DSpace Collection:

Transmissão de luz emitida por fotopolimerizador multi-picos através de braquetes cerâmicos mono e policristalinos

2026-04-09T06:17:29Z

Title: Transmissão de luz emitida por fotopolimerizador multi-picos através de braquetes cerâmicos mono e policristalinos Abstract: Objective: To evaluate light transmission through monocrystalline and polycrystalline ceramic brackets using a multi-peak light-curing unit (LCU). Materials and Methods: In vitro study with seventeen ceramic brackets: five monocrystalline (IceramS, InspireIce, Luminous, Radiance, Safira) and twelve polycrystalline (CeramicSLI, ClarityAdvancedCeramic, DamonClear, Iceclear, Iceram, Iceram, In-OvationC, In-Vu, Inflexion, OvationC, PolySafira, and Translux). LCU power and emission spectrum in normal and ortho modes were measured at zero mm from the integrating sphere aperture and transmitted through each bracket using an integrating sphere connected to a spectrometer. Irradiance and transmitted energy were calculated. Beam profiles were obtained via laser beam profiler. Data were analyzed by two-way ANOVA and Tukey's test (α = 0.05). Results: All brackets significantly reduced radiant power, irradiance, and energy compared to the light emitted by the LCU (P < 0.001). PolySafira and IceramP showed higher light transmission, while CeramicSLI and In-Vu showed the lowest values. Light transmission was not influenced by the crystalline structure. The ortho mode increased radiant power and irradiance but reduced total energy compared to the standard mode (P < 0.001). Conclusion: Light transmission depends on bracket design and optical properties, rather than crystalline structure. The activation mode modifies light emission; the ortho mode increases irradiance but reduces total energy, which is lower than required for light-activation of orthodontic resins, a factor that should be considered when selecting polymerization protocols. Keywords: Orthodontic Brackets; Ceramics; Curing Lights Dental; Photopolymerization.

Lipoxina A4 e Resolvina D1 preservam a capacidade de indução neural de células-tronco da polpa dentária cultivadas sob condições inflamatórias

2026-02-27T06:21:15Z

Title: Lipoxina A4 e Resolvina D1 preservam a capacidade de indução neural de células-tronco da polpa dentária cultivadas sob condições inflamatórias Abstract: Human dental pulp stem cells (DPSCs) exhibit neurogenic differentiation potential; however, inflammatory conditions may impair this process. This study investigated the impact of tumor necrosis factor-alpha (TNF-α) on DPSC neurodifferentiation and the modulatory role of the pro-resolving lipid mediators lipoxin A4 (LXA4) and resolvin D1 (RvD1). DPSCs were isolated and subjected to neuronal differentiation for 21 days. The optimal TNF-α concentration was determined in a pilot study using real-time PCR. The expression of OCT3/4, doublecortin, and β-III-tubulin was analyzed by MTT assay, flow cytometry, and immunofluorescence. The effects of LXA4 (10 or 100 nM) and RvD1 (10 or 100 nM) were assessed by flow cytometry. Data were analyzed using the Kruskal–Wallis test followed by the Mann–Whitney test (p<0.05) and one-way ANOVA with Tukey’s post hoc test. TNF-α at a concentration of 25 ng/mL was shown to induce inflammation without causing cytotoxicity. The high production of doublecortin indicated the neuronal differentiation potential of DPSCs, whereas reduced β-III-tubulin expression demonstrated that TNF-α inhibits the progression of neuronal differentiation. Conversely, increased β-III-tubulin expression in the presence of LXA4 (10 and 100 nM; p=0.02 and p=0.03, respectively) and RvD1 (100 nM; p=0.02) indicate that these mediators attenuate the inhibitory effects of TNF-α. These findings suggest that anti-inflammatory therapy combined with DPSCs may enhance motor recovery following neurotrauma.

Impacto da pandemia de COVID-19 nos intervalos de tempo da trajetória diagnóstica e terapêutica de pacientes com câncer da cavidade bucal

2026-02-24T06:20:32Z

Title: Impacto da pandemia de COVID-19 nos intervalos de tempo da trajetória diagnóstica e terapêutica de pacientes com câncer da cavidade bucal Abstract: This study aimed to evaluate the potential impact of the COVID-19 pandemic on the diagnostic and therapeutic trajectory of patients with oral cavity cancer. A retrospective, cross-sectional study was conducted using secondary data from patients diagnosed with oral cancer between 2017 and 2023, who were treated at a regional reference center for oncological diagnosis and treatment in the state of Minas Gerais, Brazil. The cases were categorized into three groups according to the year of diagnosis: pre-pandemic (2017–2019), pandemic (2020–2021), and post-pandemic (2022–2023). Demographic, clinical, pathological, and therapeutic information was collected for sample characterization and comparative analyses to identify significant variations. A shorter delay in seeking care for the initial diagnosis was observed during the pandemic, whereas in the post-pandemic period a longer interval between histopathological diagnosis and the first oncological consultation was observed. Overall survival did not show a statistically significant difference between the groups. These findings indicate that the pandemic impacted essential stages of the oral cancer care, particularly access to oncology services. This underscores the need for screening strategies and strengthening the referral networks to ensure early diagnosis and appropriate treatment, especially in the context of public health crises.

Superposição 3D para avaliação de alterações condilares e disfunção articular pós-cirurgia ortognática: uma série de casos

2026-02-13T06:26:24Z

Title: Superposição 3D para avaliação de alterações condilares e disfunção articular pós-cirurgia ortognática: uma série de casos Abstract: Orthognathic surgery corrects dentofacial deformities with the aim of improving function and aesthetics, but its effects on the temporomandibular joint (TMJ) remain controversial. This case series evaluated three patients with facial pattern II who underwent bimaxillary orthognathic surgery. Clinical examinations, the DC/TMD questionnaire, and computed tomography with voxel-based 3D superimposition were performed to identify subtle condylar changes, including displacements and bone resorption. Two patients presented with articular and muscular pain, joint sounds, and reduced mouth opening, while one remained asymptomatic, demonstrating clinical heterogeneity. Variations in intercondylar distances suggested that minor condylar remodeling may influence temporomandibular disorder (TMD) symptoms. These findings highlight the importance of longitudinal monitoring using 3D Imaging and standardized functional assessment for the early detection of condylar alterations and individualized treatment planning. Despite the small sample size, this study contributes to hypothesis generation and the refinement of TMJ clinical protocols.