Analysis of cervical sagittal balance in patients neck pain and no neck pain / Análise do equilíbrio sagital cervical em pacientes com e sem cervicalgia / Análisis del equilibrio sagital cervical en pacientes con y sin cervicalgia

ABSTRACT Introduction: Sagittal balance was measured by Hardacker`s et al. using the occipital method COBB C1-C2, C2-C3, C3-C4, C4-C5, C5-C6, C6-C7 in a sample of asymptomatic patients without neck and shoulder pain. In other recent studies, measurements of cervical sagittal balance included several radiographic parameters. Objective: To compare the cervical sagittal balance in groups of patients with and without neck pain submitted to cervical radiography with the upper limbs in flexion. Methods: This is a cross-sectional, quantitative, prospective, descriptive study with radiographic analysis of 50 adults aged between 30 to 70 years old. The group was divided into Group 1: without neck pain, and Group 2: with neck pain. All answered a questionnaire about age and the presence or absence of neck pain. Exclusion criteria were: inadequate X-Ray image, deformity or previous spine surgery, limited shoulder mobility, and individuals younger than 30 and older than 70. The radiographic parameters evaluated were: COBB, TIA ( THORACIC INLET ANGLE), T1 SLOPE, NECKTILT, and COG-C7 with no neck pain. α = 5% (significance when p <0.05). Results: The MANN WHITNEY nonparametric test showed no significant differences between Cobb GROUPS (p= 0.7452), T1 SLOPE GROUPS (p=0.1410), NECKTILT GROUPS (p=0.0852) and GROUPS THORACIC INLET ANGLE (p=0.1789). Conclusion: There was a significant difference only between COG-C7 GROUPS (cm) (p=0.0013). The analysis of the obtained data showed statistical significance in the variation in the COG-C7 groups. Level of Evidence II; Prospective comparative study.

Resumo: Introdução: O equilíbrio sagital foi medido por Hardacker et al. usando o método occipital COBB C1-C2, C2-C3, C3-C4, C4-C5, C5-C6, C6-C7 em uma amostra de pacientes assintomáticos sem dor no pescoço e no ombro. Em outros estudos recentes, as medidas do equilíbrio sagital cervical incluíram vários parâmetros radiográficos. Objetivo: Comparar o equilíbrio sagital cervical em grupos de pacientes com cervicalgia e sem cervicalgia submetidos à radiografia da cervical, com os membros superiores em flexão. Métodos: Trata-se de um estudo transversal, quantitativo, prospectivo, descritivo, com análise radiográfica de 50 adultos, com idade entre 30 e 70 anos. O grupo foi dividido em Grupo 1: sem cervicalgia e Grupo 2: com cervicalgia. Todos responderam a um questionário sobre idade e presença ou não de dor cervical. Os critérios de exclusão foram: imagem inadequada, deformidade ou cirurgia prévia da coluna, mobilidade limitada do ombro e indivíduos com idade inferior a 30 e superior a 70 anos. Os parâmetros radiográficos avaliados foram: COBB, TIA (ANG THORACIC INLET), T1 SLOPE, NECKTILT e COG-C7 com e sem cervicalgia. α = 5% (significância quando p < 0,05). Resultados: O teste não paramétrico de MANN WHITNEY não mostrou diferenças significativas entre os GRUPOS Cobb (p= 0,7452), GRUPOS SLOPE T1 (p=0,1410), GRUPOS NECKTILT (p=0,0852) e GRUPOS TIA (p=0,1789). Conclusão: Houve diferença significativa apenas entre os GRUPOS COG-C7 (cm) (p=0,0013). A análise dos dados obtidos demonstrou significância estatística em relação à variação nos grupos COG-C7. Nível de evidência II; Estudo comparativo prospectivo.

