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1.
Purinergic Signal ; 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38976175

RESUMEN

Medulloblastoma is the most common malignant tumor in the pediatric population. Its classification has incorporated key molecular variations alongside histological characterization. CD39 (also known as ENTPD1) and CD73 (also known as NT5E), enzymes of the purinergic signaling pathway, act in synergy to generate extracellular adenosine, creating an immunosuppressive tumor microenvironment. Our study examined the expression of mRNA of these genes in previously described transcriptome data sets of medulloblastoma patient samples from the Cavalli Cohort (n = 763). Survival distribution was estimated according to the Kaplan-Meier method using a median cut-off and log-rank statistics (p ≤ 0.05). In non-WNT and non-SHH medulloblastoma Group 4 (n = 264), the high expression of ENTPD1 and NT5E was significantly related to a lower overall survival (p = 2.7e-04; p = 2.6e-03). In the SHH-activated group (n = 172), the high expression of ENTPD1 was significantly related to lower overall survival (p = 7.8e-03), while the high expression of NT5E was significantly related to greater overall survival (p = 0.017). In the WNT group (n = 63), the expressions of ENTPD1 and NT5E were not significantly correlated with overall survival (p = 0.212; p = 0.101). In non-WNT and non-SHH medulloblastoma Group 3 (n = 113), the high expression of ENTPD1 was significantly related to greater survival (p = 0.034), while expression of NT5E was not significantly related to survival of patients (p = 0.124). This in silico analysis indicates that ENTPD1 (CD39) and NT5E (CD73) can be seen as potential prognostic markers and therapeutic targets for primary medulloblastomas in non-WNT and non-SHH Group 4.

2.
J Basic Microbiol ; 64(7): e2300671, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38736205

RESUMEN

This study investigates the presence of mycoviruses in Antarctic fungi and elucidates their evolutionary relationships. To achieve this, we aligned mycoviral gene sequences with genomes of previously sequenced Antarctic endophytic fungi, made available by our research group and accessible via Joint Genome Institute. Our findings reveal that the most prevalent genetic regions in all endophytic fungi are homologous to Partitiviruses, Baculoviridae, and Phycodnaviridae. These regions display evidence of positive selection pressure, suggesting genetic diversity and the accumulation of nonsynonymous mutations. This phenomenon implies a crucial role for these regions in the adaptation and survival of these fungi in the challenging Antarctic ecosystems. The presence of mycoviruses in Antarctic endophytic fungi may indicate shared survival strategies between the virus and its host, shedding light on their evolutionary dynamics. This study underscores the significance of exploring mycoviruses within endophytic fungi and their contributions to genetic diversity. Future research avenues could delve into the functional implications of these conserved mycoviral genetic regions in Antarctic endophytic fungi, providing a comprehensive understanding of this intriguing association and genomic retention of viral region in fungi.


Asunto(s)
Briófitas , Endófitos , Virus Fúngicos , Variación Genética , Genoma Viral , Filogenia , Regiones Antárticas , Virus Fúngicos/genética , Virus Fúngicos/aislamiento & purificación , Virus Fúngicos/clasificación , Genoma Viral/genética , Endófitos/genética , Endófitos/aislamiento & purificación , Endófitos/virología , Endófitos/clasificación , Briófitas/microbiología , Briófitas/virología , Hongos/genética , Hongos/virología , Hongos/aislamiento & purificación , Hongos/clasificación , Genómica , Evolución Molecular , Selección Genética
3.
Int Braz J Urol ; 502024 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-38446906

RESUMEN

PURPOSE: To compare biochemical recurrence, sexual potency and urinary continence outcomes of ablative therapy and radical treatment (radical prostatectomy or radiotherapy with androgen deprivation therapy). MATERIAL AND METHODS: A systematic review and meta-analysis followed the PRISMA guidelines were performed. We searched MEDLINE/PubMed. Biochemical recurrence at three and five years; incontinence rate (patients who used one pad or more) and erectile dysfunction rate at 12 and 36 months (patients who did not have sufficient erection to achieve sexual intercourse) were evaluated. The Mantel-Haenszel method was applied to estimate the pooled risk difference (RD) in the individual studies for categorical variables. All results were presented as 95% confidence intervals (95%CI). Random effects models were used regardless of the level of heterogeneity (I²). (PROSPERO CRD42022296998). RESULTS: Eight studies comprising 2,677 men with prostate cancer were included. There was no difference in biochemical recurrence between ablative and radical treatments. We observed the same biochemical recurrence between ablative therapy and radical treatment within five years (19.3% vs. 16.8%, respectively; RD 0.07; 95%CI=-0.05, 0.19; I2=68.2%; P=0.08) and continence rate at 12 months (9.2% vs. 31.8%, respectively; RD -0.13; 95%CI, -0.27, 0.01; I2=89%; P=0.32). When focal treatment was analyzed alone, two studies with 582 patients found higher erectile function at 12 months in the ablative therapy group than in the radical treatment (88.9% vs. 30.8%, respectively; RD -0.45; 95%CI -0.84, -0.05; I2=93%; P=0.03). CONCLUSION: Biochemical recurrence and urinary continence outcomes of ablative therapy and radical treatment were similar. Ablative therapy appears to have a high rate of sexual potency.

