Evaluation of the quality of meat and carcasses from sheep fed diets containing three types of oils.

The objective of this research was to evaluate the quantitative and qualitative characteristics of the carcass and meat of lambs fed with different types of oil. Thirty male, uncastrated, mixed breed (Santa Inês × Dorper) sheep were used in this experiment and were distributed in random blocks with three treatments and 10 replicates per treatment, where each animal represents a replicated experimental unit. The three treatments were the following experimental diets: soybean oil in natura; soybean oil after use in frying, and palm oil (Elaeis guineensis). The oils were incorporated into the sheep diets at a level of 4%. Carcasses were evaluated for hot and cold yield, loss due to cooling, finish, conformation, internal fat concentration, morphometric measurements, tissue composition, and commercial cuts. The addition of soybean oil in natura, residual soybean oil from frying, and palm oil to the sheep diets did not alter any of the evaluated characteristics, which therefore can be interpreted as favoring the use of any of these three oils as a supplement to their diet, and the three oils imparted good characteristics to the carcasses and the meat.

The effect of aluminum treatment on metabolism in oil palm seedlings

Due to rainfall and high temperatures, the Amazonian soil undergoes changes in its source material and leaching of base cations. This results in deep, infertile, and acidic soil. Aluminum present in acidic soil impairs plant growth and development by inhibiting root formation, enzymatic reactions, absorption, transport, and nutrient utilization. This study aimed to evaluate the effects of aluminum dosage on the metabolism of the oil palm Elaeis guineensis Jacq. The study was conducted in a greenhouse at the Federal Rural University of Amazonia. The experimental design was randomized, with five replications, in which dosages of 0, 10, 20, 30, and 40 mg L-1 aluminum chloride (AlCl3.6H2O) were administered. Electrolyte leakage, nitrate, nitrate reductase, free ammonium, soluble amino acids, proline content, and soluble proteins were analyzed in the leaves and roots of the oil palm. The highest concentration of aluminum was found in the roots. AlCl3 treatment at 40 mg L-1 increased electrolyte leakage, nitrate, ammonium, and proline concentrations in the roots, and amino acid concentrations in both the leaves and roots. Furthermore, a decrease in nitrate reductase enzyme activity was observed in the roots. This study demonstrates that the oil palm has mechanisms of tolerance to aluminum toxicity.

Medidas de biossegurança nos consultórios odontológicos durante a pandemia de COVID-19: estudo com profissionais de saúde bucal do estado do Paraná / Biosafety measures in dental offices during the COVID-19 pandemic: a study with oral health professionals in the state of Paraná

Com o surgimento da pandemia causada pelo SARS-Cov-2, houve a necessidade de reestruturação dos serviços de saúde no Brasil, incluindo a clínica odontológica. O objetivo do presente estudo é descrever as medidas de biossegurança realizadas ou modificadas na prática de saúde bucal no estado do Paraná, em nível público e privado, envolvendo três categorias profissionais: cirurgiões-dentistas (CD), técnicos em saúde bucal (TSB) e auxiliares de saúde bucal (ASB). Esta pesquisa transversal descritiva foi realizada nos meses de agosto a outubro de 2020, com o envio de questionários on-linepor e-maile divulgação em redes sociais. Foram envolvidos 1072 profissionais, sendo 75,6% CD, 16,3% ASB e 8,1% TSB. O gênero feminino foi predominante entre os participantes (81,1%), com 46,1% apresentando idade entre 40 e 59 anos. Gorro, máscara cirúrgica, óculos de proteção e protetor facial são referidos como sempre utilizados, respectivamente, por 92,3%, 81,0%, 80,0% e 79,1% dos participantes. A máscara N95/PFF2 (67,5%) e o avental impermeável (20,3%) tiverem os maiores percentuais de "nunca disponíveis ou utilizados". Cerca de 50% afirmaram que tiveram acesso à Nota Técnica GVIMS/GGTES/ANVISA Nº 04/2020. Os profissionais avaliados, em geral, realizaram mudanças em suas práticas de biossegurança, mas precisam ser acompanhados durante toda a extensão da pandemia.

