Efeito de dentifrício com alta concentração de flúor na remineralização e resistência de união de cimento de ionômero de vidro em substratos dentários com cárie artificial
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Data
2021-07-08
Autores
Gonçalves, Diego Felipe Mardegan [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O objetivo do presente estudo foi avaliar a influência de diferentes dentifrícios na dureza de superfície, em secção transversal e perfil de desgaste do esmalte, assim como na resistência de união de cimentos de ionômero de vidro de alta viscosidade (CIV-AV) à dentina, após indução de cárie artificial, ciclagem de pH e escovação. Foram utilizados 80 dentes bovinos, divididos em blocos de esmalte e dentina. Os espécimes de esmalte foram polidos e selecionados de acordo com a microdureza. Em seguida, metade de cada bloco de esmalte foi protegida com verniz ácido resistente. Os espécimes de dentina foram incluídos em resina acrílica e planificados. O protocolo de cárie artificial foi feito através de ciclos de desmineralização em esmalte (n=20) e pela imersão da dentina (n=40) em solução desmineralizadora. Vinte amostras de dentina não foram submetidas à cárie, sendo o grupo controle. Todas as amostras foram submetidas à ciclagem de pH e escovação durante 7 dias de acordo com cada dentifrício: Colgate Total 12 1450 ppm F (CT) e Clinpro 5000 ppm F + TCP (CL). Em seguida, os blocos de esmalte foram submetidos às análises de dureza de superfície, em secção transversal e perfilometria. Microscopia eletrônica de varredura foi realizada em três blocos representativos de cada grupo. Os espécimes de dentina foram subdivididos de acordo com material restaurador: CIV-AV Ketac Molar (KM) e cimento ionomérico híbrido Equia Forte (EF). Em seguida, as amostras foram armazenadas sob umidade relativa durante 24 horas e preparados para o teste de microcisalhamento. Os dados obtidos foram submetidos ao teste de normalidade, análise de variância (ANOVA) 1 critério para avaliar a recuperação mineral e perfil de desgaste, ANOVA 2 critérios com medidas repetidas para avaliar a dureza de superfície e em secção transversal, ANOVA 3 critérios para avaliar o microcisalhamento e pós teste de Tukey para comparações múltiplas, com significância de 5%. Observou-se recuperação parcial da dureza de superfície, independente do dentifrício. Os dados da dureza em secção transversal evidenciaram que CL obteve valores inferiores a CT até 90 micrômetros (m) no lado teste. O dentifrício CT apresentou maior desgaste quando comparado à CL. Em dentina, ao comparar os dentifrícios dentro de cada CIV, CT apresentou maior resistência adesiva para ambos os materiais. A comparação entre CIVs dentro do mesmo dentifrício evidenciou resistência adesiva superior para KM quando comparado à EF na dentina tratada com CL. Conclui-se que o dentifrício com maior concentração de flúor promoveu menor dureza em secção transversal no esmalte e o dentifrício convencional resultou em maior desgaste superficial. Na superfície dentinária, o dentifrício com maior concentração de flúor diminuiu a resistência adesiva de cimentos de ionômero de vidro.