4.
Purinergic Signal ; 2023 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-37402102

RESUMEN

Glioblastoma (GB) is the most common primary brain tumor in adults and carries a dismal prognosis, despite the best available treatment. The 2021 WHO Classification of CNS tumors incorporated molecular profiling to better define the characteristics and prognosis of tumor types and subtypes. These recent advances in diagnosis have not yet resulted in breakthrough therapies capable of shifting the treatment paradigm. NT5E/CD73 is a cell surface enzyme that participates in a complex purinergic pathway in synergy with ENTPD1/CD39 producing extracellular adenosine (ADO) from ATP. ADO promotes tumor progression by inducing immunosuppression, stimulating adhesion, invasion, and angiogenesis. In this study, we performed an in silico analysis of 156 human glioblastoma samples in an unexplored public database to investigate the transcriptional levels of NT5E and ENTPD1. The analysis revealed a significant increase in transcription levels of the genes under study in GB samples versus non-tumor brain tissue samples, in concordance with previous studies. High transcriptional levels of NT5E or ENTPD1 were independently related to a decrease in overall survival (p = 5.4e-04; 1.1e-05), irrespective of the IDH mutation status. NT5E transcriptional levels were significantly higher in GB IDH wild-type patients compared to GB IDH-mutant; however, ENTPD1 levels showed no significant difference, p ≤ 0.001. This in silico study indicates the need for a deeper understanding of the purinergic pathway relation to GB development, also inspiring future population studies that could explore ENTPD1 and NT5E not only as prognostic markers but also as potential therapeutic targets.

5.
Clin Oral Investig ; 27(4): 1781-1792, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36462038

RESUMEN

OBJECTIVE: To compare 2 different resin composites and 2 adhesive systems used in a new restorative protocol (partial restoration) to treat non-carious cervical lesions associated with gingival recession type 1 (RT1). MATERIAL AND METHODS: Eighty combined defects (CDs) were treated with a partial restoration and periodontal plastic surgery for root coverage. The CDs were randomly assigned to one of the following groups: NP + TE (n = 20), nanofilled composite and 2-step total-etch adhesive system; NP + UA (n = 20), nanofilled composite and universal adhesive system; MH + TE (n = 20), microhybrid composite and 2-step total-etch adhesive; MH + UA (n = 20), microhybrid composite and universal adhesive. Restorations were assessed using the United States Public Health Service (USPHS) criteria at 1 week (baseline) and 6, 12, and 24 months. Survival rate, periodontal parameters, dentin hypersensitivity (DH), and aesthetics were also evaluated. RESULTS: After 24 months, only the MH + TE group did not lose any restoration, with no significant differences between groups. For surface roughness parameter, MH presented 83.3% of the restorations scoring Bravo, whereas NP presented 48.5% of the restorations scoring Bravo. All groups presented restorations with marginal discoloration. All periodontal parameters behaved similarly, regardless of the restorative material. All groups presented significant reductions of dentin hypersensitivity and improved aesthetic perceptions (p < 0.05). CONCLUSION: Both resin composites and adhesives tested can be combined for partial restorations to treat CDs. CLINICAL RELEVANCE: This new restorative-surgical protocol to treat CDs presents satisfactory outcomes. The partial restorations can be successfully executed with both combinations of adhesives and resin composites evaluated in this investigation. TRN : ClinicalTrial.gov: NCT03215615; registration date July 12, 2017.


