SEM analysis and push-out bond strength of fiberglass posts luted with different cements of glass-ionomer in humid environment: pilot test

The objective of this study was to evaluate the push-out bond strength of fiberglass resin reinforced bonded with five ionomer cements. Also, the interface between cement and dentin was inspected by means of SEM. Fifty human canines were chose after rigorous scrutiny process, endodontically treated and divided randomly into five groups (n = 3) according to cement tested: Group I – Ionoseal (VOCO), Group II – Fugi I (GC), Group III – Fugi II Improved (GC), Group IV – Rely X Luting 2 (3M ESPE), Group V – Ketac Cem (3M ESPE). The post-space was prepared to receive a fiberglass post, which was tried before cementation process. No dentin or post surface pretreatment was carried out. After post bonding, all roots were cross-sectioned to acquire 3 thin-slices (1 mm) from three specific regions of tooth (cervical, medium and apical). A Universal test machine was used to carry out the push-out test with cross-head speed set to 0.5mm/mim. All failed specimens were observed under optical microscope to identify the failure mode. Representative specimens from each group was inspected under SEM. The data were analyzed by Kolmogorov-Smirnov and Levene’s tests and by two-way ANOVA, and Tukey’s port hoc test at a significance level of 5%. It was compared the images obtained for determination of types of failures more occurred in different levels. SEM inspection displayed that all cements filled the space between post and dentin, however, some imperfections such bubles and voids were noticed in all groups in some degree of extension. The push-out bond strength showed that cement Ketac Cem presented significant higher results when compared to the Ionoseal (P = 0.02). There were no statistical significant differences among other cements.

Push-out bond strengths of different dental cements used to cement glass fiber posts

Statement of problem: Since the introduction of glass fiber posts, irreversible vertical root fractures have become a rare occurrence; however, adhesive failure has become the primary failure mode. Purpose: The purpose of this study was to evaluate the push-out bond strength of glass fiber posts cemented with different luting agents on 3 segments of the root. Material and methods: Eighty human maxillary canines with similar root lengths were randomly divided into 8 groups (n=10) according to the cement assessed (Rely X luting, Luting and Lining, Ketac Cem, Rely X ARC, Biscem, Duo-link, Rely X U100, and Variolink II). After standardized post space preparation, the root dentin was pretreated for dualpolymerizing resin cements and untreated for the other cements. The mixed luting cement paste was inserted into post spaces with a spiral file and applied to the post surface that was seated into the canal. After 7 days, the teeth were sectioned perpendicular to their long axis into 1-mm-thick sections. The push-out test was performed at a speed of 0.5 mm/min until extrusion of the post occurred. The results were evaluated by 2-way ANOVA and the all pairwise multiple comparison procedures (Tukey test) (?=.05). Results: ANOVA showed that the type of interaction between cement and root location significantly influenced the push-out strength (P<.05). The highest push-out strength results with root location were obtained with Luting and Lining (S3) (19.5 ±4.9 MPa), Ketac Cem (S2) (18.6 ±5.5 MPa), and Luting and Lining (S1) (18.0 ±7.6 MPa). The lowest mean values were recorded with Variolink II (S1) (4.6 ±4.0 MPa), Variolink II (S2) (1.6 ±1.5 MPa), and Rely X ARC (S3) (0.9 ±1.1 MPa). Conclusions: Self-adhesive cements and glass ionomer cements showed significantly higher values compared to dual-polymerizing resin cements. In all root segments, dual-polymerizing resin cements provided significantly lower bond strength. Significant differences among root segments were found only for Duo-link cement.

Pozolanicidade dos resíduos industriais, lã de vidro e lã cerâmica

As fibras cerâmicas se caracterizam por ser um material leve, com alto grau de pureza, baixo armazenamento de calor, baixa condutividade térmica, resistência a choque térmico e alta resistência à corrosão em altas temperaturas. Essas características levam a uma grande procura das indústrias mínero-metalúrgicas e de outros setores para revestimentos de distribuidores, muflas, fornos de aquecimentos, entre outros. Após utilização no processo, por perderem sua capacidade de isolamento, os resíduos gerados precisam de destinação. Esse trabalho enfoca, especificamente, resíduos de lã cerâmica e lã de vidro. Pelo fato de a composição das fibras cerâmicas ser rica em sílica e alumina, efetuou-se uma investigação acerca da atividade pozolânica das mesmas com a cal e o cimento, especificamente CPV ARI, CPII E32 e CPIII 32RS, para avaliação da perspectiva de reciclagem em possível incorporação no concreto.

