The effect of three processing cycles on some physical and chemical properties of a heat-cured acrylic resin

Honorez, P; Catalán, Alfonso; U, Angnes; Grimonster, J

doi:10.1016/0022-3913(89)90025-5

Cited by 41 publications

(43 citation statements)

References 7 publications

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“…O polímero do metacrilato não é solúvel em água e, portanto, a solubilidade apresentada por este material é devida basicamente pela presença de monômero residual e aditivos solúveis em sua composição 16 . O monômero residual é gradualmente liberado pelo material após sua polimerização, causando porosidade que permite a infiltração de líquidos, corantes e fluidos presentes no meio bucal.…”

Section: Técnicas Agrupadasunclassified

Estabilidade dimensional de uma resina acrílica para coroas provisórias em função de diferentes técnicas de processamento ao longo do tempo

Garcı́a-López

Rezende

Hiramatsu

et al. 2013

Rev. odontol. UNESP

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ResumoIntrodução: A estabilidade dimensional das resinas acrílicas influencia na adaptação das coroas provisórias e, consequentemente, no resultado do tratamento reabilitador. Objetivo: Avaliar a estabilidade dimensional, ao longo do tempo, de uma resina acrílica processada de diferentes maneiras. Material e método: Cinco técnicas de polimerização da resina acrílica foram testadas: I -polimerização térmica utilizando líquido de polimerização rápida em mufla; II -autopolimerização sob pressão; III -autopolimerização utilizando pincel; IV -autopolimerização após mistura (pó + líquido) em pote Dappen e inserção em matriz de aço na fase arenosa; V -autopolimerização após mistura em pote Dappen com inserção na matriz metálica na fase plástica. Foram confeccionados dez corpos de prova para cada tipo de processamento. Avaliou-se a estabilidade dimensional por meio de matriz de aço inox confeccionada segundo a especificação nº19 da ADA. Os corpos de prova foram armazenados em água destilada a 37°C e examinados nos períodos de 1 hora, 1, 7, 15, 10, 90 e 180 dias após a polimerização, com o auxílio de um microscópio óptico com aumento de 20×. Os resultados foram submetidos à análise de dupla variância (Teste de Tukey para Tempo e Técnica de processamento) em nível de 5% de significância. Resultado: Todos os grupos experimentais apresentaram alterações dimensionais entre o sétimo e o 15º dia; após esse período de tempo, houve alterações dimensionais estatisticamente significantes, para as diferentes técnicas estudadas. Conclusão: A estabilidade dimensional da resina acrílica não sofreu influência das diferentes técnicas de processamento avaliadas; entretanto, foi influenciada pelo tempo de armazenamento.Descritores: Prótese parcial fixa; adaptação marginal dentária; restauração dentária temporária; polimetil metacrilato. AbstractIntroduction: The dimensional stability of acrylic resins influences the temporary crowns fitting and can affect the final restoration results. Objective: To evaluate the long-term dimensional stability of an acrylic resin used for fabrication of provisional crowns. Material and method: Five types of processing techniques were evaluated: I -thermal polymerization using fast polymerization liquid and flask; II -auto-polimerization under pressure in a stainless steel matrix; III -auto-polimerization using the bead brush technique to build the sample; IV -auto-polimerization after mixture (powder + liquid) in a dappen dish and insertion in a stainless steel matrix at the sand stage; V -auto-polimerization after mixture in a dappen dish with insertion in a stainless steel matrix at the plastic stage. For each type of processing technique, 10 samples were made. Dimensional stability was evaluated by means of a steel matrix made following the ADA specification nº19. The samples were stored in distilled water at 37 °C and examined at the periods of 1 hour, 1, 7, 15, 30, 90 and 180 days, with an optic microscope with 20× magnification. The results were subjected to the 2-way analysis of variance (Tukey Tes...

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Section: Técnicas Agrupadasunclassified

Estabilidade dimensional de uma resina acrílica para coroas provisórias em função de diferentes técnicas de processamento ao longo do tempo

Garcı́a-López

Rezende

Hiramatsu

et al. 2013

Rev. odontol. UNESP

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“…Heat-polymerization is the most widely used method of polymerization for acrylic resin denture base fabrication and usually is accomplished in a heated water-bath 10,12,26 .…”

Section: Introductionmentioning

confidence: 99%

“…The conventional method of polymerization cycle is a long, slow-temperature water-bath polymerization where the heat-polymerization of acrylic resin is processed for 9 h at 74ºC 26 . There are also post-polymerization cycles such as terminal boiling at 100ºC for durations of 30 min (short-term) or longer than 1 h (long-term) 10,12,14,32 . Furthermore, it has been reported that total polymerization time shorter than 2 h is widely preferred than the long polymerization cycles 3 .…”

