Dress por litio: reporte de un caso pediátrico / Lithium dress: a pediatric case report / Dress por Lítio: relato de caso pediátrico

La reacción a medicamentos con eosinofilia y síntomas sistémicos denominada DRESS(por sus siglas en inglés, Drug Reaction with Eosinophilia and Systemic Symptoms) hace parte de un amplio espectro denominado toxicodermias. La incidencia exacta no es conocida en niños; sin embargo, en la literatura se ha estimado una tasa de mortalidad que puede llegar a ser tan alta como el 10 %. Presentamos el caso de una paciente adolescente con antecedente personal de trastorno afectivo bipolar (TAB), quien recibía de forma ambulatoria sertralina, quetiapina y trazodona. Por presencia de alucinaciones se adicionó litio al manejo. Diez días después acude al servicio de urgencias por aparición de erupción cutánea y síntomas sistémicos, por lo que se sospechó un cuadro clínico secundario a hipersensibilidad a los medicamentos.

The reaction to drugs with eosinophilia and systemic symptoms called DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms) is part of a broad spectrum called toxicodermias. The exact incidence is not known in children; However, a mortality rate that can be as high as 10% has been estimated in the literature. We present the case of a teenage patient with a personal history of bipolar affective disorder (BD), who received sertraline, quetiapine and trazodone on an outpatient basis. Due to the presence of hallucinations, lithium was added to the management. Ten days later she went to the emergency department due to the appearance of a skin rash and systemic symptoms, for which a clinical condition secondary to hypersensitivity to medications was suspected.

A reação a medicamentos com eosinofilia e sintomas sistêmicos denominada DRESS (Por suas siglas em inglês Drug Reaction with Eosinophilia and Systemic Symptoms) faz parte de um amplo espectro denominado toxicodermias. A incidência exata não é conhecida em crianças; No entanto, uma taxa de mortalidade que pode chegar a 10% foi estimada na literatura. Apresentamos o caso de um paciente adolescente com história pessoal de transtorno afetivo bipolar (TAB), que recebeu sertralina, quetiapina e trazodona em regime ambulatorial. Devido à presença de alucinações, foi adicionado lítio ao manejo. Dez dias depois, recorreu ao pronto-socorro devido ao aparecimento de erupção cutânea e sintomas sistêmicos, suspeitando-se de quadro clínico secundário a hipersensibilidade a medicamentos.

Facile Synthesis of Pre-Lithiated LiTiO2 Nanoparticles for Quick Charge and Long Lifespan Anode in Lithium-Ion Batteries.

Titanium dioxide (TiO2) has been widely used as an alternative anodic material for lithium-ion batteries (LIBs) due to its ultrahigh capacity retention and long cycle lifespan. However, the restriction of lithium insertion, intrinsically poor electronic conductivity, and sluggish lithium ionic kinetics of bulk TiO2 hinder their specific capacity and rate performance. Herein, LiTiO2 nanoparticles (NPs) are synthesized via a facile ball milling method by the reaction of anatase TiO2 with LiH. The as-prepared LiTiO2 NPs have strong structural stability and a "zero strain" effect during the repeated intercalation/deintercalation, even at low potential. As anodic materials for LIBs, LiTiO2 NPs exhibit a superior rate performance of ∼100 mA h g-1 at 10C (3350 mA g-1) with a capacity retention of 100% after 1000 cycles, which is 5 times higher than that of the original commercial anatase TiO2 powder. The higher specific capacity of LiTiO2 NPs is attributed to the increased conversion of Ti3+ to Ti2+ on the porous surface of LiTiO2 NPs, which provides a more capacitive contribution. This study not only provides a new fabrication approach toward Ti-based anodes for ultrafast LIBs but also underscores the potential importance of embedding lithium into transition metal oxides as a strategy for boosting their electrochemical performance.

Encefalopatía posterior reversible: una complicación de la intoxicación por litio / Posterior reversible encephalopathy: a complication of lithium toxicity

Las intoxicaciones en nuestro medio se presenta con una incidencia de 45.1 por cada 100,000 habitantes. Una de las principales causas son las intoxicaciones por psicofármacos dentro de las cuales esta el litio. Este medicamento es utilizado para el manejo del trastorno afectivo bipolar. En la literatura existen diferentes factores de riesgo para la intoxicación por litio como: condiciones que favorezcan la hipovolemia, uso de diuréticos, antihipertensivos, hiponatremia , interacciones medicamentosas y ajuste de dosis. Alrededor del 75 a 90% de los pacientes tratados crónicamente con litio pueden tener niveles tóxicos durante su tratamiento. Como tal la intoxicación puede cursar con diferentes complicaciones renales, cardiovasculares y neurológicas, dentro de estas últimas ésta la encefalopatía. Presentamos el caso de una paciente que ingresa con toxicidad crónica y presenta como complicación neurológica una encefalopatía posterior reversible. El objetivo de este reporte es sensibilizar al personal medico sobre esta complicación poco frecuente pero asociada a gran morbimortalidad. (AU)

Intoxications in our enviroment has an incidence of 45.1 for each 100.000 habitants. One of the main causes are psychopharmaceuticals, one of which is lithium. This drug is used in the management of bipolar disorder. There are several risk factors depicted on literature for this intoxication, such as: conditions that favor hipovolemia, diurethic and antihypertensive use, hiponatremia, drug interactions and lithium dose adjustment. About 75 to 90% of patients chronically treated with lithium can reach toxic levels during their treatment. Lithium intoxication can present with complications affecting different systems such as renal, cardiovascular and nervious, last one includying encephalopathy. We will discuss the case of a patient that presents with chronic lithuim toxicity and develops posterior reversible encephalopathy as a neurologic complication. The goal of this case report is to sensitize medical staff with this unfrequent but dangerous complication. (AU)

Rehabilitación del sector anterior con disilicato de litio. Relato de un caso / Rehabilitation of the previous sector with lithium disilicate. Case report

Mediante este caso se describen los criterios de selección del color en restauraciones indirectas con disilicato de litio en el sector anterior. Mujer de 34 años, atendida en la Facultad de Odontología de la Universidad Nacional de Concepción (FOUNC), Paraguay, por una preocupación estética del sector anterior, en especial la diferencia de color de las piezas dentarias. La rehabilitación consistió en la confección de coronas de disilicato de litio de las piezas 11, 12, 13, 14, 21, 22, 24, 25 y laminado para carillas de la pieza 23. Fueron aplicadas técnicas de selección de color individualizadas, pruebas de color y cementación antes del cementado final para obtener resultados altamente estéticos. Gracias a los resultados fue posible observar la conjunción de factores como la correcta selección del color del sustrato dentario, el cemento resinoso, el material de restauración y la comunicación eficiente con el laboratorio, fundamental para el éxito del tratamiento.

This case describes the color selection criteria for indirect lithium disilicate restorations in the anterior sector. A 34-year-old woman treated at the Faculty of Dentistry of the National University of Concepción (FOUNC), Paraguay, due to an aesthetic concern in the anterior sector, especially the difference in color of the teeth. The rehabilitation consisted of making lithium disilicate crowns for teeth 11, 12, 13, 14, 21, 22, 24, 25 and laminate for veneers for tooth 23. Individualized color selection techniques, color and cementation prior to final cementation for highly esthetic results. Thanks to the results, it was possible to observe the conjunction of factors such as the correct selection of the color of the dental substrate, the resinous cement, the restorative material, and efficient communication with the laboratory, essential for the success of the treatment.