Resumen: Introcucción: El equilibrio sagital fue medido por Hardacker et al. utilizando el método occipital COBB C1-C2, C2-C3, C3-C4, C4-C5, C5-C6, C6-C7 en una muestra de pacientes asintomáticos sin dolor del cuello y hombros. En otros estudios recientes, las mediciones del equilibrio sagital cervical incluyeron varios parámetros radiográficos. Objetivo: Comparar el equilibrio sagital cervical en grupos de pacientes con y sin cervicalgia sometidos a radiografía cervical, con los miembros superiores en flexión. Métodos: Se trata de un estudio transversal, cuantitativo, prospectivo, descriptivo, con análisis radiográfico de 50 adultos, con edades entre 30 y 70 años. El grupo compartió el Grupo 1: Sin dolor del cuello y el Grupo 2: Dolor de cuello. Todos respondieron un cuestionario sobre edad, dolor de cuello o ausencia de dolor de cuello. Los criterios de exclusión fueron: imagen inadecuada, deformidad o cirugía previa de columna, movilidad limitada del hombro y menores de 30 años y mayores de 70 años. Los parámetros radiográficos evaluados fueron: Cobb, TIA (ANG TORACIC INLET), T1 SLOPE, NECKTILT y COG-C7 con y sin cervicalgia. α = 5% (significación cuando p < 0,05). Resultados: La prueba no paramétrica de MANN WHITNEY no mostró diferencias significativas entre los GRUPOS COBB (p=0,7452), GRUPOS T1 SLOPE (p=0,1410), GRUPOS NECKTILT (p=0,0852) y GRUPOS ANG TORACIC INLET (p=0,1789). Conclusión: Hubo diferencia significativa solo entre los GRUPOS COG-C7 (cm) (p=0,0013). El análisis de los datos obtenidos mostró significancia estática en relación a la variación en los grupos COG-C7. Nivel de Evidencia II; Estudio prospectivo comparativo.

Gestão em Saúde Pública, enfrentamentos cotidianos: direitos e deveres / Management in public health, daily confrontations: rights and duties

O guia tem a finalidade de informar e orientar profissionais, estudantes e todos os envolvidos na saúde do país, quanto à Gestão em Saúde Pública e seu enfrentamento cotidiano

Strategies to reduce joint load in the medial compartment of the knee during gait in individuals with osteoarthritis: a review of the literature / Estratégias redutoras da carga no compartimento medial do joelho durante a marcha em indivíduos com osteoartrite: uma revisão da literatura

Abstract Introduction: Increased joint load on the medial compartment of the knee during gait is a mechanical factor responsible for pain and progression of medial knee osteoarthritis. The knee external adductor moment of force is a kinetic parameter that correlates with the joint load in the medial compartment. Objective: The aim of this study was to conduct a narrative review of the biomechanics strategies during gait of individuals with medial knee osteoarthritis that reduce external adductor moment of force of the knee. Methods: The review of the literature was conducted in the databases MEDLINE, PUBMED and PEDro and included articles published between 2000 and 2011. It was selected transversal, theoretical, correlational and longitudinal studies as well as controlled clinical trials. Results: Decreased gait velocity, increased external rotation of the foot, increased internal abductor moment force of the hip and lateral trunk inclination to the side of the support limb are compensatory strategies used to reduce the external adductor moment of force of the knee during gait of individuals with medial knee osteoarthritis. The lateral trunk inclination may be beneficial in a short term, however it decreases the activity of the abductors muscles of the hip during the support phase of the gait favoring compensation that could result in the progression of medial knee osteoarthritis. Conclusion: Strengthening of the abductors muscles of the hip reduces pain, improves the function and prevents compensations that in a long term could possibly accelerate the progression of the medial knee osteoarthritis.

Resumo Introdução: O aumento da carga articular no compartimento medial do joelho durante a marcha é um fator mecânico responsável pela dor e progressão da osteoartrite medial do joelho. O momento de força externo adutor do joelho é o parâmetro cinético que correlaciona com a carga articular no compartimento medial do joelho. Objetivos: O objetivo deste estudo foi realizar uma revisão narrativa da literatura das estratégias biomecânicas durante a marcha em indivíduos com osteoartrite medial do joelho que reduzem o momento de força externo adutor do joelho. Métodos: A revisão da literatura foi realizada nas bases de dados MEDLINE, PUBMED e PEDro, incluindo artigos publicados entre 2000 e 2011. Foram selecionados artigos transversais, teóricos, de correlação e longitudinais, assim como ensaios clínicos controlados. Resultados: A diminuição da velocidade da marcha, aumento do ângulo de rotação externa do pé e do momento de força interno abdutor do quadril, inclinação lateral do tronco são estratégias compensatórias que reduzem o momento de força externo adutor do joelho durante a marcha em indivíduos com osteoartrite medial do joelho. A inclinação lateral do tronco pode ser benéfica em curto prazo, porém diminui a atividade dos músculos abdutores do quadril durante a fase de apoio da marcha favorecendo compensações que podem acarretar na progressão da osteoartrite medial do joelho. Conclusão: O fortalecimento dos músculos abdutores do quadril reduz a dor, melhora a função e previne compensações que em longo prazo poderiam acelerar a progressão da osteoartrite medial do joelho.

