Bovine hydroxyapatite/3Y-TZP bioceramic: Aligning 3Y-TZP content with sintering parameters.

This study aimed to produces and characterize bovine hydroxyapatite (HA) bioceramic with 3Y-TZP addition and analyze different sintering curves. HA was extracted from bovine bones and nanoparticulated. HA discs (0, 1, 5 and 10 wt% 3Y-TZP) were subjected to uniaxial and isostatic pressing. Dilatometry analysis was performed and the groups were sintered using 3 different firing curves (conventional, 1300 °C; 2-step, 1292 °C; 2-step, 1420 °C). The samples were analyzed by X-ray diffraction (XRD), biaxial flexural strength (BFS), Vickers microhardness (VH) and Field emission scanning electron microscopy (FE-SEM). The dilatometry results signaled the need for sintering optimization in groups added with 3Y-TZP. XRD demonstrated the characteristic crystallographic peaks of HA in the pure groups and with 1% 3Y-TZP, and decomposition of HA into ß-TCP and formation of calcium zirconate in the groups with 5 and 10% 3Y-TZP. Considering each composition, the groups of pure HA (131.3 ± 13.5 MPa; 401 ± 12.7 GPa) sintered by the conventional curve and HA+1%3Y-TZP (145 ± 8.6 MPa; 507 ± 47.9 GPa), HA+5%3Y-TZP (68.1 ± 14.2 MPa; 183 ± 9.8 GPa) and HA+10%3Y-TZP (55.6 ± 5.1 MPa; 96.1 ± 7.64 GPa) sintered by the 2-step curve at 1420 °C, combined the best BFS and VH results. The addition of 1 wt% 3Y-TZP and optimization in the sintering process improved the mechanical and microstructural properties of HA bioceramics and maintenance of its crystalline characteristics. Refinement in material processing is necessary for the future use of this bioceramic in dentistry.

Systemic and oral abnormalities in Kabuki syndrome: a case series.

OBJECTIVE: This study analyzed the systemic and oral abnormalities in individuals with Kabuki syndrome (KS) that might be investigated to enhance the early diagnosis and treatment by a multidisciplinary team, minimizing the consequences to the individual's health. STUDY DESIGN: Clinical examination was conducted on 15 individuals to investigate orodental alterations such as tooth abnormalities and cleft lip and/or palate, and the patient records were also reviewed to investigate systemic diseases such as cardiopathies, infectious and immunologic diseases, nephropathies, and delayed neuropsychomotor development. RESULTS: All individuals with KS presented cleft lip and/or palate, 11 (73.34%) tooth abnormalities, 5 (33.34%) congenital cardiopathies, 12 (80%) infectious or immunologic diseases, 1 (6.67%) nephropathy, and 14 (93.34%) had an intellectual disability. CONCLUSION: Individuals with KS often have dental anomalies such as hypodontia, cleft or palate, and systemic disorders such as congenital heart disease and infectious diseases. Intellectual disability is present in most cases. These alterations should be investigated as early as possible to prevent the increase in morbidity in these individuals.

TiO2 nanoparticles added to dense bovine hydroxyapatite bioceramics increase human osteoblast mineralization activity.

OBJECTIVES: This study evaluated the effect of TiO2 nanoparticles + dense hydroxyapatite (HA) on human osteoblast cells (SAOS-2). METHODS: Particulate bovine HA powder with or without the addition of either 5 or 8 % TiO2 (HA, HA/TiO2Np5 % or HA/TiO2Np8 %) were pressed into disks (Ø = 12.5 mm; thickness = 1.3 mm) uniaxially (100 MPa) and isostatically (200 MPa/1 min) and sintered at 1300 °C. Y-TZP disks were used as control. The following tests were performed: Scanning Electron Microscopy and Dispersive Energy Spectroscopy (SEM/EDS), Atomic Force Microscopy (AFM), cell viability assay (Alamar Blue-AB) and mineralized matrix deposition (Alizarin Red-AR). AB and AR data were submitted to 2-way ANOVA/Tukey tests and ANOVA/Tukey tests, respectively. RESULTS: SEM revealed that the surface of HA/TiO2Np5% resembles DPBHA surface, but also contains smaller granules. HA/TiO2Np8% characteristics resembles HA/TiO2Np5% surface, but with irregular topography. Y-TZP showed a typical oxide ceramic surface pattern. EDS revealed Ca, O, and P in all samples. C, O, and Zr appeared in Y-TZP samples. AFM data corroborates SEM analysis. AB test revealed excellent cellular viability for HA/TiO2Np5% group. AR test showed that all groups containing TiO2np had more mineralized matrix deposition than all other groups, with statistically differences between HA/TiO2Np8% and HA cultivated in non-osteogenic medium. Culture in osteogenic medium exhibited much more mineralized matrix deposition by TiO2np groups. SIGNIFICANCE: In conclusion, the addition of TiO2np showed chemical, superficial, and biological changes in the reinforced materials. HA/TiO2Np5% showed the best results for cell viability and HA/TiO2Np8% for mineralized matrix deposition.