Rat subcutaneous tissue response to MTA Fillapex® and Portland cement

The aim of this study was to evaluate the response of rat subcutaneous tissue to MTA Fillapex® (Angelus), an experimental root canal filling material based on Portland cement and propylene glycol (PCPG), and a zinc oxide, eugenol and iodoform (ZOEI) paste. These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7 and 15 days. The specimens were stained with hematoxylin and eosin, and evaluated regarding inflammatory reaction parameters by optical microscopy. The intensity of inflammatory response against the sealers was analyzed by two blinded and previously calibrated examiners for all experimental periods (kappa=0.96). The histological evaluation showed that all materials caused a moderate inflammatory reaction at 7 days, which subsided with time. A greater inflammatory reaction was observed at 7 days in the tubes filled with ZOEI paste. Tubes filled with MTA Fillapex presented some giant cells, macrophages and lymphocytes after 7 days. At 15 days, the presence of fibroblasts and collagen fibers was observed indicating normal tissue healing. The tubes filled with PCPG showed similar results to those observed in MTA Fillapex. At 15 days, the inflammatory reaction was almost absent at the tissue, with several collagen fibers indicating normal tissue healing. Data were analyzed by the nonparametric Kruskal-Wallis test (?=0.05). Statistically significant difference (p<0.05) was found only between PCPG at 15 days and ZOEI at 7 days groups. No significant differences were observed among the other groups/periods (p>0.05). MTA Fillapex and Portland cement added with propylene glycol had greater tissue compatibility than the PCPG paste.

In vivo evaluation of tissue response to new endodontic sealers

Introduction: The sealers can be in direct contact with the periapical tissues. Thus, these materials must have appropriate physical and biological properties, providing conditions for repair to occur. Objective: The aim of this study was to evaluate the response of rat subcutaneous tissue to endodontics sealers. Material and methods: Three materials comprised the groups: group I – Zinc Oxide, Eugenol and Iodoform paste, group II – Portland cement with propylene glycol, and group III – MTA Fillapex® (Angelus). These materials were placed in polyethylene tubes and implanted into dorsal connective tissue of Wistar rats for seven and 15 days. The specimens were stained with hematoxylin and eosin and evaluated regarding to inflammatory reaction parameters through a light microscope. The data were compared using Kruskal-Wallis test with significance level of 5%. The intensity of inflammatory response against the sealers was analyzed by two blinded and previously calibrated observers for all experimental periods. Results: The histological evaluation showed that all the materials caused a moderated inflammatory reaction at seven days which decreased with time. A greater inflammatory reaction was observed at seven days in group I. The other specimens had significantly less inflammatory cells when compared to this group. Tubes with MTA Fillapex® presented some giant cells, macrophages and lymphocytes after seven days. At 15 days, the presence of fibroblasts and collagen fibers was observed indicating normal tissue healing. The group II showed similar results to those observed in MTA Fillapex® already at seven days. At 15 days the inflammatory reaction presented was almost absent at the tissue, with many collagen fibers indicating normal tissue healing. Statistical analysis showed a significant statistical difference amongst the group I (seven days) and II (15 days) (p < 0.05). In the other groups no (Continue)

In vivo evaluation of tissue response to new endodontic sealers

Introduction: The sealers can be in direct contact with the periapical tissues. Thus, these materials must have appropriate physical and biological properties, providing conditions for repair to occur. Objective: The aim of this study was to evaluate the response of rat subcutaneous tissue to endodontics sealers. Material and methods: Three materials comprised the groups: group I – Zinc Oxide, Eugenol and Iodoform paste, group II – Portland cement with propylene glycol, and group III – MTA Fillapex® (Angelus). These materials were placed in polyethylene tubes and implanted into dorsal connective tissue of Wistar rats for seven and 15 days. The specimens were stained with hematoxylin and eosin and evaluated regarding to inflammatory reaction parameters through a light microscope. The data were compared using Kruskal-Wallis test with significance level of 5%. The intensity of inflammatory response against the sealers was analyzed by two blinded and previously calibrated observers for all experimental periods. Results: The histological evaluation showed that all the materials caused a moderated inflammatory reaction at seven days which decreased with time. A greater inflammatory reaction was observed at seven days in group I. The other specimens had significantly less inflammatory cells when compared to this group. Tubes with MTA Fillapex® presented some giant cells, macrophages and lymphocytes after seven days. At 15 days, the presence of fibroblasts and collagen fibers was observed indicating normal tissue healing. The group II showed similar results to those observed in MTA Fillapex® already at seven days. At 15 days the inflammatory reaction presented was almost absent at the tissue, with many collagen fibers indicating normal tissue healing. Statistical analysis showed a significant statistical difference amongst the group I (seven days) and II (15 days) (p < 0.05). In the other groups no significant statistical differences were observed. Conclusion: MTA Fillapex® and Portland cement with propylene glycol were more biocompatible than the other tested cements.