Asunto(s)
Sensibilidad de la Dentina , Recesión Gingival , Humanos , Resinas Compuestas , Cementos Dentales , Adaptación Marginal Dental , Restauración Dental Permanente/métodos , Sensibilidad de la Dentina/terapia , Estética Dental , Estudios de Seguimiento , Recesión Gingival/cirugía , Cementos de Resina , Cuello del Diente/patología , Protocolos Clínicos
6.
J Prosthet Dent ; 129(3): 456-463, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34238537

RESUMEN

STATEMENT OF PROBLEM: Various strategies have been proposed to reduce the cement space of foundation restorations for endodontically treated teeth. However, they may add more operative steps, or the dentist must keep different sizes of drills and posts in stock. A 2-piece universal adjustable post system has been developed to overcome this problem, but whether the system has acceptable fatigue survival performance is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the fatigue survival and stress distribution of endodontically treated teeth without a ferrule and restored with different glass fiber post strategies versus a recently introduced universal 2-piece fiber post system. MATERIAL AND METHODS: Bovine incisor roots were randomly assigned to 3 groups as per the post used (n=13): adapted glass fiber post with post space preparation of the same size, composite resin-custom glass fiber post (CTM), and universal 2-piece glass fiber-reinforced composite resin post (UNI). The posts were adhesively luted, the composite resin core was added, and a composite resin crown was produced with computer-aided design and computer-aided manufacturing (CAD-CAM), and then adhesively luted to each core. A fatigue test was performed with the stepwise stress method (10 000 cycles/step; 20 Hz; load=100 N to 750 N; step=50 N) until fracture, and the failure mode analyzed. The stress distribution was evaluated by finite element analysis with the maximum principal stress criteria by following the parameters of the in vitro test. The solids were considered homogeneous, linear, and isotropic, except for the glass fiber post (orthotropic), and a load of 450 N at 30 degrees was applied. The fatigue failure load and the number of cycles for failure were analyzed with Kaplan-Meier and Mantel-Cox (log rank test) (α=.05). The finite element analysis results were analyzed with colorimetric graphs. RESULTS: The highest fatigue failure load and the number of cycles for failure were found in the UNI system, whereas the lowest results were found in the CTM group. All groups exhibited repairable failures. The finite element analysis showed the lowest stress in root dentin in the UNI system. The CTM system had the largest stress regions at the dentin and dentin-core interface. CONCLUSIONS: The use of a 2-piece universal glass fiber post system resulted in more fatigue behavior compared with composite resin-custom glass fiber posts.


Asunto(s)
Técnica de Perno Muñón , Fracturas de los Dientes , Diente no Vital , Animales , Bovinos , Cerámica , Resinas Compuestas , Análisis del Estrés Dental , Vidrio , Ensayo de Materiales , Cementos de Resina , Propiedades de Superficie , Diente no Vital/terapia
7.
Int Braz J Urol ; 49(2): 233-242, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36826377

RESUMEN

INTRODUCTION: To evaluate the possible effects of the coronavirus disease 2019 (COVID-19) pandemic on the oncologic results of patients with prostate cancer regarding clinical staging, presence of adverse pathological outcomes, and perioperative complications. MATERIALS AND METHODS: This retrospective study included patients who underwent radical prostatectomy. The time between biopsy and surgery, staging tests, final histopathological evaluation after surgery, lymphadenectomy rate, postoperative complications, and prostatic specific antigen (PSA) levels (initial and 30 days after surgery) were analyzed and compared in a group of patients before and during the pandemic period. RESULTS: We included 226 patients: 88 in the pre-pandemic period and 138 during the pandemic period. There was no statistically significant difference in mean age, body mass index, ASA, pathological locally advanced disease, the proportion of patients who underwent lymphadenectomy, and ISUP grade in the biopsy between the groups. Positive surgical margins, prostatic extracapsular extension, and PSA levels at 30 days were also similar between the groups. The mean time between medical consultation and surgery was longer in the pandemic period than in the pre-pandemic (124 vs. 107 days, p<0.001), and the mean time between biopsy and medical consultation (69.5 days vs. 114 days, p<0.001) and between biopsy and surgery (198.5 days vs. 228 days, p=0.013) was shorter during the pandemic. The incidence of severe early and late perioperative complications was similar between the periods. CONCLUSIONS: There was no delay between diagnosis and treatment at our institution during the COVID-19 pandemic period. No worsening of the prostate cancer features was observed.