Surgical treatment of degenerative lumbar stenosis: comorbidities and complications / Tratamento cirúrgico da estenose degenerativa lombar: comorbidades e complicações / Tratamiento quirúrgico de la estenosis lumbar degenerativa: comorbilidades y complicaciones

Objectives: To study the characteristics of patients who underwent surgical treatment of degenerative spinal stenosis in the last 10 years (2000â€"2010) at the Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (USP-HCFMR) and correlate the postoperative complications and preoperative comorbidities found in the study population. Methods: Retrospective review of medical records and radiographs of patients with degenerative lumbar stenosis treated surgically. Descriptive analysis of data was done with SAS 9.0. Results: 92 patients were included, 47 (51.08%) males and 45 (48.91%) females, with ages ranging from 32 to 86 years (mean age of 64.27 years). The most prevalent comorbidities were hypertension (47.82%) and diabetes mellitus (25%). Twenty-three patients (25%) had two or more comorbidities. Postoperative infection was the most common complication found in 12 cases (13%). Patients with only one preoperative comorbidity showed similar complication rates compared to the population without comorbidities. However, patients with two or more comorbid conditions had a higher incidence of postoperative complications (p<0.001). Conclusions: Comorbidities negatively influenced the outcome of surgical treatment of degenerative lumbar stenosis with higher rates of postoperative complications. .

Objetivos: Estudar as características dos pacientes que foram submetidos ao tratamento cirúrgico da estenose lombar degenerativa nos últimos 10 anos (2000-2010) no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMR-USP), e correlacionar as complicações pós-operatórias e as comorbidades pré-operatórias encontradas na população estudada. Métodos: Avaliação retrospectiva dos prontuários e exames radiográficos dos pacientes portadores de estenose lombar degenerativa submetidos a tratamento cirúrgico. Análise dos dados descritivos com o programa SAS 9.0. Resultados: Foram incluídos 92 pacientes, sendo 47 (51,08%) do sexo masculino e 45 (48,91%) do sexo feminino, com idade que variou de 32 a 86 anos (média de 64,27). As comorbidades mais prevalentes foram a hipertensão arterial sistêmica (47,82%) e o diabetes mellitus (25%). Vinte e três pacientes (25%) apresentaram duas ou mais comorbidades associadas. A infecção pós-operatória foi a complicação mais comum, encontrada em 12 casos (13%). Os pacientes que tinham apenas uma comorbidade pré-operatória apresentaram iguais índices de complicação frente à população sem comorbidades. No entanto, pacientes com duas ou mais comorbidades apresentaram ...

Objetivos: Estudiar las características de pacientes que se sometieron a tratamiento quirúrgico de la estenosis lumbar degenerativa en los últimos 10 años (2000-2010) en el Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMR-USP) y correlacionar las complicaciones postoperatorias y las comorbilidades preoperatorias encontradas en la población estudiada. Métodos: Revisión retrospectiva de las historias clínicas y las radiografías de pacientes con estenosis lumbar degenerativa tratada quirúrgicamente. Análisis de los datos descriptivos con el programa SAS 9.0. Resultados: Se incluyeron 92 pacientes, 47 (51,08%) hombres y 45 (48,91%) mujeres, con edades entre 32 y 86 años (media 64,27 años). Las comorbilidades más frecuentes fueron la hipertensión arterial (47,82%) y la diabetes mellitus (25%). Veintitrés pacientes (25%) tenían dos o más comorbilidades. La complicación más común, encontrada en 12 casos (13%), fue la infección postoperatoria. Los pacientes que tuvieron sólo una comorbilidad preoperatoria mostraron tasas similares de complicaciones en comparación con la población sin comorbilidades. Sin embargo, los pacientes con dos o más comorbilidades tuvieron una mayor incidencia de complicaciones postoperatorias (p < 0,001). ...

Effects of neonatal castration and androgenization on sexual dimorphism in bone, leptin and corticosterone secretion.