Influence of substrate, cement and aging on the biaxial flexural strength of lithium disilicate / Influência do substrato, cimento e envelhecimento na resistência a flexão biaxial do dissilicato de lítio

Objective: To evaluate the biaxial flexural strength (BFS) of lithium disilicate (L), cemented on different substrates (epoxy resin - E and metal - M) with dual-cure resin cement (Rc) and zinc phosphate cement (Zc), not aged, thermally aged (TC) or thermo-mechanical aged (TC/MC). Material and Methods: Disks of L, E, and M were fabricated, and the cementation was performed according to the following groups: ERc (L+E+Rc); MRc (L+M+Rc); MZc (L+M+Zc); EZc (L+E+Zc). Ten samples from each described group were tested in BFS, ten more samples were subjected to TC (1×104 cycles between 5 ºC and 55 ºC water), and the last 10 samples were subjected to TC/MC (MC: 1.2×106 cycles, 50 N, 3.8 Hz). The BFS test was performed and scanning electron microscopy (SEM) was performed to evaluate the failure mode. The effect of the cementation strategy (cement/substrate) was compared in each aging method and the effect of the aging method was evaluated for each cementation strategy by one-way ANOVA and Tukey post-hoc test (α=0.05). Results: The strength values were highest to M (237.8 ~ 463.9 MPa), in comparison to the E (41.03 ~ 66.76 MPa), despite aging and luting agent. Flexural strength data decreased after TC and TC/MC in groups cemented with Zc, but was stable when cemented with Rc. SEM analysis indicated that failure origins were located at the tensile surface of the L. Conclusion: Lithium disilicate discs cemented to the metallic substrate presented the highest biaxial flexural strength. The cementation with dual-cure resin cement did not decrease BFS after aging (AU)

Objetivo: Avaliar a resistência à flexão biaxial (BFS) do dissilicato de lítio (L), cimentado sobre diferentes substratos (resina epóxi - E e metal - M) com cimento resinoso dual (Rc) e cimento de fosfato de zinco (Zc), não envelhecido, submetido ao envelhecido térmico (TC) ou ao envelhecido térmico-mecânico (TC/MC). Material e Métodos: Foram confeccionados discos de L, E e M, e a cimentação foi realizada de acordo com os seguintes grupos: ERc (L+E+Rc); MRc (L+M+Rc); MZc (L+M+Zc); EZc (L+E+Zc). Dez amostras de cada grupo descrito foram testadas em BFS, mais dez amostras foram submetidas à TC (1×104 ciclos de imersão em água entre 5 ºC e 55 ºC), e as últimas 10 amostras foram submetidas à TC/MC (MC: 1.2 ×106 ciclos, 50 N, 3.8 Hz). Foram realizados os testes de BFS e a microscopia eletrônica de varredura (MEV) para avaliar o modo de falha. O efeito da estratégia de cimentação (cimento/substrato) foi comparado em cada método de envelhecimento e o efeito do método de envelhecimento foi avaliado para cada estratégia de cimentação por ANOVA a um fator e teste post-hoc de Tukey (α=0,05). Resultados: Os valores de resistência foram maiores para M (237.8 ~ 463.9 MPa), em comparação com E (41.03 ~ 66.76 MPa), independentemente do envelhecimento e do agente cimentante utilizado. Os dados de resistência à flexão diminuíram após TC e TC/MC nos grupos cimentados com Zc, mas se mantiveram estáveis quando cimentados com Rc. A análise MEV indicou que a origem das falhas estava localizada na superfície de tração do L. Conclusão: Os discos de dissilicato de lítio cimentados ao substrato metálico apresentaram maior resistência à flexão biaxial. A cimentação com cimento resinoso dual não diminuiu o BFS após o envelhecimento (AU)

Color stability and degree of conversion of amine-free dual cured resin cement used with two different translucencies of lithium disilicate ceramics / Estabilidade de cor e grau de conversão de cimento resinoso dual sem amina usado com duas translucidezes diferentes de cerâmica de dissilicato de lítio

Objective: The present study aims to evaluate the color stability and degree of conversion of amine-free dual cured resin cement compared to light cured and amine-containing dual cured resin cements used with two different translucencies of thin esthetic restorations. Material and Methods: A total of 120 specimens were prepared for color stability testing (n=60). The specimens were divided into three main groups according to the resin cement type. Group 1: amine-free dual cured, Group 2: light cured, Group 3: amine-containing dual cured. Each group was further subdivided according to the ceramic translucency into two subgroups: high and low translucency. Color stability was assessed by a spectrophotometer before and after thermal aging. For the degree of conversion assessment (n=60), Fourier transform infrared spectroscopy was used at three different time intervals. Statistical analysis was performed using multi-factorial ANOVA, followed by one-way ANOVA with Bonferroni correction. Results: Amine-containing resin cement showed significantly higher ΔEab and ΔE00in both translucencies (4.5±0.3, 3.5±0.3 respectively for high translucency ceramic and 3.8±0.4, 3.0±0.3 respectively for low translucency) than the other tested cements (p<0.001). The highest degree of conversion (DC) was shown after 2 weeks by the amine-free dual cured resin cement (86.27±0.74). Conclusion: Amine-free dual cured resin cement can be an alternative to light cured one for cementation of thin veneers since it showed comparable color stability and high degree of conversion (AU)

Objetivo: O presente estudo tem como objetivo avaliar a estabilidade de cor e o grau de conversão do cimento resinoso dual sem amina em comparação com cimentos resinosos fotopolimerizáveis contendo amina usados com duas translucidezes diferentes em restaurações estéticas definitivas. Material e Métodos: Um total de 120 espécimes foram preparados para teste de estabilidade de cor (n=60). Os espécimes foram divididos em três grupos principais de acordo com o tipo de cimento resinoso. Grupo 1: polimerização dupla sem amina, Grupo 2: fotopolimerização, Grupo 3: polimerização dupla contendo amina. Cada grupo foi ainda subdividido de acordo com a translucidez da cerâmica em dois subgrupos: alta e baixa translucidez. A estabilidade da cor foi avaliada por um espectrofotômetro antes e após o envelhecimento térmico. Para a avaliação do grau de conversão (n=60), a espectroscopia de infravermelho com transformada de Fourier foi usada em três intervalos de tempo diferentes. A análise estatística foi realizada usando ANOVA multifatorial, seguida de ANOVA um faot com correção de Bonferroni. Resultados: O cimento resinoso contendo amina apresentou ΔEab e ΔE00 significativamente maiores em ambas as translucidezes (4,5±0,3, 3,5±0,3 respectivamente para cerâmica de alta translucidez e 3,8±0,4, 3,0±0,3 respectivamente para baixa translucidez) do que os outros cimentos testados (p< 0,001). O maior grau de conversão (DC) foi mostrado após 2 semanas pelo cimento resinoso dual sem amina (86,27±0,74). Conclusão: O cimento resinoso dual sem amina pode ser uma alternativa ao cimento polimerizável na restauração de facetas finas, uma vez que apresentou estabilidade de cor comparável e alto grau de conversão. (AU).

