Background: Antioxidizing agents have recently been suggested to compensate decreased bond\r\nstrength of resin materials to bleached tooth tissues. This study compared the shear bond strength\r\n(SBS) of three different adhesives on bleached dentin immediately after bleaching, bleached/delayed\r\nfor 1 week, and bleached/applied antioxidizing agent.\r\nMaterials and Methods: The dentinal surfaces of 132 intact extracted molars were prepared and\r\ndivided into 12 groups. The following adhesives were investigated: Optibond FL (OFL) (three-step\r\netch-and-rinse), Optibond Solo Plus (two-step etch-and-rinse), and Optibond all-in-one (OA) (onestep\r\nself-etch) (Kerr, Orange, USA). Unbleached dentin groups (groups 1-3) were prepared as negative\r\ncontrols (NC). The remainder surfaces (groups 4-12) were bleached with 20% Opalescent PF (Ultradent,\r\nUSA). Specimens were bonded immediately after bleaching (groups 4-6), after 1 week (groups 7-9), or\r\nafter using 10% sodium ascorbate (SA) gel (groups 10-12). Subsequent to bonding of composite resin,\r\nthe samples were tested for SBS and analyzed using Kruskal-Wallis and Mann-Whitney tests (a=0.05).\r\nResults: Regarding control groups, OA showed the highest SBS among the studied adhesives\r\n(P<0.05). The SBS decreased for the adhesives after bleaching except for OFL. No statistically\r\nsignificant difference in SBS were noted when the SA and delayed bonding groups were compared\r\nwith their similar NC groups (P>0.05) except the of delay bonding with OA.\r\nConclusions: The findings suggest that bond strength of resin to bleached dentin may be affected\r\nwith the adhesive system. Reduced SBS to bleached dentin can be amended by the use of SA as\r\nan antioxidizing agent. However, the amount of reversed bond strength subsequent to applying\r\nantioxidant might be related to the kind of dental adhesive.
Loading....