Objectives : Microleakage is the main concern in composite restorations. This study aimed to comp... more Objectives : Microleakage is the main concern in composite restorations. This study aimed to compare the microleakage of two bulk-fill and one conventional composite at two different time points. Methods : Class II cavities were prepared in 60 premolar teeth and divided into six groups of 20. Groups 1 and 4 were incrementally filled with Grandio composite. Groups 2 and 5 were filled with X-tra fil bulk-fill composite. Groups 3 and 6 were filled with Tetric-N-Ceram bulk-fill composite in one layer. The samples were thermocycled for 5000 cycles between 25-55°C. In groups 1-3, the samples were incubated for 24 hours and then immersed in 1% methylene blue dye. Groups 4-6 were incubated for three months and then immersed in dye. All samples were mesiodistally sectioned and degree of microleakage was scored under a light microscope. The data were analyzed using Mann Whitney and Kruskal-Wallis tests. Results : The results showed no significant difference among groups 1-5 and 6 in terms of ...
Objectives Composite surface sealants were introduced aiming to prevent or decrease the discolora... more Objectives Composite surface sealants were introduced aiming to prevent or decrease the discoloration and microleakage of compositerestorations. This study sought to assess the effect of aging on discoloration of two composite surface sealants.Methods In this experimental study, 24 samples were fabricated of Fortify Plus and BisCover LV composite surface sealants (10 mm indiameter and 1 mm in thickness) and their baseline color coordinates were measured using the CIE L* a* b* system by a reflectionspectrophotometer. The samples made of each material (n = 12) were randomly divided into 4 groups of 3 and aged in xenon chamber,tea, distilled water and dry ambient environment (control). Color change (ΔE*) was calculated in the reflectance mode. The data wereanalyzed using two-way ANOVA and t-test (P < 0.05).Results The minimum ΔE* value was 0.95 ± 0.6 belonging to Fortify Plus stored in the dry ambient environment while the maximum ΔE* valuewas 21.85 ± 4 belonging to BisCover LV aged...
Objectives: This study investigated the indirect effect of calcium-enriched mixture (CEM) cement ... more Objectives: This study investigated the indirect effect of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA), as 2 calcium silicate-based hydraulic cements, on human dental pulp stem cells (hDPSCs) through different dentin thicknesses. Materials and Methods: Two-chamber setups were designed to simulate indirect pulp capping (IPC). Human molars were sectioned to obtain 0.1-, 0.3-, and 0.5-mm-thick dentin discs, which were placed between the 2 chambers to simulate an IPC procedure. Then, MTA and CEM were applied on one side of the discs, while hDPSCs were cultured on the other side. After 2 weeks of incubation, the cells were removed, and cell proliferation, morphology, and attachment to the discs were evaluated under scanning electron microscopy (SEM). Energy-dispersive X-ray (EDXA) spectroscopy was performed for elemental analysis. Alkaline phosphatase (ALP) activity was assessed quantitatively. The data were analyzed using the Kruskal-Wallis and Mann-Whitney tests. Results: SEM micrographs revealed elongated cells, collagen fibers, and calcified nucleations in all samples. EDXA verified that the calcified nucleations consisted of calcium phosphate. The largest calcifications were seen in the 0.1-mm-thick dentin subgroups. There was no significant difference in ALP activity across the CEM subgroups; however, ALP activity was significantly lower in the 0.1-mm-thick dentin subgroup than in the other MTA subgroups (p < 0.05). Conclusions: The employed capping biomaterials exerted biological activity on hDPSCs, as shown by cell proliferation, morphology, and attachment and calcific precipitations, through 0.1-to 0.5-mm-thick layers of dentin. In IPC, the bioactivity of these endodontic biomaterials is probably beneficial.
Background: Color change is one major drawback of tooth-colored resin-based restorations. Objecti... more Background: Color change is one major drawback of tooth-colored resin-based restorations. Objectives: This study aimed to assess the color stability of three commonly used resin-based restorative materials upon exposure to tea and coffee. Materials and Methods: Discs were fabricated from Spectrum TPH (Dentsply/Caulk), Denfil (Vericom), and Filtek Z250 (3 M) microhybrid composites and immersed in coffee and tea solutions for two hours on the first day and the whole of the second, third, and fourth days. The color was assessed visually and recorded using the Lobene Stain Index after each period of immersion. The color change of the three composite resins was compared using the Kruskal-Wallis test, Mann-Whitney U test, and Friedman test. The level of significance was set at 0.05. The Cohen's Kappa was also calculated to assess inter-rater agreement. Results: The three composite resins showed statistically significant color changes after four days of immersion in a coffee solution (P = 0.014), but their color change in the tea solution was not significant (P > 0.05). A comparison of color changes in the composites after one (two hours) and four days of immersion in tea and coffee solutions revealed a significant difference in color changes between Spectrum TPH and the other two composites (P < 0.001). Conclusions: The three microhybrid composites used in this study showed variable color stability upon exposure to a coffee solution. The color stability of Spectrum TPH was inferior to that of Denfil and Filtek Z250.
International Journal of Applied Ceramic Technology
In this research, we aimed at improving the setting properties and biocompatibility of the minera... more In this research, we aimed at improving the setting properties and biocompatibility of the mineral trioxide aggregate-like cements while maintaining the main chemical formula. Consequently, chitosan and zirconium oxide were added to the cement instead of bismuth oxide to improve the mechanical behavior, limit the possible toxicity, and enhance the bioactivity of the cements. Adding zirconia resulted in a shorter setting time and adding chitosan contributed to the setting time, mechanical strength, and biocompatibility at the same time. Thus, cements containing both chitosan and zirconia had the shortest setting time, highest compressive strength, and apatite-forming ability.