Asunto(s)
COVID-19 , Neoplasias de la Próstata , Masculino , Humanos , Antígeno Prostático Específico , Pandemias , Estudios Retrospectivos , COVID-19/patología , Neoplasias de la Próstata/patología , Prostatectomía/métodos , Estadificación de Neoplasias
8.
Clin Oral Investig ; 26(10): 6295-6303, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35713701

RESUMEN

OBJECTIVES: The aim of this study was to compare the effect of three different access cavities on the tissue removal, deflection, fracture resistance, and stress distribution of extracted maxillary central incisors. MATERIALS AND METHODS: Forty human maxillary central incisors were randomly assigned in four experimental group (n = 10) including conservative access cavity "CAC," traditional access cavity "TAC," invasive access cavity "IAC," and without access cavity (control group). Cone-beam computed tomography "CBCT" scans were used to evaluate the tissue removal during the different access cavities. All specimens were restored with composite resin (Admira Fusion, Voco, Cuxhaven, Germany) and embedded in acrylic resin blocks after simulating the periodontal ligament using red wax, then the specimens were submitted to the deflection test applying a load of 250 N and to the load-to-fracture test after artificial aging in a mechanical cycling machine (150 N, 5 × 106 cycles, 10 Hz). Lastly, stress distribution was assessed by three-dimensional finite element analysis (3D-FEA), simulating the specimens restoration by two types of composite resins of low and high elastic modulus (8 and 18 GPa respectively) after the access cavities. The data were submitted to Shapiro-Wilk and KS normality tests. Then, they were analyzed by one-way ANOVA and Tukey tests with a significance level (α ≤ 0.05). RESULTS: CBCT scans showed a significant difference of worn tissues in CAC and TAC when compared to the IAC (P < 0.0001). In deflection test, CAC showed lower deformation values than the TAC and IAC. Load-to-fracture test presented no significant difference among the three experimental groups (P = 0.6901). 3D-FEA showed that the more conservative the access cavity, the higher the stress magnitude. CONCLUSIONS: CAC promote less worn tissue; however, this does not improve the stress distribution or fracture resistance of endodontically treated maxillary incisors. CLINICAL RELEVANCE: Clinicians should reconsider the pros and cons of the conservative access cavity.


Asunto(s)
Caries Dental , Fracturas de los Dientes , Diente no Vital , Resinas Acrílicas , Resinas Compuestas , Restauración Dental Permanente/métodos , Análisis del Estrés Dental , Humanos , Incisivo , Estrés Mecánico , Diente no Vital/terapia
9.
Clin Oral Investig ; 26(2): 1725-1735, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34435252

RESUMEN

OBJECTIVES: To make an in vitro assessment of fracture resistance of weakened and non-weakened teeth receiving intraradicular reinforcement using Rebilda bundled glass fiber-reinforced composite posts (GT), Rebilda conventional glass fiber posts (RP), or both systems combined (GT + RP). MATERIALS AND METHODS: Eighty sound bovine incisors were prepared and divided randomly into eight groups as follows: (a) nWnR: without simulating weakness, and without intraradicular reinforcement; (b) WnR: simulating weakness, but without intraradicular reinforcement; (c) nWGT: without simulating weakness, but with GT; (d) WGT: simulating weakness, and with GT; (e) nWRP: without simulating weakness, but with RP; (f) WRP: simulating weakness, and with RP; (g) nWGTRP: without simulating weakness, but with GT + RP; (h) WGTRP: simulating weakness, and with GT + RP. The specimens were subjected to the load-to-fracture test using the DL-2000MF universal testing machine. The finite element method assessed the mechanical behavior and stress distribution in endodontically treated teeth. RESULTS: The groups nWGTRP and WGTRP presented the best results in the load-to-fracture test, with the former being better than the latter, but with no statistically significant difference (P > 0.05). However, there was a significant difference between these and the other groups (P < 0.05), except for nWRP. Stress distribution inside the canal wall was different among the groups, with promising mechanical behavior for nWGTRP and nWRP. CONCLUSIONS: The Rebilda conventional fiber post (RP), combined with the Rebilda bundled glass fiber-reinforced composite post (GT) improves the resistance and stress distribution of immature teeth. CLINICAL RELEVANCE: Longitudinal fracture is less frequent in teeth restored with GT and RP posts.