Viscosidade cinemática de pastas cimentícias com incorporadores de ar avaliadas em diferentes temperaturas

A presença de aditivos incorporadores de ar (AIA) em suspensões cimentícias torna esses materiais sensíveis às etapas de processamento e às condições ambientais de preparo das composições. Diversos estudos têm sido reportados em literatura avaliando o efeito de incorporadores de ar nas propriedades de materiais cimentícios, sobretudo no estado endurecido. Porém o efeito da temperatura na incorporação de ar e nas propriedades reológicas dessas composições tem sido menos investigado, sendo este o objetivo do presente trabalho. Para tanto, foram avaliadas as características de pastas cimentícias, compostas por cimentos CPIIF ou CPIIE e dois tipos de AIA, em função da variação da temperatura. O conceito de viscosidade cinemática foi adotado na análise dos resultados para compensar diferenças de inércia das pastas com densidades distintas. Os resultados mostraram que o tipo de cimento, a presença do aditivo e a temperatura influenciaram significativamente na incorporação de ar e nas propriedades reológicas.

Dermatomiosite em adulto: experiência de um centro terciário brasileiro

OBJETIVOS: Relatamos os resultados de um estudo de coorte retrospectivo envolvendo 139 pacientes com dermatomiosite, conduzido de 1991 a 2011. MÉTODOS: Todos os pacientes preenchiam pelo menos quatro dos cinco critérios de Bohan and Peter (1975). RESULTADOS: A média de idade dos pacientes no início da doença foi de 41,7 ± 14,1 anos, e a duração da doença foi de 7,2 ± 5,2 anos. A amostragem constitui-se de 90,2% de indivíduos brancos, 79,9% do gênero feminino. Sintomas constitucionais foram detectados em menos da metade dos casos. Envolvimentos cutâneo e articular ocorreram em 95,7% e 41,7% dos pacientes, respectivamente. Em 48,2% dos pacientes foram apresentadas pneumopatia incipiente, opacidades em "vidro fosco" e/ou fibrose pulmonar. Todos os pacientes receberam prednisona (1 mg/kg/dia) e 51,1% receberam também metilprednisolona intravenosa (1 g/dia por três dias). Vários imunossupressores foram usados como poupadores de corticosteroide de acordo com tolerância, efeitos colaterais e/ou refratariedade. Houve recidiva de doença (clínica e/ou laboratorial) em 53,2% dos casos; 76,3% permaneceram em remissão no momento do estudo. A taxa de infecção grave foi de 35,3%, com o predomínio de herpes zoster. Houve 15 (10,8%) casos de câncer, dos quais 12 foram confirmados em um período de um ano após o diagnóstico da doença. Houve ainda 16 óbitos (11,5%) cujas causas principais foram sepse/choque séptico (27,5%), pneumopatia atribuída à doença (31,3%), neoplasias (31,3%) e eventos cardiovasculares (12,5%). CONCLUSÕES: No presente trabalho, os dados clínico-laboratoriais foram semelhantes aos de outros grupos populacionais descritos na literatura, com diferenças mínimas quanto à frequência e às características das manifestações extramusculares.

In vitro fracture resistance of glass-fiber and cast metal posts with different designs

PURPOSE: To evaluate the in vitro fracture resistance of roots with glass-fiber and metal dowels with different designs. METHODS: Fifty-endodontically treated maxillary central incisors were embedded in acrylic resin. Ten of them received only the coronary preparation, and the remaining forty were embedded (except for 4mm of the cervical area) after removing the clinical crowns. Specimens were divided into five groups (n=10): control (teeth with only coronary preparation), cylindrical cast dowel, conical cast dowel, cylindrical glass-fiber dowel and conical glass-fiber dowel. Specimens were subjected to an increasing compressive load (N) until fracture. RESULTS: ANOVA indicated significant difference (P<.05) among the groups, and the Tukey-Kramer´s test identified these differences. The control group (867±243 N) presented the highest values and was statistically similar to cylindrical glass-fiber dowel group (711±180 N). There is no significant difference among the metal dowel cylindrical (435±245 N) or conical (585±164 N) group and conical glass-fiber dowel (453±112 N). Cylindrical glass-fiber dowel (711±180 N) and conical cast dowel and core (585±164 N) groups had intermediate values and did not differ from each other. CONCLUSIONS: Cylindrical glass fiber dowels represent a viable alternative to the cast-metal dowel cylindrical or conical. Cylindrical glass fiber dowels also increase endodontically treated incisors' resistance to fracture.