Mechanical behavior of different machinable ceramic crowns using vertical and horizontal preparations: an in-vitro study / Comportamento mecânico de diferentes coroas cerâmicas usináveis usando preparos verticais e horizontais: um estudo in vitro

Objective: the aim of this study was to compare the mechanical behavior of different ceramics when used in thin vertical preparations versus traditional horizontal preparation. Material and Methods: two stainless-steel dies were milled to simulate a minimally invasive vertical preparation (VP) and a traditional horizontal preparation (HP) for an all-ceramic crown of a maxillary first premolar. The stainless-steel dies were duplicated using epoxy resin. Eighty monolithic crowns were milled and divided into 2 groups according to preparation design. Each design group was subdivided into 4 sub-groups according to material (n=10): IPS e.max CAD (lithium disilicate), Bruxzir shaded zirconia (full contour zirconia), CeraSmart (resin nanoceramic) and CEREC Tessera (advanced lithium disilicate). The crowns were cemented on their relevant epoxy resin dies using self-adhesive resin cement. All specimens were subjected to 15,000 thermocycles and then loaded to fracture in a universal testing machine. Data were analyzed using two-way ANOVA and Tukey pair wise comparison test. Results: the fracture resistance mean values of the VP (1344 + 118 N) was significantly lower than the HP design (1646 + 191 N). Ceramic crowns made of full contour zirconia had higher fracture resistance mean values (2842 + 380 N) than advanced lithium disilicate (1272 + 125 N) followed by lithium disilicate crowns (983 + 52 N) and resin nanoceramic (882 + 61 N). Conclusion: both vertical and horizontal preparations, regardless the different ceramic materials, showed clinically acceptable fracture resistance values. (AU)

Objetivo: o objetivo deste estudo foi comparar o comportamento mecânico de diferentes cerâmicas quando utilizadas em preparos verticais finos ou preparos horizontais tradicionais. Material e Métodos: dois modelos de aço inoxidável foram fresados para simular um preparo vertical minimamente invasivo (PV) e um preparo horizontal tradicional (PH) para uma coroa totalmente em cerâmica de um primeiro pré-molar superior. As matrizes de aço inoxidável foram duplicadas usando resina epóxi. Oitenta coroas monolíticas foram fresadas e divididas em 2 grupos de acordo com o desenho do preparo. Cada grupo foi subdividido em 4 subgrupos de acordo com o material (n=10): IPS e.max CAD (dissilicato de lítio), zircônia Bruxzir (zircônia de contorno total), CeraSmart (resina nanocerâmica) e CEREC Tessera (dissilicato de lítio avançado). As coroas foram cimentadas em suas respectivas matrizes de resina epóxi usando cimento resinoso autoadesivo. Todos os espécimes foram submetidos a 15.000 ciclos térmicos e então carregados até a fratura em uma máquina de teste universal. Os dados foram analisados usando ANOVA com dois fatores e teste de comparação por pares de Tukey. Resultados: os valores médios de resistência à fratura do PV (1344 + 118 N) foram significativamente menores do que PH (1646 + 191 N). As coroas de cerâmica feitas de zircônia de contorno total apresentaram maiores valores médios de resistência à fratura (2842 + 380 N) do que dissilicato de lítio avançado (1272 + 125 N), seguido por coroas de dissilicato de lítio (983 + 52 N) e resina nanocerâmica (882 + 61 N). Conclusão: preparos verticais e horizontais, independentemente dos diferentes materiais cerâmicos, apresentaram valores de resistência à fratura clinicamente aceitáveis. (AU)

Efeito do tipo de sistema de cimentação na força de união de materiais utilizados para coroas livres de metal empregados a pilares intermediários / Effect of the type of cementation system on the bond strength of materials used for metal free crowns to employed for intermediate abutments

O objetivo deste estudo foi avaliar a influência do sistema de cimentação, do tipo de material empregado para confecção do pilar intermediário e do tipo de material empregado para a confecção da coroa na força de união de próteses cimentadas sobre implantes. Para simular o desempenho do pilar noventa espécimes de zircônia (IPS E.MAX ZirCAD, Ivoclar Vivadent) e noventa espécimes de titânio (O'ring Capsule, Peclab) foram obtidos. A rugosidade superficial foi padronizada utilizando-se uma politriz circular com lixa de granulação 600 durante 1 minuto. Os espécimes que simularam as coroas foram confeccionados a partir de blocos de resina (Grandio Blocs, Voco), dissilicato de lítio (IPS E.MAX eCAD, Ivoclar Vivadent) e de zircônia translúcidos (Zirkom, OdontoMega) com 3mm de diâmetro e 4 mm de altura. Cada tipo de material de pilar recebeu a cimentação de todos os três tipos de materiais que simulam as coroas. Para cada combinação foram testados três diferentes cimentos, sendo eles Bifix Hybrid Abutment (Voco), Multilink Abutment (Ivoclar Vivadent) e Vita Adiva (VITA). Os espécimes foram submetidos a um ensaio de cisalhamento a uma velocidade de 1 mm/min. Os dados foram analisados usando ANOVA a três fatores (pilar x coroa x cimento) seguido pelo teste de Tukey (α = 5%). Os resultados mostraram que houve diferenças significativas para o tipo de pilar e de coroa (p<0.05) e para o tipo de cimento (p<0.05). Pode-se observar que o cimento Bifix propiciou uma resistência adesiva significativamente menor que o Vita, enquanto o Multilink resultou em valores intermediários. Observou-se também que a resistência de união ao titânio foi menor do que à zircônia para infraestrutura. A resistência de união entre a zircônia e a zircônia de infraestrutura obtiveram valores significativamente maiores. Podemos concluir que o tipo de sistema de cimentação, o tipo de pilar e o tipo de coroa influenciaram significativamente na força de união entre os espécimes de simularam as coroas e os espécimes que simularam o pilar intermediário. O cimento Bifix Abutment proporcionou os menores valores enquanto o Vita Adiva os maiores. A resistência de união ao pilar de titânio foi menor do que à zircônia para infraestrutura, enquanto a adesão à coroa de resina composta foi menor do que ao dissilicato de lítio, que por sua vez foi menor do que à zircônia translúcida.(AU)

The aim of this study was to evaluate the influence of the cementation system, the type of material used to make the intermediate abutment and the type of material used to make the crown on the bond strength of implant-cemented prostheses. To simulate the performance of the abutment, ninety zirconia specimens (IPS E.MAX ZirCAD, Ivoclar Vivadent) and ninety titanium specimens (O'ring Capsule, Peclab) were obtained. Surface roughness was standardized using a circular polisher with 600-grit sandpaper for 1 minute. The specimens that simulated the crowns were made from resin blocks (Grandio Blocs, Voco), lithium disilicate (IPS E.MAX eCAD, Ivoclar Vivadent) and translucent zirconia blocks (Zirkom, OdontoMega) with 3 mm in diameter and 4 mm height. Each type of abutment material was cemented from all three types of crown-simulating materials. For each combination, three different cements were tested, Bifix Hybrid Abutment (Voco), Multilink Abutment (Ivoclar Vivadent) and Vita Adiva (VITA). Specimens were secured to a shear test at a speed of 1 mm/min. Data were analyzed using three-way ANOVA (abutment x crown x cement) followed by Tukey's test (α = 5%). The results showed significant differences for the type of abutment and crown (p<0.05), and for the type of cement (p<0.05). It can be observed that Bifix cement provided significantly lower bond strength than Vita, while Multilink evolved in intermediate values. It was observed the tensile bond strength was lower than backbone zirconia. The bond strength between zirconia crown and zirconia infrastructure obtained significantly higher values. We can conclude that the type of cementation system, the type of abutment and the type of crown significantly influenced the bond strength between the crowns and the intermediate abutment. Bifix Abutment cement introduced the lowest values while Vita Adiva presented the highest values. The strength adhesion to the titanium abutment was lower than to the infrastructure zirconia, while the adhesion to the composite resin crown was lower than to the lithium disilicate, which in turn was lower than to the translucent zirconia (AU)

Stress distribution in occlusal veneers with different finish lines when applying vertical and tangential forces / Distribución de estrés en carillas con diferentes líneas de terminación aplicando fuerzas verticales y tangenciales