With the emergence of the SARS-Cov-2 pandemic, there was a need to restructure health services in Brazil, including the dental clinic. The aim of the present study was to describe the biosafety measures performed or modified in oral health practice at public and private levels, involving the three professional categories: dental surgeons (DDS), oral health technicians(OHT), and health assistants (HA) in the state of Paraná. This escriptive cross-sectional survey was carried out from August to October 2020, with an online questionnaire being sent by email and published on social networks. There were 1072 professionalsinvolved, of which 75.6% were DDS, 16.3% were OHT, and 8.1% were HA. The female gender was predominant among the participants (81.1%), and 46.1% were aged between 40 and 59 years. 92.3%, 81.0%, 80.0%, and 79.1% of the articipants, respectively, said theyalways used a cap, surgical mask, protective glasses, and face shield. The N95/PFF2 mask (67.5%) and the waterproof apron (20.3%) are two of the most frequently mentioned items as never being available or used. About 51% said they had access to Technical Note GVIMS/GGTES/ANVISA No. 04/2020. In general, the professionals evaluated have been making changes in their biosafety practices, but they still need to be monitored throughout the pandemic.

Adhesive restoration of molars affected by molar incisor hypomineralization: a randomized clinical trial.

OBJECTIVE: This randomized clinical trial evaluated the survival of direct restorations on first permanent molars (FPMs) with molar incisor hypomineralization (MIH) and its impact on self-reported dental pain and dental anxiety. MATERIAL AND METHOD: FPMs with MIH of 35 patients aged 7 to 16 years were included. The FPMs were randomized into the following two groups: total-etch (TE-37% phosphoric acid etching) and self-etch (SE-no prior etching). The FPMs were restored with universal adhesive and bulk-fill resin composites. The restoration survival was evaluated according to USPHS criteria modified by a blinded examiner. Dental anxiety (Venham picture test) and dental pain (Faces pain scale-revised) were evaluated before treatment and at 1, 6, and 12 months post-treatment. Survival rates were analyzed by the Kaplan-Meier method and the log-rank test. Nonparametric tests compared pain and anxiety in the follow-up periods. RESULTS: A total of 64 FPMs were restored (TE = 33; SE = 31). Survival rates were 96.9% (TE) and 96.7% (SE) after 1 month, 90.5% (TE) and 80.6% (SE) after 6 months, and 80.8% (TE) and 62.3% (SE) after 12 months (p > 0.05). Self-reported dental pain and anxiety level decreased after treatment in both groups (p < 0.05). Self-reported pain decreased after 1 month in SE, but it occurred at 6 months in TE. CONCLUSION: Both restorative protocols presented similar longevity, decreasing self-reported pain and anxiety levels. CLINICAL RELEVANCE: A universal adhesive could be appropriate for restoration of MIH-affected teeth, and the survival of restorations could be higher in the total-etch technique, reducing dental pain and anxiety.

Radiographic analysis of dental maturation in children with amelogenesis imperfecta: A case-control study.

AIMS: To assess dental maturation in children with amelogenesis imperfecta (AI) and compare their estimated dental age with the age of non-AI children. METHODS AND RESULTS: Panoramic radiographs of children with (n = 27) and without (n = 54) AI were retrospectively collected in the ratio of 1:2. The former consisted of case group, while the latter figured as control group. Both groups were paired by sex and age (P > .05). Dental maturation was assessed in each radiograph using Demirjian's staging technique and Willems' method. Intra- and interexaminer reproducibility reached >0.8. The mean estimated dental age in subjects with AI was 12.5 ± 2.69 years, while in subjects without AI it was 11.73 ± 2.48 years (P = .21). The comparison of mean chronological (12.26 ± 2.6 years) and estimated dental age (12.5 ± 2.69 years) in subjects with AI did not reveal statistically significant differences (P = .38). CONCLUSION: This study highlights the similarity of dental maturation between subjects with and without AI from the radiographic perspective of crown-root formation.

Multiple Adhesive Layering Influence on Dentin Bonding and Permeability.

The aim was to evaluate the effect of the number of layers on the microtensile bond strength (µTBS), permeability and nanoleakage of an etch-and-rinse adhesive (Adper Single Bond 2). Different numbers of layers (1, 2 and 4) were applied on dentin susbstrate. Specimens were obtained and tested for µTBS. Stick-shaped samples were analysed by scanning electron microscope, to observe silver nitrate penetration. One-way ANOVA and Tukey tests were applied (α=0.05) for µTBS values. The fracture mode was evaluated under a stereomicroscope and a scanning electron microscope (SEM). Groups with two and four layers of bond showed higher µTBS to dentin and they also showed lower adhesive permeability than ONE layer. The silver nitrate uptake occurred in the hybrid layer in practically all groups. Fracture occurred predominantly at the mixed interface. The authors recommend the application of more than one layer of Adper Single Bond 2, because a single layer showed lower µTBS and higher permeability values.