This study investigated the role of neonatal sex steroids in rats on sexual dimorphism in bone, as well as on leptin and corticosterone concentrations throughout the lifespan. Castration of males and androgenization of females were used as models to investigate the role of sex steroids shortly after birth. Newborn Wistar rats were divided into four groups, two male groups and two female groups. Male pups were cryoanesthetized and submitted to castration or sham-operation procedures within 24 h after birth. Female pups received a subcutaneous dose of testosterone propionate (100 µg) or vehicle. Rats were euthanized at 20, 40, or 120 postnatal days. Body weight was also measured at 20, 40, and 120 days of age, and blood samples and femurs were collected. The length and thickness of the femurs were measured and the areal bone mineral density (areal BMD) was determined by dual-energy X-ray absorptiometry (DEXA). Biomechanical three-point bending testing was used to evaluate bone breaking strength, energy to fracture, and extrinsic stiffness. Blood samples were submitted to a biochemical assay to estimate calcium, phosphorus, alkaline phosphatase, leptin, and corticosterone levels. Weight gain, areal BMD and bone biomechanical properties increased rapidly with respect to age in all groups. In control animals, skeletal sexual dimorphism, leptin concentration, and dimorphic corticosterone concentration patterns were evident after puberty. However, androgen treatment induced changes in growth, areal BMD, and bone mass properties in neonatal animals. In addition, neonatally-castrated males had bone development and mechanical properties similar to those of control females. These results suggest that the exposure to neonatal androgens may represent at least one covariate that mediates dimorphic variation in leptin and corticosterone secretions. The study indicates that manipulation of the androgen environment during the critical period of sexual differentiation of the brain causes long-lasting changes in bone development, as well as serum leptin and corticosterone concentrations. In addition, this study provides useful models for the investigation of bone disorders induced by hypothalamic hypogonadism.

Action of nicotine and ovariectomy on bone regeneration after tooth extraction in rats.

PURPOSE: The purpose of this study was to evaluate the effects of nicotine and ovariectomy on alveolar bone regeneration after exodontias in rats. MATERIALS AND METHODS: For 30 days, sham ovariectomized (OVX)/NaCl, sham OVX/nicotine, OVX/NaCl, and OVX/nicotine animals were given 2 daily injections of saline or hemisulfate of nicotine. After this period, exodontic procedures were carried out and treatment continued up to the time of euthanasia on days 7 and 14 when the alveoli were removed for further analyses. RESULTS: The data confirmed that nicotine significantly delays the alveolar regeneration process after dental extraction in rats and showed that the association of nicotine with ovariectomy exacerbates these results. CONCLUSION: These results indicate that nicotine potentiated the effect of estrogen deficiency on bone regeneration induced by ovariectomy.

Approach towards total knee arthroplasty in Brazil: cross-sectional study.

CONTEXT AND OBJECTIVE: Total knee arthroplasty (TKA) has evolved particularly since the 1970s, with improvements in implants and surgical instruments, and has thus become an effective intervention for treating knee arthrosis. Many studies have presented rates of satisfactory clinical and radiological results greater than 90%, from follow-ups of over ten years. Nevertheless, despite scientific evidence showing the efficacy of TKA, the approaches taken present controversies in certain respects. The objective of this study was to evaluate how the Brazilian orthopedists deal with TKA, with investigation of the main aspects of this procedure. DESIGN AND SETTING: Cross-sectional survey conducted during the 39th Brazilian Congress of Orthopedics and Traumatology, in São Paulo, Brazil, in November 2007. METHODS: We applied a questionnaire to orthopedists registered at the congress. The questionnaire was randomly distributed and participation was voluntary; 858 completed questionnaires were included in the analysis. RESULTS: Most of the Brazilian orthopedists were members of SBOT and worked in the southeastern region. They used imported cemented implants through an anterior access route centered on the patella, with replacement of the joint surface of the patella and preservation of the posterior cruciate ligament. They did not have experience with simultaneous bilateral TKA. Postoperatively, they used antibiotics and suction drains for 48 hours. There was no consensus regarding prophylaxis for venous thromboembolism or the frequency of the main complications. CONCLUSION: The majority of Brazilian orthopedists work in the southeastern region of the country and agree about the main aspects of the approaches towards TKA.

Approach towards total knee arthroplasty in Brazil: cross-sectional study / Abordagem da artroplastia total do joelho no Brasil: estudo transversal

