Restauração em resina composta semidireta em dente posterior: relato de caso / Semi-direct composite restoration in posterior toth: a case report

A escolha da técnica restauradora desempenha papel fundamental na eficácia e duração de um tratamento reabilitador. O objetivo deste relato de caso foi descrever a utilização da técnica semidireta para a confecção de uma restauração em resina composta em um primeiro molar inferior. A paciente apresentava uma restauração insatisfatória no dente 36, que necessitava ser substituída devido à infiltração por cárie. Optou-se pela técnica semidireta devido à amplitude da cavidade, que envolvia estruturas de suporte, e pela combinação das vantagens das abordagens direta e indireta. O procedimento envolveu a remoção de tecido cariado, a aplicação de hidróxido de cálcio pasta, seguida da aplicação de uma fina camada de ionômero de vidro e, posteriormente, resina fluída para realizar o selamento dentinário. O preparo foi realizado seguindo os princípios necessários. O elemento em questão foi moldado com silicone de adição e o arco antagonista, com alginato. Ambos modelos foram vertidos com silicone para modelos semirrígidos e montados em oclusor de peças de brinquedo. A restauração semidireta foi confeccionada em resina composta Filtek Z350 XT, respeitando a anatomia do dente 36. Pigmentos foram utilizados para aprimorar detalhes estéticos. Após acabamento e polimento, a peça foi condicionada e cimentada com cimento dual Relyx Ultimate. Pode-se concluir que a abordagem restauradora por meio da técnica semidireta construída em modelo semirrígido é uma opção terapêutica conservadora e vantajosa para dentes com extensa destruição coronária. Essa técnica possibilita a restauração de forma eficaz, garantindo tanto a estética quanto a função adequada do dente afetado(AU)

The choice of restorative technique plays a fundamental role in the effectiveness and duration of rehabilitation treatment. The objective of this case report was to describe the use of the semi-direct technique to create a composite resin restoration in a lower first molar. The patient had an unsatisfactory restoration on tooth 36, which needed to be replaced due to cavity infiltration. The semi-direct technique was chosen due to the amplitude of the cavity, which involved support structures, and the combination of advantages of the direct and indirect approaches. The procedure involved the removal of carious tissue, and the application of calcium hydroxide paste, followed by the application of a thin layer of glass ionomer and, subsequently, fluid resin to seal the dentin. The preparation was carried out following the necessary principles. The element in question was molded with addition silicone and the antagonist arch was molded with alginate. Both models were poured with silicone for semi-rigid models and mounted on toy parts occluders. The semi-direct restoration was made in Filtek Z350 XT composite resin, respecting the anatomy of tooth 36. Pigments were used to improve aesthetic details. After finishing and polishing, the piece was conditioned and cemented with Relyx Ultimate dual cement. It can be concluded that the restorative approach using the semi-direct technique built on a semi-rigid model is a conservative and advantageous therapeutic option for teeth with extensive coronal destruction. This technique allows for effective restoration, ensuring both the aesthetics and adequate function of the affected tooth(AU)

Tendencias en la cirugía de artroplastía total de rodilla en Chile. ¿Cómo las estamos operando? / Trends in total knee replacement surgery in Chile. How are we operating them?

INTRODUCCION La artroplastía total de rodilla (ATR), que ha tenido un aumento importante en la población en las últimas décadas, presenta una gran variación en su estudio y técnica entre los distintos países. En la actualidad no hay datos nacionales registrados que evalúen la forma de su implementación. Objetivo Registrar las tendencias respecto de la ATR en distintos aspectos en Chile y compararlas con los registros de otros países. MATERIALES y METODOS Se realizó una encuesta vía email a cirujanos de rodilla en Chile considerando cuatro aspectos: generalidades, estudio preoperatorio, técnica quirúrgica y técnica de cementación. Se excluyeron las encuestas que no rellenadas por completo. Se analizaron los datos generales y separados según años de experiencia (ADE). Se compararon los datos con los obtenidos en estudios internacionales. RESULTADOS Se obtuvieron 87 encuestas completas. La mayoría de los encuestados realizaba entre 25 y 50 ATR en 1 año (44%), y el 16%, más de 75. Sólo un 20% utilizaba la modalidad ambulatoria, y un 43% creía que siempre deben ser hospitalizadas (mayor frecuencia en los cirujanos con más de 10 ADE). Un 18% utilizaba algún sistema robótico, con mayor frecuencia en cirujanos con más de 10 ADE; los sistemas más usados fueron ROSA y CORI. El 90% creía que la ATR debería ser parte del programa de Garantías Explícitas de Salud (GES), sin diferencias según ADE. El 81% usaba sistema estabilizado posterior (posterior-estabilized, PS, en inglés), 96% realizaba un abordaje parapatelar medial, 82% usaba guía extramedular tibial, 41% tendía a recambiar la patela, y un 35% no usaba torniquete (ninguna de las variables mostró diferencias según ADE). Sólo un 31% utilizaba cementación al vacío (mayor frecuencia en el grupo con menos de 10 ADE), 95% colocaba el cemento en componentes y en hueso, 75% colocaba en la quilla, y 56% utilizaba el dedo para colocarlo (sólo 22% con pistola). La secuencia más frecuente de cementación fue tibia-fémur-patela. En la mayoría de los aspectos evaluados, se observaron diferencias importantes con estudios de otros países. CONCLUSION Existe una gran variabilidad en la realización de ATR en Chile, con tendencias distintas a las de otros países. En general, en relación con los distintos ADE, no hay grandes diferencias en la técnica quirúrgica, sí habiendo diferencias en la técnica de cementación y en el uso de sistemas robóticos

