Category: Nevin Manimala

Braz Dent J. 2023 Jan-Feb;34(1):80-88. doi: 10.1590/0103-6440202305129.

ABSTRACT

This study aimed to evaluate the effect of different loading conditions on the mechanical behavior and stress distribution of a leucite-reinforced glass-ceramic. Plate-shaped ceramic specimens were obtained from leucite-reinforced glass-ceramic (1.5 × 8.4 × 8.3 mm) and adhesively cemented to a dentin analog substrate. Monotonic and cyclic contact fatigue tests were performed to simulate sphere-to-flat contact, using a 6 mm diameter spherical piston; and flat-to-flat contact, using a 3 mm diameter flat piston. For the monotonic test (n=20), a gradual compressive load (0.5 mm/min) was applied to the specimen using a universal testing machine. Failure load data were analyzed with Weibull statistics. The cyclic contact fatigue test was performed using protocols (load and a number of cycles) defined by the boundary technique (n=30). Fatigue data were analyzed using an inverse power law relationship and Weibull-lifetime distribution. The stress distribution was investigated using Finite Element Analysis (FEA). The monotonic and the fatigue Weibull modulus were similar among the two contact conditions. In fatigue, the slow crack growth exponent was greater for sphere-to-flat contact, which indicates that the load level had a greater effect on the specimen’s probability of failure. In conclusion, FEA showed different stress distribution for the tested loading conditions. The stress distribution and probability of fatigue failure of specimens tested in sphere-to-flat contact showed greater dependency to load level.

PMID:36888848 | DOI:10.1590/0103-6440202305129

Braz Dent J. 2023 Jan-Feb;34(1):71-79. doi: 10.1590/0103-6440202304998.

ABSTRACT

This study aimed to investigate the failure behavior of 3 mol.% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) prosthetic crowns air-abraded with aluminum oxide (AO) particles of different sizes. Ninety ceramic premolar crowns were produced with 3Y-TZP frameworks veneered with porcelain. Crowns were randomly divided into three groups, according to the size of the air abrasion AO particles (n = 30): (GC) untreated (control); (G53) 53 µm; (G125) 125 µm. Air abrasion was performed with 0.25 mpa pressure, 10-mm distance, for 10 s. Crowns were adhesively cemented to dentin analog abutments. Specimens were loaded in compression to failure, in 37oC distilled water, using a universal testing machine (n = 30). Fractographic analysis was performed using a stereomicroscope and SEM. The roughness of the crown’s inner surface was evaluated using an optical profilometer (n = 10). Fracture load data were statistically analyzed with Weibull analysis and roughness data with Kruskal-Wallis (α = 0.05). GC had the lowest characteristic fracture load (L0), while G53 and G125 had higher and statistically similar L0 values. The Weibull modulus (m) was similar among groups. The failure modes observed were catastrophic failure and porcelain chipping. There were no differences between the roughness parameters for the experimental groups (p > 0.05). The size of the AO particles did not affect the fracture load and failure mode of 3Y-TZP crowns. Air abrasion with 53 µm and 125 µm particles resulted in a higher fracture load of ceramic crowns than the untreated group while maintaining their reliability and surface characteristics.

PMID:36888847 | DOI:10.1590/0103-6440202304998

Braz Dent J. 2023 Jan-Feb;34(1):29-38. doi: 10.1590/0103-6440202304974.

ABSTRACT

The aim of this study was to evaluate the physicochemical properties, cytotoxicity and bioactivity of a ready-to-use bioceramic material, Bio-C Repair (Angelus), in comparison with White MTA (Angelus) and Biodentine (Septodont). The physicochemical properties of setting time, radiopacity, pH, solubility, dimensional and volumetric changes were evaluated. Biocompatibility and bioactivity were assessed in Saos-2 osteoblast cell cultures by the MTT assay 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), Neutral Red (NR), Alizarin Red (ARS), and cell migration tests. Statistical analysis was performed by ANOVA, Tukey or Bonferroni tests (α = 0.05). Bio-C Repair had the longest setting time (p < 0.05), but radiopacity and solubility were accordance with the ISO 6876/2012 standards, besides linear expansion. Bio-C Repair and MTA had similar volumetric change (p > 0.05); lower than Biodentine (p < 0.05). All the materials evaluated had an alkaline pH. Bio-C Repair was cytocompatible and promoted mineralized nodule deposition in 21 days and cell migration in 3 days. In conclusion, Bio-C Repair had adequate radiopacity above 3mm Al, solubility less than 3%, dimensional expansion, and low volumetric change. In addition, Bio-C Repair promoted an alkaline pH and presented bioactivity and biocompatibility similar to MTA and Biodentine, showing potential for use as a repair material.