CONTEXT AND OBJECTIVE: Total knee arthroplasty (TKA) has evolved particularly since the 1970s, with improvements in implants and surgical instruments, and has thus become an effective intervention for treating knee arthrosis. Many studies have presented rates of satisfactory clinical and radiological results greater than 90 percent, from follow-ups of over ten years. Nevertheless, despite scientific evidence showing the efficacy of TKA, the approaches taken present controversies in certain respects. The objective of this study was to evaluate how the Brazilian orthopedists deal with TKA, with investigation of the main aspects of this procedure. DESIGN AND SETTING: Cross-sectional survey conducted during the 39th Brazilian Congress of Orthopedics and Traumatology, in São Paulo, Brazil, in November 2007. METHODS: We applied a questionnaire to orthopedists registered at the congress. The questionnaire was randomly distributed and participation was voluntary; 858 completed questionnaires were included in the analysis. RESULTS: Most of the Brazilian orthopedists were members of SBOT and worked in the southeastern region. They used imported cemented implants through an anterior access route centered on the patella, with replacement of the joint surface of the patella and preservation of the posterior cruciate ligament. They did not have experience with simultaneous bilateral TKA. Postoperatively, they used antibiotics and suction drains for 48 hours. There was no consensus regarding prophylaxis for venous thromboembolism or the frequency of the main complications. CONCLUSION: The majority of Brazilian orthopedists work in the southeastern region of the country and agree about the main aspects of the approaches towards TKA.

CONTEXTO E OBJETIVO: A artroplastia total do joelho (ATJ) evoluiu sobremaneira desde os anos 70, com melhora dos implantes e do instrumental cirúrgico, tornando-se uma intervenção efetiva para o tratamento da artrose do joelho. Muitos estudos apresentam resultados clínicos e radiológicos satisfatórios superiores a 90 por cento no acompanhamento acima de 10 anos. Apesar das evidências científicas sobre sua eficácia da ATJ, a sua abordagem apresenta controvérsias em alguns aspectos. O objetivo do estudo foi avaliar como o ortopedista brasileiro aborda a ATJ e os principais aspectos técnicos na realização deste procedimento. TIPO DE ESTUDO E LOCAL: Estudo transversal, realizado durante o 39º Congresso Brasileiro de Ortopedia e Traumatologia em São Paulo, Brasil, em novembro de 2007. MÉTODOS: Aplicamos um questionário aos ortopedistas inscritos no congresso. A distribuição foi aleatória com adesão voluntária. Foram incluídos 858 questionários para análise. RESULTADOS: A maioria dos Ortopedistas Brasileiros são membros da SBOT e atua na região sudeste. Usam o implante importado, cimentado, por via de acesso anterior centrada na patela, com substituição da superfície articular da patela e preservação do ligamento cruzado posterior e não tem experiência com a artroplastia total bilateral simultânea. No pós-operatório utilizam antibióticos e dreno de sucção por 48 horas. Não houve consenso quanto à profilaxia para tromboembolismo venoso e frequência das principais complicações. CONCLUSÃO: A maioria dos ortopedistas brasileiros trabalha na região sudeste e concorda quanto aos principais aspectos da abordagem da ATJ.

Removal of noncollagenous components affects dentin bonding.

The structural integrity of fibrillar type I collagen is critical for effective dentin bonding. Since most noncollagenous matrix components in dentin are closely associated with collagen, we hypothesized that they may also contribute to dentin bonding. To test this hypothesis, bovine dentin was acid-etched, treated with chondroitinase ABC (C-ABC), endo-beta-galactosidase (Endo-beta), or trypsin. Controls were prepared in the same manner but without the enzymes. All control and experimental specimens were then bonded with One-Step. Bond strength data were analyzed by one-way ANOVA and Fisher's PLSD test (p < 0.05). When dentin was treated with C-ABC or trypsin, bond strengths significantly decreased for the rewetted groups (p < 0.05). The treatment with Endo-beta showed no effects on bond strengths (p > 0.05). When the treated dentin surfaces were observed under SEM, the C-ABC and trypsin treated groups revealed significant loss of collagen fibril architecture. The results indicate that chondroitin sulfate glycosaminoglycans and trypsin-digestible noncollagenous proteins play roles in maintaining the open dimensions of the collagen fibril scaffold, which is essential for optimal dentin bonding.

Micromorfologia do esmalte decíduo intacto ou desgastado em função do agente condicionador / Micromorphology of grounded or ungrounded primary enamel in function of the etchant