As orientações de enfermagem e sua influência nos níveis de ansiedade dos pacientes cirúrgicos hospitalares / Nursing guidance and its influence on surgical hospital patients’ anxiety levels / Las directrices de la enfermería y su influencia sobre los niveles de ansiedad de los pacientes quirúrgicos de los hospitales

Estudo descritivo com abordagem quantitativa, visando identificar o traço e estado de ansiedade dos pacientes hospitalares submetidos às cirurgias gerais e descrever a influência das orientações de enfermagem nos níveis de ansiedade do paciente cirúrgico. A pesquisa foi realizada em uma unidade de cirurgia hospitalar, no município do Rio de Janeiro, no período de julho de 2012 a janeiro de 2013, com entrevista estruturada. Participaram do estudo 50 pacientes, cujas idades variaram entre 20-70 anos. Mediante a análise dos resultados, identificou-se que os pacientes que não receberam orientações de enfermagem aumentaram seus níveis de traço e estado de ansiedade. Conclui-se que as orientações de enfermagem no pré-operatório exercem importância fundamental tanto para o cliente como para toda a equipe que participa desse momento, com vistas ao bem-estar e à redução da ansiedade no momento cirúrgico.

This quantitative, descriptive study to identify trait and state anxiety in hospital patients undergoing general surgery, and describe the influence of nursing guidance on surgical patients’ anxiety levels, was carried out using structured interviews at a hospital surgical department in the municipality of Rio de Janeiro, between July 2012 and January 2013,. The study comprised 50 patients, aged from 20 to 70 years. Analysis of the results revealed that levels of trait and state anxiety increased in patients who received no nursing guidance. It was concluded that preoperative nursing guidance is of fundamental importance to both the client and the whole team participating in this event, by fostering well-being and reducing anxiety during surgery.

Estudio descriptivo con abordaje cuantitativo, cuyo objetivo fue identificar niveles de ansiedad de trazo y estado de los pacientes hospitalarios sometidos a las cirugías generales y describir la influencia de las orientaciones de enfermeríaen los niveles de ansiedad de los pacientes quirúrgicos. La investigación fue llevada a cabo en una unidad de cirugía hospitalaria, en el municipio de Río de Janeiro, en el período comprendido entre julio 2012 y enero 2013, con entrevista estructurada. Participaron del estudio 50 pacientes, con edades variando entre 20 y 70 años. A través del análisis de los resultados, se identificó que los pacientes que no recibieron directrices de enfermería aumentaron sus niveles de ansiedad de trazo y estado. Se concluye que las directrices de enfermería preoperatoria tienen una fundamental importancia tanto para el cliente como para todo el equipo que participa, con vistas al bienestar y a la reducción de la ansiedad en el momento quirúrgico.

Effect of sonic application mode on the resin-dentin bond strength and dentin permeability of self-etching systems.

PURPOSE: To compare manual and sonic adhesive application modes in terms of the permeability and microtensile bond strength of a self-etching adhesive applied in the one-step or two-step protocol. MATERIALS AND METHODS: Self-etching All Bond SE (Bisco) was applied as a one- or a two-step adhesive under manual or sonic vibration modes on flat occlusal dentin surfaces of 64 human molars. Half of the teeth were used to measure the hydraulic conductance of dentin at 200 cm H2O hydrostatic pressure for 5 min immediately after the adhesive application. In the other half, composite buildups (Opallis) were constructed incrementally to create resin-dentin sticks with a cross-sectional area of 0.8 mm² to be tested in tension (0.5 mm/min) immediately after restoration placement. Data were analyzed using a two-way ANOVA and Tukey's test (α = 0.05). RESULTS: The fluid conductance of dentin was significantly reduced by the sonic vibration mode for both adhesives, but no effect on the bond strength values was observed for either adhesive. CONCLUSION: The sonic application mode at an oscillating frequency of 170 Hz can reduce the fluid conductance of the one- and two-step All Bond SE adhesive when applied on dentin.