Tooth movement, orofacial pain, and leptin, interleukin-1ß, and tumor necrosis factor-α levels in obese adolescents.

OBJECTIVES: To evaluate tooth movement, orofacial pain, and leptin, interleukin (IL)-1ß, and tumor necrosis factor (TNF)-α cytokine levels in the gingival crevicular fluid (GCF) during orthodontic treatment in obese adolescents. MATERIALS AND METHODS: Participants included adolescent patients aged 12-18 years: group 1, obese (n = 30), and group 2, nonobese controls (n = 30). They were evaluated before (T0) and after 1 hour (T1), 24 hours (T2), and 1 week (T3) of fixed appliance bonding. Periodontal examination (T0), collection of GCF (T1, T2, T3), and evaluation of Little's irregularity index (T0, T3) were performed, and a visual analog scale was used to measure pain (T1, T2, T3). Evaluation of IL-1ß, TNF-α, and leptin cytokines was performed using a Luminex assay. Mann-Whitney and t-tests were used for intergroup comparisons, and a generalized estimating equation and cluster analyses were used for comparisons among observation times (P < .05). RESULTS: The obese group had a higher prevalence of probing depth of ≥4 mm and bleeding on probing. Orthodontic tooth movement was similar in both groups. Peak of pain was at T2 in both groups and was higher in the obese patients. TNF-α showed a slight increase at T1, followed by a gradual decrease at T2 and T3 in both groups. The obese group had a higher concentration of IL-1ß before and during orthodontic treatment. There was no difference in tooth movement between obese and control patients during the first week of orthodontic treatment. CONCLUSIONS: Obese adolescents had a greater subjective report of orofacial pain after 24 hours of orthodontic treatment and higher concentrations of IL-1ß proinflammatory cytokine before and during tooth movement as compared with nonobese control adolescents.

Can sterilization methods influence surface properties of resin composites? A purpose for previewing bias in laboratory bacterial adhesion tests.

This study aimed to evaluate the influence of sterilization methods on conventional and bulk-fill resin composites' (BFRCs) surface properties in an attempt to preview bias in laboratory bacterial adhesion tests. Two regular viscosity conventional resin composites [Filtek Z350 XT™ (Z350) and IPS Empress Direct™ (ED)] and two regular viscosity BFRCs [Filtek Bulk Fill™ (FILT) and Tetric N-Ceram Bulk Fill IVA™ (TBF)] were used. The materials were characterized by Scanning Electron Microscopy (SEM), surface roughness (SR), and wettability (W) after sterilization with hydrogen peroxide gas plasma (HPGP) and steam sterilization (SS). Nonsterilized samples served as a control group (n = 5). Statistical analysis was performed using two-way analysis of variance (ANOVA) and Tukey post hoc test (p < 0.05). For SR, there were no statistically significant differences among the groups (p > .05). SS method decreased the contact angle for FILT and Z350 (p < .01). The SS promoted more exposition of filler particles, while the HPGP method did not alter the tested materials' morphology. Therefore, sterilization methods affected the resin composites tested selectively. HPGP seems to be the most recommended method to sterilize the tested resin composites before laboratory bacterial adhesion tests.

Nanoparticle-modified PMMA to prevent denture stomatitis: a systematic review.

This systematic review aimed to evaluate the antifungal effectiveness of polymethylmetacrylate (PMMA) modified by nanoparticles (NPs) and to compare it with conventional acrylic resins for denture bases. The present study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Searches were performed using PubMed, SCOPUS, SciELO, EMBASE, and LILACS. Eligibility criteria were as recommended by PRISMA. The studies presented great variability regarding NP type, synthesis method, antifungal evaluation method, and antifungal effect. The most commonly used NPs were silver (AgNP) and zinc oxide (ZnONP), ranging in size from 10 to 100 nm. The incorporation methods were mechanical or agitated. Despite PMMA modification by ZnONP being shown in vitro to be a combination with the best antifungal effect, future studies are still needed to determine the minimum inhibitory concentration for Candida spp. and assess its biocompatibility before the protocol is clinically tested.

Bonding performance and mechanical properties of flowable bulk-fill and traditional composites in high c-factor cavity models.

OBJECTIVES: The aim of this study is to evaluate bond strength (BS), shrinkage stress (SS), flexural strength (FS), and elastic modulus (E) of three flowable bulk fill in comparison with conventional composites. MATERIALS AND METHODS: Three bulk fill (Filtek Bulk Fill Flow, Surefil SDR, X-tra Base) and three conventional composites (Filtek Z250 XT, Grandioso, Dentsply TPH3) were used. For BS, conical cavities (n = 10) were prepared in bovine dentine and restored with materials and were analyzed through push-out test in a universal testing machine (UTM). For FS/EM, 60 (n = 10) bar specimens (7 mm × 2 mm × 1 mm) were prepared and evaluated with a UTM. SS was measured in UTM coupled to an extensometer (n = 5). The data were statistically evaluated using one-way ANOVA/Tukey tests (P < 0.05). RESULTS: Conventional composites showed higher E when compared to bulk-fill composites. Regarding FS, they showed similar results, except for (XBF) Xtra Bulk Fill that was inferior. SS and BS of bulk-fill composites were significantly lower and higher than conventional composites, respectively, except for XBF, which showed similar BS to conventional ones. CONCLUSIONS: Flowable bulk-fill composites, except XBF, showed higher BS, lower SS, similar FS, and lower E when compared to conventional ones.