O objetivo deste estudo foi observar, ao microscópio eletrônico de varredura (MEV), a micromorfologia do esmalte de dentes decíduos intacto ou desgastado após condicionamento com ácido fosfórico a 37% ou com sistemas adesivos autocondicionantes de uma ou duas etapas. Foram selecionados 15 dentes decíduos, que foram divididos em três grupos, com 5 dentes em cada, de acordo com o agente condicionador e dentre eles, sub-divididos mantendo-se a superfície do esmalte intacta ou desgastada. G1: ácido fosfórico a 37% (Condicionador Dental Gel - Dentsply). G1A: esmalte intacto. G1B: esmalte desgastado. G2: condicionamento com primer do sistema adesivo autocondicionante de duas etapas (Adhese - Ivoclar Vivadent). G2A: esmalte intacto. G2B: esmalte desgastado. G3: condicionamento com sistema adesivo autocondicionante de etapa única (Xeno III – Dentsply). G3A: esmalte intacto. G3B: esmalte desgastado. Após os tratamentos propostos, todas as amostras foram desidratadas, montadas em bases metálicas e observadas ao MEV quanto ao padrão de condicionamento ácido. As amostras do G1A revelaram um padrão não homogêneo de condicionamento (áreas de esmalte condicionado e outras não condicionadas). No G1B foi observado um padrão homogêneo de condicionamento, prevalecendo o padrão Tipo 2 de Silverstone et al.(1975). As amostras dos G2A e G2B não revelaram um padrão homogêneo de condicionamento, tanto no esmalte íntegro como no desgastado. Concluiu-se que o uso do ácido fosfórico parece ser mais favorável para a formação de uma superfície micro retentiva, notadamente no esmalte desgastado. O uso de sistemas adesivos autocondicionantes, tanto no esmalte intacto como no desgastado não propiciou a formação de uma superfície do esmalte micro retentiva.

The aim of this study was to examinate under scanning electron microscopy (SEM) the micromorphology of grounded and ungrounded primary enamel after conditioning with 37% phosphoric acid, single or two-step self etching adhesive systems. Fiftheen primary teeth were selected and divided into three groups (n=5), according to the etchant and then sub-divided maintaining the enamel surface ungrounded or grounded. G1: 37% phosphoric acid (Condicionador Dental Gel – Dentsply). G1A: ungrounded enamel. G1B; grounded enamel. G2: etching with primer of a two-step adhesive system Adhese (Ivoclar – Vivadent). G2A: ungrounded enamel. G2B: grounded enamel.G3: etching with a single-step adhesive system (Xeno III – Dentsply). G3A: ungrounded enamel. G3B: grounded enamel. After enamel etching, all the samples were dehydrated, mounted on metal stubs and observed by SEM for etching pattern. G1A samples showed a non-uniform pattern of enamel etching (with etched and unetched areas). In G1B samples it was observed an uniform Type 2 etching pattern, according Silverstone et al. (1975). G2A and G2B samples did not reveal an uniform etching pattern, for both grounded and ungrounded enamel. It was concluded that the use of phosphoric acid seems to be more suitable to create a micro retentive surface, specially when enamel surface was grounded. Use of a self etching adhesive system on grounded or ungrounded primary enamel did not propitiate the formation of a microretentive enamel pattern.

Influence of different tests used to measure the bond strength to dentin of two adhesive systems.

PURPOSE: To investigate the behavior of two bonding systems: self-etching primer Clearfil Liner Bond 2V (CLB) and total-etch Single Bond (SB) when submitted to two bond strength tests: shear bond strength (SBS) and microtensile (MTBS). METHODS: Flat dentin surfaces were obtained at the facial surface of extracted bovine incisors. muTBS started with adhesive application and incremental resin composite insertion. Samples were then sliced into 1 mm slabs parallel to the long axis of the tooth. Half of the specimens from each group were trimmed in order to obtain dumbbell-shaped (D) specimens with a cross-sectional area of 1 mm2, and in the other half of the group, the slabs were cut into beams (B) with a cross section of 1 mm2 area. Specimens were individually fractured on a microtensile apparatus. For SBS, crown segments were embedded in polyester resin and a flat dentin surface was exposed for bonding. After adhesive and restorative procedures were accomplished, the specimens were kept in water for 24 hours prior to bond testing. The tests were performed in a universal testing machine. MPa values were analyzed by Tukey's test (P < 0.05), two-way ANOVA (muTBS) and Student's t-test (SBS). RESULTS: Mean values (SD) on muTBS were: SB/B: 42.6 (15.1), SB/D: 35.4 (6.8), CLB/B: 14.3 (10.3) and CLB/D: 27.0 (7.9). SBS values (SD) were: SB: 17.3 (5.6) and CLB 15.9 (7.2). Beam specimens bonded with CLB presented the lowest results. SBS did not show statistical differences between groups. The results showed that the shear bond test seemed to lack the sensitivity that is required to detect subtle differences between bonding agents or procedures.

