論文

JADA Found Sci. 2022 Aug 12;1:100012. doi: 10.1016/j.jfscie.2022.100012. eCollection 2022.

ABSTRACT

BACKGROUND: This in vitro study used optical coherence tomography for noninvasive evaluation of the effectiveness of current clinical techniques to remove deep coronal dentin cracks.

METHODS: Standard dentin cracks were induced on the pulpal floor of 40 decoronated, extracted, sound human posterior teeth using a diamond disk, resembling cracks extending from marginal ridges. The specimens were randomly assigned to 1 of 5 treatment groups for crack removal using airborne-particle abrasion or a bur (fissure, small round, medium round, or tapered fine diamond). Optical coherence tomographic scans were obtained before and after the crack removal. Three-dimensional image registration analyzed the amount of dentin removed and the dimensions of cracks initiated or propagated in each treatment group.

RESULTS: Particle abrasion resulted in the smallest crack propagation in each dimension, which was significantly different from all bur groups (Mann-Whitney, P < .01). Removed dentin depth and width differed among burs (P < .05). All burs resulted in a degree of crack formation, and there was no difference in crack dimensions among bur groups (P > .05). The amount of removed dentin during crack treatment was the largest in the particle abrasion group, which was significantly different from those of the bur groups (Mann-Whitney, P < .005).

CONCLUSIONS: Dental burs used with the purpose of removing pulpal floor dentin cracks induced new small cracks and extended existing cracks, and the volume of removed dentin depended on the shape and size of the bur. Air particle abrasion induced the fewest new cracks despite removing larger dentin volume.

PMID:42238660 | PMC:PMC13229053 | DOI:10.1016/j.jfscie.2022.100012

JADA Found Sci. 2022 Aug 12;1:100012. doi: 10.1016/j.jfscie.2022.100012. eCollection 2022.

ABSTRACT

BACKGROUND: This in vitro study used optical coherence tomography for noninvasive evaluation of the effectiveness of current clinical techniques to remove deep coronal dentin cracks.

METHODS: Standard dentin cracks were induced on the pulpal floor of 40 decoronated, extracted, sound human posterior teeth using a diamond disk, resembling cracks extending from marginal ridges. The specimens were randomly assigned to 1 of 5 treatment groups for crack removal using airborne-particle abrasion or a bur (fissure, small round, medium round, or tapered fine diamond). Optical coherence tomographic scans were obtained before and after the crack removal. Three-dimensional image registration analyzed the amount of dentin removed and the dimensions of cracks initiated or propagated in each treatment group.

RESULTS: Particle abrasion resulted in the smallest crack propagation in each dimension, which was significantly different from all bur groups (Mann-Whitney, P < .01). Removed dentin depth and width differed among burs (P < .05). All burs resulted in a degree of crack formation, and there was no difference in crack dimensions among bur groups (P > .05). The amount of removed dentin during crack treatment was the largest in the particle abrasion group, which was significantly different from those of the bur groups (Mann-Whitney, P < .005).

CONCLUSIONS: Dental burs used with the purpose of removing pulpal floor dentin cracks induced new small cracks and extended existing cracks, and the volume of removed dentin depended on the shape and size of the bur. Air particle abrasion induced the fewest new cracks despite removing larger dentin volume.

PMID:42238660 | PMC:PMC13229053 | DOI:10.1016/j.jfscie.2022.100012

Dent Mater. 2026 May;42(5):825-832. doi: 10.1016/j.dental.2026.01.006. Epub 2026 Jan 19.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 May;42(5):825-832. doi: 10.1016/j.dental.2026.01.006. Epub 2026 Jan 19.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 May;42(5):825-832. doi: 10.1016/j.dental.2026.01.006. Epub 2026 Jan 19.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 Jan 19:S0109-5641(26)00015-1. doi: 10.1016/j.dental.2026.01.006. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 Jan 19:S0109-5641(26)00015-1. doi: 10.1016/j.dental.2026.01.006. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 Jan 19:S0109-5641(26)00015-1. doi: 10.1016/j.dental.2026.01.006. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 Jan 19:S0109-5641(26)00015-1. doi: 10.1016/j.dental.2026.01.006. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 May;42(5):825-832. doi: 10.1016/j.dental.2026.01.006. Epub 2026 Jan 19.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 May;42(5):825-832. doi: 10.1016/j.dental.2026.01.006. Epub 2026 Jan 19.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 May;42(5):825-832. doi: 10.1016/j.dental.2026.01.006. Epub 2026 Jan 19.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 May;42(5):825-832. doi: 10.1016/j.dental.2026.01.006. Epub 2026 Jan 19.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 Jan 19:S0109-5641(26)00015-1. doi: 10.1016/j.dental.2026.01.006. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 Jan 19:S0109-5641(26)00015-1. doi: 10.1016/j.dental.2026.01.006. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 Jan 19:S0109-5641(26)00015-1. doi: 10.1016/j.dental.2026.01.006. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 May;42(5):825-832. doi: 10.1016/j.dental.2026.01.006. Epub 2026 Jan 19.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 Jan 19:S0109-5641(26)00015-1. doi: 10.1016/j.dental.2026.01.006. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 Jan 19:S0109-5641(26)00015-1. doi: 10.1016/j.dental.2026.01.006. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006

Dent Mater. 2026 Jan 19:S0109-5641(26)00015-1. doi: 10.1016/j.dental.2026.01.006. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).

RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

PMID:41558951 | DOI:10.1016/j.dental.2026.01.006