INTRODUCTION Total knee replacement (TKR) significantly increased among the population in recent decades, and it shows great variation in its study and technique in different countries. There is no registered Chilean data to assess TKR implementation. Objective To record the trends in TKR in different aspects within Chile and compare them with records from other countries. MATERIALS AND METHODS We conducted an email survey among knee surgeons in Chile considering four aspects: general features, preoperative study, surgical technique, and cementation technique. We excluded surveys not completed in full. The analyses included overall data and data per years of experience (YOEs), and we compared the results with those of international studies. RESULTS We obtained 87 complete surveys. Most respondents performed 25 to 50 TKRs each year (44%), with only 16% performing over 75 TKRs. Only 20% used the ambulatory modality, while 43% believed patients always require hospitalization (especially surgeons with more than 10 YOEs). Robotic systems were used by 18% of the surgeons, especially those with more than 10 YOEs; the most used systems were ROSA and CORI. In total 90% of the respondents believed TKR should be part of the Explicit Health Guarantees (Garantías Explícitas de Salud, GES, in Spanish) program, with no differences in terms of YOEs. A total of 81% used the posterior-stabilized (PS) system, 96% performed a medial parapatellar approach, 82% used an extramedullary tibial guide, 41% tended to replace the patella, and 35% did not use a tourniquet (none of the variables showed differences according to YOEs). Only 31% used vacuum cementation (with a higher frequency in the group with fewer than 10 YOEs), 95% placed cement on components and bone, 75% placed it in the keel, and 56% used finger packing (only 22% with a gun). The most common cementation sequence was tibia femur-patella. In most aspects evaluated, we observed important differences compared with studies from other countries. CONCLUSION There is a high variability in the performance of TKR in Chile, with different trends compared with those of other countries. Overall, there are no major differences in the surgical technique concerning YOEs, although there is variation in the cementation technique and the use of robotic systems

Explore the Diagnosis and Treatment of Gastric Cancer Accompanied by Depression Based on"Depression Caused by Illness"and"Illness Caused by Depression" / 浙江中医药大学学报

[Objective]To discuss the occurrence and gastric cancer accompanied by depression from the perspective of"depression caused by illness"and"illness caused by depression",and provide theoretical support for the treatment by traditional Chinese medicine(TCM).[Methods]By consulting the ancient and modern literature of TCM,and collecting the academic views of some doctors on the theory of"depression caused by illness"and"illness caused by depression"of gastric cancer,combined with clinical practice experience,it discusses the diagnosis and treatment of gastric cancer accompanied by depression.[Results]The etiology and pathogenesis of gastric cancer accompanied by depression can be summarized as follows:loss of middle Qi,the rise and fall of surly for its root;cementation of stasis and toxin,seven emotions disorder is its root;tumor gathering locally,poison overflowing into the blood vessels,illness and depression intermingled as its symptom,and it accordingly points out that the treatment of gastric cancer accompanied by depression should mediate middle Qi and smooth the Qi transformation of spleen and stomach;regulate Qi and open depression,regulate the rise and fall of Qi of the body;remove blood stasis and detoxify,dredge the body's Qi,blood and body fluid;form and spirit in tune,restore the complex of the five viscera of the human body.[Conclusion]Stasis,toxin and depression are important pathological factors affecting the occurrence,development and outcome of gastric cancer accompanied by depression.These three factors often affect each other as causation.Discussion of gastric cancer accompanied by depression from the perspective of"depression caused by illness"and"illness caused by depression"is not only helpful to improve the etiological and pathogenesis theory of gastric cancer accompanied by depression,but also helpful to provide theoretical reference for its clinical treatment.

The coronary heart disease of phlegm-stasis cementation syndrome in mini-swine based on platelet proteomics / 药学学报

Based on the technology of platelet proteomics, the key regulatory proteins and pathogenesis of coronary heart disease with phlegm and blood stasis syndrome were explored and analyzed. Based on the previous laboratory research, the model of coronary heart disease in mini-swine with phlegm-stasis cementation syndrome was duplicated. The model was judged by the changes in blood lipid and myocardial tissue characteristics. Furthermore, the platelet proteins were studied by quantitative proteomics, and the differentially expressed proteins were screened. The critical regulatory proteins and biological pathways of coronary heart disease with phlegm-stasis cementation syndrome were analyzed by bioinformatics. After ten weeks of modeling, the levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), very low density lipoprotein (VLDL-C), triglyceride (TG), creatine kinase (CK) and creatine kinase-MB (CK-MB) in the model group were significantly increased, reflecting the pathological changes such as increased blood lipid, abnormal coagulation function and myocardial ischemia in the model group. In addition, compared with the sham group, there were 26 up-regulated proteins and 8 down-regulated proteins in the platelets of the model group. Combined with bioinformatics analysis, it was found that differential proteins mainly involved in glycolysis/gluconeogenesis, pyruvate metabolism, lipid and atherosclerosis, Ras protein signal transduction. Among them, lactate dehydrogenase B (LDHB), alcohol dehydrogenase 5 (ADH5), neuroblastoma ratsarcoma viral oncogene homolog (NRAS) and Kirsten ratsarcoma viral oncogene homolog (KRAS) play a central role when interacting with other proteins and simultaneously participate in multiple action pathways. The results showed that LDHB, ADH5, NRAS, and KRAS may be the marker proteins in CHD with phlegm-stasis cementation syndrome by regulating glycolysis/gluconeogenesis, pyruvate metabolism, lipid and atherosclerosis, Ras protein signal transduction and other biological processes.

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

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

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

The Effect of Immediate Dentin Sealing on the Marginal Adaptation of LithiumDisilicate Overlay Restorations using different types of luting agents / Efeito do selamento imediato da dentina na adaptação marginal de restaurações overlay de dissilicato de lítio utilizando diferentes tipos de agentes de cimentação: estudo in vitro

Objective:This study evaluated the effect of immediate dentin sealing on the marginal adaptation of lithium disilicate overlays with three different types of resin-luting agents: preheated composite, dual-cure adhesive resin, and flowable composite. Materials and Methods: Forty-eight maxillary first premolars of similar size were prepared with a butt joint preparation design. The teeth were separated into two primary groups, each with twenty-four teeth: Group DDS: Delay dentin sealing (non-IDS) teeth were not treated. Group IDS: dentin sealing was applied immediately after teeth preparation. Each group was subsequently separated into three separate subgroups. Subgroups (DDS+Phc, IDS+Phc): cemented with preheated composite (Enamel plus HRi, Micerium, Italy), Subgroups (DDS+Dcrs, IDS+Dcrs): cemented with dual-cured resin cement (RelyX Ultimate, 3M ESPE, Germany) and Subgroups (DDS+Fc, IDS+Fc): Cemented with flowable composite (Filtek supreme flowable, 3M ESPE, USA). Using a digital microscope with a magnification of 230x, the marginal gap was measured before and after cementation at four different locations from each surface of the tooth, and the mean of measurements was calculated and analyzed statistically using the independent t-test, one-way ANOVA test, Bonferroni correction at a significance level of 0.05. Results: The samples that were immediately sealed with dentin bonding agent showed lower marginal gaps than delayed dentin sealing, both pre-and post-cementation for all subgroups, with a statistically significant difference (p˂0.01). The marginal gap was significantly lower in the IDS+Fc (48.888 ±5.5 µm) followed by the IDS+Dcrs group (53.612 ±5.8 µm) and IDS+Phc (79.19 9±6.9 µm) respectively, while the largest marginal gaps were observed in the DDS+Phc group (86.505 ±5.4 µm). Conclusion: Generally, the teeth with IDS showed better marginal adaptation than teeth without IDS. The marginal gap was smaller with flowable composite and dual-cure resin cement than with preheated composite (AU)

