Influence of root dentin treatment on the push-out bond strength of fibre-reinforced posts

This study evaluates the influence of root dentin treatment with NaOCl alone and combined with EDTA, with and without ultrasound activation, on the push-out bond strength (BS) of fiber-reinforced posts in weakened roots, cemented with RelyX or Panavia. The root canals of 42 maxillary canines were instrumented with Reciproc and 2.5% NaOCl. In the coronal 12mm of all canals, experimental weakening of the roots was produced by reducing dentin thickness with 2.44mm diameter diamond burs. The roots were assigned to 3 groups (n = 14) according to root dentin treatment: 2.5% NaOCl; 2.5% NaOCl + 17% EDTA; and 2.5% NaOCl + 17% EDTA, with solutions agitated using passive ultrasonic irrigation. After cementation of the fiber-reinforced posts the roots were divided in thirds. The first slice of each third was used for the push-out BS test, the second slice for confocal laser scanning microscopy and dentin microhardness (Knoop) analysis. Data were analysed by a two-way ANOVA and Tukey test (a = 0.05). NaOCl + EDTA provided highest BS values than NaOCl (p < 0.0001). Specimens cemented with Panavia presented significantly higher BS than those with RelyX in the three root thirds (p < 0.0001). The highest BS values occurred in the cervical third (p < 0.001). Ultrasound-activated NaOCl + EDTA promoted the greatest reduction in dentin microhardness, followed by NaOCl/EDTA and NaOCl. Ultrasonic activation of NaOCl and EDTA reduced root dentin microhardness, but did not improve the push-out BS of resin-based cements. Panavia presented higher BS than RelyX. RelyX was not influenced by the root dentin treatment protocols.

Influence of root dentin treatment on the push-out bond strength of fibre-reinforced posts

Abstract This study evaluates the influence of root dentin treatment with NaOCl alone and combined with EDTA, with and without ultrasound activation, on the push-out bond strength (BS) of fiber-reinforced posts in weakened roots, cemented with RelyX or Panavia. The root canals of 42 maxillary canines were instrumented with Reciproc and 2.5% NaOCl. In the coronal 12mm of all canals, experimental weakening of the roots was produced by reducing dentin thickness with 2.44mm diameter diamond burs. The roots were assigned to 3 groups (n = 14) according to root dentin treatment: 2.5% NaOCl; 2.5% NaOCl + 17% EDTA; and 2.5% NaOCl + 17% EDTA, with solutions agitated using passive ultrasonic irrigation. After cementation of the fiber-reinforced posts the roots were divided in thirds. The first slice of each third was used for the push-out BS test, the second slice for confocal laser scanning microscopy and dentin microhardness (Knoop) analysis. Data were analysed by a two-way ANOVA and Tukey test (a = 0.05). NaOCl + EDTA provided highest BS values than NaOCl (p < 0.0001). Specimens cemented with Panavia presented significantly higher BS than those with RelyX in the three root thirds (p < 0.0001). The highest BS values occurred in the cervical third (p < 0.001). Ultrasound-activated NaOCl + EDTA promoted the greatest reduction in dentin microhardness, followed by NaOCl/EDTA and NaOCl. Ultrasonic activation of NaOCl and EDTA reduced root dentin microhardness, but did not improve the push-out BS of resin-based cements. Panavia presented higher BS than RelyX. RelyX was not influenced by the root dentin treatment protocols.

Hardness and microshear bond strength to enamel and dentin of permanent teeth with hypocalcified amelogenesis imperfecta.

BACKGROUND: Adhesive procedures are often required to restore teeth affected by hypocalcified amelogenesis imperfecta (HAI). AIM: To evaluate the hardness of enamel/dentin of teeth affected by HAI and the bond strength to these substrates, as well the influence of 5% NaOCl on bond strength. DESIGN: Permanent molars presenting HAI and sound third molars were used. Enamel surfaces were wet-flattened and Knoop hardness was assessed. The two-step, etch-and-rinse adhesive Single Bond 2 (3M ESPE) was applied and resin cylinders bonded to the surfaces and submitted to microshear testing. The subjacent medium dentin was then exposed by wet-grinding. Hardness readings and microshear testing were carried out again. The relationship between hardness and bond strength was assessed by nonlinear regression analysis. RESULTS: Hardness of normal enamel was higher than hardness of enamel affected by HAI, whereas dentin hardness did not differ from normal to HAI-affected teeth. Enamel and dentin hardness were similar for teeth affected by HAI. Higher bond strengths were obtained to the normal tooth tissues. Dentin bond strength was higher than enamel bond strength. NaOCl exposure did not influence bond strengths. A positive linear relationship between enamel hardness and bond strength was observed. CONCLUSION: HAI imposes challenges to bonding to enamel and dentin.

