• The Journal of Korean Academy of Prosthodontics
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• v.52 no.2
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• pp.74-81
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• 2014

Purpose: While studies have examined microleakage in endodontically treated teeth restored with posts, microleakage among post and adhesive systems remains a concern. This study compared the sealing properties of 3 adhesively luted post systems. Materials and methods: Thirty-six endodontically treated permanent maxillary central incisors were divided into 3 groups: Zirconia-glass fiber, Quartz-glass fiber, Polyethylene fiber posts. Post space was prepared and each post was adhesively luted with 3 systems. The specimens were separately immersed in freshly prepared 2% methylene blue solution for 1 week. The cleaned specimens were then embedded in autopolymerizing acrylic resin. The root portion of tooth were horizontally sectioned into three pieces (apical, middle, and coronal portions). An occlusal view of each section was digitally photographed with a stereomicroscope. The methylene blue-infiltrated surface for each specimen was measured. Dye penetration was estimated as the ratio of the methylene blue-infiltrated surface to the total dentin surface. Results: No significant differences were found among post types. The variables of middle section and 3-stage adhesive produced significant differences in microleakage between the following post pairs: zirconia-glass fiber versus quartz-glass fiber, zirconia-glass fiber versus polyethylene fiber, and quartz-glass fiber versus polyethylene fiber (P<.05). There were significant differences between the apical and coronal sections of each post type, and between apical versus middle sections of quarze-glass fiber and polyethylene fiber posts (P<.05). Conclusion: No significant differences were found among post types. The 3-stage adhesive produced significant differences in microleakage between the following post pairs.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.309-323
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• 2009

In this study we evaluated the influence of both the thickness of residual enamel and the color of the composite resins applied to lingual surface on the labial surface color. Background plates were made by randomly (A1, A2, A6D, B1, B2, B3, C1, C2, C6D) selected colors of Filtek Supreme (3M ESPE, St. Paul, U.S.A.) composite resin. Crown portion of 9 maxillary central incisors were cut off and embedded with acrylic resin except labial surface. Samples of average thickness of 2.2 mm were obtained after cutting it in a thickness of 2.5 mm from the labial surface and sandpaper polish. The shade of composite resin background was measured using Spectrophotometer ($Spectrolino^{(R)}$, GretagMacbeth, Regensdorf, Switzerland). And CIE $L^{\ast}a^{\ast}b^{\ast}$value of 2.2 mm thickness tooth samples were measured on the 9 composite resin backgrounds. And then, the cutting side of tooth samples was ground to the extent of 1.9 mm, 1.6 mm, 1.3 mm, 1.0 mm and placed on composite resin backgrounds and measured $L^{\ast}a^{\ast}b^{\ast}$values with the same method. In all samples, $L^{\ast}$value and $b^{\ast}$value seemed to have a tendency of decreasing as thickness of tooth sample becomes thinner regardless of background colors (p < 0.05). But, $a^{\ast}$value didn't show the significant differences depending on the thickness.