PMID:36888842 | DOI:10.1590/0103-6440202304974

Braz Dent J. 2023 Jan-Feb;34(1):123-132. doi: 10.1590/0103-6440202304590.

ABSTRACT

This case series included a tomographic, microbiological, and histopathological description of 15 secondary apical periodontitis (SAP) lesions obtained by apical microsurgery performed in 10 patients to better understand the etiology and pathogenesis of SAP. Preoperative tomographic analyses were performed through Cone beam computerized tomography – Periapical index (CBCT-PAI), and apical microsurgeries were then carried out. The removed apices were used for microbial culturing and for molecular identification using PCR for the detection of 5 strict anaerobic bacteria (P. gingivalis, P. intermedia, P. nigrescens, T. forsythia, and T.denticola) and 3 viruses Herpes simplex viruses (HSV), Cytomegalovirus (CMG) and Epstein-Barr Virus (EBV) by nested PCR. The removed apical lesions were histologically described. Univariate statistical analyses were performed by using STATA MP/16 (StataCorp LLC, College Station, TX, United States). CBCT-PAI analyses revealed PAI 4 and PAI 5 score lesions that involved cortical plate destruction. Eight SAPs were positive by culture, while nine SAP lesions were positive by PCR. Fusobacterium species were the most frequently cultured organisms in 7 SAP lesions, followed by D. pneumosintes in 3. In contrast, by single PCR, T. forsythia and P. nigrescens were detected in 5 lesions, T. denticola in 4 lesions, and P. gingivalis in 2 lesions. Twelve periapical lesions were granulomas, and the remaining three SAP lesions were radicular cysts. In conclusion, this case series study revealed that secondary apical lesions presented tomographic involvement of PAI 3 to 5, and that most SAP lesions were apical granulomas containing anaerobic and facultative microorganisms.

PMID:36888839 | DOI:10.1590/0103-6440202304590

Rev Bras Ter Intensiva. 2022 Oct-Dec;34(4):507-518. doi: 10.5935/0103-507X.20220145-pt.

ABSTRACT

OBJECTIVE: To verify strategies for the prevention and treatment of abstinence syndrome in a pediatric intensive care unit.

METHODS: This is a systematic review in the PubMed database®, Lilacs, Embase, Web of Science, Cochrane, Cinahl, Cochrane Database Systematic Review and CENTRAL. A three-step search strategy was used for this review, and the protocol was approved in PROSPERO (CRD42021274670).

RESULTS: Twelve articles were included in the analysis. There was great heterogeneity among the studies included, especially regarding the therapeutic regimens used for sedation and analgesia. Midazolam doses ranged from 0.05mg/kg/hour to 0.3mg/kg/hour. Morphine also varied considerably, from 10mcg/kg/hour to 30mcg/kg/hour, between studies. Among the 12 selected studies, the most commonly used scale for the identification of withdrawal symptoms was the Sophia Observational Withdrawal Symptoms Scale. In three studies, there was a statistically significant difference in the prevention and management of the withdrawal syndrome due to the implementation of different protocols (p < 0.01 and p < 0.001).

CONCLUSION: There was great variation in the sedoanalgesia regimen used by the studies and the method of weaning and evaluation of withdrawal syndrome. More studies are needed to provide more robust evidence about the most appropriate treatment for the prevention and reduction of withdrawal signs and symptoms in critically ill children.

PROSPERO REGISTER: CRD 42021274670.

