IADR Abstract Archives
Comparing Two Self-adhesive Resin Cements With a Photopolymerized Self-etch Primer
Objectives:
Manufacturers introduced self-adhesive resin cements without dentin primers to simplify indirect restoration cementation. Last year, we compared enamel and dentin shear bond-strength (SBS) of two self-adhesive resin cements used with and without separate self-etch primer. All test groups with primer yielded significantly higher SBS than control groups using manufacturer protocols. The primer manufacturer had concerns of bond interference due to proprietary catalytic properties of their primer if not followed by photopolymerization of an adhesive layer. This study cured the primer before resin cement was placed on the tooth surface.
Methods:
Extracted human molars (N=80) were hemi-sectioned and embedded in epoxy with either enamel or dentin surface exposed. Samples were polished through 600 grit, stored in water, and randomly assigned to four groups: enamel-bonded; and dentin-bonded with either SpeedCem and RelyX Unicem2 Automix. All groups were bonded with Clearfil SE Protect primer (CSEP) after curing for 10 Seconds. An Ultradent bonding jig was used to place self-adhesive resin cement onto primed tooth surfaces. Two minutes self-cure was followed by 20 seconds light-curing. Samples were stored for 24 hours in water then SBS tested with Instron E3000 universal testing machine (crosshead speed of 0.5mm/min). Mean values were compared with Student’s T-Test (α=0.05).
Results:
Groups with photopolymerized primer had somewhat higher, but not statistically significant, SBS compared to non-photopolymerized primer groups. Our original study showed primer groups had stronger SBS than control groups by factors of 4-6X for the dentin subgroups and 2.7-4X for enamel subgroups. The current study followed the trend closely but with higher SBS values. The failure mode observed showed higher percentage of cohesive tooth failure than the previous study.
Conclusions:
Adding a photopolymerized self-etch primer to self-adhesive resin cements, did not interfere with, but significantly strengthened the SBS to tooth structure of the “all-in-one” resin cements tested in this study.
Manufacturers introduced self-adhesive resin cements without dentin primers to simplify indirect restoration cementation. Last year, we compared enamel and dentin shear bond-strength (SBS) of two self-adhesive resin cements used with and without separate self-etch primer. All test groups with primer yielded significantly higher SBS than control groups using manufacturer protocols. The primer manufacturer had concerns of bond interference due to proprietary catalytic properties of their primer if not followed by photopolymerization of an adhesive layer. This study cured the primer before resin cement was placed on the tooth surface.
Methods:
Extracted human molars (N=80) were hemi-sectioned and embedded in epoxy with either enamel or dentin surface exposed. Samples were polished through 600 grit, stored in water, and randomly assigned to four groups: enamel-bonded; and dentin-bonded with either SpeedCem and RelyX Unicem2 Automix. All groups were bonded with Clearfil SE Protect primer (CSEP) after curing for 10 Seconds. An Ultradent bonding jig was used to place self-adhesive resin cement onto primed tooth surfaces. Two minutes self-cure was followed by 20 seconds light-curing. Samples were stored for 24 hours in water then SBS tested with Instron E3000 universal testing machine (crosshead speed of 0.5mm/min). Mean values were compared with Student’s T-Test (α=0.05).
Results:
Groups with photopolymerized primer had somewhat higher, but not statistically significant, SBS compared to non-photopolymerized primer groups. Our original study showed primer groups had stronger SBS than control groups by factors of 4-6X for the dentin subgroups and 2.7-4X for enamel subgroups. The current study followed the trend closely but with higher SBS values. The failure mode observed showed higher percentage of cohesive tooth failure than the previous study.
Conclusions:
Adding a photopolymerized self-etch primer to self-adhesive resin cements, did not interfere with, but significantly strengthened the SBS to tooth structure of the “all-in-one” resin cements tested in this study.