Objetivo:Esse estudo avaliou o efeito do selamento imediato da dentina na adaptação marginal de overlays em dissilicato de lítio com três tipos diferentes de agentes de cimentação resinosos: resina composta pré-aquecida, adesivo resinoso dual e resina fluida. Materiais e métodos: Quarenta e oito primeiros pré-molares maxilares com tamanho similar foram preparados com término em ombro. O dente foi separado em dois grupos primários, cada um com vinte e quatro dentes: Grupo DDS: retardado selamento da dentina (non-IDS) dente não foi tratado. Grupo IDS: selamento dentinário foi aplicado imediatamente após a preparação do dente. Cada grupo foi separado de modo subsequente em três subgrupos. Subgrupo (DDS+Phc, IDS+Phc): cimentado com resina pré-aquecida (Enamel plus HRi, Micerium, Italy), Subgrupo (DDS+Dcrs, IDS+Dcrs): cimentado com cimento resinoso dual (RelyX Ultimate, 3M ESPE, Germany) e Subgrupo (DDS+Fc, IDS+Fc): cimentado com resina fluida (Filtek supreme flowable, 3M ESPE, USA). Usando um microscópio digital com magnificação de 230x, o gap marginal foi medido antes e após a cimentação em quatro diferentes localizações de cada superfície do dente e a média das medidas foi calculada e estatisticamente analisada através do uso do teste ANOVA um-fator e teste independente de Tukey e correção Bonferroni com nível de significância de 0,05. Resultado: As amostras que foram imediatamente seladas com agente adesivo dentinário apresentaram menores gaps marginais do que o selamento dentinário retardado, ambos pré e pós cimentação para todos os subgrupos apresentaram diferença estatística significante (p˂0.01). O gap marginal foi significativamente menor para IDS+Fc (48.888 ±5.5 µm) acompanhado do IDS+Dcrs group (53.612 ±5.8 µm) e IDS+Phc (79.19 9 ±6.9 µm) respectividamente, enquanto o maior gap marginal foi observado no grupo DDS+Phc (86.505 ±5.4 µm). Conclusão:Geralmente, o dente com IDS apresentou melhor adaptação marginal do que o dente sem IDS. O gap marginal foi menor com resina fluida e cimento resinoso dual do que com a resina composta pré-aquecida (AU)

Effect of ceramic thicknesses and opacities on water sorption and solubility of a light-curing resin cement by different units

Aim: This study evaluated the water sorption and solubility of a light-cured resin cement, under four thicknesses and four opacities of a lithium disilicate ceramic, also considering three light-emitting diode (LED) units. Methods: A total of 288 specimens of a resin cement (AllCem Veneer Trans ­ FGM) were prepared, 96 samples were light-cured by each of the three light curing units (Valo ­ Ultradent / Radii-Cal ­ SDI / Bluephase II ­ Ivoclar Vivadent), divided into 16 experimental conditions, according to the opacities of the ceramic: High Opacity (HO), Medium Opacity (MO), Low Translucency (LT), High Translucency (HT), and thicknesses (0.3, 0.8, 1.5, and 2.0 mm) (n = 6). The specimens were weighed at three different times: Mass M1 (after making the specimens), M2 (after 7 days of storage in water), and M3 (after dissection cycle), for calculating water sorption and solubility. Results: The higher thickness of the ceramic (2.0 mm) significantly increased the values of water sorption (44.0± 4.0) and solubility (7.8±0.6), compared to lower thicknesses. Also, the ceramic of higher opacity (HO) generated the highest values of sorption and solubility when compared to the other opacities, regardless of the thickness tested (ANOVA-3 factors / Tukey's test, α = 0.05). There was no influence of light curing units. Conclusion: Higher thicknesses and opacities of the ceramic increased the water sorption and solubility of the tested light-cured resin cement

Rehabilitación estética y funcional en paciente con compromiso gastroesofágico y desorden temporomandibular: reporte de un caso / Rehabilitación estética y funcional en paciente con compromiso gastroesofágico y desorden temporomandibular: reporte de un caso

Paciente masculino, de 32 años, acudió a la Clínica de Prótesis Parcial Fija (PPF), de la Facultad de Odontología de Araçatuba-Universidad Estadual Paulista, manifestando como queja principal que sus dientes anteriores estaban "feos y rotos". Después del exa- men clínico, el paciente fue diagnosticado con desorden temporomandibular, bruxismo y presencia de erosiones dentarias (intrínsecas y extrínsecas). Se propuso el acompaña- miento de un médico gastroenterólogo y la rehabilitación con prótesis libres de metal (11, 12, 21 y 22) confeccionadas en silicato de litio reforzado con zirconio por el sistema CAD/CAM. Después de la endodoncia de los incisivos antero-superiores, fueron insta- lados los pernos de fibra de vidrio anatomizados con resina compuesta; la impresión fue realizada con hilo retractor y silicona de adición. Después de la prueba estética y ajustes oclusales, las PPFs de e-max Ceram, fueron preparadas para cementación resinosa con el sistema Variolink II color Light. Después de 1 semana, se tomó la impresión de la arcada superior y posteriormente se le instaló una placa miorrelajante. El paciente y los profesionales involucrados aprobaron el resultado final, comprobando la eficacia estética asociada al uso de prótesis libre de metal, a pesar de que el paciente presenta compromiso gastroesofágico y desorden temporomandibular.

A 32-year-old male patient attended in the Fixed Partial Prosthesis Clinic (PPF), of the Araçatuba Dental School-Paulista State University, stating as the main complaint that his anterior teeth were "ugly and broken". After clinical examination, the patient was diagnosed with temporomandibular disorder, bruxism and the presence of dental ero- sions (intrinsic and extrinsic). It was proposed to be followed up by a gastroenterologist and rehabilitation with metal-free prostheses (11, 12, 21 and 22) made of lithium silicate reinforced with zirconium by the CAD / CAM system were proposed. After endodontics of the anterior-superior incisors, the anatomized fiberglass posts with composite resin were installed; the impression was made with retractor wire and addition silicone. After aesthetic testing and occlusal adjustments, the e-max Ceram PPF ̈s were prepared for resin cementation with the Variolink II color Light system. After 1 week, the impression of the upper arch was taken and subsequently a muscle relaxant plate was installed. The patient and the professionals involved approved the final result, verifying the aesthetic efficacy associated with the use of a metal-free prosthesis, despite the fact that the patient has gastroesophageal involvement and temporomandibular disorder.