Plug apical com MTA em dente adjacente à área da fissura labiopalatina

O tratamento endodôntico de dentes com forame apical amplo requer consideração especial, devido ao risco de extravasamento do material obturador nos tecidos periapicais durante a obturação, de maneira relevante em áreas próximas às fissuras labiopalatinas. A criação de uma barreira apical é indicada em casos de difícil travamento do cone principal e consequente deficiência do selamento apical. O MTA em decorrência de suas excelentes propriedades biológicas, é o material de escolha para permanecer em contato com tecidos periodontais e periapicais, fazendo parte do arsenal endodôntico especificamente nestes casos de ápice aberto para a confecção de plug apical. Relato clínico: Indivíduo do gênero feminino, com fissura labiopalatina bilateral transforame, a distal dos dentes 11 e 21; compareceu no setor de endodontia do Hospital de Reabilitação de Anomalias Craniofaciais (HRAC-USP), apresentando necrose pulpar do dente 21. Na primeira sessão foi realizado o acesso cirúrgico, neutralização do conteúdo séptico/tóxico em sentido corono-apical, odontometria, biomecânica, curativo intracanal (pasta Calen) selamento provisório com cimento de ionômero de vidro. Na segunda sessão, foi realizada a obturação onde ocorreu extravasamento de material obturador, verificado através da radiografia comprobatória; justificando sua remoção e nova obturação, com prévia confecção de plug apical com MTA. Foi realizada proservação aos 6 meses pós tratamento endodôntico. Conclusão: neste caso, o plug apical com MTA possibilitou a obturação final do canal radicular com segurança, pela confecção de um anteparo apical, evitando extravasamento de material obturador e preservando a área de fissura labiopalatina.

Tratamento odontológico pré-operatório para crianças com fissura labiopalatina

Introdução: Crianças com fissura labiopalatina apresentam diversos fatores de risco à cárie dentária e algumas necessidades diferenciadas quanto ao tratamento odontológico. Este trabalho descreverá as etapas de um tratamento odontológico definitivo previamente a cirurgia primária de queiloplastia, com o objetivo de adequação do meio bucal de um paciente com fissura labiopalatina. Material e métodos: Será apresentada revisão da literatura, com ênfase para as particularidades odontológicas e fatores de risco, incluindo a apresentação de um caso para ilustrar o tratamento odontológico pré-operatório necessário antes das cirurgias reparadoras primárias. Resultados e discussão: Paciente do gênero masculino, negro, compareceu ao HRAC-USP aos oito anos de idade, sem tratamento prévio, apresentando fissura transforame incisivo unilateral direita. O exame clínico intrabucal revelou a presença de várias lesões cariosas e necessidade de exodontias. O plano de tratamento odontológico envolveu várias sessões e foi iniciado por condicionamento odontopediátrico, seguido por restaurações com amálgama e cimento de ionômero de vidro e exodontias, iniciando por regiões com lesões menores e onde a anestesia local causa menor desconforto. A extração dos dentes anteriores, próximos à região da fissura, foi feita sob anestesia geral no centro cirúrgico antes da queiloplastia. Conclusão: O tratamento odontológico pré-cirúrgico definitivo e com remoção completa do tecido cariado é fundamental para pacientes com fissuras labiopalatinas, pois a cárie é uma doença infecciosa e, se presente, pode contaminar a cirurgia primária, podendo inclusive comprometer seus resultados.

Luminescence quantum efficiency at 1.5 µm of Er3+- doped tellurite glass determined by thermal lens spectroscopy

Erbium doped tellurite glasses (TeO2 + Li2O + TiO2) were prepared by conventional melt-quenching method to study the influence of the Er3+ concentration on the luminescence quantum efficiency (η) at 1.5 µm. Absorption and luminescence data were used to characterize the samples, and the η parameter was measured using the well-known thermal lens spectroscopy. For low Er3+ concentration, the measured values are around 76%, and the concentration behavior of η shows Er-Er and Er-OH- interactions, which agreed with the measured lifetime values.