Eighteen-month randomized clinical trial on the performance of two etch-and-rinse adhesives in non-carious cervical lesions.

PURPOSE: An 18-month randomized, controlled prospective study evaluated, in an intra-individual comparison, the clinical performance of two-step etch-and-rinse adhesives in non-carious cervical lesions (NCCL). METHODS: 35 subjects, with at least two similar sized NCCL participated in this study. After sample size calculation, 70 restorations were placed, according to one of the following groups: Adper Single Bond 2 (SB) and Ambar (AM). The restorations were placed incrementally using a resin composite (Opallis). The restorations were evaluated at baseline and after 6 and 18 months according to the FDI criteria. The differences in the ratings of the two materials after 6 and 18 months were tested with Fisher's exact test (α = 0.05), and the performance of the each material at baseline and after 6 and 18 months was evaluated by Wilcoxon test (α = 0.05). RESULTS: All subjects attended the 18-month recall. No significant differences were observed between the materials for any criteria evaluated. Only four restorations (two from each material) were lost after 18 months. Thus, the retention rates of both materials at 18 months were 94.2% (95% CI 81-98%). Nine restorations (four Ambar and five Adper Single Bond 2) showed marginal discoloration which was solved with a polishing procedure. Both adhesive systems showed acceptable clinical retention rates after 18 months.

Durability of silorane repair with silorane and methacrylate resin / Durabilidade do reparo de resina composta à base de silorano realizado com a mesma ou com resina à base de metacrilato

Objective: The durability of bonded interface between silorane (SIL) and methacrylate-based (MET) composite resins wasn’t investigated yet. The purpose was to evaluate the repair strength (RS) and nanoleakage of the SIL repair using silorane- or methacrylate-based materials immediately [IM] or after 6 months of water storage [6M]. Material & Methods: fifteen resin blocks (Filtek P90, 3MESPE) were polished, sandblasted with 50-μm aluminum oxide sandblasting and cleaned with 37% phosphoric acid. Then the specimens were divided into three groups: SIL-SIL (adhesive and composite resin); SIL-MET (silorane adhesive and methacrylate based composite) and MET-MET (methacrylate-based adhesive and composite resin) were used for the repair. Composite-composite bonded sticks (0.9 mm2) were sectioned and divided to be tested in tension (1.0 mm/min) IM or 6M. Two sticks from each tooth, at each time, were immersed in a 50% silver nitrate solution and evaluated by SEM. Data were analyzed by two-way repeated measures ANOVA and Tukey´s tests. Results: The RS of the SIL was not dependent upon the adhesive and composite used for the repair. A significant reduction of the RS was observed for all groups after 6M. Conclusion: Both materials can be used for the repair of the silorane composite, despite degradation occur after 6M.

Objetivo: A durabilidade da interface de união entre resinas à base de silorano (SIL) e à base de metacrilato (MET) ainda não foi estudada. O objetivo foi avaliar a resistência de união ao reparo de (RS) e nanoinfiltração da resina SIL com ela mesma ou com MET imediatamente (IM) ou após 6 meses de armazenamento em água (6M). Material e Métodos: quinze blocos de resina composta (Filtek P90, 3MESPE) foram confeccionados, polidos, asperizados com jato de óxido de alumínio 50-μm e limpos com ácido fosfórico 37%. Em seguida, foram divididos em três grupos: SIL-SIL (adesivo e resina à base de silano); SIL-MET (adesivo à base de silano e resina à base de metacrilato) and MET-MET (adesivo e resina à base de metacrilato) para o reparo. Foram seccionados palitos de aproximadamente 0,9 mm2, divididos entre IM e 6M e levados para máquina de microtração (1,0 mm/min). Dois palitos de cada bloco, de cada tempo, foram imersos em nitrato de prata 50% e avaliados em MEV. Os dados foram avaliados por ANOVA de dois fatores e teste de Tukey. Resultados: A RS da resina SIL não foi dependente da resina ou do adesivo utilizado para o reparo. Uma redução significativa da RS foi observada para todos os grupos após 6M. Conclusão: ambos os materiais podem ser usados para reparo de resinas SIL, apesar de a degradação ocorrer após 6M.