Abstract To evaluate stress distribution when applying vertical and tangential forces to 1mm thick occlusal veneers with different finish lines preparations, using the finite element method. One extracted third molar was prepared for occlusal veneers, firstly without any bevel. It was scanned in order to design two groups of lithium disilicate (G1A, G2A) and composite resin (G1B, G2B) occlusal veneers. Then, the third molar preparation was modified, beveling the finish line and it was subsequently scanned again to design the occlusal veneer groups with bevel (LD: G3A, G4A and CR: G3B, G4B). The four groups were subjected to different forces (400 N vertical and 900 N tangential). At 400 N, the non-beveled veneers showed slightly higher Von Mises stress values (G1A: 783 MPa and G1B 736.5 MPa) than the beveled veneers (G3A: 685.7 MPa and G3B: 675.8 MPa). However, when 900 N tangential forces were applied, the beveled occlusal veneers showed higher Von Mises stress values (G4A: 4297 MPa and G4B: 4133 MPa) than the non-beveled occlusal veneers (G2A: 2581.1 MPa and G2B: 3519.1 MPa). Furthermore, it was observed that the tissue under the occlusal veneers with bevel showed higher Von Mises stress values than the models without any bevel. Beveled and non-beveled occlusal veneers of lithium disilicate and composite resin presented similar stress distribution values when vertical forces of 400 N were applied; whereas with tangential forces of 900 N applied near to the finish line, the beveled groups presented notably higher stress values than the non-beveled groups. However, both finish line preparations presented adequate values for possible clinical performance.

Resumen Evaluar la distribución de estrés al aplicar fuerzas verticales y tangenciales en carillas oclusales de 1mm de espesor con diferentes líneas de terminación marginal por el método de elementos finitos. Se preparó un tercer molar extraído para carilla oclusal, primero sin bisel. Se escaneó para diseñar dos grupos de carillas oclusales de disilicato de litio (G1A, G2A) y resina compuesta (G1B, G2B). Después, esta preparación molar fue modificada, biselando la línea de terminación y escaneándola nuevamente para diseñar los grupos de carillas oclusales con bisel (DL: G3A, G4A and RC: G3B, G4B). Los 4 grupos fueron sometidos a fuerzas diferentes (400 N vertical y 900 N tangencial). Con 400 N, las carillas sin bisel presentaron ligera mayor tensión de Von Mises (G1A: 783 MPa y G1B 736.5 MPa) que las carillas con bisel (G3A: 685.7 MPa y G3B: 675.8 MPa). De distinta forma, al aplicar fuerzas tangenciales de 900 N, las carillas oclusales con bisel presentaron mayor tensión de Von Mises (G4A: 4297 MPa y G4B: 4133 MPa) que las carillas oclusales sin bisel (G2A: 2581.1 MPa y G2B: 3519.1 MPa). Además, se observó que los tejidos subyacentes a las carillas oclusales con bisel, presentaron mayor tensión de Von Mises, frente a los modelos sin bisel. Las carillas oclusales con y sin bisel de disilicato de litio y resina compuesta presentaron una distribución de estrés similar con fuerzas verticales de 400 N, por otro lado, con fuerzas tangenciales de 900 N, los grupos con bisel presentaron notablemente mayor tensión que los grupos sin bisel. Sin embargo, ambos diseños de terminación marginal presentaron valores adecuados para un posible desempeño clínico.

Efecto antisuicida del litio a dosis infraterapéutica, a propósito de un caso / Anti-suicidal effect of lithium at sub-therapeutic doses, a case report

Ha sido bien documentado un efecto antisuicida entratamientos prolongados con Litio, con evidencias dealta calidad en trastorno bipolar y depresión unipolar,demostrado significativamente superior al de otros estabilizadores del ánimo, con reducción del riesgo suicidaen un 50-80%.Presentamos el caso de un varón de 70 años que ingresa en nuestra unidad por intento de ahorcamiento trassuspensión del tratamiento con Litio debido a detecciónde daño renal. Se había mantenido estabilidad clínica desde el debut de la enfermedad con dosis de 1200 mg/d, decidiéndose entonces reducción hasta 600 mg/d, obteniéndose litemias mantenidas en niveles infraterapéuticos de0,32-0,34 mEq/L, persistiendo estabilidad psicopatológicavarios años más. Posteriormente, se realiza retirada progresiva de Litio en un periodo de 6 meses, produciéndoseaproximadamente al mes de la retirada completa descompensación depresiva con delirio de perjuicio, sin mejoríacon pauta antidepresiva y antipsicótica; que culmina en elgesto autolítico mencionado.A pesar de un evidente efecto estabilizador del ánimo,antisuicida y del hecho de que un tercio de pacientes contrastorno bipolar se consideran excelentes respondedoresa Litio en monoterapia, con remisión completa de recaídasafectivas; su uso ha declinado en distintos países durantelas últimas décadas, en favor de otros fármacos con efectoestabilizador del ánimo. (AU)

An antisuicidal effect has been well documented in prolonged Lithium treatments, with high-quality evidence inbipolar disorder and unipolar depression, shown to be significantly superior to other mood stabilizers, with a 50-80%of reduction in suicide risk.We present the case of a 70-year-old man who was admitted to our unit for attempted suicide by hanging afterdiscontinuation of Lithium treatment due to detection ofkidney damage. Clinical stability had been maintained sincethe onset of the disease with a dose of 1200 mg/d, decidingthen to reduce it to 600 mg/d, obtaining maintained infratherapeutic levels of Lithium of 0.32-0.34 mEq/L, persistingpsychopathological stability for several more years.Subsequently, progressive lithium withdrawal is performed over a 6-month period, occurring approximately onemonth after complete withdrawal, depressive decompensation with delusion of harm, without improvement with antidepressant and antipsychotic regimen; culminating in theattempted suicide.Despite an evident mood stabilizing, antisuicidal effectand the fact that one third of patients with bipolar disorderare considered excellent responders to Lithium monotherapy,with complete remission of affective relapses; its use has declined in different countries during the last decades, in favorof other drugs with a mood stabilizing effect. (AU)

Efectos adversos severos de los estabilizadores del ánimo: revisión de la literatura

Introducción: El trastorno bipolar TB es una enfermedad crónica y recurrente, según el DSM 5 se clasifica en los subtipos: trastorno bipolar I, trastorno bipolar II, ciclotimia y categorías residuales de formas atípicas que no encajan en los subtipos antes mencionados. La prevalencia del TB tipo I es similar entre hombres y mujeres, mientras que el TB tipo II ocurre con mayor frecuencia en mujeres. Según la Encuesta nacional de salud mental la prevalencia estimada del trastorno bipolar tipo I en Colombia es del 1,9% en los hombres y del 0,6% en las mujeres, para un porcentaje total de 1,3%. La etiología de TB incluye factores genéticos, neuro bioquímicos, neuro anatómicos, así como médicos y ambientales. El tratamiento del trastorno bipolar se puede dividir en dos fases distintas: manejo de un episodio inicial y tratamiento a largo plazo para prevenir recaídas, los fármacos utilizados comúnmente son: litio, antipsicóticos y anticonvulsivantes. Los estabilizadores del estado del ánimo aceptados por la FDA son: litio, carbamazepina, divalproato, y lamotrigina. Una reacción adversa a medicamentos (RAM) se define como cualquier respuesta nociva y no intencionada a un medicamento, constituye una importante causa de morbimortalidad y de aumento de los costes sanitarios. Los sistemas de farmaco-vigilancia permiten la identificación y prevención de los riesgos asociados al uso de medicamentos. Metodología: Se realizó una búsqueda bibliográfica mediante la base de datos PubMed, utilizando términos MeSH. Los criterios de inclusión utilizados fueron: a) Artículos publicados entre el año 2016 y 2021, b) Idioma inglés o español, c) Población a estudio: pacientes con diagnóstico de trastorno bipolar según criterios del DSM. Resultados: Se encontró que los efectos adversos severos de los estabilizadores del estado del ánimo como la carbamazepina y el ácido valproico son variados, se pueden presentar manifestaciones cutáneas como el síndrome de Stevens-Johnson, necrólisis epidérmica tóxica; manifestaciones hematológicas como anemia aplásica y manifestaciones hepáticas como lo son la hepatotoxicidad e hiperamonemia.

