A feasible in vitro method to evaluate bacterial infiltration in three implant-abutment connection systems / Método in vitro factible para evaluar la infiltración bacteriana en tres sistemas de conexión implante-pilar

Introduction: Microorganism infiltration through the im-plant-abutment interface causes oral health problems such as periimplantitis, leading to implant loss. Materials and Methods: A feasible new method to quantify the Streptococcus mutans (S. mutans) infiltration through the implant-abutment interface gap is introduced in the present work. Internal hexagon (IH; n = 10), external hexagon (EH; n = 10), Morse taper (MT; n = 10), and a control for each group (n = 1) were tested. Bacteria suspension was prepared at 1.5x108 CFU/mL (CFU: colony forming units), and the implants were individually submerged up to the connection level, allowing the bacteria to contact it. The abutment was removed, and bacteria count was performed. Results: The implant sets were tested under normal bacterial growth and early and late biofilm growth conditions. Colony-forming units per mL were obtained, and the results were compared among groups. Differences in bacterial count between the MT and EH (p<0.001) and the MT and IH (p<0.001) groups were significantly higher in the MT-type implant. There was a significant increment of bacterial infiltration in the MTs submitted to late biofilm growth conditions. EH and IH connections are more effective in preventing bacterial infiltration independent of the growth condition. Conclusions: The proposed methodology is feasible to evaluate the infiltration of microorganisms through the implant-abutment interface.

Introducción: La infiltración de microorganismos a través de la interfaz implante-pilar provoca problemas de salud bucal como la periimplantitis, que conduce a la pérdida del implante. Materiales y Métodos: En el presente trabajo se presenta un nuevo método factible para cuantificar la infiltración de Streptococcus mutans (S. mutans) a través de la brecha de la interfaz implante-pilar. Se probaron el hexágono interno (IH; n = 10), el hexágono externo (EH; n = 10), el cono Morse (MT; n = 10) y un control para cada grupo (n = 1). Se preparó una suspensión de bacterias a 1,5x108 UFC/mL y los implantes se sumergieron individualmente hasta el nivel de conexión, permitiendo que las bacterias entraran en contacto con él. Resultados: Se retiró el pilar y se realizó recuento de bacterias. Los conjuntos de implantes se probaron en condiciones de crecimiento bacteriano normal y de crecimiento temprano y tardío de biopelículas. Se obtuvieron unidades formadoras de colonias por ml y los resultados se compararon entre grupos. Las diferencias en el recuento bacteriano entre los grupos MT y EH (p<0,001) y MT e IH (p<0,001) fueron significativamente mayores en el implante tipo MT. Hubo un incremento significativo de la infiltración bacteriana en los MT sometidos a condiciones tardías de crecimiento de biopelículas. Las conexiones EH e IH son más efectivas para prevenir la infiltración bacteriana independientemente de las condiciones de crecimiento. Conclusión: La metodología propuesta es factible para evaluar la infiltración de microorganismos a través de la interfaz implante-pilar.

Influence of different opacities and layering technique of nanotechnology composite resins regarding the wavelength and fluorescence intensity: in vitro study / Influencia de diferentes opacidades y la técnica de estratificación de resinas compuestas de nanotecnología en la longitud de onda e intensidad de fluorescencia: estudio in vitro

Objective: To evaluate the influence of opacity and the layering technique on the fluorescence of different composite resins. Materials and Methods: Two opacities (enamel and dentin) and the layering technique (enamel + dentin) of the composite resins: Filtek® Z350 and Palfique LX5 were evaluated in vitro. Composite resin discs were fabricated using a preformed matrix of 10 mm diameter and 0.5 mm thick for the single opacity groups and 10 mm thick for the layering technique groups, using 2 layers of 0.5 mm thickness of each opacity (n = 5). Specimens were analyzed using the Raman spectroscopy method. Data were analyzed using the Kruskall-wallis and Mann-Whitney U tests. Results: When evaluating the intensity of fluorescence, no statistically significant difference was found when comparing the layering technique and enamel opacity (p2> 0.05) and an increase in the dentin opacity value for both brands of composite resin. Regarding wavelength, no statistically significant difference was found when comparing the layering technique with enamel opacity and dentin opacity for both Filtek® Z350 and Palfique LX5® composite resins (p2 > 0.05). Conclusions: The fluorescence intensity of the layering technique is similar to enamel opacity for both composite resins. Likewise, the wavelength of the layering technique is similar to the enamel opacity and dentin opacity for both brands.

Objetive: Evaluar la influencia de la opacidad y de la técnica de estratificación en la fluorescencia de diferentes resinas compuestas. Materiales y Métodos: Se evaluó in vitro 2 opacidades (Esmalte y Dentina) y la técnica de estratificación (Esmalte + Dentina) de las resinas compuestas: Filtek® Z350 y Palfique LX5. Se fabricaron discos de resina compuesta, utilizando una matriz preformada de 10 mm de diámetro y 0,5 mm de grosor para los grupos de opacidad única y 10 mm de grosor para los grupos de técnica estratificada, utilizando 2 capas de 0,5 mm de cada opacidad (n = 5). Los especímenes se analizaron mediante el método de Espectroscopía Raman. Los datos se analizaron utilizando la prueba de Kruskall-wallis y Prueba U de Mann Whitney. Resultado: Al evaluar la intensidad de fluorescencia no se encontró diferencia estadísticamente significativa entre los pares: Técnica estratificada versus Opacidad Esmalte para ambas marcas de resina compuesta Filtek® Z350 y para Palfique LX5® (p2 > 0,05). Para longitud de onda no se encontró diferencia estadísticamente significativa entre los pares: Técnica estratificada versus Opacidad Esmalte y Técnica estratificada VS Opacidad Dentina para ambas resinas compuesta Filtek® Z350 y Palfique LX5® (p2> 0,05). Conclusión: La intensidad de fluorescencia de la técnica estratificada es similar a la opacidad Esmalte para ambas resinas compuestas. De igual manera la longitud de onda de la técnica estratificada es similar a la opacidad Esmalte y opacidad Dentina para ambas marcas.

