Effect of Additional Dry Heat Curing on Microflexural Strength in Three Types of Resin Composite: An In Vitro Study

Aim: Additional dry heat curing is a method that favorably influences the mechanical properties of an indirect resin composite restoration. Microflexural strength is a property currently applied for the evaluation of indirect resin composite restorations. The aim of the present study was to assess the effect of additional dry heat curing on microflexural strength in three types of direct-use resin composites. Materials and Methods: This in vitro study consisted of 70 resin composites samples made with a 6 × 2 × 1 mm metal matrix and divided into seven experimental groups, which included Gr1a: Tetric N-Ceram without additional dry heat curing (n = 10); Gr1b: Tetric N-Ceram with additional dry heat curing (n = 10); Gr 2a: Filtek Z350 XT without additional dry heat curing (n = 10); Gr2b: Filtek Z350 XT with additional dry heat curing (n = 10); Gr3a: Filtek Z250 without additional dry heat curing (n = 10); Gr3b: Filtek Z250 with additional dry heat curing (n = 10); and Gr4: SR Nexco Paste (control) without additional dry heat curing (n = 10). The samples were stored in distilled water at 37 °C for 24 h. A universal testing machine with a 2000 N load cell at a speed of 1 mm/min was used to assess flexural strength. The data were analyzed with a parametric ANOVA test with Tukey’s post hoc intergroup factor (for groups without heat treatment) and a nonparametric Kruskall Wallis test with Bonferroni’s post hoc (for groups with heat treatment). In addition, the comparison of independent groups in each resin composite type with and without heat treatment was performed with a Mann Whitney U test. A significance level of p < 0.05 was considered. Results: The Filtek Z250 resin composite with and without additional dry heat curing presented the highest microflexural strength values with 137.27 ± 24.43 MPa and 121.32 ± 9.74 MPa, respectively, while the SR Nexco Paste (control) resin composite presented the lowest microflexural strength values with 86.06 ± 14.34 MPa compared to all the resin composites with additional dry heat curing. The Filtek Z250 and Filtek Z350XT resin composites with and without additional dry heat curing presented significantly higher microflexural strength versus the SR Nexco (p < 0.05) and Tetric N-Ceram (p < 0.05) resin composites. In addition, the Filtek Z350XT and Tetric N-Ceram resin composites with additional dry heat curing showed significantly higher microflexural strength (p < 0.05) compared to those without additional dry heat curing. Conclusions: The Filtek Z250 and Z350XT resin composites had significantly higher microflexural strength values with and without additional dry heat curing. In addition, the Filtek Z350XT and Tetric N-Ceram resin composites subjected to additional dry heat curing showed significantly higher microflexural strength compared to when they did not receive the same procedure, a situation that did not occur with the Filtek Z250 resin composite.Revisión por pare

Anti-Spike antibodies 3 months after SARS-CoV-2 mRNA vaccine booster dose in patients on hemodialysis: the prospective SENCOVAC study

Background: Patients on hemodialysis are at high-risk for complications derived from coronavirus disease 2019 (COVID-19). The present analysis evaluated the impact of a booster vaccine dose and breakthrough severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections on humoral immunity 3 months after the booster dose. Methods: This is a multicentric and prospective study assessing immunoglobulin G anti-Spike antibodies 6 and 9 months after initial SARS-CoV-2 vaccination in patients on hemodialysis that had also received a booster dose before the 6-month assessment (early booster) or between the 6- and 9-month assessments (late booster). The impact of breakthrough infections, type of vaccine, time from the booster and clinical variables were assessed. Results: A total of 711 patients [67% male, median age (range) 67 (20-89) years] were included. Of these, 545 (77%) received an early booster and the rest a late booster. At 6 months, 64 (9%) patients had negative anti-Spike antibody titers (3% of early booster and 29% of late booster patients, P =. 001). At 9 months, 91% of patients with 6-month negative response had seroconverted and there were no differences in residual prevalence of negative humoral response between early and late booster patients (0.9% vs 0.6%, P =. 693). During follow-up, 35 patients (5%) developed breakthrough SARS-CoV-2 infection. Antibody titers at 9 months were independently associated with mRNA-1273 booster (P =. 001), lower time from booster (P =. 043) and past breakthrough SARS-CoV-2 infection (P <. 001). Conclusions: In hemodialysis patients, higher titers of anti-Spike antibodies at 9 months were associated with mRNA-1273 booster, lower time from booster and past breakthrough SARS-CoV-2 infectionThe present project has been supported by Fresenius Medical Care, Diaverum, Vifor Pharma, Vircell, Fundación Renal Iñigo Álvarez de Toledo and ISCIII FEDER funds RICORS2040 (RD21/0005