The aim of the present study was to evaluate the influence of different dentifrices on surface hardness and cross-sectional hardness, wear profile on enamel, as well as on the bond strength of high viscosity glass ionomer cements (HV-GIC) to dentin, after to produce artificial caries, pH cycling and brushing. Eighty bovine teeth were used, divided into enamel and dentin blocks. The enamel specimens were polished and selected according to microhardness. Then, half of each enamel block was covered with resistant acid varnish. Dentin specimens were embedded in acrylic resin and flattened. The artificial caries protocol was carried out through enamel demineralization cycles (n= 20), and the dentin (n= 40) was immersed in demineralizing solution. Twenty dentin specimens were not subjected to artificial caries, being the control group. All blocks were subjected to pH cycling and brushing for 7 days according to each dentifrice: Colgate Total 12 1450 ppm F (CT) and Clinpro 5000 ppm F + TCP (CL). Then, the protected enamel surfaces were exposed for the analysis of surface hardness, cross sectional hardness and profilometry. Scanning electron microscopy was performed in three representative blocks of each group. The dentin specimens were subdivided according to restorative material: HV-GIC Ketac Molar (KM), and hybrid GIC Equia Forte (EF). Then, the specimens were stored under relative humidity for 24 hours and prepared for the micro-shear test. The data were submitted to normality test, one-way analysis of variance (ANOVA) to assess mineral recovery and wear, two-way repeated measures ANOVA to assess surface and cross-sectional hardness, and three-way ANOVA to analyze the bond strength. Tukey post-test was used for multiple comparisons, with a significance level of 5%. It was observed a partial recovery of superficial microhardness, regardless of the dentifrice. Cross sectional hardness data showed that CL obtained values below CT up to 90 micrometers (m) on the test side. CT dentifrice presented greater wear when compared to CL. In dentin, when the dentifrices were compared within each GIC, CT showed greater adhesive resistance for both materials. A comparison between GICs within the same dentifrice showed superior adhesive resistance for KM when compared to EF in dentin treated with CL. It was concluded that the dentifrice with the highest fluoride concentration promoted less cross-sectional hardness in the enamel and the conventional dentifrice resulted in greater surface wear. On the dentin, the dentifrice with the highest fluoride concentration decreased the adhesive strength of glass ionomer cements.
The aim of the present study was to evaluate the influence of different dentifrices on surface hardness and cross-sectional hardness, wear profile on enamel, as well as on the bond strength of high viscosity glass ionomer cements (HV-GIC) to dentin, after to produce artificial caries, pH cycling and brushing. Eighty bovine teeth were used, divided into enamel and dentin blocks. The enamel specimens were polished and selected according to microhardness. Then, half of each enamel block was covered with resistant acid varnish. Dentin specimens were embedded in acrylic resin and flattened. The artificial caries protocol was carried out through enamel demineralization cycles (n= 20), and the dentin (n= 40) was immersed in demineralizing solution. Twenty dentin specimens were not subjected to artificial caries, being the control group. All blocks were subjected to pH cycling and brushing for 7 days according to each dentifrice: Colgate Total 12 1450 ppm F (CT) and Clinpro 5000 ppm F + TCP (CL). Then, the protected enamel surfaces were exposed for the analysis of surface hardness, cross sectional hardness and profilometry. Scanning electron microscopy was performed in three representative blocks of each group. The dentin specimens were subdivided according to restorative material: HV-GIC Ketac Molar (KM), and hybrid GIC Equia Forte (EF). Then, the specimens were stored under relative humidity for 24 hours and prepared for the micro-shear test. The data were submitted to normality test, one-way analysis of variance (ANOVA) to assess mineral recovery and wear, two-way repeated measures ANOVA to assess surface and cross-sectional hardness, and three-way ANOVA to analyze the bond strength. Tukey post-test was used for multiple comparisons, with a significance level of 5%. It was observed a partial recovery of superficial microhardness, regardless of the dentifrice. Cross sectional hardness data showed that CL obtained values below CT up to 90 micrometers (m) on the test side. CT dentifrice presented greater wear when compared to CL. In dentin, when the dentifrices were compared within each GIC, CT showed greater adhesive resistance for both materials. A comparison between GICs within the same dentifrice showed superior adhesive resistance for KM when compared to EF in dentin treated with CL. It was concluded that the dentifrice with the highest fluoride concentration promoted less cross-sectional hardness in the enamel and the conventional dentifrice resulted in greater surface wear. On the dentin, the dentifrice with the highest fluoride concentration decreased the adhesive strength of glass ionomer cements.
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Palavras-chave
Esmalte dentário, Dentina, Cimentos de ionômeros de vidro, Dentifrícios, Tooth enamel, Dentin, Glass ionomer cement, Toothpaste, Cremes dentais