Based on the findings of this in vitro study, the use of ZnO nanoparticles is recommended, since they did not negatively affect the properties of the materials evaluated.
Objective
To analyze the influence of three pigment incorporation methods on color change, dimensional stability, and detail reproduction of the MDX4–4210 and A-2186 silicones.
Materials and Methods
The A-2186 and MDX4–4210 silicones were used for preparation of samples, with the incorporation of bronze, black and pink pigments, usingconventional, mechanical, and industrial incorporation methods. Samples were submitted to the initial readings of color (
n
= 10; 22-mm diameter × 2-mm thickness), detail reproduction, and dimensional stability (
n
= 10; 30-mm diameter × 3-mm thickness). Readings were also taken at the end of 252, 504 and 1,008 hours of aging cycles.
Results
Quantitative data were evaluated by ANOVA and Tukey test, with a level of significance of 5%. The mechanical and industrial methods caused smaller color changes of all samples compared with the conventional method (
p
< 0.05). In most cases, the mechanical and industrial methods caused less samples’ contraction than the conventional method after aging (
p
< 0.05). The color change values increased progressively in each aging period for all samples (
p
< 0.05). The contraction values increased progressively in each aging period for all samples (
p
< 0.05). In the qualitative analysis of detail reproduction, all samples presented full reproduction of the three grooves, with accurate angles, initially and after the aging periods.
Conclusions
The industrial and mechanical methods showed the best results for color and dimensional stability. Despite the statistical differences, all pigment incorporation methods generated acceptable dimensional and color changes of the MDX4-4210 and A-2186 silicones, regardless of the pigment and aging. In addition, the detail reproduction was satisfactory after aging periods in all cases of this study, showing the excellent quality of the A-2186 and MDX4–4210 silicones.
Objective. The aim of this study was to evaluate the tear strength of MDX4-4210 and A-2186 silicones with different intrinsic pigments incorporated by mechanical and industrial methods, comparing nonaged and aged groups. Materials and Methods. Twenty-four groups were created according to the American Society for Testing and Materials D-624/type C, half nonaged and half aged (n = 10): bronze mechanical MDX4-4210, bronze industrial MDX4-4210, black mechanical MDX4-4210, black industrial MDX4-4210, pink mechanical MDX4-4210, pink industrial MDX4-4210, bronze mechanical A-2186, bronze industrial A-2186, black mechanical A-2186, black industrial A-2186, pink mechanical A-2186, and pink industrial A-2186. All specimens were submitted to tear strength analysis. Data were submitted to the ANOVA and Tukey test (p<0.05). Results. An increase in the tear strength values was observed only for the bronze and black MDX4-4210, comparing nonaged and aged silicones (p<0.05), regardless of the manufacturing method. There was a difference in all comparisons between MDX4-4210 and A-2186 silicones with the same pigment type (p<0.05), regardless of the manufacturing method. In all cases, there was no difference in the manufacturing method comparing the MDX4-4210 or A-2186 groups with the same pigment. Conclusion. Accelerated aging did not influence the tear strength in all aged A-2186 silicones and in aged pink industrial and mechanical MDX4-4210 silicones. The other MDX4-4210 groups had an increase in the results after aging. In all cases compared, the A-2186 groups had higher tear strength values than the MDX4-4210 groups. Mechanical and industrial methods can be used for silicone preparation, without changing the tear strength.
Dental implants installed in the irradiated area of an oral cavity have a high survival rate, but strict monitoring is needed to prevent complications, thereby reducing possible failures.
It can be considered that there is not always a consensus and standardization in the classification of implant stability related to the values obtained by RFA and DCA devices, which could create disagreements and miscommunication among dentistry professionals.
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