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Showing 2 results for Spectrophotometry
Laboratorial comparison of color stability of resin composites after rebonding with two different adhesive materials
Azita Kaviani, Asadoallah Ahmadzadeh, Maryam Zarei,
Volume 26, Issue 1 (3-2013)
Abstract

Background and Aims: Discoloration of resin composites is considered to be the major factor in esthetic restoration failures. The aim of this study was to evaluate the color stability of resin composites after rebonding with two different adhesive materials.

Materials and Methods: Forty five composite disc samples were divided into three groups (n=15). The surface of specimens was finished by polishing disc and rubber. In group 1, any additional phase was not performed. In group 2, composite discs were etched by %37 orthophosphoric acid, then Margin- bond was used for rebonding. In group 3, the etching procedure was in the same manner used for group 2, but Permaseal was used after etching. After the first phase of spectrophotometric measurement, the specimens were dipped in coffee mix for 3 weeks for aging the specimens. Then the second phase of spectrophotometric evaluation was performed. Collected data was analyzed using one-way ANOVA test followed by Tukey test. P<0.05 was considered as the level of significance.

Results: The mean total color difference (∆E) observed in groups 1 to 3 were 1.4±0.34, 5.24±1.51, and 7.44±1.34, respectively. Statistical significant differences were shown between the groups (P<0.001).

Conclusion: Rebonding with adhesive materials used in this study did not increase the color stability of composite restorations.


Effects of bleaching on color stability of enamel lesions treated with resin infiltrant
Mansoureh Emami Arjomand, Seyde Sahar Masoumi, Haleh Heshmat, Zahra Nouralizadeh,
Volume 35, Issue 0 (5-2022)
Abstract
Background and Aims: Considering the preventive and therapeutic effects of resin infiltration (RI) and the unknown effect of bleaching on the enamel treated with this method, this in-vitro study aimed to assess the effect of bleaching on color stability of enamel lesions treated with RI.
Materials and Methods: In this in-vitro, experimental study, enamel-dentin samples measuring 5×5×3 mm were prepared on the buccal and lingual surfaces of 30 extracted humans third molars with no caries, cracks or enamel defects by a microtome. The specimens were divided into three groups of 10 specimens: 1) sound enamel (control), 2) demineralized enamel, 3) demineralized enamel plus RI. White spot lesions were artificially created by immersing the samples in hydroxyethyl cellulose demineralizing gel with a pH of 4.5 for 4 days. Next, Icon RI was applied on the samples in group 3. The baseline color of the specimens was measured using a spectrophotometer. Then, 35% hydrogen peroxide was applied on the specimens in three cycles and time interval of 10 min. After the end of the last cycle, the samples were completely washed for 1 min and then, underwent colorimetry again. Data were analyzed using one-way ANOVA.
Results: The results of this study showed that the highest level of color change (ΔE) in the demineralized group was 6.3±2.003, while the least amount of ΔE in the enamel lesion group treated with resin infiltration was 3.54±0.98 and in the control group ΔE was 4.13±1.14. Therefore, there was a significant difference between demineralized and treated by infiltratant groups (P=0.005). However, there was no significant difference between control group and treated with resin infiltration group (P=0.54).
Conclusion: Bleaching induced a less change in the color of the enamel lesions treated by resin infiltration compared with that of the demineralized teeth.
 
 

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