SUMMARY Introduction: Bipolar disorder TB is a chronic and recurrent disease, according to DSM 5 it is classified into subtypes: bipolar I disorder, bipolar II disorder, cyclothymia and residual categories of atypical forms that do not fit into aforementioned subtypes. Prevalence of type I TB is similar between men and women, while type II TB occurs more frequently in women. According to the National Mental Health Survey, estimated prevalence of type I bipolar disorder in Colombia is 1.9% in men and 0.6% in women, for a total percentage of 1.3%. Etiology of TB includes genetic, neuro biochemical, neuro anatomical, as well as medical and environmental factors. Treatment of bipolar disorder can be divided into two phases: management of an initial episode and long-term treatment to prevent relapses, drugs normally used are: Lithium, antipsychotics and anticonvulsants. Mood stabilizers accepted by FDA are: Lithium, carbamazepine, divalproex, and lamotrigine. An adverse drug reaction (ADR) is defined as any harmful and unintended response to a drug, it constitutes a major cause of morbidity and mortality and increased healthcare costs. Pharma-covigilance systems allow identification and prevention of risks associated with use of drugs. Methodology: A graphic search was performed using PubMed database, using MeSH terms. Inclusion criteria used were: a) Articles published between 2016 and 2021, b) English or Spanish language, c) Study population: Patients with a diagnosis of Bipolar Disorder according to DSM criteria. Results: It was found that severe adverse effects of mood stabilizers such as carbamazepine and valproic acid are varied, skin manifestations such as Stevens-Johnson's syndrome, toxic epidermal necrolysis can occur; Hematological manifestations such as aplastic anemia and hepatic manifestations such as hepatotoxicity and hyperammonemia.

Introdução: O transtorno bipolar TB é uma doença crônica e recorrente, segundo o DSM 5 é classificada em subtipos: transtorno bipolar I, transtorno bipolar II, ciclo-timia e categorias residuais de formas atípicas que não se enquadram nos subtipos mencionados. A prevalência de TB tipo I é semelhante entre homens e mulheres, enquanto a TB tipo II ocorre com mais frequência em mulheres. De acordo com a Pesquisa Nacional de Saúde Mental, a prevalência estimada de transtorno bipolar tipo I na Colômbia é de 1,9% nos homens e 0,6% nas mulheres, para um percentual total de 1,3%. A etiologia da TB inclui fatores genéticos, neuro-bioquímicos, neuro-anatômicos, médicos e ambientais. O tratamento do transtorno bipolar pode ser dividido em duas fases distintas: manejo de um episódio inicial e tratamento de longo prazo para prevenção de recidivas, os medicamentos comumente utilizados são: lítio, antipsicóticos e anticonvulsivantes. Os estabilizadores de humor aceitos pela FDA são: lítio, carbamazepina, divalproex e lamotrigina. Uma reação adversa a medicamento (ADR) é definida como qualquer resposta prejudicial e não intencional a um medicamento, é uma das principais causas de morbidade e mortalidade e aumento dos custos de saúde. Os sistemas de farmacovigilância permitem a identificação e prevenção dos riscos associados ao uso de medicamentos. Metodologia: Foi realizada pesquisa bibliográfica na base de dados PubMed, utilizando termos MeSH. Os critérios de inclusão utilizados foram: a) Artigos publicados entre 2016 e 2021, b) Língua inglesa ou espanhola, c) População do estudo: Pacientes com diagnóstico de Bipolar Desordem de acordo com os critérios do DSM. Resultados: Verificou-se que os efeitos adversos graves dos estabilizadores do humor como a carbamazepina e o ácido valpróico são variados, podendo ocorrer manifestações cutâneas como a síndrome de Stevens-Johnson, podendo ocorrer necrólise epidérmica tóxica; Manifestações hematológicas como anemia aplástica e manifestações hepáticas como hepatotoxicidade e hiperamonemia.

Correlation between cognitive performance and structural neuroanatomy in patients with type I bipolar affective disorder treated with and without lithium.

INTRODUCTION: Lithium treatment of bipolar disorder (BD) has been associated with less cognitive impairment and fewer changes in structural brain anatomy compared to other treatments. However, the studies are heterogeneous and few assess whether these effects are related. The objective of this study was to evaluate and relate cognitive performance and structural neuroanatomy in patients treated with and without lithium. METHODS: Cross-sectional study that included 48 subjects with BD-I, of which 22 were treated with lithium and 26 without lithium. Performance was assessed on Wechsler III (WAIS III), TMT A and B (Trial Making Test) neuropsychological tests, California verbal learning test (CVLT), Rey complex figure test and Wisconsin card sorting test. Brain structures obtained by magnetic resonance imaging (MRI) were evaluated. The standardised mean difference (SMD) between both groups was calculated, adjusted for confounding variables using a propensity score, and the Spearman correlation coefficient (ρ) was used to assess the relationship between cognitive performance and neuroanatomical regions. RESULTS: Compared to the group without lithium, the group with lithium had fewer perseverative errors in the Wisconsin test (SMD = -0.69) and greater left and right cortical areas (SMD = 0.85; SMD = 0.92); greater surface area in the left anterior cingulate (SMD = 1.32), right medial orbitofrontal cortex (SMD = 1.17), right superior frontal gyrus (SMD = 0.82), and right and left precentral gyrus (SMD = 1.33; SMD = 0.98); greater volume of the right amygdala (SMD = 0.57), right hippocampus (SMD = 0.66), right putamen (SMD = 0.87) and right thalamus (SMD = .67). In the lithium group, a correlation was found with these errors and the thickness of the left precentral gyrus (ρ = -0.78), the volume of the right thalamus (ρ = -0.44), and the right amygdala (ρ = 0.6). CONCLUSIONS: The lithium group had better cognitive flexibility and greater dimension in some frontal and subcortical cortical regions. Furthermore, there was a moderate to high correlation between performance in this executive function and the thickness of the right precentral gyrus, and the volumes of the thalamus and the right amygdala. These findings could suggest a neuroprotective effect of lithium.

Lithium Intoxication as a cause of reversible dementia mimicking FDG PET features of Alzheimer's disease / Intoxicação por lítio como causa de demência rapidamente progressiva: um relato de caso e revisão da literatura

ABSTRACT. Rapidly progressive dementia (RPD) is a rare neurological disorder. Drug toxicity is among the differential diagnoses, including the use of lithium, in which an overdosage might cause cognitive dysfunction. Clinical suspicion, laboratory confirmation, and drug interruption are key points in the management of lithium intoxication. We described a 66-year-old female patient under treatment with lithium who developed an RPD associated with parkinsonian symptoms. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) showed an "Alzheimer-like" pattern, while cerebrospinal fluid biomarkers for the disease were negative. There was a significant clinical and radiological improvement after lithium interruption. Lithium intoxication is a potentially reversible cause of RPD, as demonstrated in this case report. Drug discontinuation should be considered even in patients with normal levels of this metal, if cognitive impairment is detected. 18F-FDG PET/CT images may show an "Alzheimer-like" image pattern in acute intoxication and are useful for monitoring these patients.