Asunto(s)
Técnica de Perno Muñón , Fracturas de los Dientes , Diente no Vital , Animales , Bovinos , Resinas Compuestas , Materiales Dentales , Análisis del Estrés Dental , Vidrio , Ensayo de Materiales , Estrés Mecánico , Fracturas de los Dientes/prevención & control
10.
Clin Oral Investig ; 26(3): 2513-2526, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34643807

RESUMEN

OBJECTIVES: This study evaluated the effect of deep margin elevation (DME) and restorative materials (leucite-reinforced glass-ceramics [C] vs. indirect resin composite [R]) on the fatigue behavior and stress distribution of maxillary molars with 2-mm deep proximal margins restored with MOD inlay. METHODS: Fifty-two extracted human third molars were randomly assigned into four groups (n = 13): C; DME + C; R; and DME + R. Inlays were fabricated in CAD-CAM and bonded to all teeth. The fatigue behavior was assessed with the stepwise stress test (10,000 cycles/step; step = 50 N; 20 Hz; initial load = 200 N). Fatigue failure loads and the number of cycles were analyzed with 2-way ANOVA and Tukey's test (p < 0.05) and Kaplan-Meier survival plots. The stress distribution was assessed with finite element analysis. The models were considered isotropic, linear, and homogeneous, and presented bonded contacts. A tripod axial load (400 N) was applied to the occlusal surface. The stress distribution was analyzed with the maximum principal stress criterion. RESULTS: For fatigue, there was no difference for DME factor (p > 0.05). For the material factor, the load and number of cycles for failure were statistically higher in the R groups (p < 0.05). The finite element analysis showed that resin composite inlays concentrated more stress in the tooth structure, while ceramic inlays concentrated more stress in the restoration. Non-reparable failures were more frequent in the resin composite inlays groups. CONCLUSIONS: DME was not negative for fatigue and biomechanical behaviors. Resin composite inlays were more resistant to the fatigue test, although the failure mode was more aggressive. CLINICAL SIGNIFICANCE: DME does not impair mechanical behavior. Resin composite inlays failed at higher loads but with a more aggressive failure mode.


Asunto(s)
Porcelana Dental , Incrustaciones , Resinas Compuestas/química , Porcelana Dental/química , Análisis del Estrés Dental , Humanos , Ensayo de Materiales , Diente Molar , Estrés Mecánico
11.
J Prosthet Dent ; 2022 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-35717209

RESUMEN

STATEMENT OF PROBLEM: The trueness and precision of intraoral scanners (IOSs) and the effect of intracoronal restorations have been reported. However, studies addressing the accuracy of IOSs in reproducing different complete coverage onlay preparation designs are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the influence of complete coverage onlay preparation design and intraoral scanning devices on the accuracy of digital scans in terms of trueness and precision. MATERIAL AND METHODS: Three preparation designs on the mandibular first molar were considered: a traditional preparation design with isthmus reduction (IST), a traditional preparation design without isthmus reduction (wIST), and simplified nonretentive preparation (nRET). Digital scans of epoxy resin mandibular arch reference models of the preparations (containing second premolar, first molar, and second molar) were obtained by using 3 IOSs (iTero Element 2 [ELE], Trios 3 [TRI], and Primescan [PRI]) (n=10). Trueness (µm) and precision (µm) were analyzed by superimposing the digital scan on the digital reference models obtained with a high-accuracy industrial scanner (ATOS Core 80) in a tridimensional metrology software program. Accuracy was quantified by the absolute deviation (µm). Local and overall mean positive and negative deviations for trueness were also obtained. Data were analyzed by using the Kruskal-Wallis and Dunn tests with a statistical software program (α=.05). RESULTS: The nonretentive preparation groups obtained higher trueness (3.8 µm) and precision (2.7 µm) than the IST and wIST groups (trueness=7.5 to 6.3 µm, precision=5.5 to 4.6 µm). Trueness values were lower with ELE×IST (16 µm), followed by ELE×wIST (13 µm), and PRI×IST (7.8 µm). In general, no difference was found between PRI and TRI scanners (6.3 to 5.9 µm), with lower performance for ELE (13 µm). Positive deviations were higher on the proximal box of the IST and wIST preparation and on the occlusal box of the IST group. Negative deviation was higher on the ELE×IST occlusal box. CONCLUSIONS: Different intraoral scanners and preparation designs influenced the accuracy of digital scans. A more complex preparation such as IST and wIST showed higher deviation. The iTero Element 2 scanner exhibited higher deviation for both trueness and precision.