Miedo al Covid-19 y su asociación con los niveles de ansiedad, depresión y estrés en estudiantes de odontología

Objetivo: El objetivo fue evaluar el miedo al COVID-19 y su asociación con depresión, ansiedad y estrés en estudiantes de odontología peruanos, según sus factores sociodemográficos. Método: Este estudio observacional y transversal se realizó en 398 estudiantes de odontología. Se utilizó la escala DASS-21 para diagnosticar depresión, ansiedad y estrés. Se utilizó la escala FCV-19S para detectar el miedo al COVID-19. Se usó el chi-cuadrado de Pearson y el modelo logístico mediante odds ratio (OR) para evaluar la depresión, ansiedad y estrés de los estudiantes con los factores asociados. Se consideró un nivel de significación de p<0,05. Resultados: Los estudiantes que tenían miedo al COVID-19 tenían OR = 2,74; (intervalo de confianza [IC] 95%: 1,62 - 4,64), OR = 5,59 (IC: 3,14 - 9,97) y OR = 3,31 (IC: 1,88 - 5,83), para desarrollar depresión, ansiedad y estrés, respectivamente. Además, quienes reportaron antecedentes de enfermedad mental tenían cuatro veces más probabilidades de desarrollar depresión (OR = 4,02; IC: 1,96 - 8,25) y ansiedad (OR = 4,50; IC: 2,06 - 9,82), mientras que quienes vivían con personas vulnerables a COVID-19 tenían el doble de probabilidades de desarrollar estrés (OR = 2,06; IC: 1,16 - 3,66). Conclusión: Quienes tenían miedo al COVID-19 presentaron tres veces más probabilidades de desarrollar depresión y estrés, y cinco veces más de desarrollar ansiedad. Por otro lado, el factor más influyente para depresión y ansiedad fue el antecedente de enfermedad mental, mientras que el factor de convivencia con personas vulnerables fue el más influyente para estrés

Sociodemographic factors associated with the level of knowledge about management of epileptic patients in Peruvian dental students: a cross-sectional study under a multivariable analysis

Background: Epilepsy is a chronic neurological disease that could indirectly affect oral health, and it is necessary for dentists to be familiar with the specific needs of patients with epilepsy. Therefore, aim of the present study was to assess the factors associated with the level of knowledge about management of epileptic patients in Peruvian dental students. Methods: This analytical, observational, cross-sectional and prospective study assessed 312 dental students from a Peruvian university during February to April 2022. A validated questionnaire of 20 closed multiple-choice questions was used to measure the level of knowledge about dental management in epileptic patients. A logit model was used to assess the influence of variables: gender, age, year of study, marital status, place of origin and area of residence, with the level of knowledge in dental students considering a significance level of p 0.05). Conclusion: Most of the students showed a poor and fair level of knowledge about the dental management of epileptic patients, with gender, academic year and place of origin being influential factors. It is advisable that authorities and teachers in the dental profession organize recurrent training programs on the care of patients with chronic diseases requiring special attention, since knowing general concepts, pharmacological management and dental care of epileptic patients will allow future dentists to develop competencies to improve and implement good quality care protocols for this group of patients.Revisión por pare

Adhesive Strength in Dentin Conditioned with 18% Ethylenediaminetetraacetic Acid versus 35% Phosphoric Acid: In Vitro Study with 1-Year Artificial Aging