Clinical effect of a guided resin cementation technique in the treatment of vertical food impaction / 口腔疾病防治

Objective@# To explore the clinical effect of a guided resin cementation technique on vertical food impaction symptoms and to provide a new method for the treatment of vertical food impaction. @* Methods @#Treatment of 76 patients with vertical food impaction with guided resin cementation was performed. A specially fabricated contact shaping wire was used to aid the shaping of the contact. Cementation was applied under a rubber dam with the total-etch technique with flowable composite resin. Patient subjective perception was recorded after treatment (i.e., “totally relieved”=3, “significantly improved”=2, “slightly improved”=1 and “no change”=0). Follow-up visits lasted for one year. Scores of 1 to 3 were recorded as effective. The efficiency rates at different times were calculated. @*Results@#Patient subjective perceptions scored 2.47, 2.21, 1.79, 1.30 and 0.97 on the day immediately after and 1, 3, 6, and 12 months after treatment, respectively. There were significant differences among scores at each time point (P<0.01). The Efficacy rate reached 91.78% immediately after treatment and was sustained above 50% within half a year. Management of resin debonding or fracture successfully relieved the symptoms again.@*Conclusion@#The guided resin cementation technique relieves vertical food impaction symptoms immediately, and the effect of the guided resin cementation technique is maintained for a short period of time. Management of resin debonding or fracture helps consolidate treatment outcomes.

Fracture resistance and strain analysis of zirconia copings with vertical knife edge and three horizontal finish line designs; chamfer, deep chamfer and shoulder with two cementation techniques / Resistência à fratura e análise de deformação de copings de zircônia com término cervical em lâmina de faca e três términos horizontais; chanfro, chanfro largo e ombro com duas técnicas de cimentação

Objective: The purpose of this in vitro study is to evaluate the effect of four finish line configurations and two cement types on the fracture resistance of zirconia copings. Material and Methods: Forty yttrium tetragonal zirconia polycrystals copings were manufactured on epoxy resin dies with four preparation designs: knife edge, chamfer, deep chamfer 0.5, 1 mm and shoulder 1 mm. The copings were cemented with two cement types (glass ionomer and resin cement); (n = 5). Two strain gauges were attached on each coping before they were vertically loaded till fracture with a universal testing machine. Data were analyzed by 2-way analysis of variance ANOVA (p < .05). Fractured specimens were examined for mode of failure with digital microscope. Results: Knife edge showed the highest mean fracture resistance (987.04 ± 94.18) followed by Chamfer (883.28 ± 205.42) followed by Shoulder (828.64 ± 227.79) and finally Deep chamfer finish line (767.66 ± 207.09) with no statistically significant difference. Resin cemented copings had higher mean Fracture resistance (911.76 ± 167.95) than glass ionomer cemented copings (821.55 ± 224.24) with no statistically significant difference. Knife edge had the highest strain mean values on the buccal (374.04 ± 195.43) and lingual (235.80 ± 103.46) surface. Shoulder finish line showed the lowest mean strain values on the buccal (127.47 ± 40.32) and lingual (68.35 ± 80.68) with no statistically significant difference. Resin cemented copings had higher buccal (295.05 ± 167.92) and lingual (197.38 ± 99.85) mean strain values than glass ionomer copings (149.14 ± 60.94) and (90.27 ± 55.62) with no statistically significant difference. Conclusion: Vertical knife edge finish line is a promising alternative and either adhesive or conventional cementation can be used with zirconia copings (AU)

Objetivo: O objetivo deste estudo in vitro é avaliar o efeito de quatro configurações de términos cervicais e dois tipos de cimentos na resistência à fratura de copings de zircônia. Material e Métodos: Quarenta copings de zircônia tetragonal policristalina estabilizada por ítrio foram confeccionados em matrizes de resina epóxi com quatro tipos de términos cervicais: lâmina de faca, chanfro, chanfro largo 0,5, 1 mm e ombro 1 mm. Os copings foram cimentados com dois tipos de cimento (ionômero de vidro e cimento resinoso); (n = 5). Dois extensômetros foram fixados em cada coping antes de serem carregados verticalmente até a fratura com uma máquina de teste universal. Os dados foram analisados por análise de variância ANOVA 2 fatores (p < 0,05). Os espécimes fraturados foram examinados quanto ao modo de falha com microscópio digital. Resultados: A Lâmina de faca apresentou a maior média de resistência à fratura (987,04 ± 94,18) seguida pelo Chanfro (883,28 ± 205,42), pelo Ombro (828,64 ± 227,79) e finalmente o Chanfro largo (767,66 ± 207,09), sem diferença estatisticamente significativa. Os copings cimentados com cimento resinoso apresentaram maior média de resistência à fratura (911,76 ± 167,95) em relação aos copings cimentados com ionômero de vidro (821,55 ± 224,24), sem diferença estatisticamente significativa. A lâmina de faca apresentou os maiores valores médios de deformação na superfície vestibular (374,04 ± 195,43) e lingual (235,80 ± 103,46). O término em ombro apresentou os menores valores médios de deformação na superfície vestibular (127,47 ± 40,32) e lingual (68,35 ± 80,68), sem diferença estatisticamente significativa. Os copings cimentados com resina apresentaram maiores valores médios de deformação na superfície vestibular (295,05 ± 167,92) e lingual (197,38 ± 99,85) do que os copings cimentados com ionômero de vidro (149,14 ± 60,94) e (90,27 ± 55,62), sem diferença estatisticamente significativa. Conclusão: O término cervical em lâmina de faca é uma alternativa promissora e a cimentação adesiva ou convencional pode ser usada na cimentação de copings de zircônia. (AU)

Influence of resin cement and thermocycling on milled lithium disilicate ceramic microshear bond strength / Influência do cimento resinoso e da termociclagem na resistência de união à cerâmica de dissilicato de lítio fresada