RESUMO. Demência rapidamente progressiva é uma condição rara, cujos diagnósticos diferenciais incluem intoxicação por drogas como lítio, podendo causar importante disfunção cognitiva. A suspeita clínica, a confirmação laboratorial e a interrupção do uso medicamentoso são elementos fundamentais em seu diagnóstico e manejo. Trata-se de paciente feminina, de 66 anos de idade, que apresentou quadro demencial após intoxicação por lítio. Tal quadro foi acompanhado de sintomas parkinsonianos, além de Tomografia por Emissão de Pósitrons com 18F-Fluodeoxiglicose (18F-FDG PET/CT) compatível com padrão "Alzheimer-like". Houve melhora objetiva de parâmetros clínicos e imaginológicos após a interrupção do uso medicamentoso. A intoxicação por lítio é uma causa potencialmente reversível de demência rapidamente progressiva. A descontinuação da droga deve ser considerada também em pacientes com níveis normais do metal no sangue se alterações cognitivas forem encontradas. Imagens 18F-FDG PET/CT podem demonstrar achados sugestivos de doença de Alzheimer na intoxicação aguda e parecem ser um método útil no seguimento.

Correlación entre el desempeño cognitivo y la neuroanatomía estructural en pacientes con trastorno afectivo bipolar tipo I tratados con y sin litio / Correlation Between Cognitive Performance and Structural Neuroanatomy in Patients with Type I Bipolar Affective Disorder Treated with and Without Lithium

RESUMEN Introducción: El tratamiento del trastorno afectivo bipolar (TAB) con litio se ha relacionado con menos deterioro cognitivo y menores cambios en la anatomía estructural cerebral comparado con otros tratamientos. Sin embargo, los estudios son heterogéneos y son pocos los que evalúan si estos efectos están relacionados. El objetivo de este estudio es evaluar y relacionar el desempeno cognitivo y la neuroanatomía estructural en pacientes tratados con y sin litio. Métodos: Estudio de corte trasversal que incluyó a 48 sujetos con TAB I: 22 tratados con litio y 26 sin litio. Se evaluó el desempeno en las pruebas neuropsicológicas Wechsler III (WAIS III), TMTAyB (Trial Making Test), prueba de aprendizaje verbal de California (TAVEC), prueba de Figura compleja de Rey y prueba de clasificación de tarjetas de Wisconsin. Se evaluaron estructuras cerebrales obtenidas por resonancia magnétiva (RM) cerebral. Se calculó la diferencia de medias estandarizada (DME) entre ambos grupos, con ajuste por variables de confusión mediante puntuación de propensión, y se empleó el coeficiente de correlación de Spearman (p) para evaluar la relación existente entre el desempeno cognitivo y las regiones neuroanatómicas. Resultados: Respecto al grupo sin litio, el grupo con litio tuvo menos errores perseverativos en el Wisconsin (DME = -0,69) y mayores áreas corticales derecha e izquierda (DME = 0,85 y DME = 0,92); mayor superficie en el cíngulo anterior izquierdo (DME = 1,32), la corteza orbi-tofrontal medial derecha (DME = 1,17), el giro frontal superior derecho (DME = 0,82), los giros precentrales derecho e izquierdo (DME = 1,33 y DME = 0,98); mayor volumen de la amígdala derecha (DME = 0,57), el hipocampo derecho (DME = 0,66), el putamen derecho (DME = 0,87) y el tálamo derecho (DME = 0,67). En el grupo con litio, se encontró una correlación con dichos errores y el espesor del giro precentral izquierdo (p = -0,78), el volumen del tálamo derecho (p = -0,44) y la amígdala derecha (p = 0,6). Conclusiones: El grupo con litio tuvo mejor flexibilidad cognitiva y mayor dimensión en algunas regiones corticales frontales y subcorticales. Además, hubo correlación moderada a alta entre el desempeno en esta función ejecutiva y el espesor del giro precentral derecho, y los volúmenes del tálamo y la amígdala derecha. Estos hallazgos podrían indicar un efecto neuroprotector del litio

ABSTRACT Introduction: Lithium treatment of bipolar disorder (BD) has been associated with less impairment and fewer changes in structural brain anatomy compared to other treatments. However, the studies are heterogeneous and few assess whether these effects are related. The objective of this study was to evaluate and relate cognitive performance and structural neuroanatomy in patients treated with and without lithium. Methods: Cross-sectional study that included 48 subjects with BD-I, of which 22 were treated with lithium and 26 without lithium. Performance was assessed on Wechsler III (WAIS III), TMT A and B (Trial Making Test) neuropsychological tests, California verbal learning test (CVLT), Rey complex figure test and Wisconsin card sorting test. Brain structures obtained by magnetic resonance imaging (MRI) were evaluated. The standardised mean difference (SMD) between both groups was calculated, adjusted for confounding variables using a propen-sity score, and the Spearman correlation coefficient (p) was used to assess the relationship between cognitive performance and neuroanatomical regions. Results: Compared to the group without lithium, the group with lithium had fewer perse-verative errors in the Wisconsin test (SMD = -0.69) and greater left and right cortical areas (SMD = 0.85; SMD = 0.92); greater surface area in the left anterior cingulate (SMD = 1.32), right medial orbitofrontal cortex (SMD = 1.17), right superior frontal gyrus (SMD = 0.82), and right and left precentral gyrus (SMD = 1.33; SMD = 0.98); greater volume of the right amyg-dala (SMD = 0.57), right hippocampus (SMD = 0.66), right putamen (SMD = 0.87) and right thalamus (SMD=.67). In the lithium group, a correlation was found with these errors and the thickness of the left precentral gyrus (p = -0.78), the volume of the right thalamus (p =-0.44), and the right amygdala (p = 0.6). Conclusions: Thelithium group had better cognitive flexibility and greater dimension in some frontal and subcortical cortical regions. Furthermore, there was a moderate to high correlation between performance in this executive function and the thickness of the right precentral gyrus, and the volumes of the thalamus and the right amygdala. These findings could suggest a neuroprotective effect of lithium.

A Facile Pre-Lithiated Strategy towards High-Performance Li2Se-LiTiO2 Composite Cathode for Li-Se Batteries.

Conventional lithium-ion batteries with a limited energy density are unable to assume the responsibility of energy-structure innovation. Lithium-selenium (Li-Se) batteries are considered to be the next generation energy storage devices since Se cathodes have high volumetric energy density. However, the shuttle effect and volume expansion of Se cathodes severely restrict the commercialization of Li-Se batteries. Herein, a facile solid-phase synthesis method is successfully developed to fabricate novel pre-lithiated Li2Se-LiTiO2 composite cathode materials. Impressively, the rationally designed Li2Se-LiTiO2 composites demonstrate significantly enhanced electrochemical performance. On the one hand, the overpotential of Li2Se-LiTiO2 cathode extremely decreases from 2.93 V to 2.15 V. On the other hand, the specific discharge capacity of Li2Se-LiTiO2 cathode is two times higher than that of Li2Se. Such enhancement is mainly accounted to the emergence of oxygen vacancies during the conversion of Ti4+ into Ti3+, as well as the strong chemisorption of LiTiO2 particles for polyselenides. This facile pre-lithiated strategy underscores the potential importance of embedding Li into Se for boosting electrochemical performance of Se cathode, which is highly expected for high-performance Li-Se batteries to cover a wide range of practical applications.