The success and longevity of a resin composite restoration is determined by its good bonding to the tooth structure, with the adhesion being a challenge to dentin due to its complexity and structural heterogeneity. The present study aimed to compare the adhesive strength of dentin conditioned with 18% ethylenediaminetetraacetic acid (EDTA) versus 35% phosphoric acid (H3PO4) in human premolars. Materials and Methods: This in vitro experimental study was performed on 40 human premolars. The occlusal thirds were sectioned and randomly placed into four groups according to the type of dentin conditioning: Group 1 (control), Group 2 (18% EDTA), Group 3 (35% H3PO4) and Group 4 (18% EDTA plus 35% H3PO4). Then, 10,000 thermocycles between 5 +/&minus; 2 &deg;C and 55 +/&minus; 2 &deg;C were applied. Adhesive strength was tested by shearing with a digital universal testing machine at a crosshead speed of 0.75 mm/min. The values obtained were analyzed in megapascals (MPa). The mean and standard deviation were used as measures of central tendency and dispersion. In addition, a one-factor intergroup ANOVA test was applied with Tukey&rsquo;s post hoc test considering a significance level of p &lt; 0.05. Results: The 18% EDTA and 18% EDTA plus 35% H3PO4 showed significantly higher adhesive strength compared to the control group that did not receive dentin conditioning (p = 0.047 and p &lt; 0.001, respectively). However, the group conditioned with 18% EDTA did not present significant differences compared to the group conditioned with 35% H3PO4 (p = 0.997). In addition, the group conditioned with 18% EDTA plus 35% H3PO4 showed significantly higher adhesive strength compared to the groups conditioned with 18% EDTA (p = 0.002) and 35% H3PO4 (p = 0.001). Conclusion: The adhesion of bulk fill resin composite to dentin was favorable when preconditioning was performed using 18% EDTA followed by 35% H3PO4. In contrast, when both etchants were used separately, the bulk fill resin composite showed similar bond strength values in both cases, but significantly lower compared to their sequential application

Surface Microhardness of Bulk-Fill Resin Composites Handled With Gloves

ABSTRACT: Aim: It has been reported that resin composites may experience alterations in their mechanical properties when they come into contact with glove powder. Therefore, the present study aimed to compare the surface microhardness of 3 bulk-fill resin composites handled with latex and nitrile gloves prior to light curing. Methods: This in vitro experimental study consisted of 90 resin composite specimens with a 6-mm diameter and a 4-mm height divided equally and randomly into 9 groups. Prior to light curing, the resin composites were handled with latex gloves, nitrile gloves, or only a spatula (control). Subsequently, the surface microhardness was measured with an Electronic Vickers Hardness Tester. The Kruskal–Wallis nonparametric H test with Bonferroni correction was used for comparisons. A significance level of 5% (P < .05) was considered. Results: When comparing surface microhardness of each resin composite according to type of handling received, significant differences were observed in Filtek One Bulk Fill (P < .001) and Opus Bulk Fill (P < .001). In addition, these resin composites presented significantly higher surface microhardness than Tetric N-Ceram Bulk Fill resin (P < .05) when handled with latex gloves, nitrile gloves, and only a spatula. Finally, Filtek Bulk Fill resin presented significantly higher surface microhardness compared to Opus Bulk Fill resin when handled with nitrile gloves (P = .038) and a spatula only (P = .033). Conclusions: The surface microhardness of Filtek One Bulk Fill and Opus Bulk Fill resin composites decreased significantly when handled with latex or nitrile gloves, showing no variation in Tetric N-Ceram Bulk Fill resin composite. In addition, Filtek One Bulk Fill resin composite showed significantly higher surface microhardness than Opus Bulk Fill and Tetric N-Ceram Bulk Fill resin composites when handled with nitrile gloves. It is recommended that bulk-fill resin composites be handled with a spatula, because the use of latex or nitrile gloves could adversely affect their clinical performance

XVII International Congress of Control Electronics and Telecommunications: "Advanced Science, Technology and Innovation to move towards a new socio-technical system: Sustainable Social Transformation"

