The effects of non-thermal plasma and conventional treatments on the bond strength of fiber posts to resin cement.

OBJECTIVES: This study compared the effect of hexamethyldisiloxane (HMDSO) and ammonia (NH3) plasmas on the bond strength of resin cement to fiber posts with conventional treatments. MATERIALS AND METHODS: Sixty-five fiber posts were divided into 5 groups: Control (no surface treatment); H2O2 (24% hydrogen peroxide for 1 min); Blasting (blasting with aluminum oxide for 30 sec); NH3 (NH3 plasma treatment for 3 min); HMDSO (HMDSO plasma treatment for 15 min). After the treatments, the Ambar adhesive (FGM Dental Products) was applied to the post surface (n = 10). The fiber post was inserted into a silicon matrix that was filled with the conventional resin cement Allcem Core (FGM). Afterwards, the post/cement specimens were cut into discs and subjected to a push-out bond strength (POBS) test. Additionally, 3 posts in each group were evaluated using scanning electron microscopy. The POBS data were analyzed by one-way analysis of variance and the Tukey's honest significant difference post hoc test (α = 0.05). RESULTS: The Blasting and NH3 groups showed the highest POBS values. The HMDSO group showed intermediate POBS values, whereas the Control and H2O2 groups showed the lowest POBS values. CONCLUSION: Blasting and NH3 plasma treatments were associated with stronger bonding of the conventional resin cement Allcem to fiber posts, in a procedure in which the Ambar adhesive was used.

Efeito do NaOCl na resistência de união de pinos de fibra cimentados à dentina utilizando um cimento convencional e um autoadesivo / Effects of NaOCl on bond strength of fiber posts cemented to dentin using a conventional and a self-adhesive cement

Objetivo: avaliar o efeito do hipoclorito de sódio (NaOCl) na resistência de união (RU) de pinos de fibra de vidro cimentados à dentina, utilizando o cimento resinoso convencional AllCem ou o autoadesivo RelyX U200. Material e Métodos: foram utilizados 40 dentes bovinos, que tiveram suas coroas removidas e as raízes padronizadas em 7mm, referente aos terços cervical e médio. Os condutos foram preparados e as raízes divididas em 4 grupos (n = 10). Nos grupos AD/U200 e AD/AAC os condutos foram irrigados com água destilada. Nos grupos NaOCl/U200 e NaOCl/AAC, os condutos foram imersos em NaOCl a 5,25% durante 20 minutos e, em seguida, irrigados com água destilada. Os pinos foram cimentados ao conduto com o cimento RelyX U200 nos grupos AD/U200 e NaOCl/U200, e com o cimento Allcem nos grupo AD/AAC e NaOCl/AAC. As raízes foram segmentadas e os discos submetidos a ensaio de push-out. Os valores de RU foram analisados estatisticamente pelos testes de Kruskal-Wallis e Mann Whitney (α = 0,05). A análise do padrão de fratura das amostras foi realizada em lupa estereoscópica. Resultados: o NaOCl mostrou um efeito deletério na resistência adesiva para ambos os cimentos. Os valores de RU foram superiores para os grupos Âmbar/AllCem em comparação aos grupos RelyX U200. Em relação ao padrão de fratura, houve predomínio de fratura tipo I, adesiva cimento/dentina. Conclusão: o NaOCl mostrou um efeito deletério na resistência de união de pinos de fibra cimentados à dentina utilizando os cimentos RelyX U200 e Âmbar/AllCem.