ABSTRACT The aim of this study was to compare the microshear bond strength of different resin cements to CAD/CAM-created lithium disilicate ceramics after 24 hours and after 1 year (10,000 thermocycles). Forty (40) ceramic bars were subjected to pretreatment comprising airborne abrasion with aluminum oxide particles, etching with 10% hydrofluoric acid and Monobond N application. Bars were divided into 4 groups (n = 10), based on cement type: light-cured Variolink Esthetic LC (VLC) and dual-cured Variolink N (VN) at two different times: after 24 hours and after 1 year. Silicone molds were used to prepare cement cylinders on a ceramic surface. The set was stored in distilled water at 37ºC, for 24 hours or subjected to 10,000 thermocycles. The molds were removed and microshear bond strength was tested. Data were submitted to two-way analysis of variance and Tukey's test (α = 0.05). Based on the comparison between cement values at different aging times (p = 0.035), VN after 24 hours (27.10 ± 0.92) and after 1 year (20.62 ± 1.25) presented significantly higher values than VLC after 24 hours (14.79 ± 0.76) and after 1 year (6.61 ± 0.81). Bond strength recorded for both cements after 24 hours (VN: 27.10 ± 0.92 and VLC: 14.79 ± 0.76) was significantly higher than the one recorded after 1 year (VN: 20.62 ± 1.25 and VLC: 6.61 ± 0.81). The thermocycling reduced the values observed for both investigated cements; bond strength was greater for dual-cure resin cement than for light-cured resin cement.

RESUMO O objetivo nesse estudo foi comparar a resistência de união de diferentes cimentos resinosos à cerâmica de dissilicato de lítio processada por CAD/CAM após 24 horas e após 1 ano (10.000 termociclos). Foram utilizadas 40 barras cerâmicas com tratamento prévio por jateamento com óxido de alumínio, condicionamento com ácido fluorídrico 10% e aplicação do Monobond N. As barras foram divididas em 4 grupos (n=10) de acordo com o tipo de cimento: fotopolimerizável Variolink Esthetic LC (VLC) e dual Variolink N (VN) em diferentes tempos: após 24 horas e 1 ano. Matrizes de silicone foram usadas para preparar cilindros de cimento na superfície cerâmica. O conjunto foi armazenado em água destilada a 37ºC por 24 horas ou submetidos protocolo de termociclagem com 10.000 ciclos. As matrizes foram removidas e o teste de microcisalhamento realizado. Os dados foram avaliados por análise de variância a dois fatores e teste de Tukey (α=0,05). Ao comparar os valores dos cimentos em diferentes tempos de envelhecimento (p=0,035), observou-se que VN, após 24 horas (27,10 ± 0,92) e 1 ano (20,62 ± 1,25) apresentou valores significativamente superior a VLC após 24 horas (14,79 ± 0,76) e 1 ano (6,61 ± 0,81). A resistência para ambos os cimentos após 24 horas (VN: 27,10 ± 0,92 e VLC: 14,79 ± 0,76) foi significativamente superior que 1 ano (VN: 20,62 ± 1,25 e VLC: 6,61 ± 0,81). A termociclagem promoveu diminuição nos valores de ambos os cimentos estudados e o cimento resinoso dual mostrou maior resistência de união que o cimento resinoso fotopolimerizável.

Effect of two processing techniques used to manufacture lithium disilicate ceramics on the degree of conversion and microshear bond strength of resin cement / Efeito de duas técnicas de processamento utilizadas na fabricação da cerâmica de dissilicato de lítio no grau de conversão e na resistência de união ao microcisalhamento do cimento resinoso

ABSTRACT The aim of the current study was to compare the effect of two lithium disilicate ceramic processing techniques (pressing and CAD/CAM) on the degree of conversion of resin cement when it is photoactivated and the microshear bond strength of resin cement to ceramics. Two ceramic discs were manufactured: one by the Press technique and another by CAD/CAM technique. Five Variolink Veneer resin cement samples were photoactivated through each ceramic disc and subjected to attenuated total reflectance Fourier transform infrared spectroscopy to evaluate their degree of conversion. To evaluate microshear bond strength, 20 ceramic bars were prepared: 10 using the Press technique and 10 using the CAD/CAM technique. The bars were air abraded with 50-μm Al2O3 particles, treated with 10% hydrofluoric acid for 20 s and subjected to RelyX Ceramic Primer application. Adper Scotchbond Multi-Purpose Adhesive was applied to the bars and cured for 10 s. Two 1-mm-height plastic tubes were placed on each bar and filled with Variolink Veneer resin cement. Each cylinder was cured for 20 s. Then the plastic tubes were removed and the microshear bond strength of each cylinder was tested. Data for degree of conversion (%) and microshear bond strength (MPa) were subjected to Student's t-test (α = 0.05). Both degree of conversion of resin cement photoactivated through ceramic and microshear bond strength of resin cement to ceramic were statistically higher in the group in which ceramic was prepared by CAD/CAM technique (44.74% and 22.18 MPa) than in the group in which the ceramic was prepared by the Press technique (25.71% and 19.83 MPa). The lithium disilicate ceramic processing techniques affected the degree of conversion of resin cement when it is photoactivated through the ceramics and the microshear bond strength of resin cement to ceramics.

RESUMO O objetivo do presente estudo foi comparar o efeito de duas técnicas de processamento da cerâmica de dissilicato de lítio (prensada e CAD/CAM) no grau de conversão do cimento resinoso quando fotoativado e na resistência de união ao microcisalhamento do cimento resinoso às cerâmicas. Foram fabricados dois discos de cerâmica: um pela técnica prensada e outro pela técnica CAD/CAM. Cinco amostras de cimento resinoso Variolink Veneer foram fotoativadas através de cada disco cerâmico e submetidas à espectroscopia no infravermelho por transformada de Fourier com reflectância total para avaliar seu grau de conversão. Para avaliar a resistência de união ao microcisalhamento, foram preparadas 20 barras de cerâmicas: 10 utilizando a técnica prensada e 10 utilizando a técnica CAD/CAM. As barras foram tratadas com partículas de Al2O3 (50 μm), com ácido fluorídrico a 10% por 20 s e submetidas à aplicação do RelyX Ceramic Primer. Em seguida, o adesivo multiuso Adper Scotchbond foi aplicado nas barras e fotoativado por 10 s. Dois tubos de plástico de 1 mm de comprimento foram colocados em cada barra e preenchidos com cimento resinoso Variolink Veneer. Cada cilindro foi fotoativado por 20 s. Os tubos de plástico foram removidos e a resistência de união ao microcisalhamento de cada cilindro foi testada. Os dados de grau de conversão (%) e resistência de união ao microcisalhamento (MPa) foram submetidos ao teste t de Student (α = 0,05). Tanto o grau de conversão do cimento resinoso fotoativado através da cerâmica quanto a resistência de união do cimento resinoso à cerâmica foram estatisticamente maiores no grupo em que a cerâmica foi confeccionada pela técnica CAD/CAM (44,74% e 22,18 MPa) do que no grupo em que a cerâmica foi confeccionada pela técnica prensada (25,71% e 19,83 MPa). As técnicas de processamento de cerâmica dissilicada de lítio afetaram o grau de conversão do cimento resinoso quando fotoativado através das cerâmicas e a resistência de união do microcisalhamento do cimento resinoso às cerâmicas.

