To ensure a safe and minimally invasive miniscrew insertion a surgical guide was used. Digital models and lateral cephalograms were obtained and analyzed before orthodontic treatment and at 6-month follow-up. Intergroup differences were determined using T- test. The significance was set at p ?0.05. The intra-operator reliability was evaluated using a 2 sample T-test. The difference was not statistically significant (P ?0.05 ), demonstrating an intra-operator reliability. In Group A, a greater maxillary first molar distalization was recorded (P=0.002). Considering the dentoalveolar side effects, in Group A, a spontaneous distalization of the first premolars and a retroclination of central incisors were determined. In Group B, the first premolars tipped mesially with a proclination of the maxillary central incisors. Miniscrew-supported distal jet appliance achieved a greater first molar distalization at 6-month follow-up and did not cause dento-alveolar side effects, such as the mesial drift of the premolars and the incisors
A 36-month follow-up prospective cohort study on peri-implant bone loss of Morse Taper connection implants with platform switching
No full textA prospective cohort study was designed to measure marginal bone level changes at 36-month follow-up and to evaluate the influence of biologically relevant, anatomic and stress-related variables. STROBE guidelines were followed. Totally, 748 implants were inserted into 350 patients. Standardized periapical radiographs were taken at 2- (stage-two surgery), 12-, 24-, and 36-month follow-ups. Descriptive statistics were used and inter- and intra-examiner reliability were determined. A mixed-model was used to evaluate predictor variables. Statistical analysis was performed at implant level (statistical significance: P < 0.05). A total of 34 (4.5%) implants failed; of the 34 implants, 6 were early failures (0.8%) and 28 were late failures (3.7%). A total of 576 implants reached 36-month follow-up (mean follow-up: 25.58 months; SD: 10.32). Mean marginal bone remodeling was -0.56 mm. (SD: 1.30; range: -6.80 ± 3.65). A statistically significant, higher marginal bone loss was found for subcrestal implants and subcrestal implants inserted into the maxilla, for implants inserted into patients aged over 50 years, and for early-delayed implants inserted into patients aged over 50 years. In conclusion, a low, mean crestal bone loss at 36-month follow-up was recorded but implant positioning in the apico-occlusal dimension was found to be the most significant variable that influenced bone loss
Giulia Veronica Varisco
No full textThe headword explains the biography and the contribution of the author Giulia Varisco to the children's literatur
Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure
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Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure
by Giulia Di Iorio,Laura Paglia *ORCID,Giulia PedrizzettiORCID,Virgilio GenovaORCID,Francesco MarraORCID,Cecilia BartuliORCID andGiovanni PulciORCID
INSTM Reference Laboratory for Materials and Surface Engineering, Sapienza University of Rome, Eudossiana 18, 00184 Rome, Italy
*
Author to whom correspondence should be addressed.
Coatings 2023, 13(9), 1602; https://doi.org/10.3390/coatings13091602
Original submission received: 10 August 2023 / Revised: 31 August 2023 / Accepted: 11 September 2023 / Published: 13 September 2023
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Abstract
SiC/SiC ceramic matrix composites (SiCf/SiC CMCs) are regarded as the new materials for the hot-section components of aircraft gas turbine engines, since they have one-third of the density of metallic superalloys, a higher temperature capability, good mechanical strength, and excellent thermal shock resistance. However, high-temperature water-vapor-rich combustion gases can induce severe surface recession phenomena in SiC/SiC leading to component failure. For this reason, it is necessary to design protective coatings, i.e., environmental barrier coatings (EBCs), able to protect the SiC/SiC surface in combustion environments. In the present work, ytterbium monosilicate (Yb2SiO5), stable when exposed to water vapor at high temperatures, and ytterbium disilicate (Yb2Si2O7), characterized by a thermal expansion coefficient closer to that of the substrate, were selected for a multilayer EBC system. EBCs were processed using the atmospheric plasma spray (APS) technique. A set of deposition parameters were tested, varying the power of the torch, and the composition and microstructure of the deposited coatings were studied in terms of porosity, crack density, and post-deposition phase retention by performing SEM, EDS, and XRD analysis. The results allow for the definition of the influence of deposition parameters on the final properties of multilayer EBC coatings
Correction to: Safety and Psychological Outcomes of Tandem t:Slim X2 Insulin Pump with Control-IQ Technology in Children, Adolescents, and Young Adults with Type 1 Diabetes: A Systematic Review
No full textThe second author name was incorrectly published as Giula Maria Smylie. The correct name is Giulia Marie Smylie. The original article has been corrected
Scrivere senza anestesia. La chiarezza di Giulia Niccolai
No full textIl saggio colloca storicamente la narratrice e poetessa Giulia Niccolai nel canone del Novecento letterario italiano discutendone poetica e cifre stilistiche. L'ampia analisi proposta tocca tutte le opere dell'autrice evidenziandone i legami intertestuali, anche tra poesia e narrativa, e i progressivi sviluppi in un arco cronologico esteso, tra anni Sessanta e primi anni Duemila. Lo studio coglie anche l'importanza dei riferimenti alle arti visive, in particolare alla fotografia, che Giulia Niccolai ha praticato in prima persona negli anni della Neoavanguardia, e alla pittura americana.The essay places the narrator and poet Giulia Niccolai in the canonical twentieth century Italian literary discussing her poetics and stylistic figures. The wide analysis proposed touches all the works of the author highlighting the intertextual links, also between poetry and narrative, and the progressive developments in an extended chronological period, between the Sixties and early Twenties. The study also captures the importance of references to the visual arts, especially photography, which Giulia Niccolai has practiced in the years of the Neo-avant-garde, and to American painting
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L'afrofuturismo tra Stati Uniti e Italia. Dalla memoria storica ai viaggi intergalattici per re-immaginare futuri postumani
No full textIn this article the author explores the cultural movement called Afrofuturism, tracing its origins, features, simbology, and its historical and political meanings. Starting from the (supposed) discoursive gap between African and African American people on one side and technology and science fiction on the other, this paradigm addresses themes related to the intersection of African Diaspora and African cultures with technology and science fiction, with the aim to recover the history of slavery and racism through the projections into alternative space-time contexts. In particular, the author explores the feminist afrofuturism perspective in order to examine the specific oppression and cultural production of African and African American women. In doing so, the author analyzes the development of afrofuturism in Italy, focusing on the work of the singer and beatmaker Karima 2G
BDC-Decomposition for global influence analysis
No full textIn biochemical networks, the steady-state input-output influence is the sign of the output steady-state variation due to a persistent positive input perturbation; if the sign does not depend on the value of the strictly positive system parameters, the influence is structural. As recently shown for small perturbations, when the linearized system approximation is valid, steady-state input-output influences can be structurally assessed, for biochemical networks with m unknown parameters, by means of a vertex algorithm with complexity 2m. This letter shows that the structural input-output influence of a biochemical network is a global property, which does not require any small-perturbation assumption. It also shows that, using a new algorithm, the complexity can be reduced down to 2m-n , where n is the system order, thus drastically reducing the computation time. Finally, when the uncertain parameters belong to known intervals, non-conservative bounds are given for the steady-state ratio between output and input, allowing for sensitivity analysis.Accepted Author ManuscriptTeam Tamas Keviczk
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