Coronavirus (SARS-CoV-2) and the risk of obesity for critically illness and ICU admitted: Meta-analysis of the epidemiological evidence.

OBJECTIVES: To investigate the relationship between coronavirus disease 2019 (COVID-19) and obesity in critically ill patients admitted to the intensive care unit (ICU). METHODS: We systematically searched PubMed, SCOPUS, Embase, LILACS, and Web of Science for studies published up to April 27, 2020. The outcome of interest was composite poor outcome, comprising mortality and severe COVID-19. We used a standardized data extraction form to collect information from published reports of eligible studies. Heterogeneity and publication bias were assessed using I2 statistic and funnel plots, respectively. RESULTS: Nine studies including 6577 patients were selected for evaluation. The COVID-19 patients were 59.80% male and had comorbidities such as hypertension (51.51%), diabetes (30.3%), cardiovascular disease (16.66%), lung disease (15.99%), renal disease (7.49%), cancer (5.07%), and immunosuppression (1.8%). For patients with severe complications, the overall pooled event rates were 56.2% (random; 95% CI: 35.3-75.1; p = 0.015; I2 = 71.461) for obesity, 23.6% (random; 95% CI: 17.9-30.5; p = 0.000; I2 = 87.705) for type 2 diabetes, 45.9% (random; 95% CI: 38.0-53.9; p = 0.000; I2 = 90.152) for hypertension, 20.0% (random; 95% CI: 7.9-42.0; p = 0.000; I2 = 94.577) for smoking, 21.6% (random; 95% CI: 14.1-31.4%; p = 0.000, I2 = 92.983) for lung diseases, and 20.6% (random; 95% CI: 15.2-27.5; p = 0.000, I2 = 85.735) for cardiovascular diseases. DISCUSSION: This systematic review indicated the relationship between obesity, ICU admission, severe COVID-19, and disease progression in patients with COVID-19. Obese patients with hypertension, type 2 diabetes, smoking habit, lung disease, and/or cardiovascular disease should be cared for with increased attention.

Effects of ZnO/TiO2 nanoparticle and TiO2 nanotube additions to dense polycrystalline hydroxyapatite bioceramic from bovine bones.

OBJECTIVES: A bovine dense hydroxyapatite ceramic (HA) was produced as new biomaterial, however, the production of a material with consistently high flexural strength remains challenging. The objective of this study was to evaluate the effects of ZnO nanoparticles, TiO2 nanoparticles, and TiO2 nanotubes (1%, 2%, and 5% by weight) on the microstructure and flexural strength of a bovine dense hydroxyapatite ceramic (HA). METHODS: Discs (Ø=12.5mm; thickness=1.3mm) were prepared and subjected to X-ray diffraction (XRD), and observation with a field emission scanning electron microscope (FE-SEM), biaxial flexural strength (BFS) testing, and Vickers hardness (VH) testing. The BFS and VH data were subjected to ANOVA and Tukey post-hoc tests (α=0.05) and Weibull analysis. RESULTS: The XRD showed that the addition of nanomaterials caused the formation of a secondary phase when 5% of the ZnO nanoparticles was used, or when all percentages of the TiO2 nanoparticles/nanotubes were used, and the HA crystallographic planes were maintained. Differences were not observed between the higher BFS values obtained with pure HA and those obtained with the 5% addition of TiO2 nanoparticles. However, the results were different compared with the other groups (α=0.05). The results obtained by Weibull analysis revealed that the 1%, 2%, and 5% addition of TiO2 nanotubes, and the 1% and 2% addition of TiO2 nanoparticles decreased the HA characteristic strength (σ0), while the Weibull modulus (m) increased when 5% of TiO2 nanoparticles, 1% and 2% of ZnO nanoparticles, and 2% of TiO2 nanoparticles were added, but with no statistical difference from the pure HA. The 5% addition of ZnO2 nanoparticles decreased the σ0 without changing m. Moreover, the 5% addition of TiO2 nanoparticles resulted in an m closest to that of pure HA. Regarding the VH results, the blend of HA with 1% and 2% addition of TiO2 nanoparticles exhibited the higher values, which were similar between the different addition ratios (p=0.102). Moreover, the addition of 5% TiO2 nanoparticles resulted in higher value compared with pure HA. SIGNIFICANCE: This study demonstrated that the HA blend with 5% of TiO2 nanoparticles has the greatest potential as a bovine HA dense bioceramic reinforcement.