Avaliação da resistencia de uniao de diferentes sistemas adesivos em dentina / Shear bond strengths evaluation of different adhesive systems to dentin

O objetivo deste estudo foi comparar a resistência de união em dentina de quatro sistemas adesivos de frasco único e dois autocondicionantes. Noventa fragmentos obtidos da porção coronária de dentes bovinos foram incluídos em resina de poliestireno e desgastados com lixas abrasivas até se obter uma superfície plana em dentina. Em seguida, os espécimes foram divididos aleatoriamente em seis grupos (n=15), de acordo com o sistema adesivo: [SB]Single Bond; [PB]Prime & Bond NT; [EX]Excite; [OCB]One Coat Bond; [CLF]Clearfil SE Bond e [OUB]One-Up Bond F. Sobre cada superfície dentinária foi aplicado o sistema adesivo e confeccionado um cilindro de resina composta Z250, utilizando-se uma matriz de teflon bipartida. Após 7 dias, o teste de cisalhamento foi realizado em uma máquina de ensaio universal (EMIC) com velocidade de O,5mm/min. Os dados obtidos em MPa foram submetidos à análise estatística (ANOV A e Tukey, p

Effects of sodium hypochlorite gel and sodium hypochlorite solution on dentin bond strength.

The aim of this study was to determine the effect of 10% NaOCl gel and 10% NaOCl solution on dentin bond strengths of four adhesive systems. One hundred eighty bovine incisors were ground to achieve a flat polished surface, then divided into 12 groups: Gluma One Bond [G1-control; G2-NaOCl solution; G3-NaOCl gel]; Prime & Bond 2.1 [G4-control; G5-NaOCl solution; G6-NaOCl gel]; Single Bond [G7-control; G8-NaOCl solution; G9-NaOCl gel]; Prime & Bond NT [G10-control; G11-NaOCl solution; G12-NaOCl gel]. Dentin was etched, rinsed, and blot dried. For the experimental groups, after acid etching, 10% NaOCl solution or 10% NaOCl gel was applied for 60 s, rinsed, and blot dried. Composite resin was inserted and light cured. Shear bond strengths were tested with a crosshead speed of 0.5 mm/min. The mean values MPa (SD) were analyzed with two-way ANOVA and Tukey's tests (alpha < 0.01). Ten percent NaOCl solution significantly increased Gluma One Bond strength. No effect was observed for the other adhesives. The 10% NaOCl gel did not affect bond strengths. Ten percent NaOCl gel was less effective on collagen removal as compared to 10% NaOCl solution. The influence of collagen removal on bond strength is dependent on adhesive system, where both the solvent and the monomer can influence the results.

Long-term bond strength of restorations subjected to thermo-mechanical stresses over time.

PURPOSE: To evaluate the long-term effect of thermal and mechanical cycling on dentin bond strength to cervical margins of Class II restorations. METHODS: Sixty Class II slot cavities were prepared in bovine incisors. The cavities were restored with Single Bond and Z-250 composite according to manufacturer's instructions. The teeth were then divided into two groups (n = 30): specimens that would receive thermo-mechanical load cycling (2,000 cycles 5-55 degrees C/100,000 cycles of 50 N loading) (TM) and the control (C). Fifteen specimens from each group were tested at baseline and the remaining 30 specimens were stored in distilled and deionized water at 37 degrees C and tested after 1 year. For microtensile evaluation, the restorations were sectioned perpendicular to the cervical bonded interface into 0.7 +/- 0.2 mm thick slabs. The slabs were further trimmed at the interface to 1.4 < or = 0.2 mm with a fine diamond bur to produce a cross-sectional surface area of ca. 1 mm2. Specimens were then subjected to microtensile bond testing. The bond strength data were analyzed using two-way ANOVA and Fisher's PLSD test (P < 0.05). Fracture mode analysis was performed using SEM. RESULTS: At baseline, bond strength of the TM group was significantly lower when compared to the C group (P = 0.012). However, after 1 year storage, a significant decrease in bond strength was observed for the C group compared to baseline. No significant differences were noted between the C and TM groups at 1 year. No interaction was observed between groups (C and TM) and storage time (P = 0.098). For the fracture mode evaluation, at baseline, mixed failure was predominant for the C group, and increased after TM. Decreased mixed failure was observed after 1-year storage, with a concomitant increase in interphase failure.

Influence of load cycling and tubule orientation on ultimate tensile strength of dentin.