Contenido: Approach to the diagnostic of cesarean birth using bio-inspired models. ; Design of a tool in a virtual reality environment to manipulate anatomical models. ; The effect of COVID-19 restrictions on the electricity price forecasting models. ; Depression prevention through artificial intelligence. ; State of the art in Prototypes as complements to the learning of the Colombian Sign Language (LSC). ; A computational proposal for gene expression deterministic analysis in associated disorders to depression and anxiety. ; Evaluation of postural stability from the predictability of the measurement of the center of pressure. ; Psychophysiological Analysis of Sound Stimuli.; Delphi method for the identification of relevant variables in the development of low-power photovoltaic solar projects. ; Socioeconomic impact of a refrigerator powered by a photovoltaic system in La Guajira. ; Energy Efficiency: characteristics that allow the reduction of greenhouse gases in. ; Possibilities for the implementation of a bioreactor from organic waste. ; Energy Potential with Small Hydroelectric Power Plants in Non- interconnected Zones of Colombia. ; Energy Potential in Photovoltaic Solar Solutions in Non-Interconnected Areas of Colombia. ; Photovoltaic system, towards the energy transition from home. ; Blockchain model to increase the transparency of public sector processes. ; Intelligent agricultural irrigation prescription system based on sensor networks and crop modeling. ; Design and implementation of a digital modulation classification system using intelligent algorithms. ; A mobile application proposal to minimize intermediation during agricultural process distribution of products in supply chain. ; Accompanying strategy for the social appropriation of new technologies in vulnerable agricultural communities: case in communities producing Gulupas fruits (Passiflora edulis Sims). ; Predictive model of transparency as an indicator of Public Policies. ; Smart system for recognition of ripening level in blackberry fruits. ; Project-based learning as an alternative methodology for technological education in electronics. ; Design and construction of an automated system for N. ; Four bar mechanisms (FBM) and their Software-Based applications: a reviewFT aquaponic culture of Red Carp and Crespa Lettuce. ; Intelligent search implementation for the construction of states of the art: a python application. ; Indoor and Outdoor propagation models on 5G environments: state of the art. ;The electronic detection of offenders (DOO) in the District Secretary of mobility of Bogotá: a step forward in the configuration of the concept of digital citizenship in Colombia. ; Monitoring through ICT of Mobility: technological collaborative feature to incorporate IoT in a Smart City. ; Characterization model of asphalt mixtures using digital image processing. ; Review: identification of diseases and/or pests in fruit trees through image processing techniques and artificial intelligence. ; VRS applicated to Nasa Yuwe language. ; Application of Pix2Pix for edge reconstruction in images. ; Brushless DC Motor Control System for Active Myoelectric Prosthesis. ; Implementation of a Water Conductivity Measuring System. ; 2 DOF robot programmed with MatLab® (guide and Peter Corke) and Arduino uno for writing alphabetical characters. ; Simulator of the behavior of the center of mass in a quadruped robot. ; Biomimetic prototype for flapping movement of batsContent: Contenido: Approach to the diagnostic of cesarean birth using bio-inspired models. ; Design of a tool in a virtual reality environment to manipulate anatomical models. ; The effect of COVID-19 restrictions on the electricity price forecasting models. ; Depression prevention through artificial intelligence. ; State of the art in Prototypes as complements to the learning of the Colombian Sign Language (LSC). ; A computational proposal for gene expression deterministic analysis in associated disorders to depression and anxiety. ; Evaluation of postural stability from the predictability of the measurement of the center of pressure. ; Psychophysiological Analysis of Sound Stimuli.; Delphi method for the identification of relevant variables in the development of low-power photovoltaic solar projects. ; Socioeconomic impact of a refrigerator powered by a photovoltaic system in La Guajira. ; Energy Efficiency: characteristics that allow the reduction of greenhouse gases in. ; Possibilities for the implementation of a bioreactor from organic waste. ; Energy Potential with Small Hydroelectric Power Plants in Non- interconnected Zones of Colombia. ; Energy Potential in Photovoltaic Solar Solutions in Non-Interconnected Areas of Colombia. ; Photovoltaic system, towards the energy transition from home. ; Blockchain model to increase the transparency of public sector processes. ; Intelligent agricultural irrigation prescription system based on sensor networks and crop modeling. ; Design and implementation of a digital modulation classification system using intelligent algorithms. ; A mobile application proposal to minimize intermediation during agricultural process distribution of products in supply chain. ; Accompanying strategy for the social appropriation of new technologies in vulnerable agricultural communities: case in communities producing Gulupas fruits (Passiflora edulis Sims). ; Predictive model of transparency as an indicator of Public Policies. ; Smart system for recognition of ripening level in blackberry fruits. ; Project-based learning as an alternative methodology for technological education in electronics. ; Design and construction of an automated system for N. ; Four bar mechanisms (FBM) and their Software-Based applications: a reviewFT aquaponic culture of Red Carp and Crespa Lettuce. ; Intelligent search implementation for the construction of states of the art: a python application. ; Indoor and Outdoor propagation models on 5G environments: state of the art. ;The electronic detection of offenders (DOO) in the District Secretary of mobility of Bogotá: a step forward in the configuration of the concept of digital citizenship in Colombia. ; Monitoring through ICT of Mobility: technological collaborative feature to incorporate IoT in a Smart City. ; Characterization model of asphalt mixtures using digital image processing. ; Review: identification of diseases and/or pests in fruit trees through image processing techniques and artificial intelligence. ; VRS applicated to Nasa Yuwe language. ; Application of Pix2Pix for edge reconstruction in images. ; Brushless DC Motor Control System for Active Myoelectric Prosthesis. ; Implementation of a Water Conductivity Measuring System. ; 2 DOF robot programmed with MatLab® (guide and Peter Corke) and Arduino uno for writing alphabetical characters. ; Simulator of the behavior of the center of mass in a quadruped robot. ; Biomimetic prototype for flapping movement of bat