Lithium and endocrine dysfunction / Litio y disfunción endocrina

Abstract Lithium carbonate is a commonly prescribed drug for bipolar disorders. In addition to its action on the central nervous system, lithium has systemic effects on multiple organs such as kidney, heart, motor end plate, thyroid and parathyroid glands. It can cause hypothyroidism, hyperthyroidism, goiter and oph thalmopathy by different mechanisms. It increases intrathyroid iodine content or compete for iodine transport, resulting in low iodine uptake by the thyroid. It also inhibits the coupling of iodotyrosine residues to form iodothy ronines and inhibits the release of T4 and T3. Lithium has direct actions on parathyroid glands by antagonizing the calcium sensing receptor, which may induce hypercalcemia or even hyperparathyroidism, requiring surgery in some cases. Furthermore, it inhibits the expression of aquaporins, mainly aquaporin 2, in the renal collecting tubule by unknown mechanisms leading to nephrogenic diabetes insipidus. This adverse effect is usually reversible after drug withdrawal. However, some patients may present irreversible kidney damage due to chronic interstitial nephropathy.

Resumen El carbonato de litio es un fármaco que se prescribe comúnmente para el tratamiento de trastornos bipolares. Además de su acción sobre el sistema nervioso central, el litio tiene repercusiones sistémicas, afectando a múltiples órganos como el riñón, el corazón, la placa motora terminal y glándulas tiroides y paratiroides. Puede causar hipotiroidismo, hipertiroidismo, bocio y oftalmopatía por diferentes mecanismos; también aumentar el contenido de yodo intratiroideo o competir por el transporte de yodo, lo que resulta en una baja captación tiroidea de yodo. Inhibe el acoplamiento de residuos de yodotirosina para formar yodotironinas e inhibe la liberación de T4 y T3. Tiene acciones directas sobre las glándulas paratiroides antagonizando el receptor sensor de calcio, lo que puede inducir hipercalcemia e incluso hiperparatiroidismo, y puede requerir cirugía en algunos casos. Inhibe la expresión de acuaporinas en el túbulo colector renal, prin cipalmente acuaporina 2, por mecanismos que aún no se conocen, produciendo diabetes insípida nefrogénica; este efecto adverso suele ser reversible tras la suspensión del fármaco. Sin embargo, algunos pacientes pueden presentar daño renal irreversible por nefropatía intersticial crónica.

Terapia a longo prazo com lítio e o risco de danos renais: revisão integrativa da literatura / Long-term lithium therapy and the risk of kidney damage: integrative literature review

Este estudo objetivou avaliar os potenciais efeitos adversos nos rins associado ao tratamento de longo prazo com lítio em pacientes com transtorno bipolar, a partir de uma revisão integrativa literatura. Os artigos foram identificados nas bases de dados SciELO, Medline (Pubmed) e Biblioteca Virtual em Saúde (BVS), publicados entre 2010 e 2021. Aplicados os critérios de inclusão e exclusão, identificaram-se 18 artigos para a análise. Verificou-se que o tratamento com lítio durante um período prolongado está associado à redução da taxa de filtração glomerular, porém, outras variáveis devem ser consideradas como idade e comorbidades associadas. Por outro lado, não foi associado evolução da doença renal crônica em estágio terminal por uso do medicamento. A investigação dos estudos revelou que a droga em doses terapêuticas e com monitoramento laboratorial contínuo não demonstrou toxicidade ou efeitos colaterais severos nos rins sendo a sua descontinuação relacionada com exarcebações do humor. [au]

This study aimed to assess the potential adverse effects on the kidneys associated with long-term lithium treatment in patients with bipolar disorder, based on an integrative literature review. The articles were identified in the SciELO, Medline (Pubmed) and Virtual Health Library (VHL) databases, published between 2010 and 2021. After applying the inclusion and exclusion criteria, 18 articles were identified for analysis. It was found that treatment with lithium for a prolonged period is associated with a reduction in the glomerular filtration rate, however, other variables must be considered, such as age and associated comorbidities. On the other hand, evolution of end-stage chronic kidney disease due to drug use was not associated. The investigation of the studies revealed that the drug at therapeutic doses and with continuous laboratory monitoring did not show toxicity or severe side effects in the kidneys and its discontinuation was related to mood exacerbations. [au]

Influência da espessura de restaurações cerâmicas a base de dissilicato de lítio para reabilitação oclusal de dentes posteriores: revisão de literatura / Influence of the thickness of lithium disilicate-based ceramic restorations for occlusal rehabilitation of posterior teeth: literature review

Reabilitações estéticas e funcionais são tratamentos realizados com bastante frequência na clínica diária do Cirurgião Dentista. Para tais intervenções existem diversos materiais citados na literatura, dentre eles, amálgama, ligas metálicas, resinas compostas e cerâmicas odontológicas. As cerâmicas apresentam inúmeras vantagens que integram estética e resistência, além de adesão aos tecidos dentários, todavia é alvo de uma vasta discussão a respeito de sua resistência mecânica quando se trata de trabalhos minimamente invasivos. A utilização das restaurações cerâmicas em dentes anteriores, submetidos a estresse mecânico reduzido, quando em condições oclusais satisfatórias, é vastamente citada na literatura, inclusive em espessuras extremamente conservadoras. Entretanto, quando se trata de dentes posteriores, onde as cargas oclusais são aumentadas, a espessura torna-se fator preponderante na utilização de tais materiais. Para esclarecer tais dúvidas, o presente estudo tem como objetivo realizar uma revisão da literatura a respeito da influência da espessura das cerâmicas a base de dissilicato de lítio em dentes posteriores na resistência a fratura de tais restaurações. Foi realizado levantamento bibliográfico de artigos publicados nas bases de dados PubMed, Lilacs, Medline, Scielo e Portal de Periódicos CAPES nos últimos 10 anos e, após a leitura dos resumos, selecionados os artigos presentes nesse trabalho. Conclui-se que cerâmicas a base de dissilicato de lítio de espessuras reduzidas devem ser utilizadas em dentes posteriores com cautela, haja vista a importância do equilíbrio oclusal e dos possíveis hábitos parafuncionais muito frequentes nos nossos pacientes.

Aesthetic and functional rehabilitations are treatments performed quite frequently in the daily clinic of the Dental Surgeon. For such interventions there are several materials cited in the literature, among them, amalgam, metal alloys, composite resins and dental ceramics. Ceramics have numerous advantages that integrate aesthetics and resistance, in addition to adhesion to dental tissues, however, it is the subject of a vast discussion regarding their mechanical resistance when it comes to minimally invasive works. The use of ceramic restorations in anterior teeth, submitted to reduced mechanical stress, when in satisfactory occlusal conditions, is widely cited in the literature, including in extremely conservative thicknesses. However, when it comes to posterior teeth, where occlusal loads are increased, thickness becomes a preponderant factor in the use of such materials. To clarify these doubts, the present study aims to review the literature regarding the influence of the thickness of lithium disilicate ceramics in posterior teeth on the fracture resistance of such restorations. A bibliographic survey of articles published in PubMed, Lilacs, Medline, Scielo and Portal de Periódicos CAPES in the last 10 years was carried out and, after reading the abstracts, the articles present in this work were selected. It is concluded that reduced thickness lithium disilicate ceramics should be used in posterior teeth with caution, given the importance of occlusal balance and possible parafunctional habits that are very common in our patients.