12.
J Prosthet Dent ; 125(3): 469.e1-469.e6, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33279154

RESUMEN

STATEMENT OF PROBLEM: Chairside computer-aided design and computer-aided manufacturing (CAD-CAM) materials that do not require any firing steps are a promising option to expedite restoration production; however, little information is available to determine the most suitable material for each clinical situation. PURPOSE: The purpose of this in vitro study was to evaluate the effect of simulated toothbrushing on surface gloss, roughness, and wear of chairside CAD-CAM materials. MATERIAL AND METHODS: Disk-shaped specimens (n=15) were prepared of the following materials: ENA-VITA Enamic; LAV-Lava Ultimate; EMP-IPS Empress CAD; CER-Cerasmart; GRA-Grandio blocs. Gloss (Gloss Unit-GU) and surface roughness (Ra-µm) were evaluated before and after simulated toothbrushing (100 000 strokes). Wear (µm) was assessed by contact profilometry. Additional analyses of microhardness by scanning electron microscopy were also performed. Data were analyzed with 2-way repeated measures ANOVA test for roughness and gloss, and 1-way ANOVA for wear (α=.05). To estimate the correlation between Ra and GU, the Pearson correlation was calculated. RESULTS: Before brushing, CER showed the lowest Ra (P<.001), and GRA the lowest GU values. After brushing, the feldspathic ceramic-based materials (ENA and EMP) presented the highest gloss, whereas the ceramic group (EMP) showed the lowest Ra. Before and after brushing, GRA showed the lowest GU values. Higher wear values were found for the composite resin groups (CER>GRA), with the exception of LAVA, which was similar to ENA, and EMP showing improved wear resistance. A strong negative correlation (-0.925) between GU and Ra values was detected (P<.001). CONCLUSIONS: The materials containing a glass phase (ENA and EMP) presented higher wear resistance, higher gloss, and lower roughness after brushing than the other materials tested. The correlation test showed that the higher the surface roughness, the lower the gloss.


Asunto(s)
Resinas Compuestas , Cepillado Dental , Cerámica , Diseño Asistido por Computadora , Porcelana Dental , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Propiedades de Superficie
13.
Molecules ; 26(20)2021 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-34684695

RESUMEN

The aim of this study was to evaluate the effect of biologically oriented preparation technique on the stress concentration of endodontically treated upper central incisors restored with zirconia crown (yttria-stabilized zirconia polycrystalline ceramic) through finite element analysis (FEA). Four models of maxillary central incisors containing enamel, dentin, periodontal ligament, cortical and medullary bone were created in CAD. Each model received a polymeric core-build up with nanofilled dental resin composite. The evaluated models were SM-preparation in shoulder 90°; CM-chamfer preparation; BOPT-biologically oriented preparation technique and BOPTB-BOPT preparation 1 mm below the cement-enamel junction. All models received zirconia crowns (5Y-TZP), fiberglass post and 1 mm ferrule. The models were imported into the analysis software with parameters for mechanical structural testing using the maximum principal stress and the tensile strength as the analysis criteria. Then, load of 150 N was applied at the cingulum with 45° slope to the long axis of the tooth, with the fixed base for each model. The type of marginal preparation affected the stresses concentration in endodontically treated teeth and in the zirconia crown margin. Considering the stress magnitude only, BOPT is a viable option for anterior monolithic zirconia crowns; however, with the highest stress magnitude at the restoration margin.


Asunto(s)
Cerámica/química , Resinas Compuestas/química , Coronas , Análisis de Elementos Finitos/normas , Incisivo/cirugía , Diente no Vital/cirugía , Circonio/química , Vidrio/química , Humanos , Incisivo/anatomía & histología , Incisivo/efectos de los fármacos , Estrés Mecánico , Resistencia a la Tracción
14.
Gen Dent ; 69(6): 64-68, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34678746

RESUMEN

Prefabricated glass fiber-reinforced composite posts have been widely used because of their esthetic properties and favorable biomechanical behavior; however, because they are prefabricated, they may not adapt to the anatomy of all root canals. This case report describes a procedure for restoring teeth with a custom, 1-piece, fiber-reinforced composite post and core fabricated using computer-aided design/computer-aided manufacturing (CAD/CAM). The excellent adaptation of this custom endodontic post enables the use of a thinner, homogenous cement layer; in addition, it eliminates the need to construct a composite resin core build-up. Although more clinical and in vitro studies are needed to better define the appropriate clinical protocols and assess various materials, CAD/CAM technology allows post and core restorations to be manufactured in a predictable and simplified way.