PURPOSE: The purpose of this study was to evaluate the effect of mechanical load cycling and tubule orientation on the ultimate tensile strength of crown and root dentin. MATERIALS AND METHODS: Twenty bovine teeth were cleaned and their incisal surfaces reduced, resulting in a flat surface 4 mm above the cementoenamel junction. The teeth were divided into 4 groups: G1 = control (no mechanical load cycling); G2 = 1,000,000 load cycles at 50 N; G3 = 1,000,000 load cycles at 100 N; G4 = 1,000,000 load cycles at 200 N. Sections of 0.5+/-0.1 mm thick were cut mesiodistally and the slabs further trimmed to 0.5+/-0.1 mm in an hourglass shape, according to the tubule orientation (parallel and/or perpendicular to the long axis of the tooth) in the root and crown, with a fine diamond bur to produce a cross-sectional surface area of 0.25 mm2. All specimens were then subjected to ultimate tensile strength testing at a crosshead speed of 1 mm/min. Means and standard deviations were expressed in MPa. The bond strength data were analyzed with three-way ANOVA and Fisher's PLSD test (p < 0.05). RESULTS: Ultimate tensile strength values did not differ statistically significantly between the loaded group and the control. However, statistical differences existed between root and coronal dentin (p < 0.001) and between parallel and perpendicular orientation of tubules (p < 0.001), where root and sections parallel to the tubules presented higher values than coronal and perpendicular, respectively. These differences were not related to mechanical loading. CONCLUSION: There was no effect of in vitro load cycling on ultimate tensile strength of dentin. Differences presented between ultimate tensile strength of crown vs root dentin and parallel vs perpendicular to the tubule orientation can be influenced by differences in the amount of organic and inorganic content as well as composition of the dentin matrix. It is important to consider these aspects when predicting the quality and durability of restorations according to the types of dentin and tubule orientation to be restored.

Effect of thermal and mechanical load cycling on nanoleakage of Class II restorations.

PURPOSE: To evaluate the effect of thermal and mechanical cycling on the degree and pattern of nanoleakage on cervical margins of Class II restorations. MATERIALS AND METHODS: Forty box-type Class II cavities were prepared on bovine incisors. The cavities were restored with Single Bond and Z-250 composite resin (3M-ESPE) according to manufacturer's instructions. The teeth were randomly assigned to 4 groups: G1, control; G2, thermal cycling (2000 cycles, 5 to 55 degrees C); G3, mechanical load cycling (100,000 cycles, 50 N); G4, thermal and mechanical load cycling group (2000 cycles 5 to 5 degrees C/100,000 cycles, 50 N). The specimens were then sealed leaving a 1 mm window around the cervical margin interface. Samples were immersed in a 50% w/v ammoniacal silver nitrate solution for 24 h, and exposed to a photodeveloping solution for 8 h. Specimens were sectioned longitudinally, embedded in epoxy resin, polished and mounted on stubs, gold sputter coated, and examined under SEM using backscattered electron mode. Silver particle penetration length was measured directly on the SEM monitor and calculated as the percentage of the total length of cut dentin surface that was penetrated by silver nitrate. The data were analyzed with ANOVA and Fisher's PLSD test (p < 0.05). RESULTS: The degree of nanoleakage significantly increased when thermal and mechanical cycling was performed on the same specimens, as compared to the other groups (p < 0.05). No differences were observed between the control, thermal cycling, and mechanical cycling groups. No difference in nanoleakage pattern was observed between the groups. CONCLUSION: Thermal and mechanical cycling combined adversely affected nanoleakage values. Simulation of the oral condition might be crucial to better evaluate and understand the performance of adhesive materials.

Stability of dentin bond strengths using different bonding techniques after 12 months: total-etch, deproteinization and self-etching.

This study evaluated the influence of (1) different dentin treatments and (2) storage time on dentin shear bond strengths. Two hundred and twenty-five bovine incisors were collected, ground to expose a flat dentin surface and randomly divided into three groups according to dentin surface treatment: (1) Total etch + Single Bond; (2) Total etch + collagen depletion with 10% NaOCl + Single Bond and (3) No etch + experimental self-etching adhesive. Composite was applied to the treated surfaces using a 3 x 5 mm cylindrical Teflon matrix and was light-cured. Each group was further stratified in five subgroups according to storage time in water at 37 degrees C: 1 day, 7 days, 30 days, 6 months and 12 months. Shear bond strengths (SBS) were determined and expressed in MPa. Data was analyzed for statistical significance with two-way ANOVA and Tukey's test (p=0.05). No interaction was observed between surface treatment and storage time. Storage time did not significantly affect bond strengths. Statistically significant differences were observed among the different surface treatments. Single Bond applied after total-etch presented higher mean SBS when compared to the other surface treatment methods. Collagen removal negatively influenced SBS, and the experimental self-etching adhesive presented intermediate values.