PMID:36888832 | DOI:10.5935/0103-507X.20220145-pt

Rev Peru Med Exp Salud Publica. 2022 Oct-Dec;39(4):474-479. doi: 10.17843/rpmesp.2022.394.11992. Epub 2023 Mar 6.

ABSTRACT

Motivation for the study: there is a lack of studies in Latin America on the frequency of metabolic syndrome in patients who receive liver transplants. Main findings: two-thirds (66%) of patients who received liver transplantation between 2013 and 2017 at the Specialized Center San Vicente Fundación de Rionegro, Antioquia, Colombia, subsequently presented metabolic syndrome. Implications: this study confirms that liver transplant recipients very frequently develop metabolic syndrome; however, the frequency found by this study (66%) was almost double that reported in other regions of the world, suggesting that patients from the Specialized Center San Vicente Fundación de Rionegro, Antioquia, Colombia, may present some additional condition. The medical records of all liver transplant patients attended at the Centro Especializado San Vicente Fundación between January 2013 and June 2017 were reviewed in order to determine the frequency of post-transplant metabolic syndrome (MS). We collected sociodemographic data, pathological history, toxicological history, complications, and ATP III criteria in a validated instrument. The statistical analysis was carried out with OpenEpi 3.01; p<0.05 was considered as statistically significant. Of the 102 reviewed medical records, 73 met the inclusion criteria (no MS diagnosis prior to transplant and complete information for the instru-ment) and were analyzed. Most patients were male (59%), older adults (64%) and married (62%). The frequency of MS after liver transplant was 66%. The association between MS and history of hypertension and diabetes was significant. We confirmed that MS is a frequent complication in liver transplant recipients and that history of hypertension and diabetes are the most frequent associated factors.

PMID:36888811 | DOI:10.17843/rpmesp.2022.394.11992

Rev Lat Am Enfermagem. 2023 Jan-Dec;31:e3831. doi: 10.1590/1518-8345.6123.3831.

ABSTRACT

OBJECTIVE: to analyze the psychosocial impacts of the COVID-19 pandemic among Brazilian women from rural settlements.

METHOD: this is a quantitative and longitudinal study conducted with 13 settled women. The data were collected between January 2020 and September 2021 using questionnaires on the perception of the social environment (quality of life, social support, self-efficacy), common mental disorder symptoms and sociodemographic aspects. The data were analyzed using descriptive statistics, cluster analysis and variance analysis.

RESULTS: intersecting vulnerability conditions were identified that possibly intensified the challenges arising from the pandemic. The Quality of Life physical domain fluctuated differently and inversely according to the mental disorder symptoms. As for the psychological domain, at the end of the segment, an increase over time was identified in the entire sample, as the women’s perception was better than before the pandemic.

CONCLUSION: worsening of the participants’ physical health deserves to be highlighted and, probably, it can be related to the difficulty accessing health services in this period as well as to the fear of contamination. Despite this, the participants were emotionally resilient throughout the period, including signs of improvement in terms of psychological aspects, suggesting a possible effect of the community organization of the settlement.

PMID:36888794 | DOI:10.1590/1518-8345.6123.3831

Arq Bras Cardiol. 2023 Feb;120(2):e20220294. doi: 10.36660/abc.20220294.

ABSTRACT

BACKGROUND: Early risk stratification with simple biomarkers is essential in patients with non-ST segment-elevation myocardial infarction (NSTEMI).

OBJECTIVE: This study aimed to evaluate the association between plasma big endothelin-1 (ET-1) level and the SYNTAX score (SS) in patients with NSTEMI.

METHODS: A total of 766 patients with NSTEMI undergoing coronary angiography were recruited. Patients were divided into three groups: low SS (≤22), intermediate SS (23-32), and high SS (>32). Spearman correlation, smooth curve fitting, logistic regression, and receiver operating characteristic (ROC) curve analysis were performed to evaluate the association between plasma big ET-1 level and the SS. A p-value <0.05 was considered statistically significant.