Asunto(s)
Técnica de Perno Muñón , Resinas Compuestas , Diseño Asistido por Computadora , Análisis del Estrés Dental , Humanos , Ensayo de Materiales , Cementos de Resina
15.
Am J Dent ; 33(5): 227-234, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33017523

RESUMEN

PURPOSE: To evaluate the influence of different post-endodontic techniques on the fatigue survival and biomechanical behavior of crowned restored central incisors. METHODS: The crowns of 69 bovine incisors were cut, and the roots were treated endodontically and assigned randomly into three groups (n=23): resin composite buildup (BUP), glass fiber post-retained resin composite buildup (GFP), and cast post-and-core (CPC). They received full crown preparation with 2 mm ferrule, and a leucite-reinforced ceramic crown was cemented adhesively. Three specimens from each group were tested monotonically. The remaining specimens were subjected to the stepwise stress fatigue test until fracture or suspension after 1.5 x 106 cycles in a chewing simulator. The load and step at which each specimen failed were analyzed by Kaplan-Meier and Mantel-Cox (log-rank test) statistics, followed by multiple pairwise comparisons, at 5% significance level. The three groups tested (BUP, GFP, and CPC) were 3D modeled (Rhinoceros 4.0) and the maximum principal stress (MPa) criteria were used to calculate the results using FEA. RESULTS: There was no statistical difference between the treatments regarding the load or the number of cycles (Mantel-Cox log-rank test for trend, X²= 0.015, df=1, P= 0.901, X²=3.171, df=1, P= 0.995). Crown cracks were the predominant failure mode, and oblique root fractures were only observed in groups GFP and CPC. In endodontically treated incisors with a 2-mm ferrule, the post-endodontic treatment had no significant effect on fatigue survival. Non-restorable fractures only occurred in teeth restored with posts. CLINICAL SIGNIFICANCE: Although the clinical significance of laboratory studies has some limitations, this study suggests that composite buildups without posts may be an option for restoring endodontically treated incisors with 2 mm ferrule height.


Asunto(s)
Incisivo , Técnica de Perno Muñón , Animales , Bovinos , Resinas Compuestas , Coronas , Análisis del Estrés Dental
16.
J Prosthet Dent ; 124(4): 494.e1-494.e5, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32444205

RESUMEN

STATEMENT OF PROBLEM: Manufacturers of the recently introduced nanofilled bis-acryl composite resins no longer recommend polishing to produce interim restorations; however, whether this advice is appropriate is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the effect of the type of interim resin material, polishing procedure, and artificial staining on surface roughness, gloss, and color. MATERIAL AND METHODS: Disk-shaped specimens were prepared from 1 unfilled acrylic resin (Duralay) and 3 bis-acryl composite resins (Structur 3-nanofilled, Systemp C&B-microhybrid, Proviplast-microhybrid). The specimens of each material were assigned to 2 subgroups (n=15): polished and unpolished. Surface roughness (Ra-µm), gloss (UB), and color (ΔE) were analyzed at baseline and after 14 days of artificial staining. Roughness and gloss data were separately analyzed by 3-way ANOVA and color by 2-way ANOVA, followed by the post hoc Tukey test (α=.05). RESULTS: The baseline roughness of all materials was significantly reduced by the polishing procedure, whereas the baseline gloss was increased (P<.001). Only the unpolished Proviplast had a significant increase in Ra values after aging. Structur 3 had higher gloss than Systemp C&B and Proviplast. The acrylic resin had the lowest color change after staining. CONCLUSIONS: The polishing procedure produced smother and glossier surfaces for all the materials tested. The nanofilled bis-acryl composite resin material had higher gloss than the microhybrid bis-acryls tested, but it was not different from the acrylic resin. The 14 days of artificial staining did not promote significant changes in Ra or gloss values, except for Ra in the unpolished Proviplast subgroup, indicating excellent performance of the materials. The acrylic resin had the highest color stability.


Asunto(s)
Resinas Compuestas , Pulido Dental , Resinas Acrílicas , Color , Ensayo de Materiales , Polonia , Propiedades de Superficie
18.
J Indian Prosthodont Soc ; 18(4): 329-335, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30449961

RESUMEN

BACKGROUND: Carious lesions and dental fractures cause weakening in the dental structure. In these situations, endodontic treatment and prosthetic rehabilitation using an intraradicular post are indicated. However, the postspace preparation of the root canal further weakens the dental remnant, especially if there is no ferrule present. This study aimed to evaluate the stress distribution in endodontically treated upper premolars treated with different rehabilitation approaches. MATERIALS AND METHODS: An endodontically treated first upper premolar was modeled for finite element analysis. Three different approaches were carried out on this model: rehabilitation with fiberglass post (FCP), endocrown (ECW), or buildup. The models were exported in STEP format to the analysis software (ANSYS 17.2, ANSYS Inc., Houston, TX, USA). The solids were considered isotropic, homogeneous, and linearly elastic. A mechanical, structural static analysis was used as the criterion of maximum principal stress to show regions under tensile stress to evaluate the stress distribution in the restoration, cementation line, and root. A load of 400 N (90°) was applied to the lingual triangular ridge. The values of maximum principal stress in MPa were evaluated through colorimetric graphs. RESULTS: Similar stress concentration was observed for all groups. However, the ECW group presented higher values in the restoration/cement interface and root dentin. CONCLUSIONS: All the treatment modalities had favorable mechanical behavior to support the masticatory loads; nevertheless, the ECW group presented a higher risk of detachment failure.