Açaí juice stains a glazed resin-modified glass-ionomer cement / Suco de apaí provoca o manchamento do glaze do cimento de ionomero de vidro modificado por resina

ABSTRACT Coloured compounds (anthocyanins) in açaí can stain resin-modified glass-ionomer cement (RMGIC) due to its low staining resistance. Aim The aim of this study was to assess whether açaí compromises the surface colour and roughness of RMGIC in vitro. Materials and Method Disc-shaped specimens (2 mm thick, 8 mm in diameter) of Vitremer™ (3M ESPE, St Paul, MN, USA) were prepared according to the manufacturer 's instructions. The mixture was inserted into a silicone mouldplaced between two mylar strips, and light cured. Specimens were randomly divided into three groups (n=25) according to the solutions to be used for chemical degradation: artificial saliva (control), açaí sorbet and açaí juice. A spectrophotometer CM-2600d/2500d (Konica Minolta, Tokyo, Japan) was used to analyse the colour (CIELa*b* scale). Surface roughness (Ra, mm) was measuredusing theprofilometer Surfcorder SE 1700 (Kosaka Corp, Tokyo, Japan). The specimens were subjected to three daily soaks (6 ml, 15 minutes) for 14 days at 37°C. They were washed in distilled water and placed in fresh saliva (30 minutes in the interval). After the third soak in a day, they were stored in fresh saliva overnight. Outcomes were analysed at baseline (L*, a*, b*, Ra) and after degradation (L'*, a'*, b'*, Ra'). Results The pH values of saliva, sorbet, and juice were 7.0, 3.8, and 4.9, respectively. ΔE* values were 6.6 for saliva, 6.9 for sorbet and 7.8 for juice. There was a significant ΔE* difference between saliva (p=0.005) and juice (p=0.002), and between juice and sorbet (p=0.019), but none between saliva and sorbet (p=0.401). There was no significant Δb* difference between the solutions. No difference between juice and sorbet was observed for Δa*, but they were significantly different from saliva (p<0.001). Brightness (L*) changed significantly. Juice showed the highest ΔE* (7.8) and ΔL* (7.7). No significant change was observed for roughness and there was no difference between the solutions for ARa. Conclusions Açaí and saliva led to unacceptable staining, but no significant roughness changes in the resin-modified glass-ionomer cement.

RESUMO As antocianinas presentes no açaí podem manchar o cimento de ionomero de vidro modificado por resina (CIVMR) devido a baixa resistencia ao manchamento do material. Objetivo O objetivo desse estudo foi avaliar se o açaí compromete a cor e a rugosidade de superficie de um CIVMR in vitro. Materials e Método Amostras (2 mm de espessura, 8 mm de diámetro) de Vitremer™ (3M ESPE, St Paul, MN, USA) foram preparadas de acordo com as instrugoes do fabricante. O materialfoi espatulado, inserido em um molde de silicone colocado entre duas tiras de poliestireno e fotopolimerizado. Após, as amostras foram randomizadas e alocadas em tres grupos (n=25) de acordo com as solugoes usadas para a degradagao química: saliva artificial (controle) e sorbet de açaí e suco de açaí. Utilizou-se o espectrofotometro CM-2600d/2500d (Konica Minolta, Tokyo, Japan) para a análise da cor (escala CIELa*b*) e o rugosímetro Surfcorder SE 1700 (Kosaka Corp, Tokyo, Japan) para a rugosidade de superficie (Ra, mm). As amostras foram submetidas a tres imersoes diárias (6 ml, 15 minutos) em cada solugao por 14 dias a 37°C, tendo sido lavadas em água destilada e mantidas em saliva fresca (30 minutos) nos intervalos. Após a terceira imersao no dia, as amostras foram mantidas em saliva renovada até o dia seguinte. As variáveis foram analisadas antes (L*, a*, b*, Ra) e depois da degradagao química (L'*, a'*, b'*, Ra'). Resultados Os valores de pH da saliva, sorbet e suco foram, respectivamente 7,0, 3,8 e 4,9. Houve diferenga significante para ΔE* entre saliva (p=0.005) e suco (p=0.002) e entre suco e sorbet (p=0.019), mas nao entre saliva e sorbet (p=0.401). Nao foi observada diferenga significante para Δb* entre as solugoes. Nao houve diferenga significante para Δa* entre suco e sorbet, mas eles foram significativamente diferentes da saliva (p<0.001). A luminosidade (L*) mostrou alteragao significante. O suco mostrou os maiores valores de ΔE* (7,8) e ΔL* (7,7)". Nao houve mudanga significante para a rugosidade e nao foi observada diferenga significante entre as solugoes para ARa (p>0.05). Conclusao O açaí e a saliva causaram manchamento inaceitável do glaze do CIVMR e insignificante alteragao da rugosidade.

Assessing the toxicity of one-step-synthesized PEG-coated gold nanoparticles: in vitro and in vivo studies

ABSTRACT Objective To evaluate the in vitro and in vivo toxicities of polyethylene glycol-coated gold nanoparticles synthesized using a one-step process. Methods Gold nanoparticles were prepared via a co-precipitation method using polyethylene glycol, and the synthesis product was characterized. For the in vitro evaluation, a flow cytometry analysis with Annexin V and iodide propidium staining was used to assess cytotoxicity in MG-63 cells labeled with 10, 50, and 100µg/mL of nanoparticle concentration. For the in vivo evaluation, nanoparticles were administered intraperitoneally at a dose of 10mg/kg dose in 10-week-old mice. Toxicity was assessed 24 hours and 7 days after administration via histopathological analysis of various tissues, as well as through renal, hepatic, and hematopoietic evaluations. Results Synthesized nanoparticles exhibited different hydrodynamic sizes depending on the medium: 51.27±1.62nm in water and 268.12±28.45nm (0 hour) in culture medium. They demonstrated a maximum absorbance at 520nm and a zeta potential of -8.419mV. Cellular viability exceeded 90%, with less than 3% early apoptosis, 6% late apoptosis, and 1% necrosis across all labeling conditions, indicating minimal cytotoxicity differences. Histopathological analysis highlighted the accumulation of nanoparticles in the mesentery; however, no lesions or visible agglomeration was observed in the remaining tissues. Renal, hepatic, and hematopoietic analyses showed no significant differences at any time point. Conclusion Polyethylene glycol-coated gold nanoparticles exhibit extremely low toxicity and high biocompatibility, showing promise for future studies.

Evaluación in vitro de la actividad antifúngica de extractos fluidos de Dichrostachys cinerea L. (marabú) frente a Candida albicans

Introducción: La Dichrostachys cinerea L. (marabú) es una planta que crece en Cuba, de la que se estudian propiedades medicinales. La resistencia de levaduras del género Candida a los antifúngicos sintéticos disponibles en la actualidad es cada vez mayor, por lo que se buscan nuevos compuestos de origen vegetal que puedan ser eficaces en el tratamiento de infecciones causadas por este germen. Objetivo: Evaluar la actividad antifúngica in vitro de Dichrostachys cinerea L. contra una cepa de Candida albicans. Métodos: Se realizó un estudio observacional analítico transversal in vitro para evaluar la actividad antifúngica de extractos fluidos de hojas y de tallos de D. cinerea L mediante el método de macrodilución en caldo y como sustancia de referencia el alcohol. Resultados: A través del proceso se mostró la actividad antifúngica del extracto fluido de tallos de D. cinerea L. al 50 % hasta la dilución 1/32, determinada como la concentración mínima inhibitoria; el extracto fluido de hojas al 30 % no logró inhibir el crecimiento de la cepa de Candida albicans ATCC 10231. Conclusiones: La actividad antifúngica del extracto fluido al 50 % de las hojas de Dichrostachys cinerea L. fue efectiva, no así el preparado farmacéutico al 30 %. Se determinó la concentración mínima inhibitoria del extracto fluido de hojas al 50 % y se demostró que ésta superó a la del alcohol al 50 % en tres diluciones contra la Candida albicans.