Objective: to evaluate the effect of sodium hypochlorite (NaOCl) on the bond strength (BS) of fiberglass posts cemented to dentin using the conventional cement Allcem or the self-adhesive cement RelyX U200. Materials and Methods: forty bovine teeth had their crowns removed and the roots standardized in 7 mm, referring to the cervical and middle thirds. The root canals were prepared and roots were divided into four groups (n = 10). In AD/U200 and AD/AAC groups, the root canals were irrigated with distilled water. In NaOCl/U200 and NaOCl/AAC groups, the root canals were immersed in 5.25% NaOCl for 20 min and then irrigated with distilled water. The posts were cemented with RelyX U200 in groups AD/U200 and NaOCl/U200, and with Allcem cement in groups AD/AAC and NaOCl/AAC. The roots were segmented and discs were subjected to the push-out test. The BS values were statistically analyzed by Kruskal-Wallis and Mann-Whitney tests (α = 0.05). The fracture pattern was analyzed using a stereomicroscope. Results: the NaOCl showed a deleterious effect on bond strength for both cements. The RU values were higher for Ambar/Allcem groups compared with the U200 groups. Regarding the fracture pattern, there was a predominance of type I, adhesive cement/dentin. Conclusion: NaOCl showed a deleterious effect on the bond strength of fiber posts cemented to dentin using RelyX U200 and Allcem cements.

Análise comparativa da resistência de união de um cimento convencional e um cimento autoadesivo após diferentes tratamentos na superfície de pinos de fibra de vidro / Bond strength comparative analysis of a conventional cement with a self-adhesive cement after different treatments on the fiberglass post surface

Introdução: Os pinos de fibra de vidro são uma alternativa aos núcleos metálicos e apresentam vantagens, tais como: estética, módulo de elasticidade semelhante à dentina e cimentação imediata após o término do tratamento endodôntico. Ainda, apresentam a capacidade de aderir ao cimento resinoso e este, à dentina, por meio de técnicas adesivas. Objetivo: Comparar a adesão de um cimento resinoso convencional e um autoadesivo a pinos de fibra de vidro, e os efeitos de diferentes tratamentos de superfície na resistência adesiva dos pinos. Material e método: Trinta pinos foram divididos em três grupos: Controle: sem tratamento na superfície; Jateamento: jateamento com óxido de alumínio por 30 segundos, e Peróxido: imersão em peróxido de hidrogênio 24% por um minuto. Em seguida, corpos de prova foram obtidos a partir de cilindros de cimento resinoso contendo o pino de fibra posicionado no centro de seu longo eixo. Em cada grupo, cinco pinos foram associados ao adesivo Âmbar + cimento convencional AllCem Core e os outros cinco pinos, ao cimento autoadesivo RelyX U200. O conjunto pino/cimento foi segmentado e avaliado em relação à resistência de união (RU) por push-out. Os dados foram analisados estatisticamente pelos testes de ANOVA e Tukey (p< 0,05). Resultado: Os cimentos avaliados exibiram valores de RU semelhantes. Em relação aos tratamentos de superfície, os maiores valores de RU foram encontrados no grupo Jateamento. Conclusão: O cimento convencional, AllCem Core, e o cimento autoadesivo, RelyX U200, mostraram valores de resistência de união semelhantes. Ainda, o jateamento com óxido de alumínio favoreceu a adesão dos pinos aos cimentos.

Introduction: The fiberglass posts are an alternative to the metal cast, presenting some advantages, such as aesthetics, tensile modulus similar to dentin and can be placed in a single session, immediately after the endodontic treatment. It also has the ability to adhere to the resin cement and the last to dentin by means of bonding techniques. Objective: To compare the adhesion of a conventional resin cement with a self-adhesive to fiberglass posts, and the effects of different surface treatments on adhesion of posts. Material and method: Thirty fiber posts were divided into 3 groups: control: untreated surface; Blasting: blasting with aluminum oxide for 30 seconds and peroxide: immersion in 24% hydrogen peroxide for 1 minute. Then, the samples were obtained from resin cement cylinders containing the fiber post positioned in the center of its long axis. In each group 5 posts were associated with the adhesive Ambar+conventional cement Allcem Core and the other 5 posts with the self-adhesive cement RelyX U200. The post/cement sample was segment in discs and evaluated for bond strength (BS) by push-out test. Data were analyzed statistically by ANOVA and Tukey tests (p< 0.05). Result: The cements evaluated exhibited similar BS values. Regarding surface treatments, the highest BS values were found in blasting group. Conclusion: Conventional cement, Allcem Core, and self-adhesive, RelyX U200, showed similar bond strength values. Also, blasting with aluminum oxide favored the adhesion of posts to cements.