RESULTS: There was a significant correlation between the big ET-1 and the SS (r=0.378, p<0.001). The smoothing curve indicated a positive correlation between the plasma big ET-1 level and the SS. The ROC curve analysis showed that the area under the curve was 0.695 (0.661-0.727) and the optimal cutoff of plasma big ET-1 level was 0.35pmol/l. Logistic regression showed that elevated big ET-1 was an independent predictor of intermediate-high SS in patients with NSTEMI, whether entered as a continuous variable [OR (95% CI): 1.110 (1.053-1.170), p<0.001] or as a categorical variable [OR (95% CI): 2.962 (2.073-4.233), p<0.001].

CONCLUSION: In patients with NSTEMI, the plasma big ET-1 level was significantly correlated with the SS. Elevated plasma big ET-1 level was an independent predictor for intermediate-high SS.

PMID:36888778 | DOI:10.36660/abc.20220294

Arq Bras Cardiol. 2023 Feb;120(2):e20220070. doi: 10.36660/abc.20220070.

ABSTRACT

BACKGROUND: The increase of hypertension in children and adolescents has attracted the attention of the scientific community largely due to its association with the obesity epidemic.

OBJECTIVES: To describe the incidence of hypertension and its relationship with the cardiometabolic and genetic profile in children and adolescents from a city in southern Brazil in a three-year period.

METHODS: This longitudinal study followed 469 children and adolescents, aged 7-17 years old (43.1% boys), assessed at two-time points. We evaluated systolic and diastolic blood pressures (SBP and DBP), waist circumference (WC), body mass index (BMI), body fat percentage (%BF), lipid profile, glucose, cardiorespiratory fitness (CRF), and rs9939609 Polymorphism ( FTO ). Cumulative incidence of hypertension was calculated, and multinomial logistic regression was conducted. The statistical significance was established as p < 0.05.

RESULTS: After three years, the incidence of hypertension was 11.5%. Overweight or obese individuals were more likely to become borderline hypertensive (overweight OR: 3.22, 95% CI: 1.08-9.55; obesity OR: 4.05, 95% CI: 1.68-9.75), and obese individuals were more likely to become hypertensive (obesity OR: 4.84, 95% CI: 1.57-14.95). High-risk WC and %BF values were associated with hypertension development (OR: 3.41, 95% CI: 1.26-9.19; OR: 2.49, 95% CI: 1.08-5.75, respectively).

CONCLUSIONS: We found a higher incidence of hypertension in children and adolescents as compared with previous studies. Individuals with higher values of BMI, WC and %BF at baseline were more likely to develop hypertension, suggesting the importance of adiposity in the development of hypertension even in such a young population.

PMID:36888776 | DOI:10.36660/abc.20220070

Acta Cir Bras. 2023 Mar 6;38:e380623. doi: 10.1590/acb380623. eCollection 2023.

ABSTRACT

PURPOSE: To evaluate the in vivo efficiency of commercial polymeric membranes for guided bone regeneration.

METHODS: Rat calvarial critical size defects was treated with LuminaCoat (LC), Surgitime PTFE (SP), GenDerm (GD), Pratix (PR), Techgraft (TG) or control (C-) and histomorphometric analysis determined the percentage of new bone, connective tissue and biomaterial at 1 or 3 months. Statistical analysis used ANOVA with Tukey’s post-test for means at same experimental time and the paired Student’s t test between the two periods, considering p < 0.05.

RESULTS: New bone at 1 month was higher for SP, TG and C-, at 3 months there were no differences, and between 1 and 3 months PR had greater increase growthing. Connective tissue at 1 month was higher for C-, at 3 months for PR, TG and C-, and between 1 and 3 months C- had sharp decline. Biomaterial at 1 month was higher for LC, in 3 months for SP and TG, and between 1 and 3 months, LC, GD and TG had more decreasing mean.

CONCLUSIONS: SP had greater osteopromotive capacity and limitation of connective ingrowth, but did not exhibit degradation. PR and TG had favorable osteopromotion, LC less connective tissue and GD more accelerated biodegradation.

PMID:36888756 | DOI:10.1590/acb380623