Introduction: Dichrostachys cinerea L. (marabou) is a plant that grows in Cuba, medicinal properties of this plant are being studied. The resistance of yeasts of the Candida genus to current available synthetic antifungals is increasingly greater. This is why, new compounds of plant origin are being searched for the effective treatment of infections caused by this germ. Objective: To evaluate the in vitro antifungal activity of Dichrostachys cinerea L against a strain of Candida albicans. Methods: An in vitro a cross-sectional analytic observational study was carried out to evaluate the antifungal activity of fluid extracts of D. cinerea L leaves and stems using the broth macro-dilution method and alcohol as the reference substance. Results: Through the process was shown the antifungal activity of the fluid extract of Dichrostachys cinerea L. stems at 50% up to the 1/32 dilution; it was determined as the minimum inhibitory concentration. The leaves fluid extract at 30% failed to inhibit the growth of the Candida albicans ATCC 10231 strain. Conclusions: The antifungal activity of the fluid extract at 50% of the leaves was effective, but not the pharmaceutical preparation at 30%. The minimum inhibitory concentration of the fluid extract of leaves at 50% was determined and it was shown that it exceeded that of alcohol at 50% in three dilutions against Candida albicans.

The influence of different culture media on Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus biofilm formation

Microorganisms such as Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus are frequently isolated in samples of urinary, blood, intestinal, and respiratory infections, among others. These bacteria are also associated with microbial biofilm formation. E. coli, P. aeruginosa, and S. aureus biofilm infections are particularly hard to manage and often associated with nosocomial problems. This study investigated the influence of different culture media on E. coli, P. aeruginosa, and S. aureus biofilm formation. Bacterial performance was evaluated in brain heart infusion broth, Mueller-Hinton broth, or tryptic soy broth, with or without supplementing with different glucose levels (1-5%). The study quantified biofilm biomass and the count of viable biofilm colonies. This is the first study that compares the biofilm formation of E. coli, P. aeruginosa and S. aureus in polystyrene using different culture media and with different glucose concentrations. The most robust growth of E. coli, P. aeruginosa, and S. aureus occurred in brain heart infusion broth supplemented with 5% glucose, Mueller-Hinton broth without glucose, and tryptic soy broth with 2% glucose, respectively. Our data demonstrate that behavioral and morphological characteristics of each bacterium require a specific broth to enhance the growth of these microorganisms. These findings will contribute to future tests for therapeutic alternatives with anti-biofilm potential.

Evaluation of different protocols for culturing mesenchymal stem cells derived from murine bone marrow

ABSTRACT Introduction: Culturing bone marrow mesenchymal stem cells (BM-MSCs) is a key point in different fields of research, including tissue engineering and regenerative medicine and studies of the bone marrow microenvironment. However, isolating and expanding murine BM-MSCs in vitro has challenged researchers due to the low purity and yield of obtained cells. In this study, we aimed to evaluate five different protocols to culture murine BM-MSCs in vitro. Methods: All protocols were based on the adhesion capacity of BM-MSCs to the tissue culture plastic surface and varied in the types of plate, culture media, serum, additional supplementation and initial cell density. Flow cytometry analysis was used to investigate lineage purity after expansion. Results: The expression of CD45 and CD11b was detected in the cultures generated according to all protocols, indicating low purity with the presence of hematopoietic cells and macrophages. The cellular growth rate and morphology varied between the cultures performed according to each protocol. Cells cultured according to protocol 5 (8 × 107cells/plate, Roswell Park Memorial Institute (RPMI) culture medium during first passage and then Iscove's Modified Delbecco's Medium (IMDM) culture medium, both supplemented with 9% fetal bovine serum, 9% horse serum, 12μM L-glutamine) presented the best performance, with a satisfactory growth rate and spindle-shape morphology. Conclusion: Our results point out that the purity and satisfactory growth rate of murine BM-MSC cultures are not easily achieved and additional approaches must be tested for a proper cell expansion.

Actividad antimicrobiana in vitro del extracto de hojas de Bixa orellana L. contra bacterias anaerobias asociadas a la vaginosis bacteriana y Lactobacillus spp / In vitro antimicrobial activity of Bixa orellana L. leaves extract against anaerobic bacteria associated to bacterial vaginosis and Lactobacillus spp.

Objetivos . Describir la actividad antimicrobiana in vitro del extracto metanólico de las hojas de Bixa orellana L. contra las bacterias anaerobias asociadas a la vaginosis bacteriana y Lactobacillus spp. Materiales y métodos . Se incluyeron en el estudio ocho cepas de referencia ATCC; Gardnerella vaginalis, Prevotella bivia, Peptococcus niger, Peptostreptococcus anaerobius, Mobiluncus curtisii, Atopobium vaginae, Veillonella parvula y Lactobacillus crispatus, y 22 aislamientos clínicos; once aislados de Gardnerella vaginalis y once aislados de Lactobacillus. La susceptibilidad antimicrobiana se determinó mediante el método de difusión en agar. La concentración mínima inhibitoria (CMI) y la concentración bactericida mínima (CBM) fueron determinadas utilizando el método de dilución en agar y un método de dilución modificado, respectivamente. Resultados . Todas las cepas de referencia ATCC tuvieron un alto nivel de susceptibilidad al extracto, con excepción de P. vibia, V. parvula y L. crispatus. Interesantemente, los aislamientos clínicos de G. vaginalis y la cepa ATCC de G. vaginalis fueron los más susceptibles al extracto dados los bajos valores de CMI (1,0 - 2,0 mg/mL) y CBM (1,0 - 4,0 mg/mL), mientras que, los aislamientos clínicos de Lactobacillus spp. y la cepa ATCC de L. crispatus fueron los menos susceptibles debido a los altos valores de CMI (32,0 mg/mL) y CBM (≥ 32,0 mg/mL). Conclusiones . Los experimentos in vitro sugieren que el extracto posee propiedades antibacterianas selectivas dada su alta actividad contra bacterias anaerobias asociadas a vaginosis bacteriana y baja actividad contra especies de Lactobacillus.