Estudo in vitro da influência de diferentes plugs coronários sobre o remanescente da obturação, após preparo para pino, na retenção de pinos metálicos fundidos / In vitro assessment of the influence of different protection plugs over obturation remnant space, after post preparation, on the retention of cast metal posts

Objetivo: Avaliar a influência de diferentes plugs de proteção, acomodados sobre o remanescente da obturação após preparo para pino, na retenção de pinos metálicos fundidos. Métodos: Cinquenta dentes bovinos foram decoronados, manualmente instrumentados até a lima manual Kerr #80 e obturados. A desobturação parcial de 10mm do conduto foi realizada com uma broca Largo e os grupos foram divididos de acordo com os diferentes materiais utilizados como plugs (n=10): Grupo I (Controle, sem plug); Grupo II (plug de Coltosol®); Grupo III (plug, em consistência de massa, de Sealapex® + óxido de zinco); Grupo IV (plug de etil-cianoacrilato); e Grupo V (plug de fosfato de zinco). Uma camada de 1mm de espessura dos diferentes plugs (Grupos II, III, IV ou V) foi acomodada sobre a obturação remanescente. Os espécimes foram selados e armazenados em 100% de umidade, por 7 dias. Após moldagem do conduto, foram confeccionados pinos metálicos fundidos e cimentados com fosfato de zinco. Os espécimes permaneceram em câmara úmida por 45 dias antes do teste de tração, realizado em uma máquina universal de ensaios. Os valores foram expressos em Mega pascal (MPa) e submetidos aos testes ANOVA e Tukey (p<0,05). Resultados: O etilcianoacrilato diminuiu a retenção dos pinos metálicos fundidos (p<0,01). Não houve diferença entre os outros grupos (p>0,05), semelhante- mente ao controle. Conclusão: A proteção da obturação com plugs confeccionados com etil-cianoacrilato prejudica a retenção de pinos metálicos fundidos cimentados com fosfato de zinco, enquanto Sealapex® acrescido de óxido de zinco, fosfato de zinco endurecido ou Coltosol® não interferem na adesividade (AU).

Resistencia a la tracción diametral in vitro de cinco cementos dentales usados como cementantes de puentes y coronas en prótesis fijas / In vitro diametral tensile strength of five dental cements used as bridge and crown cement in fixed prostheses

RESUMEN Objetivo: El propósito de la investigación fue evaluar la resistencia a la tracción diametral in vitro de cinco cementos dentales: BisCem, Duolink, Ketac Cem, Meron, Allcem, cuatro adhesivos convencionales y un autoadhesivo polimerizado químicamente utilizados como cementantes de puentes y coronas en prótesis fijas. Materiales y métodos: Se prepararon 100 especímenes conformados por cementos: BisCem, Duolink, Ketac Cem, Meron, Allcem, los cuales se dividieron aleatoriamente en 5 grupos de 20 especímenes cada grupo sujetas a fotopolimerización y auto polimerización de 8mm de diámetro y 5mm de alto, con 2mm de distancia aproximadamente de la lámpara para la polimerización, se utilizó un formador de probetas de polietileno de alta densidad estandarizado, el tipo de muestreo es no probabilístico. Se sometieron a los especímenes de cada grupo a la prueba de tracción utilizando una máquina de ensayo universal (zwickiLine by Zwick/Roell), hasta lograr el fracaso del cemento, sometidas a una fuerza continua de 500 kg, con una velocidad de desplazamiento fija de 1 cm/min. Resultados: La resistencia promedio a la tracción diametral de probetas del cemento BisCem fue de 38,75 ± 11,56 MPa, del cemento Duolink fue 64,30 MPa, del cemento Meron 57,14 MPa, del cemento Ketac Cem es de 32,23 MPa, del cemento BisCem (38,753 MPa) y el cemento Ketac Cem (39,233 MPa). El cemento dental Duolink es aquel que presenta mayor resistencia a la tracción diametral de probetas en comparación a Meron (57,137 MPa) que es su similar. La tabulación y el análisis han sido sometidos a los test de Shapiro Wilk, análisis de varianza ANOVA y la prueba de Tuckey los valores de cada muestra se distribuyen normalmente existiendo diferencias significativas entre los grupos estudiados. Conclusiones: Las probetas del cemento de resina adhesiva Duolink evidenció una mayor resistencia a la tracción diametral con mejores valores significativos de resistencia a diferencia de los cementos Ketac Cem, Allcem, Meron y BisCem.

SUMMARY Objetive: The purpose of the research was to evaluate the in vitro diametral tensile strength of five dental cements: BisCem, Duolink, Ketac Cem, Meron, Allcem, four conventional adhesives and a chemically polymerized self-adhesive used as bridge cements and crowns in fixed dentures . Materials and methods : 100 specimens consisting of cements were prepared: BisCem, Duolink, Ketac Cem, Meron, Allcem, which were randomly divided into 5 groups of 20 specimens each group subject to photopolymerization and self-polymerization of 8mm in diameter and 5mm high, with an approximate distance of 2mm from the lamp for polymerization, a standardized high density polyethylene specimen was used, the type of sampling is not probabilistic. The specimens of each group were subjected to tensile testing using a universal testing machine (zwickiLine by Zwick / Roell), until the failure of the cement was achieved, subjected to a continuous force of 500 kg, with a fixed displacement speed of 1 cm / min Results: The average tensile strength of diametral tensile specimens of BisCem cement was 38.75 ± 11.56 MPa, Duolink cement was 64.30 MPa, Meron cement 57.14 MPa, Ketac Cem cement was 32.23 MPa, BisCem cement (38.753 MPa ) and Ketac Cem cement (39,233 MPa). Duolink dental cement is the one with the highest tensile strength of diametral specimens compared to Meron (57,137 MPa), which is similar. The tabulation and the analysis have been submitted to the Shapiro Wilk test, ANOVA analysis of variance and the Tuckey test. The values of each sample are normally distributed with significant differences between the studied groups. Conclusions : Duolink adhesive resin cement specimens showed a higher diametral tensile strength with better significant strength values unlike Ketac Cem, Allcem, Meron and BisCem cements.