19.
Ann Plast Surg ; 79(5): 426-429, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28604545

RESUMEN

INTRODUCTION: Lipodystrophy syndrome associated with highly active antiretroviral therapy (HAART) may lead to low self-esteem and poor compliance with the drug treatment on patients infected with human immunodeficiency virus (HIV), which is a matter of concern for the health system. The aim of this study was to evaluate patients with HIV submitted to gluteal augmentation with intramuscular silicone implants to correct gluteal lipoatrophy related to the use of HAART. METHODS: This is a retrospective evaluation of 10 patients submitted to gluteal augmentation with intramuscular silicone implant for correction of gluteal lipoatrophy related to the use of HAART, operated between 2012 and 2015. Postoperative complications and the degree of patient's satisfaction were analyzed. RESULTS: There were 3 postoperative complications including 1 case of surgical wound dehiscence and 2 cases of seroma. Six months after surgery, 8 patients had an excellent degree of satisfaction, and 2 patients had a good degree of satisfaction related to the procedure. Although this intervention does not offer functional advantages, it improves the body contour, increases patients' self-esteem, and helps them to accept their body image. These advantages can lead to higher compliance with prolonged HAART. CONCLUSIONS: Gluteal augmentation with intramuscular silicone implant can be a viable option to treat patients with HIV with gluteal lipoatrophy related to the use of HAART. The patients were satisfied with the outcomes of the procedure, and there were only minor self-limited postoperative complications.


Asunto(s)
Terapia Antirretroviral Altamente Activa/efectos adversos , Nalgas/cirugía , Síndrome de Lipodistrofia Asociada a VIH/cirugía , Prótesis e Implantes , Geles de Silicona , Adulto , Estética , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Síndrome de Lipodistrofia Asociada a VIH/etiología , Síndrome de Lipodistrofia Asociada a VIH/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Implantación de Prótesis/métodos , Estudios Retrospectivos , Muestreo , Cirugía Plástica/métodos , Resultado del Tratamiento
20.
Aesthetic Plast Surg ; 41(4): 872-877, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28233133

RESUMEN

BACKGROUND: Gluteoplasty has gained notoriety over the last decades, which has motivated the development of various surgical techniques. Nevertheless, the fear of dissection of the intramuscular plane without direct visualization may inhibit learning and development of gluteal augmentation with implants. Moreover, literature detailing the technical steps of intramuscular dissection for the construction of the implant pocket is scarce. This study presents a new approach to intramuscular dissection for gluteal augmentation with silicone implants, a variation of the conventional surgical technique. METHODS: We performed a retrospective analysis of a series of 12 female patients submitted to a variation of the intramuscular dissection technique for gluteal augmentation with silicone implants. Data from patients, implants, follow-up time, postoperative complications, and the degree of patient satisfaction were obtained. This technique follows the principle of alternating spatulas to perform the blunt dissection of the implant pocket. RESULTS: In this series, the proposed technique is controlled and safe for intramuscular dissection, which can be used for both experienced and training surgeons. This technique is based on well-known anatomical points and references. We observed that the implant was well positioned and covered, the patients were satisfied with the result, and the number of complications was low. CONCLUSIONS: This variation of the intramuscular dissection technique for gluteal augmentation with silicone implants provides an easily reproducible and safe procedure that involves well-controlled technical steps, especially during dissection of the intramuscular pocket. In this series of patients, training surgeons learned faster, results were satisfactory, and the number of complications was low. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .


Asunto(s)
Nalgas/cirugía , Prótesis e Implantes , Implantación de Prótesis/métodos , Geles de Silicona , Adulto , Brasil , Nalgas/diagnóstico por imagen , Estudios de Cohortes , Estética , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Posicionamiento del Paciente/métodos , Satisfacción del Paciente/estadística & datos numéricos , Estudios Retrospectivos , Cirugía Plástica/métodos , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento , Adulto Joven
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