Objective. To describe the in vitro antimicrobial activity of the methanolic extract of Bixa orellana L. leaves against anaerobic bacteria associated to bacterial vaginosis and Lactobacillus spp. Materials and methods. Eight ATCC reference strains; Gardnerella vaginalis, Prevotella bivia, Peptococcus niger, Peptostreptococcus anaerobius, Mobiluncus curtisii, Atopobium vaginae, Veillonella parvula, and Lactobacillus crispatus, and twenty-two clinical isolates; eleven Gardnerella vaginalis and eleven Lactobacillus strains, were included in the study. The antimicrobial susceptibility was determined by the agar diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by using agar dilution and a modified dilution plating method, respectively. Results. All ATCC reference strains showed high levels of susceptibility to the extract, except P. vibia, V. parvula and L. crispatus. Interestingly, all G. vaginalis clinical isolates and the G. vaginalis ATTC strain were the most susceptible to the extract, given their low MIC (1.0 - 2.0 mg/mL) and MBC (1.0 - 4.0 mg/mL) values, whereas, the Lactobacillus spp. clinical isolates and the L. crispatus ATCC strain were the least susceptible bacteria given their high MIC (32.0 mg/mL) and MBC (≥ 32.0 mg/mL) values. Conclusions. In vitro experiments suggest that the extract possesses selective antimicrobial properties given its high activity against bacterial vaginosis-associated anaerobic bacteria and low activity against Lactobacillus species.

Avaliação da composição química de um óleo de copaíba (Copaifera spp) e seu efeito em células-tronco mesenquimais / Evaluation of the chemical composition of a copaiba oil (Copaifera spp) and its effect on mesenchymal stem cells

A oleorresina obtida de copaíferas é amplamente utilizada na medicina tradicional brasileira. Este estudo avaliou a composição química por Cromatografia Gasosa (CG) e o efeito da oleorresina de Copaifera officinalis em células-tronco. Para isso as células foram tratadas com a oleorresina nas concentrações de 0,5, 20, 110, 140, 170 ou 200 µg/ml por 24h. A avaliação por CG identificou os sesquiterpenos ß-cariofileno, trans-α-bergamoteno e óxido de cariofileno II como os compostos majoritários da oleorresina. As menores concentrações de oleorresina utilizadas apresentaram resultados semelhantes ao grupo controle e as maiores concentrações diminuíram significativamente a viabilidade celular e apresentaram maior citotoxicidade. Como conclusão, os principais componentes encontrados na oleorresina de copaíba foram os sesquiterpenos e as baixas concentrações testadas não foram citotóxicas. O aumento das concentrações de oleorresina de copaíba promoveu diminuição da viabilidade celular e aumento dos efeitos citotóxicos nas células-tronco. Embora a oleorresina de copaíba tenha uso etnofarmacológico na cicatrização, este estudo demonstrou efeito citotóxico em células-tronco, as quais estão relacionadas ao processo de regeneração corpóreo. Portanto, deve-se ter cuidado com a dosagem de oleorresina a ser utilizada, uma vez que este estudo in vitro mostrou citotoxicidade e um impacto negativo na viabilidade das células-tronco nas mais altas concentrações testadas. [au]

Oleoresinobtained from Copaifera trees is extensively used in Brazilian traditional medicine. This study hasevaluated the chemical composition and effect of Copaifera officinalisoleoresin on stem cells. The oleoresin was analyzed by Gas Chromatography (GC) and the cells were treated with the oleoresin at concentrations of 0.5, 20, 110, 140, 170 or 200 µg/ml for 24h for cellular tests. GC identified the sesquiterpenes beta-caryophyllene, trans-alpha-bergamotene, and caryophyllene oxide II as the main compounds in oleoresin. The cell viability and cytotoxicity assays showed the lowest concentrations of oleoresin used presented similar results to the control group and the higher concentrations tested significantly decreased cell viability and increased cytotoxicity. In a conclusion, the main components found in copaiba oleoresin were sesquiterpenes and the low tested concentrations were not cytotoxic. The increased concentrations of copaiba oleoresin promoted a decrease in cell viability and an increase of cytotoxicity in the stem cells. Although copaiba oleoresin has ethnopharmacology use in healing, this study showed toxicity in stem cells, which are related to the corporeal regeneration process. Therefore, caution must be taken with the dosage of the oleoresin to be used since this in vitro study showed cytotoxicity and a negative impact on stem cell viability at the higher tested concentrations. [au]

Parámetros para la evaluación visual e instrumental del color dental en estudios in-vitro. Revisión de la literatura / Parameters for visual and instrumental assessment of tooth colour in in-vitro studies. Literature review

Objetivo: establecer los parámetros para la evaluación visual e instrumental del color dental en estudios in-vitro a partir de la literatura científca publicada entre 2015 y 2021. Métodos: se realizó la búsqueda en las bases de datos: PubMed, Web of Science, Science Direct, Scopus, Scielo y Lilacs; también en el motor de búsqueda Google Académico y las bibliotecas de las editoriales Wiley y Springer. Las palabras clave utilizadas fueron tooth, color, in-vitro, color perception, shade matching, thresholds, appearance, surrounding, "CIELAB" y "CIEDE2000". Teniendo en cuenta los criterios de elegibilidad, se seleccionaron los estudios de acuerdo al título, resumen y texto completo. Resultados: la búsqueda arrojó un total de 37 publicaciones que se agruparon en tres tópicos: 1. toma de color visual: condiciones ambientales, observadores y nivelación; 2. toma de color instrumental: instrumentos; y 3. procesamiento de datos: cálculo de la diferencia de color y umbrales de perceptibilidad (PT) y aceptabilidad (AT). Conclusiones: los aspectos más importantes en la evaluación visual son la iluminación, el ambiente para registro (sitio, entorno y fondo alrededor de la muestra), las condiciones geométricas de visualización, los observadores y el uso de guías. En la evaluación instrumental es relevante elegir el aparato apropiado de acuerdo con su precisión y reproducibilidad, como los espectroradiómetros y los espectrofotómetros de uso clínico. Se presenta el procesamiento de datos para establecer las variaciones de cada coordenada, las diferencias de color (ΔE): CIELAB y CIEDE2000, los umbrales y los lineamientos.

Objective: To establish the parameters for the visual and instrumental evaluation of tooth color in in-vitro studies based on the scientifc literature published between 2015 and 2021. Methods: The search was carried out in the databases of PubMed, Web of Science, Science Direct, Scopus, Scielo, Lilacs; search engine Google Scholar and publishers' library of Wiley and Scielo, using the keywords "tooth", "color", "in vitro", "color perception", "shade matching", "thresholds", "appearance", "surrounding", "CIELAB", and "CIEDE2000". The literature was selected according to the title, abstract and full text taking into the eligibility criteria. Results: It yielded a total of 37 publications, which were grouped into three topics: 1. visual color acquisition: environmental conditions for color acquisition, observers and levelling. 2. instrumental color sampling: instruments. 3. Data processing: Calculation of color diference and perception thresholds (PT) and acceptability thresholds (AT). Conclusions: The most important aspects in the visual assessment are lighting, the environment for color registration (site, environment and background around the sample), the geometric conditions of visualization, the observers and the use of guides. Regarding the instrumental assessment of color, the appropriate devices must be chosen according to its precision and reproducibility, being the spectrophotometers and spectroradiometers the most precise ones. It is presented how the data processing is carried out to establish the variations of each coordinate, the color diferences (ΔE): CIELAB and CIEDE2000, thresholds and guidelines.