Conductas suicidas en adolescentes: factores de riesgo, fisiopatología y el uso de litio como terapia preventiva / SUICIDAL BEHAVIOURS IN ADOLESCENTS: RISK FACTORS, PATHOPHYSIOLOGY, AND THE USE OF LITHIUM AS A PREVENTIVE THERAPY

El suicidio en adolescentes representa una problemática de salud de suma importancia en la sociedad. El presente trabajo analiza los factores de riesgo asociados a la conducta suicida, sus correlaciones fisiopatológicas y su tratamiento con carbonato de litio. Los factores de riesgo asociados incluyen: el estrés, las crisis vitales propias de la población de estudio, y factores externos como el uso de pantallas y consumo de medios de comunicación. A su vez, las patologías psiquiátricas de base, en especial el trastorno depresivo mayor, se relacionan de manera positiva con conductas suicidas en adolescentes. Las conductas suicidas estarían vinculadas con cambios morfológicos y moleculares en el sistema nervioso. Los estados proinflamatorios mediados principalmente por la enzima glucógeno sintasa quinasa 3 beta (GSK3 ), se observarían con mayor frecuencia en sujetos con conductas suicidas. A su vez, la disminución de la expresión del factor neurotrófico derivado del cerebro (BDNF) a nivel central predispondría a mayor incidencia de suicidio. La alteración del tono serotoninérgico central sería otro factor de riesgo de suicidio en adolescentes. Las alteraciones serotoninérgicas se vincularían con conductas suicidas de tipo violentas, agresivas e impulsivas, con alta prevalencia en población adolescente. El presente trabajo muestra que el efecto anti-suicida del litio estaría mediado por la inhibición de la GSK3 , como así también por el aumento del tono serotoninérgico. De esta forma el litio disminuiría el estado proinflamatorio central, generaría un aumento de BDNF (con incremento de la supervivencia neuronal), con la subsecuente modulación de la respuesta serotoninérgica. Dada la alta prevalencia de suicidio en dicha población, es necesario contar con opciones terapéuticas eficaces y seguras, respaldados por ensayos clínicos que respalden su uso.

Suicide in adolescents represents a critical health problem in society. The present work analyzes the risk factors associated with suicidal behavior, their pathophysiological correlations, and their treatment with lithium carbonate. Associated risk factors include stress, vital crises typical of the study population, and external factors such as the use of screens and consumption of communication media. In turn, primary psychiatric pathologies, especially major depressive disorder, are positively related to suicidal behaviors in adolescents. Suicidal behaviors would be linked to morphological and molecular changes in the nervous system. Pro-inflammatory states mediated mainly by the enzyme glycogen synthase kinase 3 beta (GSK3 ) would be observed more frequently in subjects with suicidal behaviors. In turn, decreased expression of brain-derived neurotrophic factor (BDNF) at the central level would predispose to a higher incidence of suicide. The alteration of the central serotonergic tone would be another risk factor for suicide in adolescents. Serotonergic alterations would be associated with violent, aggressive and impulsive suicidal behaviors, with a high prevalence in the adolescent population.The anti-suicidal effect of lithium might be mediated by the inhibition of GSK3 , as well as the increase in serotonergic tone. In this way, lithium might decrease the central pro-inflammatory state, generate an increase in BDNF (with increased neuronal survival), and subsequently modify the serotonergic response. Given the high prevalence of suicide in this population, it is necessary to have effective and safe therapeutic options supported by clinical trials that support their use.

Transmittance of lithium disilicate ceramic of different thicknesses and opacities with different curing units / Transmitancia de cerámicas de disilicato de litio, de diferentes espesores y opacidades, con diferentes unidades de curado intrabucal

ABSTRACT The aim of this study was to evaluate the amount of radiating energy transmitted through lithium disilicate discs of different thicknesses and opacities with different curing units (CU). Discshaped specimens 8 mm in diameter and 1.5 mm or 0.7 mm thick were designed with Zbrush® and Cura 3D® software, milled from HT and MO IPS e-maxCAD blocks (Ivoclar Vivadent) with Ceramill Mikro 4 (Amann Girrbach, Austria) and processed according to manufacturer instructions. Thickness was checked with a Mitutoyo (México) caliper. Four groups (n=4) were formed: G1(HT/1.5 mm), G2(MO/1.5 mm), G3(HT/0.7 mm) y G4(MO/0.7 mm), and the effect of three CUs: Coltolux (Coltene- Whaledent), LED.C, (Woodpecker Medical Instrument Co.Ltd) and Deepcure L(3M-ESPE) was tested Measurements were taken with a halogen and LED radiometer (Woodpecker® LM-1-Guilin Woodpecker Medical Instrument Co.Ltd) after applying the guide of each CU directly on the reading window (d) and after interposing each of the specimens. The ratio of transmitted energy was determined in each case and data was analyzed with repeated measures ANOVA and Tukey test for multiple comparisons. LED.C: d:1600 mW/cm2, G1: 0.31(0.00), G2: 0.14(0.00) G3: 0.54(0.01), G4: 0.38(0.01); Deepcure L: d:1500 mW/cm2, G1: 0.34(0.01), G2: 0.20(0,00), G3: 0.56(0.01), G4: 0.41(0.02); Coltolux: d:1275 mW/cm2, G1: 0.44(0.01), G2: 0.24(0,00), G3: 0.65(0.01), G4: 0.47(0,00). Statistically significant differences were found among the curing units (P<0.001) and for the interaction CU-thickness (P<0.001) and CU-opacity (P=0.023). Within the conditions of this study, the ratio of light transmitted through lithium disilicate structures is related to their thickness and opacity, and to the curing unit employed.

RESUMEN Uno de los factores relacionados con éxito de las restauraciones y prótesis de cerámica de matriz vítrea es el logro de una fijación adhesiva para lo cual la correcta polimerización del medio de fijación es un requisito fundamental. El objetivo de este trabajo fue valorar la transmitancia de una cerámica a base de disilicato de litio de diferentes opacidades y espesores, con distintas unidades de curado. Probetas con forma de discos de 8mm de diámetro y dos diferentes espesores (1.5 mm y 0.7 mm) fueron diseñadas con Zbrush® y Cura 3D®, maquinadas a partir de bloques HT y MO de IPS e-maxCAD (Ivoclar Vivadent) con Ceramill Mikro 4 (Amann Girrbach, Austria) y procesadas según instrucciones del fabricante. Se obtuvieron cuatro grupos (n=4): G1(HT/1.5 mm), G2(MO/1.5 mm), G3(HT/0.7 mm) y G4(MO/0.7 mm),los espesores se controlaron con un calibre (Mitutoyo, México). A continuación, se registró la irradiancia con cada una de las unidades de curado (UC) Coltolux (Coltene- Whaledent) LED.C, (Woodpecker Medical Instrument Co.Ltd) y Deepcure L(3M-ESPE), aplicadas sobre la ventana de un radiómetro (Halogen and led radiometer Woodpecker® LM-1-Guilin Woodpecker Medical Instrument Co.Ltd) en forma directa (d), y luego de interponer los diferentes especímenes y se calculó la proporción de energía transmitida en cada caso. Los datos se analizaron con ANOVA de medidas repetidas y prueba de Tukey para las comparaciones múltiples. LED.C: d:1600 mw/ cm2, HT/0,7mm: 0,54(0,01), HT/1,5mm:0,31(0); MO/0,7mm: 0,38(0,01), MO/1,5mm: 0,14(0,00); Deepcure L: d:1500 mW/ cm2, HT/0,7 mm: 0,56(0,01), HT/1,5 mm: 0,34(0,01), MO/0,7 mm: 0,41(0,02), MO/1,5 mm: 0,20(0,00); Coltolux: d:1275 mw/ cm2, HT/0,7 mm:0,65 (0,01), HT/1,5 mm:0,44(0,01), MO/0,7 mm: 0,47(0,00), MO/1,5mm: 0,24(0,00). Se encontraron diferencias estadísticamente significativas entre las diferentes unidades de curado (P<0,001), y en la interacción unidades de curado-espesor (P<0,001) y unidades de curado-opacidad (P=0,023). La proporción de energía luminosa transmitida por una estructura de cerámica de disilicato de litio depende del espesor y opacidad de la restauración y de la unidad de curado utilizada.