Mecanismos de enfrentamento desencadeados por pacientes em situações estressoras: cirurgia ambulatorial / Coping mecanism by surgical patients in stress situations: ambulatory surgery / Mecanismos de enfrentamiento presentados por pacientes en situanciones de estrés: quirurgia ambulatorial

Estudo descritivo analítico com abordagem quantitativa e qualitativa, visando identificar os mecanismos de enfrentamento (coping) mais utilizados por pacientes e seus sentimentos diante do procedimento cirúrgico. A pesquisa foi realizada em uma unidade de cirurgia ambulatorial, no município do Rio de Janeiro, no período de junho a dezembro de 2012, com entrevista semiestruturada. Participaram do estudo 12 pacientes, cujas idades variam entre 16 e 74 anos. Mediante a análise de conteúdo dos depoimentos, foram elaboradas duas categorias que ressaltaram a religião e o apoio da família como mecanismos adaptadores no período cirúrgico; e a falta de orientação sobre a cirurgia, sentimentos de medo e falta de confiança. A maioria não estava adequadamente esclarecida sobre a cirurgia e os possíveis cuidados pré-operatórios. Conclui-se que, para superar tais carências, deve ser criada estratégia para fornecer aos clientes as orientações de enfermagem no período pré-operatório.

Analytic, descriptive study with a quantitative and qualitative approach, that identify the most used coping mechanisms and the feelings of the surgical patients by the analysis of their responses before the surgery. The research was developed in Ambulatorial Surgery Unit in the county of Rio de Janeiro, between June and December of 2012, with a semistructured interview. Participated on this study 12 patients between 16 and 74 years old. Through the analysis of the data, 2 cathegories were elaborated, emphasizing the religion and the family’s support as adaptive mechanisms during the surgical period. Most of the patients that undergo ambulatorial surgeries were not well informed about the procedure and the pré-operatory care. Therefore, an strategy must be created to give the nursing orientation of the pré-operatory.

Estudio descriptivo analítico con abordaje cuantitativo y cualitativo, visando identificar los mecanismos de enfrentamiento (coping) más utilizados y los sentimientos de los pacientes quirúrgicos a través de sus respuestas antes de la cirugía. La pesquisa fue realizada en una unidad de cirugía ambulatorial, en el município de Rio de Janeiro-RJ-Brasil, en el período de junio a diciembre de 2012, con entrevista semiestructurada. Participaron del estudio 12 pacientes, cuya edad varió entre 16 y 74 años. Mediante el análise de contenido de los datos, fueron elaboradas dos categorías que resaltaron la religión y el apoyo de la família como mecanismos adaptadores en el período quirúrgico, y que la mayoría de los pacientes sometidos a la cirugía ambulatorial, no estavan adecuadamente esclarecidos sobre la cirugía y los posibles cuidados pré-operatorios. Se concluye que, para superar tales carencias, se debe adoptar una estrategia para fornecer a los clientes las orientaciones de enfermería em el pre-operatorio.

Effect of enamel bevel on the clinical performance of resin composite restorations placed in non-carious cervical lesions.

STATEMENT OF THE PROBLEM: Laboratory testing of enamel bevel reports many advantages; however clinical studies on this topic are scarce and controversial. PURPOSE OF THE STUDY: To evaluate the effect of enamel bevel on the retention rates of composite restorations placed in non-carious cervical lesions (NCCLs). MATERIALS AND METHODS: Forty-two patients with more than 20 teeth in occlusion and having at least two NCCLs participated in this study. The cavities were divided into non-beveled (control) and beveled (short bevel [45°, 1-2 mm long] prepared with a diamond bur) groups. The NCCLs were restored with the 2-step etch-and-rinse adhesive ExciTE and the resin composite 4 Seasons (Ivoclar Vivadent). Eight-four restorations were placed and evaluated at baseline, after 6 and 12 months according to the modified U.S. Public Health Service criteria. RESULTS: The 12-month retention rates (95% confidence interval) for the beveled (91% [77-97%]) and non-beveled [88% (73-95%)] groups were similar. No significant differences were detected between groups in other criteria (Fisher test, p > 0.05). No significant differences were detected in the same group compared across different recall times (McNemar test, p > 0.05). CONCLUSION: Enamel beveling may not be clinically relevant for the retention of composite restorations in NCCLs after 12 months. CLINICAL SIGNIFICANCE: Beveling enamel margins may not be necessary in NCCL restorations restored with the 2-step etch-and-rinse systems.