Atividade fotoprotetora e antioxidante de compostos fenólicos: uma revisão sistemática de testes in vitro / Photoprotective and antioxidant activity of phenolic compounds: a systematic review of in vitro tests / Actividad fotoprotectora y antioxidante de compuestos fenólicos: una revisión sistemática de ensayos in vitro

RESUMO Introdução: Os compostos fenólicos, devido a sua estrutura química, possuem a capacidade de absorver a energia ultravioleta e reduzir a formação de radicais livres. Objetivo: Avaliar a atividade fotoprotetora e antioxidante de compostos fenólicos a partir da observação de resultados in vitro e verificar a importância do uso de modelos biológicos nessa perspectiva. Metodologia: Foi realizada uma pesquisa de artigos publicados, na base de dados Pubmed, entre 2010 e 2020, que atendessem aos objetivos deste trabalho, 44 artigos foram selecionados. Resultados: Os métodos instrumentais utilizados para avaliação da atividade fotoprotetora apresentaram boa correlação in vivo e mostram-se rápidos e eficazes na determinação do fator de proteção solar. Além desses, têm-se aplicado métodos biológicos para a avaliação de aspectos que não são mensurados por métodos físico-químicos, relacionado aos danos ao DNA, decorrentes da exposição solar. Para a avaliação da atividade antioxidante, o método do radical DPPH foi empregado em 92,6 % dos estudos analisados e foi observado que os antioxidantes podem incrementar a proteção solar e, ainda, auxiliar na estabilidade de filtros solares sintéticos. Conclusão: Os compostos fenólicos, especialmente aqueles com propriedades antioxidantes, podem ser utilizados como agentes fotoprotetores em formulações tópicas para reduzir os danos à pele induzidos pela radiação UV.

SUMMARY Introduction: Phenolic compounds, due to their chemical structure, can absorb ultraviolet energy and reduce the formation of free radicals. Aim: To evaluate the photoprotective and antioxidant activity of phenolic compounds from the observation of in vitro results and to verify the importance of the use of biological models in this perspective. Methodology: A search for articles published in the Pubmed database was carried out between 2010 and 2020, which met the objectives of this work, 44 articles were selected. Results: According to the literature, the instrumental methods used to assess independent photoprotective activity, good correlation in vivo, and demonstrating rapid and effective determination of the sun protection factor. In addition to these, biological methods have been provided for the evaluation of aspects not measured by physical-chemical methods, related to DNA damage, resulting from sun exposure. For the evaluation of antioxidant activity, the DPPH radical method was registered in 92.6 % of published studies and it was observed that antioxidants can increase sun protection and also help in the stability of synthetic sunscreens. Conclusion: Phenolic compounds, especially with antioxidant properties, can be used as photoprotective agents in topical formulations to reduce skin damage induced by UV radiation.

RESUMEN Introducción: Los compuestos fenólicos, por su estructura química, tienen la capacidad de absorber la energía ultravioleta y reducir la formación de radicales libres. Objetivo: Evaluar la actividad fotoprotectora y antioxidante de compuestos fenólicos a partir de la observación de resultados in vitro y comprobar la importancia del uso de modelos biológicos en esta perspectiva. Metodología: Se realizó una búsqueda de artículos publicados en la base de datos Pubmed entre 2010 y 2020, que cumplieron con los objetivos de este trabajo, se seleccionaron 44 artículos. Resultados: Los métodos instrumentales utilizados para evaluar la actividad fotoprotectora mostraron una buena correlación in vivo y demostraron ser rápidos y eficientes en la determinación del factor de protección solar. Además de estos, se aplicaron métodos biológicos para evaluar aspectos no medidos por métodos físico-químicos, relacionados con el daño en el ADN por exposición solar. Para la evaluación de la actividad antioxidante se utilizó el método radical DPPH en el 92,6% de los estudios analizados y se observó que los antioxidantes pueden aumentar la protección solar y también ayudar en la estabilidad de los protectores solares sintéticos. Conclusión: Los compuestos fenólicos, especialmente aquellos con propiedades antioxidantes, pueden utilizarse como agentes fotoprotectores en formulaciones tópicas para reducir el daño cutáneo inducido por la radiación UV.

Estudo comparativo para avaliação da eficácia cicatrizante de formulações tópicas contendo Triticum aestivum L. (sinônimo Triticum vulgare) em modelo de pele humana nativa / Comparative study to evaluate the wound healing efficacy of topical formulations containing Triticum aestivum L. (Triticum vulgare) in a native human skin model

Introdução: extratos vegetais e ativos derivados de plantas tem sido desenvolvidos com o objetivo de melhorar e potencializar o processo de cicatrização cutânea, dentre eles, o Triticum aestivum L. (sinônimo Triticum vulgare). Objetivo: avaliar o efeito do extrato de grão inteiro (EGTA-PR) e extrato aquoso (EATA-FI) de Triticum aestivum L. na cicatrização cutânea em pele humana ex vivo. Métodos: fragmentos de pele obtidos de cirurgia plástica eletiva foram submetidos a lesões teciduais e tratados com os extratos durante oito dias para avaliação histológica da reepitelização e marcação proteica do fator de crescimento epidérmico (EGF). Resultados: EGTA-PR e EATA-FI aceleraram o processo de reepitelização em cultura de pele humana submetida a lesão tecidual. Adicionalmente, foi observado um aumento da marcação proteica de EGF após o tratamento com EGTA-PR. Conclusão: EGTA-PR apresentou um melhor desempenho na reepitelização quando comparado ao EATA-FI, pois apresentou uma maior marcação proteica para EGF em cultura de pele humana. Da mesma forma, os resultados histológicos mostraram que a redensificação dérmica obtida com o EGTA-PR foi visualmente superior à observada com EATA-FI. Os resultados obtidos são promissores e corroboram as diversas ações biológicas já reportadas na literatura para extrato de Triticum aestivum L. nas etapas da cicatrização tecidual.