Effect of commercial silanes on bond strength of resin cement to lithium disilicate ceramic / Efeito de silanos comerciais na resistência de união do cimento resinoso à cerâmica de dissilicato de lítio

The aim of this study was to evaluate the effect of different commercial silanes on microshear bond strength of resin cement to lithium disilicate ceramic. Twenty ceramic samples with 10 mm in length, 10 mm wide and 3 mm in thickness were fabricated, etched with 10% hydrofluoric acid for 20 seconds, and divided into 5 groups, according to the commercial silane applied: G1- RelyX Ceramic Primer (3M ESPE), G2- Angelus Silane, G3- Prosil (FGM), G4- Dentsply Silane (Dentsply) and G5- Bis-Silane (Bisco). Silanes were applied in accordance to manufacturers' recommendations. Addition silicone molds with 1 mm in thickness, 10 mm in diameter and 3 perforations with 1 mm in diameter each one, were placed on ceramic and filled with the resin cement RelyX ARC (3M ESPE) in all groups. Light activation was performed with LED Bluephase G2 (Ivoclar Vivadent) at 1200 mW/cm2, for 30 seconds. Samples were maintained in 100% humidity at 37°C for 24 hours and submitted to microshear test. The data (MPa) were submitted to one-way ANOVA and Tukey test (α=0.05). The results obtained for each group were: G1: 22.39±2.99; G2: 23.35±4.08; G3: 26.05±5.46; G4: 18.56±4.09; G5: 25.26±4.10. Statistical analysis showed significantly lower microshear bond strength for G4. Fracture pattern analysis showed predominance of adhesive failures in G1 and G2. G3 and G5 presented higher percentage of cohesive failures in ceramic, and G4 showed mixed, adhesive and cohesive fractures with similar percentages. It was concluded that different silanes showed influence on the lithium disilicate ceramic ­ resin cement bond strength

O objetivo neste estudo foi avaliar o efeito de diferentes silanos comerciais na resistência de união ao microcisalhamento do cimento resinoso à cerâmica de dissilicato de lítio. Foram confeccionadas 20 amostras de cerâmica (10mm de comprimento, 10mm de largura e 3mm de espessura), condicionadas com ácido fluorídrico a 10% por 20 segundos e divididas em 5 grupos, de acordo com o silano aplicado: G1- RelyX Ceramic Primer (3M ESPE), G2- Silano Angelus, G3-Prosil (FGM), G4- Silano Dentsply e G5-Bis-Silane (Bisco). Matrizes de silicone por adição (1 mm de espessura, 10 mm de diâmetro e 3 perfurações com 1 mm de diâmetro) foram colocadas sobre a cerâmica e preenchidas com cimento resinoso RelyX ARC (3M ESPE). A fotoativação foi realizada com LED Bluephase G2 (Ivoclar Vivadent) a 1200 mW/cm2, por 30 segundos. As amostras foram mantidas em 100% de umidade a 37°C por 24 horas e submetidas ao teste de microcisalhamento. Os dados (MPa) (G1: 22,39+2,99; G2: 23,35+4,08; G3: 26,05+5,46; G4: 18,56+ 4,09; G5: 25,26+4,10) foram submetidos a análise de variância e ao teste de Tukey (p<0,05). A análise estatística mostrou valor de resistência de união significantemente menor para G4. A análise do padrão de fratura mostrou predominância de falha adesiva para G1 e G2. G3 e G5 apresentaram maior porcentagem de falha coesiva em cerâmica, e o G4 apresentou fraturas mista, adesiva e coesiva em igual porcentagem. Concluiu-se que os diferentes silanos apresentaram influência na resistência de união do cimento resinoso à cerâmica de dissilicato de lítio

Operational specification for clinical use of dental intraradicular fiber post / 中华口腔医学杂志

Fiber-reinforced resin composite posts (fiber posts) are used extensively for the restoration of root-treated teeth with excessive loss of coronal structure. However, the longevity of a fiber post restoration still needs to be improved because of the various confounding factors that affect bonding procedures. Operational specification for clinical use of dental intraradicular fiber post was established based on the in-depth discussions by a panel of experts from Society of Prosthodontics, Chinese Stomatological Association. This specification should be helpful in standardizing the clinical technique of fiber post placement and improving the clinical longevity of a fiber post restoration.

Glass fiber posts: influence of cementation techniques on push-out bond strength

Aim: Glass fiber posts are indicated in the rehabilitation of extensively damaged teeth; their cementation represents a critical step in restorative dentistry. The aim of this study was to quantify and compare the push-out bond strength of glass fiber posts cemented by conventional technique, two-step technique with luting agent and two-step technique associating bulk-fill composite and luting agent. Methods: Eighty maxillary bovine incisors were endodontically treated and divided into eight groups (n = 10) according to the luting agent (Rely X ARC and Duo-link) and cementation technique (conventional technique; two-step technique with luting agent; and two-step technique associating bulk-fill composite ­ Filtek Bulk-fill flow or Surefil SDR flow ­ and luting agent). Samples were submitted to pushout bond strength test, and the fracture pattern was evaluated through scanning electron microscope. Data were submitted to two-way ANOVA and Tukey's test (α = 0.05). Results: When Rely X ARC was used, the conventional cementation technique obtained higher bond strength values than the twostep technique associated with Filtek Bulk-fill flow. When Duolink was used, the two-step technique associated with Filtek Bulk-fill flow presented higher bond strength values than the conventional technique. The most prevalent fracture patterns were adhesive between luting agent and dentin, and adhesive between bulk-fill composite and dentin. Conclusion: Two-step cementation technique associated with bulk-fill composite may be promising depending on the luting agent used

Evaluation of physical-mechanical properties of self-adhesive versus conventional resin cements