Análise do nível de estresse e dos fatores de risco de doença cardiovascular em professores da Universidade Federal do Piauí - Campus Parnaíba / Análisis de L nivel de estrés y de los factores de riesgo de enfermedad cardiovascular en profesores de la Universidad Federal de Piauí - sede Parnaíba / Analysis of stress levels and risk factos for cardiovascular disease in teachers Federal University of Piauí - campus Parnaiba

O trabalho objetivou analisar o nível de estresse e a prevalência de fatores de risco de doenças cardiovasculares em professores da Universidade Federal do Piauí (UFPI) ­ Campus Ministro Reis Velloso (Parnaíba). É um estudo epidemiológico, transversal, realizado com aplicação de um questionário baseado nos seguintes instrumentos: Inventários de sintomas de estresse de Lipp e questionário de Michigan Heart Association (MHA). Utilizou-se o teste qui-quadrado para comparação do nível de estresse e risco coronariano de acordo com sexo, tempo de docência, curso e titulação. Adotou-se um nível de significância de p<0,05. A pesquisa contemplou 51 professores, sendo 29 do sexo masculino e 22 do feminino. Quanto ao nível de estresse encontrado nos avaliados, 11 encontravam-se na fase 2. Em relação ao risco coronariano, 26 se classificaram no "risco médio", sendo o índice maior em homens, que em mulheres. Dentre os fatores de risco, os que prevaleceram foram o sedentarismo e o sobrepeso, com incidência de 10 e 11, entre os avaliados, respectivamente. Conclui-se que a prevalência de fatores de risco coronariano em professores foi "risco médio", e o nível de estresse, que apresentou sintomatologia, classificou-se na fase de resistência. Contudo, propomos a inclusão de medidas que previnam os fatores de risco.

The study aimed to analyze the stress level and the prevalence of risk factors for cardiovascular diseases in teachers of the Federal University of Piauí (UFPI) ­ Campus Parnaiba. It is an epidemiological cross-sectional conducted with a questionnaire based on the following instruments: Lipp Inventories of stress symptoms questionnaire and the Michigan Heart Association (MHA). We used the chi-square test for comparison of the levels of stress and coronary risks according to gender, time of teaching, course and titration. It was adopted a significance level of p<0.05. The survey included 51 teachers in wich 29 were male and 22 were female. Eleven evaluated subjects rated their level of stress in stage 2, Regarding the coronary risk, 26 were classified at "average risk", and is was found a number higher in men than in women. Among the risk factors, sedentary and overweight prevailed, with an incidence of 10 and 11, among those evaluated, respectively. We conclude that the prevalence of coronary risk factors in teachers was at "medium risk" in symptoms, were classified in the resistance. However, we propose to include measures to prevent the risk factors.

El objetivo del trabajo fue analizar el nivel de estrés y la prevalencia de factores de riesgo de enfermedades cardiovasculares en profesores de la Universidad Federal de Piauí (UFPI) ­ Sede Ministro Campus Reis Velloso (Parnaíba). Es un estudio epidemiológico transversal realizado con la aplicación de un cuestionario basado en los siguientes instrumentos: Inventarios de síntomas de estrés de Lipp y cuestionario de Michigan Heart Association (MHA). Se utilizó el test qui-cuadrado para comparar el nivel de estrés y el riesgo coronario según el sexo, el tiempo de la docencia, curso y titulación. Se adoptó un nivel de significación de p <0,05. En la investigación participaron 51 profesores, de los cuales 29 eran del sexo masculino y 22 del femenino. En cuanto al nivel de estrés que encontrado en los evaluados, 11 se encontraban en la fase 2. Con respecto al riesgo coronario, 26 fueron clasificados en el "riesgo medio", con la tasa más alta en los hombres que en las mujeres. Entre los factores de riesgo, los que prevalecieron fueron el sedentarismo y sobrepeso, con una incidencia de 10 y 11, entre los evaluados, respectivamente. Se concluye que la prevalencia de factores de riesgo coronario en docentes fue "riesgo medio", y el nivel de estrés, que presentó sintomatología, se clasificó en la fase de resistencia. Sin embargo, proponemos la inclusión de medidas que prevengan los factores de riesgo.