Introduction: Plant extracts and actives derived from plants were developed to improve and enhance the skin healing process including Triticum aestivum L. (Triticum vulgare). Purpose: To evaluate the effect of whole grain extract (EGTA-PR) and aqueous extract (EATA-FI) of Triticum aestivum L., on ex vivo skin healing. Methods: Skin fragments obtained from elective plastic surgery were subjected to tissue damage and treated with extracts for eight days for histological evaluation of re-epithelialization and immunofluorescence for epidermal growth factor (EGF). Results: EGTA-PR and EATA-FI accelerated the re-epithelialization process in human skin culture submitted to tissue injury. Additionally, we observed increased EGF protein labeling after treatment with EGTA-PR. Conclusion: EGTA-PR showed a better performance in re-epithelialization when compared to EATA-FI, as it presented a higher protein labeling for EGF in human skin culture. Likewise, the histological results showed that the dermal redensification obtained with EGTA-PR was visually superior to that observed with EATA-FI. The results obtained are promising and corroborate the several biological actions already reported in the literature for Triticum aestivum L. extract in tissue healing stages

Establishment and functional identification of in vitro culture system of small intestine organoid in normal mice / 中华肾脏病杂志

Objective:To establish an in vitro culture system of small intestinal organoid in normal mice and perform functional identification, and to provide an in vitro research tool for material transport in the intestine under chronic kidney disease. Methods:The small intestinal crypts of C57BL/6J mice were isolated, extracted and cultured in an in vitro three dimension culture system. The formation of small intestinal organoid was observed with inverted microscope. The tissue structure of the small intestinal organoid was observed by hematoxylin and eosin staining. The cellular composition of the small intestinal organoid was identified by immunofluorescence. The expression of substance absorption-related transporters in the small intestinal organoid was detected by real time fluorescence quantitative PCR. Results:The small intestinal crypts were successfully extracted. The organoids of small intestine and different intestinal segments were successfully constructed. The cultured organoids had vigorous proliferation ability and maintained proliferation ability after passing through generations. Immunofluorescence results showed that the small intestinal organoids expressed mucin2, chromogranin A, oflm4 and lysozyme, which were different types of intestinal cell biomarkers. The PCR results showed that small intestinal organoids expressed calcium, phosphate and sodium absorption-related transporters, and the mRNA expression levels of major transporters for sodium and phosphate absorption in different intestinal segments-like organs were consistent with those in vivo, which was consistent with the characteristics of small intestinal segmental absorption. Conclusions:The successful construction of small intestine and different intestinal segments organoids, and the first observation of the expression of substance absorption-related transporters in such organoid, provide a stable and convenient in vitro research tool for the development of intestinal substance transport in chronic kidney disease.

A review of alternative methods to the use of animals in safety evaluation of cosmetics

ABSTRACT Alternative methods to the use of animals in research have been a global trend, mainly after the publication of the 3R's principle (Replacement, Reduction, and Refinement), proposed by Russel and Burch. In the cosmetic sector, safety and efficacy assessments using animals have generated controversial debates. For this reason, in vitro research techniques are widely used to assess acute toxicity; corrosivity and irritation; skin sensitization; dermal and percutaneous absorption; repeated dose toxicity; reproductive toxicity; mutagenicity and genotoxicity; carcinogenicity; toxicokinetic studies; photo-induced toxicity; and human data. Although there are many methodologies described, validated, and widely used in the cosmetic area, the evaluation of the safety of cosmetic ingredients and products is still an expanding field. It needs global collaboration among regulatory agencies, universities, and industry, to meet several unmet needs in the fields of sensitization, carcinogenicity, systemic action, among other issues involving safety of users of cosmetic products. This review article will cover the currently most relevant in vitro models regarding irritation, corrosion, sensitization, mutagenicity, genotoxicity, and phototoxicity, to help to choose the most appropriate test for evaluating the safety and toxicity of cosmetic ingredients and products.

Effect of implant crestal position on primary stability before and after loading: an in vitro study / Efeito do posicionamento crestal do implante na estabilidade primária antes e após carga: um estudo in vitro

Introduction: Primary stability is one of the goals of modern implant dentistry and if achieved, reduces treatment time for prosthetic rehabilitation and the number of interventions made in patients mouth. Several companies state as protocol for connical conection implants, a subcrestally positioning. Objective: This in vitro study aimed to evaluate the effect of placing a conical connection implant equicrestally and subcrestally on static and loading condition in two types of bone density. Material and method: A total of 200 bone cylinders were extracted from femur of pigs, standardized by means of x-rays and computerized microtomography scan (microCT) and separated in low and high density specimens. The implants were placed on the center of the bone cylinders and were evaluated before and after loading by means of microCT and histomorphometry. Result: The results showed that placing the evaluated implant subcrestally provided better primary stability and performance on static and loading situations on low and high density bone. Conclusion: Placing implant subcrestally improve primary stability outcomes under loading and static situations.

Introdução: A estabilidade primária é um dos objetivos da implantodontia moderna e, caso atingida, reduz o tempo de tratamento para a reabilitação protéticas e o número de intervenções realizadas. Diversas empresas preconizam a posição subcrestal no uso de implantes com conexão cônica interna. Objetivo: Este estudo in vitro avaliou o efeito do posicionamento de implantes de conexão conica interna sub e equicrestal sob condições estáticas e em função, considerando dois tipos de densidades ósseas. Material e método: um total de 200 espécimes de osso extraído do femur de suínos e padronizados por meio de radiografias e microtomografias computadorizadas foram separados em densidade alta e baixa. Implantes foram instalados no centro dos especimes e for a avaliados por meio de microCT e histomorfometria. Resultado: Os resultados demonstraram que a colocação de implante subcrestalmente promoveu melhor estabilidade primária e performance em todas as situações, irrespectivamente à densidade óssea. Conclusão: A colocação de implantes subcrestalmente melhora a estabilidade primária em todas as situações, sendo indicada quando da utilização de conexões cônicas internas.

Estrategias para la evaluación de extractos de polifenoles en modelos in vitro de cáncer de vías digestivas / Strategies for Evaluation of Polyphenol Extracts on in vitro Models of Digestive Tract Cancer / Estratégias para a avaliação de extratos de polifenóis em modelos in vitro de câncer do sistema digestivo

Introducción: Los polifenoles son compuestos que se encuentran naturalmente en alimentos como frutas, verduras, té, vino y chocolates, a los que se les atribuyen beneficios a la salud humana por su capacidad antioxidante. El cáncer de las vías digestivas se encuentra entre la tercera y quinta causas de muerte para la población, por lo que se ha incrementado el interés por realizar los estudios dirigidos a encontrar compuestos polifenólicos que ayuden en su prevención o tratamiento. Objetivo: Identificar las estrategias disponibles para la evaluación de polifenoles en células de cáncer de vías digestivas. Metodología: Búsqueda de literatura en bases de datos como Ovid, Pubmed, Science Direct y Elsevier Journal. Se seleccionaron artículos en los cuales se reporta el efecto biológico de los polifenoles sobre líneas celulares de cáncer de vías digestivas publicados entre 2012 y 2022. Resultados: Varios estudios han reportado el uso de un buen número de líneas celulares como modelos in vitropara estudios de polifenoles en cáncer y han resaltado las líneas AGS y HT-29, además de técnicas para la caracterización de los polifenoles, como el ensayo 2,2-Difenil-I-Picril Hidrazilo (DPPH). Sin embargo, para evaluar el efecto biológico se identifican diversas pruebas que deben analizarse antes de su implementación. Conclusiones: En la literatura se identifica que existen varias alternativas y estrategias para la evaluación de extrac-tos vegetales en cultivos in vitro de cáncer de vías digestivas; no obstante, antes de pasar al diseño experimental, deben tenerse en cuenta una serie de consideraciones para garantizar la utilidad de los resultados.