Objectives : Microleakage is the main concern in composite restorations. This study aimed to comp... more Objectives : Microleakage is the main concern in composite restorations. This study aimed to compare the microleakage of two bulk-fill and one conventional composite at two different time points. Methods : Class II cavities were prepared in 60 premolar teeth and divided into six groups of 20. Groups 1 and 4 were incrementally filled with Grandio composite. Groups 2 and 5 were filled with X-tra fil bulk-fill composite. Groups 3 and 6 were filled with Tetric-N-Ceram bulk-fill composite in one layer. The samples were thermocycled for 5000 cycles between 25-55°C. In groups 1-3, the samples were incubated for 24 hours and then immersed in 1% methylene blue dye. Groups 4-6 were incubated for three months and then immersed in dye. All samples were mesiodistally sectioned and degree of microleakage was scored under a light microscope. The data were analyzed using Mann Whitney and Kruskal-Wallis tests. Results : The results showed no significant difference among groups 1-5 and 6 in terms of ...
Objectives Composite surface sealants were introduced aiming to prevent or decrease the discolora... more Objectives Composite surface sealants were introduced aiming to prevent or decrease the discoloration and microleakage of compositerestorations. This study sought to assess the effect of aging on discoloration of two composite surface sealants.Methods In this experimental study, 24 samples were fabricated of Fortify Plus and BisCover LV composite surface sealants (10 mm indiameter and 1 mm in thickness) and their baseline color coordinates were measured using the CIE L* a* b* system by a reflectionspectrophotometer. The samples made of each material (n = 12) were randomly divided into 4 groups of 3 and aged in xenon chamber,tea, distilled water and dry ambient environment (control). Color change (ΔE*) was calculated in the reflectance mode. The data wereanalyzed using two-way ANOVA and t-test (P < 0.05).Results The minimum ΔE* value was 0.95 ± 0.6 belonging to Fortify Plus stored in the dry ambient environment while the maximum ΔE* valuewas 21.85 ± 4 belonging to BisCover LV aged...
Objectives: This study investigated the indirect effect of calcium-enriched mixture (CEM) cement ... more Objectives: This study investigated the indirect effect of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA), as 2 calcium silicate-based hydraulic cements, on human dental pulp stem cells (hDPSCs) through different dentin thicknesses. Materials and Methods: Two-chamber setups were designed to simulate indirect pulp capping (IPC). Human molars were sectioned to obtain 0.1-, 0.3-, and 0.5-mm-thick dentin discs, which were placed between the 2 chambers to simulate an IPC procedure. Then, MTA and CEM were applied on one side of the discs, while hDPSCs were cultured on the other side. After 2 weeks of incubation, the cells were removed, and cell proliferation, morphology, and attachment to the discs were evaluated under scanning electron microscopy (SEM). Energy-dispersive X-ray (EDXA) spectroscopy was performed for elemental analysis. Alkaline phosphatase (ALP) activity was assessed quantitatively. The data were analyzed using the Kruskal-Wallis and Mann-Whitney tests. Results: SEM micrographs revealed elongated cells, collagen fibers, and calcified nucleations in all samples. EDXA verified that the calcified nucleations consisted of calcium phosphate. The largest calcifications were seen in the 0.1-mm-thick dentin subgroups. There was no significant difference in ALP activity across the CEM subgroups; however, ALP activity was significantly lower in the 0.1-mm-thick dentin subgroup than in the other MTA subgroups (p < 0.05). Conclusions: The employed capping biomaterials exerted biological activity on hDPSCs, as shown by cell proliferation, morphology, and attachment and calcific precipitations, through 0.1-to 0.5-mm-thick layers of dentin. In IPC, the bioactivity of these endodontic biomaterials is probably beneficial.
Background: Color change is one major drawback of tooth-colored resin-based restorations. Objecti... more Background: Color change is one major drawback of tooth-colored resin-based restorations. Objectives: This study aimed to assess the color stability of three commonly used resin-based restorative materials upon exposure to tea and coffee. Materials and Methods: Discs were fabricated from Spectrum TPH (Dentsply/Caulk), Denfil (Vericom), and Filtek Z250 (3 M) microhybrid composites and immersed in coffee and tea solutions for two hours on the first day and the whole of the second, third, and fourth days. The color was assessed visually and recorded using the Lobene Stain Index after each period of immersion. The color change of the three composite resins was compared using the Kruskal-Wallis test, Mann-Whitney U test, and Friedman test. The level of significance was set at 0.05. The Cohen's Kappa was also calculated to assess inter-rater agreement. Results: The three composite resins showed statistically significant color changes after four days of immersion in a coffee solution (P = 0.014), but their color change in the tea solution was not significant (P > 0.05). A comparison of color changes in the composites after one (two hours) and four days of immersion in tea and coffee solutions revealed a significant difference in color changes between Spectrum TPH and the other two composites (P < 0.001). Conclusions: The three microhybrid composites used in this study showed variable color stability upon exposure to a coffee solution. The color stability of Spectrum TPH was inferior to that of Denfil and Filtek Z250.
International Journal of Applied Ceramic Technology
In this research, we aimed at improving the setting properties and biocompatibility of the minera... more In this research, we aimed at improving the setting properties and biocompatibility of the mineral trioxide aggregate-like cements while maintaining the main chemical formula. Consequently, chitosan and zirconium oxide were added to the cement instead of bismuth oxide to improve the mechanical behavior, limit the possible toxicity, and enhance the bioactivity of the cements. Adding zirconia resulted in a shorter setting time and adding chitosan contributed to the setting time, mechanical strength, and biocompatibility at the same time. Thus, cements containing both chitosan and zirconia had the shortest setting time, highest compressive strength, and apatite-forming ability.
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