Durability of composite repair using different surface treatments.

OBJECTIVE: To evaluate the surface treatment and hydrophilicity of the bonding agent on the composite repair strength (RS), silver nitrate uptake (SNU), surface roughness (SR) and estimation of surface area (SA). METHODS: Fifty resin blocks (Opallis, FGM) were polished and divided in 5 groups: no treatment (NT); roughening with a fine (FDB); medium (MDB); coarse-grit (CDB) and 50-µm aluminium oxide sandblasting (AO). A hydrophobic (Adhesive, Scotchbond Multi-Purpose Plus, 3M ESPE) or hydrophilic (Adper Single Bond 2, 3M ESPE) adhesive was applied, followed by composite placement (Opallis, FGM). Composite-composite bonded sticks (0.9 mm2) were tested in tension (1.0mm/min) immediately [IM] or after 6 months [6M] of water storage. Two sticks from each tooth, at each time, were immersed in a 50% silver nitrate solution and evaluated by SEM. A profilometer was used to measure SR. SEM images were used to estimate the SA using the Image J software. Data were analysed by ANOVA and Tukey's tests. RESULTS: The AO showed the highest CR strength for both adhesives, whilst the NT group showed the lowest, irrespective of the storage period. The diamond burs had intermediate performance. Silver nitrate deposits were seen after 6M for the hydrophilic adhesive. The ranking of SR values (Ra) from the lowest to the highest was: NT

Application of etch-and-rinse adhesives on dry and rewet dentin under rubbing action: a 24-month clinical evaluation.

BACKGROUND: Researchers conducting laboratory investigations have reported that bonding to dry demineralized dentin can be feasible technically as long as the adhesives are rubbed vigorously onto the dentin surface. The authors aimed to evaluate the 24-month clinical performance of resin-based composites in noncarious cervical lesions (NCCLs) in teeth restored with two etch-and-rinse adhesives that had been applied with a vigorous rubbing action to both dry and rewet dentin. METHODS: The authors enrolled 40 patients in this study. They inserted 160 restorations and evaluated them at baseline and at six, 12 and 24 months of service. They divided the restorations into four groups: One-Step (OS) Universal Dental Adhesive System (Bisco, Schaumburg, Ill.) (acetone-based adhesive) with rewet dentin; OS with dry dentin; Adper Single Bond (SB) Plus Adhesive (3M ESPE, St. Paul, Minn.) (ethanol/water-based adhesive) with rewet dentin; and SB with dry dentin. The authors used the same resin-based composite for all restorations. They evaluated the restorations according to modified U.S. Public Health Service criteria. RESULTS: The 24-month retention rates for the rewet and dry conditions, respectively, were 95.0 percent and 97.5 percent for SB and 97.5 percent and 91.9 percent for OS. The authors detected no significant difference between rewet and dry groups for either adhesive (P > .05). In terms of marginal discoloration, OS performed significantly worse than did SB, irrespective of dentin moisture (P > .05). CONCLUSIONS AND CLINICAL IMPLICATIONS: Dentin moisture seems not to be important for the retention of etch-and-rinse adhesives as long as the adhesives have been rubbed vigorously onto the dentin surface. The ethanol/water-based adhesive showed a better overall performance than did the acetone-based system.

Improvement of exposure times: effects on adhesive properties and resin-dentin bond strengths of etch-and-rinse adhesives.

PURPOSE: This study evaluated the effect of prolonged polymerization times on the microtensile resin-dentin bond strength (µTBS), degree of conversion of adhesive films (DC) and silver nitrate uptake (SNU) for an ethanol/water- (Adper Single Bond 2, [SB]) and an acetone-based (One Step Plus, [OS]) etch-and-rinse adhesive. MATERIALS AND METHODS: Thirty caries-free extracted molars were included in this study. The occlusal enamel of all teeth was removed by wet grinding the occlusal enamel on 180-grit SiC paper. Adhesives were applied according to the manufacturer's instructions, but they were light cured for 10, 20 and 40 s at 600 mW/cm2. Bonded sticks (0.6 mm2) were tested in tension (0.5 mm/min). Two bonded sticks from each tooth were immersed in an ammoniacal solution of silver nitrate (24 h), photodeveloped (8 h), and analyzed by SEM. The DC of the adhesives was evaluated under Fourier Transformed Infra-Red spectroscopy (FTIR). Data for each property were analyzed by two-way ANOVA and Tukey's test (α = 0.05). RESULTS: Statistically higher µTBS and DC were observed for SB and OS when both adhesives were light cured for 40 s in comparison with 10 s. For OS, the µTBS in the 20- and 40-s groups did not differ statistically, while for SB it did. Higher prolonged exposure times did not prevent nanoleakage within the hybrid layer for all groups regardless of the adhesive. CONCLUSION: This study supports the hypothesis that exposure times longer than those recommended can improve the degree of conversion of adhesive films and the immediate resin-dentin bonds. The prolonged curing times (20 and 40 s) for polymerization of simplified adhesives resulted in an increase in the degree of conversion of the adhesive films and resin-dentin bond strengths but did not reduce the nanoleakage within the hybrid layer.