Introduction: Polyphenols are compounds naturally found in foods such as fruits, vegetables, tea, wine and chocolates, and it was attributed with benefits to human health due to their antioxidant capacity. Cancer of the digestive tract is between the third and fifth cause of death for the population, increasing the interest in carrying out studies aimed at finding polyphenolic compounds that help in their prevention or treatment. Objective: Identify the available strategies for the evaluation of polyphenols in digestive tract cancer cells. Method: A literature search was performed in databases such Ovid, Pubmed, Science Direct and Elsevier Journal and selected articles reporting the biological effect of polyphenols on digestive tract cancer cell lines, published between 2012 and 2022. Results: Currently studies report the use of a good number of cell lines as in vitro models for poly-phenol studies in cancer highlighting the AGS and HT-29 lines, in addition to techniques for the characterization of polyphenols such as the α, α-diphenyl-ß-picrylhydrazyl DPPH assay, however, to evaluate the biological effect various tests are identified that should be analyzed before implemen-tation. Conclusions: The literature identifies that there are many alternatives and strategies for the evaluation of plant extracts in in vitro cultures of digestive tract cancer, however, before moving on to the experimental design, a number of considerations should be taken into account to ensure the usability of the results

Introdução: Os polifenóis são compostos encontrados naturalmente em alimentos como frutas, legumes, chá, vinho e chocolates, aos quais são atribuídos benefícios para a saúde humana devido à sua capacidade antioxidante. O câncer do sistema digestivo está entre a terceira e a quinta principais causas de morte na população, o que levou a um interesse crescente em estudos destinados a encon-trar compostos polifenólicos que ajudem a prevenir ou tratar esse tipo de câncer. Objetivo: Identificar as estratégias disponíveis para a avaliação dos polifenóis nas células cancerosas do sistema digestivo. Metodologia: Pesquisa bibliográfica em bases de dados como Ovid, Pubmed, Science Direct e Elsevier Journal. Foram selecionados artigos que relatam o efeito biológico dos polifenóis em linhas celulares de câncer do sistema digestivo, publicados entre 2012 e 2022. Resultados: Vários estudos relataram a utilização de várias linhas celulares como modelos in vitro para estudos de polifenóis no câncer destacando as linhas AGS e HT-29, bem como técnicas para a ca-racterização de polifenóis, como o ensaio 2,2-Difenil-I-Picril Hidrazil (DPPH). No entanto, para avaliar o efeito biológico, são identificados vários testes que devem ser analisados antes da sua aplicação. Conclusões: A literatura identifica que existem várias alternativas e estratégias para a avaliação de extratos de plantas em culturas in vitro de câncer do sistema digestivo; no entanto, antes de passar à concepção experimental, é necessário ter em conta uma série de considerações para garantir a uti-lidade dos resultados

Alimentos con potencial efecto inmunomodulador y antiviral a propósito de la pandemia COVID-19 / Potential Immunomodulatory and Antiviral Food Effect in The Context of COVID-19 Pandemic

Resumen Antecedentes: los tratamientos con base en medicamentos contra la COVID-19 no han sido aprobados hasta la actualidad. La forma más efectiva de enfrentar este problema de salud pública es la prevención con una adecuada alimentación, medidas de higiene y protección. Los alimentos han sido históricamente utilizados por la población para mejorar su nutrición y complementar el tratamiento o prevención de enfermedades. Se conocen los diversos compuestos bioactivos de algunos alimentos, que en estudios experimentales demostraron su acción antiviral e inmunomoduladora. Objetivo: identificar los compuestos bioactivos o preparados de alimentos con potencial efecto inmunomodulador, inmunoestimulante y antiviral contra el coronavirus. Materiales y métodos: se realizó una búsqueda en Google Scholar, Scopus y en la Biblioteca Virtual de Salud en Bases de datos de Medicina Tradicional, Complementaria e Integrativa utilizando los términos food, immunomodulatory, immunostimulatory y antiviral en cuatro búsquedas sucesivas. Resultados: se obtuvieron 93 artículos y se identificó mayor evidencia sobre el efecto antiviral e inmunológico contra el coronavirus en nueve alimentos: Allium sativum, Cinnamomum zeylanicum, Citrus sinensis, Zingiber officinale, Vitis vinífera, Allium cepa, Curcuma longa, Punica granatum y Sambucus nigra. Los cuatro primeros mostraron actividad contra el SARS-CoV-2. Conclusiones: se evidenció el efecto inmunológico y antiviral contra el coronavirus de nueve alimentos; sin embargo, son estudios in silico e in vitro, por ello se requiere mayor investigación preclínica y clínica que lo confirmen.

Abstract Background: Up to date drug-based treatments for COVID-19 have not been approved. The most effective way to face this public health problem is prevention with adequate nutrition, hygiene, and protection measures. Food has historically been used by people to improve their nutrition and complement the treatment or prevention of diseases. The various bioactive compounds of some foods are known, which in experimental studies demonstrated their antiviral and immunomodulatory action. Objective: To identify bioactive compounds of foods or food preparations with potential immunomodulatory, immunostimulatory, and antiviral effects against coronavirus. Material and Methods: A search was carried out in Google Scholar, Scopus, and Virtual Health Library on Traditional Complementary and Integrative Medicine using the terms food, immunomodulatory, immunostimulatory, and antiviral in four successive searches. Results: 93 articles were obtained, and further evidence of antiviral and immunological effect against coronavirus was identified on nine foods: Allium sativum, Cinnamomum zeylanicum, Citrus sinensis, Zingiber officinale, Vitis vinifera, Allium cepa, Curcuma longa, Punica granatum, and Sambucus nigra. The first four of them showed activity against SARS-CoV-2. Conclusions: The immunological and antiviral effect against coronavirus of nine foods was evidenced; however, they are in silico and in vitro studies, therefore it is required further preclinical and clinical research to confirm this.