Atendimento odontológico a adolescentes infratores: abordagem qualitativa em clínica de graduação / Dental care for delinquent adolescents: qualitative approach in an undergraduate dental clinic

Esse estudo avaliou a percepção de adolescentes infratores sobre a convivência familiar e dentro da instituição, sobre a saúde geral e bucal. Foi adotada abordagem qualitativa, com a participação de adolescentes infratores (13 a 17 anos) em processo de ressocialização. Esses adolescentes estavam sendo atendidos em clínica odontológica por alunos de graduação, sob supervisão docente. Após assinatura do termo de consentimento, os adolescentes foram entrevistados, sendo suas falas gravadas, transcritas e submetidas à análise de conteúdo. Para a maioria dos adolescentes, a família foi definida como um espaço de conflitos e distante das suas vidas diárias. Na instituição, eles relataram múltiplas e variadas atividades, esportivas, de arte e educação, que devem ser cumpridas em horários rígidos. Todos falaram, em algum momento da entrevista, sobre a recompensa com diferentes "benefícios", pelo bom comportamento dentro da instituição, sendo a liberdade o mais desejado por todos. A saúde foi definida como: emprego, acesso a programas educativos, acesso a cuidados médicos e de enfermagem e participação nos cursos oferecidos na instituição. Aspectos pessoais de autocuidado, como uma boa alimentação, a prática de esportes e a higiene do corpo foram também citados como determinantes da saúde. Para alguns deles, saúde é liberdade, abandono das drogas e do crime. A saúde bucal foi definida como higiene bucal por todos os adolescentes (AU).

This study evaluated the perception of delinquent adolescents toward family, the correctional institution they attended, and oral and general health. We adopted a qualitative approach with the participation of adolescents (age 13­17) in the process of re-socialization. The adolescents were being treated in a dental clinic by undergraduate students under supervision. After signing a consent form, the adolescents were interviewed and their statements were recorded, transcribed and submitted to content analysis. For most adolescents, family was defined as an area of conflict and remote from their daily lives. As for their correctional institution, they reported that it offered several different activities, sports, art and education, all of which had to be completed according to a rigorous schedule. At some point in the interview, all mentioned the reward gained from different "benefits" for good behavior within the institution, and the greater freedom desired by all. Health was defined as employment, access to educational programs, access to medical care and nursing, and participation in courses offered at the institution. Personal aspects of self-care, such as a good food, sports practice and body hygiene, were also mentioned as determinants of health. To some, health meant freedom, abandonment of drugs and of crime. Oral health was defined by all adolescents as oral hygiene (AU).

Reparo em restaurações de resinas compostas com laser: influência da irradiação com laser de ER: YAG na microinfiltração marginal / Influence of Er: YAG laser irradiation in microlekeage in repair of restorations

Este estudo visa avaliar influência da irradiação com laser de Er:Yag na microinfiltração marginal em reparos de restaurações de reina composta. Quarenta terceiros molares humanos receberam preparos cavitários na face vestibular que foram restaurados com resina composta. Os dentes foram divididos em oito grupos de cinco dentes cada em função do tratamento da superfície que variou em: G1 e 2 foram repreparados com ponta diamantada esférica e reparados com resina, sendo utilizado no G1 - ácido fosfórico 37% + sistema adesivo, e no G2 - sistema adesivo. Nos grupos 3 a 8, o Laser de Er:YAG foi usado na produção de um defeito da seguinte maneira: G3(3hZ,60mJ,6J,103 pulsos). G4 (4hZ, 60mJ, 6J, 103 pulsos), G5 (3hZ, 100mJ, 6J, 63 pulsos). G6 (4hZ, 100mJ, 6J, 63 pulsos). G7(3hZ, 120mJ, 6J, 54 pulsos), eG8(4hZ, 120mJ,6J,55 pulsos); e reparados com resina empregando sistema adesivo sem condicionamento ácido prévio. Os corpos de prova foram termociclados (500 ciclos) e imersos em Nitrato de Prata a 50% por 24 horas. Os resultados da análise (ANOVA) evidenciaram que a menor microinfiltração foi observada quando 4Hz, 60mJ, 6J e 103 pulsos e 4 Hz, 120mJ, 6J e 55 pulsos foram utilizados. Concluiu-se que o laser quando bem calibrado possibilita resultados superiores ao da técnica convencional (G1).

Estudo in vitro da microinfiltração marginal em reparos de restaurações de resina composta após irradiação com laser de Er Yag / Study in vitro of the marginal microinfiltration in repairs of composite resin restaurations after irradiation with laser de Er Yag

O reparo de restaurações em resina composta é uma prática muito empregada, sendo o Laser de Er YAG uma das possibilidades de tratamento. Este estudo visa analisar ôin vitroö a microinfiltração em reparos derestaurações com resina composta (resina/resina) cuja superfície foi tratada com Laser de Er YAG. Quarenta terceiros molares humanos receberam preparos cavitários na face vestibular que foram restaurados com resinacomposta. Os dentes foram divididos em oito grupos de cinco dentes cada em função do tratamento da superfície que variou em: G1 e 2 foram repreparados com ponta diamantada esférica e reparados com resina, sendo utilizado no G1 - ácido fosfórico 37 por cento + sistema adesivo, G2 - sistema adesivo. Nos grupos 3 a 8, o Laser de Er YAG foi usado na produção de um defeito da seguintemaneira: G3 (3hZ,60mJ,6J,103 pulsos). G4 (4hZ, 60mJ, 6J, 103 pulsos), G5 (3hZ, 100mJ, 6J, 63 pulsos). G6 (4hZ, 100mJ, 6J, 63 pulsos). G7 (3hZ, 120mJ, 6J, 54 pulsos), e G8 (4hZ, 120mJ, 6J, 55 pulsos); e reparados com resinaempregando sistema adesivo sem condiconamento ácido prévio. Os corpos de prova foram termociclados (500 ciclos) e imersos em Nitrato de Prata a 50 por centopor 24 horas. Os resultados da análise (ANOVA) videnciaram que a menor microinfiltração foi observada quando 4Hz, 60mJ, 6J e 103 pulsos e 4 Hz,120mJ, 6J e 55 pulsos foram utilizados