Aim: The purpose of this study was to compare the microhardness, diametral tensile strength, compressive strength and the rheological properties of self-adhesive versus conventional resin cements. Methods: Specimens of a conventional (RelyX ARC) and 3 self-adhesive (RelyX U200, Maxcem Elite, Bifix SE) types of resin cements were prepared. The Knoop test was used to assess the microhardness, using a Microhardness Tester FM 700. For the diametral tensile strength test, a tensile strength was applied at a speed of 0.6 mm/minute. A universal testing machine was used for the analysis of compressive strength and a thermo-controlled oscillating rheometer was used for the Rheology test. One-way ANOVA and Tukey's test (α=0.05) were used for data analysis. Results:According to microhardness analysis, all the cements were statistically similar (p>0.05), except for Maxcem that presented lower hardness compared with the other cements in relation to the top surface (p<0.05). In the diametral tensile strength test, Relyx U200 and RelyX ARC cements were statistically similar (p>0.05), presented higher value when compared to the Maxcem and Bifix cements (p<0.05). The compressive strength of RelyX ARC and Maxcem Elite cements was statistically higher than RelyX U200 and Bifix cements (p<0.05). Regarding the rheology test, Maxcem Elite and RelyX ARC cements showed a high modulus of elasticity. Conclusions: The self-adhesive cements presented poorer mechanical properties than conventional resin cement. Chemical structure and types of monomers employed interfere directly in the mechanical properties of resin cements

Retention strength of ball-attachment titanium post for removable partial denture or overdenture

Aim: To evaluate the retention of an endodontic titanium postwith a spherical head for removable partial denture or overdentureattachment according to surface treatment type. Methods: Sixtyhealthy single-rooted teeth, sectioned at the enamel/cementumjunction, were treated endodontically and steadily fixed in theembedding acrylic resin. The titanium posts were subdivided intofour groups: control, no surface treatment (Ctrl); posts with macroretentivegrooves (MR); air abrasion of the post surface (AB); andposts with macro-retentive grooves and air abrasion of the postsurface (MR+AB). The posts were luted in the root canal usingself-adhesive dual resin cement. Pull-out testing was performedusing a universal testing machine until complete detachment wasachieved. After pull-out testing, the metallic posts were examinedunder an optical microscope and the failures were classifiedbased on the cement distribution pattern on the extracted posts:0, no cement left on the post (cement/post failure); 1, postsurface partially covered by adhered cement (post/cement anddentin/cement mixed failure); 2, post surface completely coveredby cement (dentin/cement failure). The retention data wereanalyzed by one-way ANOVA, Bonferroni­Dunn test (p<0.05)and Weibull analysis. Results: AB showed the highest retentionvalue (485.37±68.36), followed by MR+AB (355.80±118.47), MR(224.63±42.54) and Ctrl (113.12 ± 51.32). AB and MR showedthe highest Weibull moduli. Conclusions: The data indicatedthat air abrasion alone could significantly increase the retentionof titanium posts/attachments for use with overdentures orremovable partial denture

Influência do selamento dentinário imediato com sistema adesivo universal na resistência de união / Influence of immediate dentin sealing on dentin bond strength with universal adhesive system

Resumo Introdução O selamento dentinário imediato consiste na aplicação imediata de um sistema adesivo sobre exposições dentinárias após o preparo dental e previamente aos procedimentos de moldagem. Objetivo O objetivo do estudo foi avaliar a influência do selamento dentinário imediato (SDI) na resistência adesiva do sistema adesivo universal (Single Bond Universal, 3M ESPE) em dentina, na forma de aplicação autocondicionante. Material e método 30 incisivos bovinos foram divididos em 3 grupos (n = 10): grupo S (Sem Selamento Dentinário Imediato), grupo SDI (Selamento Dentinário Imediato) e grupo SDIF (Selamento Dentinário Imediato + Resina Flow). A superfície vestibular foi desgastada com pontas diamantadas até a exposição superficial de dentina. A simulação da lama dentinária foi realizada com lixa d'água por 30s e a dentina tratada de acordo com o respectivo grupo. Para simulação da restauração provisória, foram cimentados blocos de resina bisacrílica com cimento de óxido de zinco. Após 7 dias, foi realizada a cimentação definitiva de blocos de resina com cimento resinoso dual (RelyX ARC, 3M ESPE). Os espécimes foram seccionados para obtenção de filetes de 1mm2 e submetidos ao teste de microtração, em uma máquina universal de ensaios (Instron). Os resultados foram tabulados e submetidos a Análise de Variância (ANOVA) e teste de Tukey a 5% de significância. Resultado Observaram-se maiores valores de resistência de união para o grupo SDIF (23,53 MPa), diferindo estatisticamente do Grupo S (17,65 MPa) (p=0,008). O grupo SDI apresentou valor médio de resistência de união (19,25 MPa), não diferindo estatisticamente dos grupos S (p=0,68) e SDIF (p=0,07). Conclusão Recomenda-se a técnica de selamento dentinário imediato seguido da uma camada de resina flow, em exposições dentinárias ocasionadas pelo preparo dental para restaurações indiretas.

Abstract Introduction Imediate dentin sealing (IDS) is a procedure where a dentin adhesive is applied on the exposed dentin surfaces after its preparation to indirect restorations and before impression procedures. Objective The objective of the study was to evaluate the effectiveness of the immediate dentin sealing technique (SDI) in adhesive resistance, using the Universal adhesive system (Single Bond Universal, 3M ESPE). Material and method 30 bovine incisors were selected and divided into 3 groups (n = 10): Groups S (Without Immediate Dentin Seal), SDI (Immediate Dentin Seal with Adhesive) and SDIF (Immediate Dentin Seal with Adhesive + Flow Resin). The vestibular surface was worn with diamond-tipped conical tips until superficial dentin exposure. The smear layer simulation was carried out with # 600 granulation sandpaper for 30s and the dentin was treated according to the respective group. To simulate the temporary restoration, blocks of bisacrylic resin were cemented with zinc oxide cement. After 7 days, the final cementation of resin blocks with dual resin cement (RelyX ARC, 3M ESPE) was carried out. The specimens were sectioned to obtain 1mm2 fillets and subjected to the microtensile test. Result The ANOVA test showed a statistical difference between the groups evaluated. Higher values of bond strength were observed for the SDIF group (23.53 MPa), differing statistically from Group S (17,65 MPa) (p = 0.008). The SDI group showed an average bond strength (19.25 MPa), which did not differ statistically from groups S (p = 0.68) and SDIF (p = 0.07). Conclusion Based on the results, it is recommended the immediate dental sealing technique with adhesive + flow resin in dental exposures caused in the dental preparation for indirect restorations.