Effects of increased exposure times of simplified etch-and-rinse adhesives on the degradation of resin-dentin bonds and quality of the polymer network.

One of the reasons for resin-dentin degradation is poor polymerization of the adhesive layer. This study evaluated the effect of prolonged polymerization times on the immediate and 6-month resin-dentin bond strengths, silver nitrate uptake, and polymer quality of etch-and-rinse adhesives. Thirty extracted teeth were obtained, and a flat dentin surface was exposed on each tooth. Adhesives (Adper Single Bond 2 and One Step Plus) were applied to the dentin surface of these teeth and light-cured for 10, 20, or 40 s at 600 mW cm(-2) . Bonded sticks (0.6 mm(2) ) were tested in tension (0.5 mm min(-1) ) and analyzed, after immersion in 50% silver nitrate, using scanning electron microscopy. The polymer quality of adhesive films was evaluated using thermogravimetric analysis. Statistically higher bond strengths were observed for both adhesives when light-cured for 40 s. Degradation of dentin bonds occurred under all experimental conditions but it was less pronounced for adhesives light-cured for 40 s. Longer exposure times reduced silver nitrate uptake for Adper Single Bond 2. Solvent retention and the amount of residual monomer were statistically lower when both adhesives were light-cured for 40 s. Although longer exposure times than those recommended cannot prevent degradation of the dentin bonds, they can increase bond strength, probably because of the removal of an increased amount of solvent and the presence of a lower amount of residual monomer.

Durability of surface treatments and intermediate agents used for repair of a polished composite.

OBJECTIVE: To evaluate the effects of surface treatment and intermediate agent hydrophilicity on durability of the composite repair by means of the microtensile bond strength test (microTBS) and silver nitrate uptake (SNU) and the effects of surface treatment on composite roughness (Ra) and micromorphological features (SEM). METHODS: Thirty resin composite blocks (4x6x6 mm) (Opallis, FGM) were polished after seven days and divided into three groups: no treatment (NT); roughening with a fine-grit diamond bur (DB); 50 microm aluminum oxide sandblasting (AO). A hydrophobic (Adhesive bottle, Scotchbond MultiPurpose [SBMP]) or hydrophilic adhesive (Adper Single Bond 2 [SB]) was then applied. The same composite was used for repair. Composite-composite bonded sticks (0.6 mm2) were tested immediately ([IM) or after six months (6 M) of water storage in tension (1.0 mm/minute). Two bonded sticks from each resin composite block were immersed in a 50% (w/v) solution of silver nitrate, photo-developed and analyzed by SEM. The composite specimens after surface treatments were analyzed with a contact profilometer (Ra) and SEM. Three-way repeated measures and one-way ANOVA were used to analyze data from the microTBS and Ra, respectively (alpha = 0.05). RESULTS: AO showed the highest composite repair strength (MPa) and Ra (microm) (52.7 +/- 6.4; 4.1 +/- 0.5), while the no treatment group (36.1 +/- 6.1; 0.57 +/- 0.5) showed the low est. DB (44.1 +/- 5.6; 1.5 +/- 0.2) had an intermediate performance. The Ra results were confirmed by SEM images. SNU was observed only in SB specimens after 6M for all groups. CONCLUSIONS: Aluminum oxide treatment provides the highest composite repair strength, regardless of the hydrophilicity of the intermediate agent and storage period. Early signs of degradation were detected for SB after six months as silver nitrate deposits within the adhesive layer.