Section: Introductionmentioning

confidence: 99%

Effect of leaching residual methyl methacrylate concentrations on in vitro cytotoxicity of heat polymerized denture base acrylic resin processed with different polymerization cycles

et al. 2011

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ObjectivesResidual methyl methacrylate (MMA) may leach from the acrylic resin denture bases and have adverse effects on the oral mucosa. This in vitro study evaluated and correlated the effect of the leaching residual MMA concentrations ([MMA]r) on in vitro cytotoxicity of L-929 fibroblasts. Material and MethodsA total of 144 heat-polymerized acrylic resin specimens were fabricated using 4 different polymerization cycles: (1) at 74ºC for 9 h, (2) at 74ºC for 9 h and terminal boiling (at 100ºC) for 30 min, (3) at 74ºC for 9 h and terminal boiling for 3 h, (4) at 74ºC for 30 min and terminal boiling for 30 min. Specimens were eluted in a complete cell culture medium at 37ºC for 1, 2, 5 and 7 days. [MMA]r in eluates was measured using high-performance liquid chromatography. In vitro cytotoxicity of eluates on L-929 fibroblasts was evaluated by means of cell proliferation using a tetrazolium salt XTT (sodium 3´-[1-phenyl-aminocarbonyl)-3,4-tetrazolium]bis(4-methoxy-6-nitro)benzenesulphonic acid) assay. Differences in [MMA]r of eluates and cell proliferation values between polymerization cycles were statistically analyzed by Kruskal-Wallis, Friedman and Dunn's multiple comparison tests. The correlation between [MMA]r of eluates and cell proliferation was analyzed by Pearson's correlation test (p<0.05). Results[MMA]r was significantly (p≤0.001) higher in eluates of specimens polymerized with cycle without terminal boiling after elution of 1 and 2 days. Cell proliferation values for all cycles were significantly (p<0.01) lower in eluates of 1 day than those of 2 days. The correlation between [MMA]r and cell proliferation values was negative after all elution periods, showing significance (p<0.05) for elution of 1 and 2 days. MMA continued to leach from acrylic resin throughout 7 days and leaching concentrations markedly reduced after elution of 1 and 2 days. ConclusionDue to reduction of leaching residual MMA concentrations, use of terminal boiling in the polymerization process for at least 30 min and water storage of the heat-polymerized denture bases for at least 1 to 2 days before denture delivery is clinically recommended for minimizing the residual MMA and possible cytotoxic effects.

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“…The residual monomer content and its release from denture poly(methylmethacry1ate) (PMMA) have been determined in several studies. It is well known that there IS less residual monomer in heat-cured PMMA than in autopolymerizing PMMA (1)(2)(3)(4)(5)(6). The reason for the higher residual monomer content in the autopolymerizing PMMA is the low degree of polymerization achieved by the use of a chemical activator as opposed 10 that generated by heat activation.…”

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confidence: 96%

The effect of surface treatment of denture acrylic resin on the residual monomer content and its release into water

Vallittu

1996

Acta Odontologica Scandinavica

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The test specimens were processed by autopolymerizing poly(methylmethacrylate) (PMMA), and their surfaces were untreated, polished in a conventional manner with a rag wheel, or coated with a light-curing resin. The residual methylmethacrylate (MMA) content and its release into water from the specimens were measured with high-performance liquid chromatography. The light-curing resin coating reduced most effectively the release of residual MMA into water during a 2-day storage, but conventional polishing of the PMMA surface had a similar effect when the mean values of groups were tested by means of one-way ANOVA (p < 0.001). The residual MMA content was lowest in the test specimens coated with a light-curing resin, whereas only a slight difference was seen when the untreated and polished test specimens were compared. This study suggests that not only light-curing resin coating but also the conventional polishing of the denture PMMA reduces residual MMA release into water in vitro.

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The effect of three processing cycles on some physical and chemical properties of a heat-cured acrylic resin

Cited by 41 publications

References 7 publications

Estabilidade dimensional de uma resina acrílica para coroas provisórias em função de diferentes técnicas de processamento ao longo do tempo

Estabilidade dimensional de uma resina acrílica para coroas provisórias em função de diferentes técnicas de processamento ao longo do tempo

Effect of leaching residual methyl methacrylate concentrations on in vitro cytotoxicity of heat polymerized denture base acrylic resin processed with different polymerization cycles

The effect of surface treatment of denture acrylic resin on the residual monomer content and its release into water

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