Direct pedicle screw insertion pullout strength / Resistência ao arrancamento do parafuso pedicular de inserção direta

ABSTRACT Objective: Study the in vitro pullout strength of SpineGuard/Zavation Dynamic Surgical Guidance Z-Direct Screw (DSG Screw), a screw pedicle designed to be inserted using a direct insertion technique. Methods: DSG Screws of 5.5 mm and 6.5 mm were introduced into polyurethane blocks with a density of 10 PCF (0,16 g/cm3). According to the experimental group, screws were inserted without pilot hole, with pilot without tapping, undertapping and line-to-line tapping. Screw pullout tests were performed using a universal test machine after screw insertion into polyurethane blocks. Results: Screws inserted directly into the polyurethane blocks without pilot hole and tapping showed a statistically higher pullout strength. Insertion of the screw without tapping or with undertapping increases the pullout screw strength compared to line-to-line tapping. Conclusion: DSG Screw showed the highest pullout strength after its insertion without pilot hole and tapping. Level of Evidence V, Expert Opinion.

RESUMO Objetivo: Estudar a resistência ao arrancamento in vitro do parafuso de inserção direta da SpineGuard/Zavation (parafuso DSG), um parafuso pedicular projetado para ser inserido usando a técnica de inserção direta. Métodos: Parafusos DSG de 5,5 mm e 6,5 mm foram introduzidos em blocos de poliuretano com densidade de 10 PCF (0,16 g/cm3). De acordo com o grupo experimental, os parafusos foram inseridos sem orifício piloto, com orifício e sem macheamento e macheamento diâmetro inferior com mesma geometria. Os testes de resistência dos parafusos foram realizados usando uma máquina de teste universal após a inserção dos parafusos nos blocos de poliuretano. Resultados: Os parafusos inseridos diretamente nos blocos de poliuretano sem orifício piloto e sem macheamento apresentaram uma resistência de arrancamento com significância estatística maior. A inserção do parafuso sem macheamento ou com macheamento com diâmetro inferior apresenta maior resistência ao arrancamento em comparação com o macheamento do mesmo diâmetro. Conclusão: O parafuso DSG apresentou a maior resistência ao arrancamento após sua inserção sem orifício piloto e sem macheamento. Nível de Evidência V, Opinião do Especialista.

Techniques for removing root canal posts: an vitro study / Técnicas para remoção de pinos intrarradiculares: um estudo in vitro

Objetivo: O objetivo deste estudo foi responder qual é a melhor técnica para remoção de pinos de fibra de vidro e pinos metálicos fundidos considerando tempo, preservação da estrutura dentária e custos. Métodos: Foi realizado um estudo in vitro, randomizado e cego. Sessenta dentes tratados endodonticamente foram randomizados em dois grupos de acordo com o tipo de pino. Uma segunda randomização foi realizada para cada tipo de técnica de remoção (ultrassom, broca ou combinada; n=10). One-way ANOVA foi usado para comparar o tempo de remoção do pino, teste t pareado comparou a quantidade de estrutura dentária removida e Kruskal Wallis seguido pelo teste post hoc de Mann-Whitney foram usados para análise de custo (P = 0,05). Resultados: Não houve diferença no tempo de remoção do pino considerando o tipo ou técnica do pino (P=0,630). A perda média de estrutura dentária na região cervical foi superior a 30% quando apenas uma ponta diamantada foi usada para remover pino de fibra de vidro (P<0,00001) e pino metálico fundido (P=0,008). Conclusão: De acordo com os resultados deste estudo, podemos concluir que a seleção da técnica de remoção dependerá da habilidade do operador, e sempre ocorrerá alguma perda de estrutura dentária, embora seja esperada uma perda maior quando apenas pontas diamantadas são usadas para este fim.(AU)

Objective: The aim of this study was to answer which is the best technique to removing glass fiber post and cast metal post considering time, preservation of tooth structure, and costs. Methods: An in vitro, randomized, blinded study was conducted. Sixty endodontically treated teeth were randomized into two groups according to post type. A second randomization was performed for each type of removal technique (ultrasound, drill, or combined; n=10). One-way ANOVA was used to compare the time to post removal, paired t-test compared the amount of tooth structure removed and Kruskal Wallis followed by post hoc Mann-Whitney test were used for cost analysis (P=0.05). Results: There was no difference in post removal time considering post type or technique (P=0.630). The average loss of tooth structure in the cervical region was greater than 30% when only a diamond bur was used to remove fiber glass post (P<0.00001) and cast metal post (P=0.008). Conclusion: According to the results of this study, we can conclude that the selection of the removal technique will depend on the skill of the operator, and some loss of tooth structure will always occur, although greater loss is expected when only diamond burs are used for this purpose.(AU)

Efecto del Camphenol Plus sobre el músculo liso vascular de vena porta en ratas Wistar / Effect of Camphenol Plus on portal vein vascular smooth muscle in Wistar rats

RESUMEN Introducción: uno de los antisépticos comúnmente empleado en Estomatología desde el pasado siglo y que mantiene su uso hasta la actualidad, lo constituye el Camphenol Plus. Son escasos los reportes científicos de su efecto sobre el endotelio y la dinámica contráctil del músculo liso vascular, en especial de tejidos venosos como la vena porta hepática. Objetivo: determinar el efecto del Camphenol Plus sobre el músculo liso vascular de la vena porta. Métodos: se realizó una investigación experimental preclínica, con la utilización de 21 venas porta obtenidas de ratas Wistar. Las preparaciones realizadas se colocaron en baño de órganos, se registró la tensión desarrollada por el músculo liso vascular tras la adición de diez microlitros de Camphenol Plus, en diferentes concentraciones y durante diferentes intervalos de tiempo. Resultados: el Camphenol Plus, tras la preactivación del musculo liso vascular de la vena porta, indujo vasorelajación, la que se incrementó durante todo el tiempo de estudio y según el incremento de las concentraciones del medicamento. Existieron diferencias significativas entre los valores de tensión promedios registrados en los diferentes intervalos de tiempo con los de la tensión espontánea basal y la tensión base inicial. Conclusiones: el Camphenol Plus, indujo "in vitro", relajación de la musculatura lisa de la vena porta a través de un acoplamiento excitación-contracción de tipo farmacomecánico.

ABSTRACT Introduction: Camphenol Plus is one of the antiseptics commonly used in Dentistry since the last century and still in use today. There are few scientific reports of its effect on the endothelium and contractile dynamics of vascular smooth muscle, especially in venous tissues such as the hepatic portal vein. Objective: to determine the effect of Camphenol Plus on the vascular smooth muscle of the portal vein. Methods: a preclinical experimental investigation was carried out using 21 portal veins obtained from Wistar rats. The preparations were placed in an organ bath and the tension developed by the vascular smooth muscle was recorded after the addition of ten microliter of Camphenol Plus, at different concentrations and during different time intervals. Results: Camphenol Plus, after the preactivation of the vascular smooth muscle of the portal vein, induced relaxation, which increased throughout the study time and according to the increase in drug concentrations. There were significant differences between the average tension values recorded in the different time intervals with those of the basal spontaneous tension and the initial baseline tension. Conclusions: Camphenol Plus induced "in vitro" relaxation of portal venous smooth muscles through a pharmacomechanical excitation-contraction coupling.