Effect of Color and Surface Roughness of Glass Ionomer Cements Submitted to Solutions Based on Ilex paraguariensis

ABSTRACT: The present study analyzed the color change (DE) and surface roughness (Ra) of glass ionomer cements (GICs) subjected to typical herbaceous South American beverage action - Ilex paraguariensis. 90 specimens (n = 10) were made: M1 - GIC Riva Light Cure® (SDI); M2 - GIC Riva Self Cure® (SDI); M3 - GIC Vitremer® (3M ESPE). After light curing/ polymerization of GICs, specimens were divided for being submitted to solutions for one hour a day for 21 days: S1 - Yerba Mate Pajarito Traditional (Pajarito); S2 - Erva Mate Chimarrão (Barão de Cotegipe); S3 - Water (control). Four DE and Ra readings were taken: T0 - initial; T1 - 7 days; T2 - 14 days and T3 - 21 days, with a spectrophotometer and a roughness meter respectively. The obtained data were submitted to ANOVA statistical analysis and Bonferroni. S1 and S2 at T1 and T2 there was no statistical difference between the materials, and at T3 Materials M1=M2, M1=M3, and M2>M3. For S3 at T1, T2 and T3 there was no difference between the materials. Analyzing surface roughness, there was no statistical significance. Concluded that all materials changed color with greater influence of time, but without changing surface roughness.

RESUMEN: En el presente estudio se analizó el cambio de color (DE) y la rugosidad superficial (Ra) de los cementos ionómero de vidrio (CIV) sometidos a la acción típica de las bebidas herbáceas sudamericanas - Ilex paraguariensis. Se realizaron 90 especímenes (n = 10): M1 - GIC Riva Light Cure® (SDI); M2 - GIC Riva Self Cure® (SDI); M3 - GIC Vitremer® (3M ESPE). Después de la fotopolimerización/ polimerización de los CIV, los especímenes se dividieron y fueron sometidos a soluciones durante una hora al día durante 21 días: S1 - Yerba Mate Pajarito Tradicional (Pajarito); S2 - Erva Mate Chimarrão (Barão de Cotegipe); S3 - Agua (control). Se tomaron cuatro lecturas de DE y Ra: T0 - inicial; T1 - 7 días; T2 - 14 días y T3 - 21 días, con espectrofotómetro y rugosímetro respectivamente. Los datos obtenidos fueron sometidos a análisis estadístico ANOVA y Bonferroni. S1 y S2 en T1 y T2 no hubo diferencia estadística entre los materiales y en T3 Materiales M1=M2, M1=M3 y M2>M3. Para S3 en T1, T2 y T3 no hubo diferencia entre los materiales. Al analizar la rugosidad de la superficie, no hubo significación estadística. En conclusion, todos los materiales cambiaron de color con mayor influencia del tiempo, pero sin cambiar la rugosidad de la superficie.

Influência da topografia de superfície nanométrica na estabilidade primária de mini-implantes dentários / Influence of the nanometric surface topography on the primary stability of dental mini-implants

Resumo Introdução A modificação físico-química da superfície de mini-implantes utilizados no suporte de overdentures pode influenciar o desempenho mecânico dos mesmos. Objetivo Avaliar a influência de um tratamento de superfície do tipo nanométrico no desempenho mecânico de novos designs de mini-implantes. Material e método Foram utilizados 40 mini-implantes (Ti-6Al-4V), com Ø 2 mm × 10 mm de comprimento e dois designs diferentes, rosqueado e helicoidal, divididos em quatro grupos (n=10), de acordo com o modelo e a presença ou a ausência de tratamento superficial. O desempenho mecânico foi avaliado por meio de torque de inserção e ensaio de arrancamento em cilindros ósseos suínos. Análise de variância ANOVA e teste de Tukey, com significância de 5%, foram utilizados para análise estatística dos dados. Resultado Foi observada diferença estatisticamente significante entre os grupos com e sem tratamento para torque de inserção (p<0,001), e ensaio de arrancamento (p=0,006), sendo a maior média para o grupo com tratamento, independentemente do design. Na comparação entre os designs, o rosqueado apresentou média significativamente maior (p<0,001) que o helicoidal. Conclusão: O tratamento de superfície nanométrico viabilizou melhor desempenho mecânico dos mini-implantes avaliados. Com relação aos novos designs testados, o rosqueado apresentou resultados superiores ao helicoidal.

Abstract Introduction The physical-chemical modification of the surface of mini-implants used in the support of overdentures can influence the mechanical performance and survival of the same. Objective To evaluate the influence of a nanometric surface treatment on the mechanical performance of new mini-implant designs. Material and method 40 mini-implants (Ti-6Al-4V) with Ø 2 mm x 10 mm in length and two different designs, threaded and helical, were divided into four groups (n = 10) according to model, presence or absence of surface treatment. The mechanical performance was evaluated by means of insertion torque and pullout test in swine bony cylinders. Analysis of variance ANOVA and Tukey test, with significance of 5% were used for statistical analysis of the data. Result A statistically significant difference was observed between the groups with and without treatment for insertion torque (p <0.001) and pullout test (p = 0.006), being the highest mean for the treatment group, regardless of the design. In the comparison between the designs, the thread presented a significantly higher average (p <0.001) than the helicoid. Conclusion The nanometric surface treatment enabled better mechanical performance of the mini-implants evaluated. With respect to the new designs tested, the thread presented superior results to the helicoidal one.

Analysis of the surface deformation of dental implants submitted to pullout and insertion test.

Objective: The aim of the present study was to evaluate the possible deformations in the surface of dental implants submitted to pullout and insertion test in polyurethane synthetic bone, using scanning electron microscopy. Material and Methods: Four different types of implants were used: Master Screw, Master Porous, Master Conect AR and Master Conect Conical (n = 8). These implants were into the femoral head synthetic bone (Synbone) and removed through the pullout test, performed with a universal testing machine (EMIC MEM 2000). All the screws, before and after the mechanical tests, were micro structurally analyzed in a Scanning Electron Microscope (SEM - Zeiss EVO50), utilizing a magnification of 35 times. The results were subjected to ANOVA and Tukey tests (α =0.05). Results: Only the Master Conect Conical and Master Porous implants presented statistically significant difference to pullout and maximum deformation (P = 0.014 and P = 0.009, respectively). The SEM images did not show morphological changes of the implants when compared before and after the mechanical tests. Conclusion: We concluded that Master Porous presented higher pullout resistance, suggesting a greater primary stability.