Methods: Citrus fruits derived hesperidin (HPN) 0.5 to 5 wt% or grape seed derived proanthocyanidin (PA) 0.5wt% was incorporated into the Clearfil SE primer (Kuraray Noritake Dental Inc). Freshly extracted human molar teeth were restored using the experimental primers or the pure primer (control). I beam restored specimens were further sub-divided for immediate (one day) and long term (one year storage in artificial saliva) tensile bond strength test and nano-indentation measurement of resin-dentin interface.
Results: The immediate µTBS significantly increased with HPN 0.5 % (87.6±8.9 MPa), HPN 1.0 % (88.05±10.1 MPa) and HPN 2.0 % (89.65±9.9 MPa) when compared with the control (77.4±8.8 MPa). The long term µTBS was significantly higher with 1% HPN (70.3±10.8 MPa) and 2%HPN (76.8±10.2 MPa), when compared with the control (63.9±10.1 MPa). The mechanical properties of bonded interface were improved with the use of HPN-in primers. The PA group failed to improve the µTBS and the mechanical properties.
Conclusions:
Incorporation of HPN into the self-etching primer had the positive effect on µTBS and mechanical properties of resin-dentin interface, which improved the long term bond durability.
Acknowledgement: This work was partially supported by a grant from the Japanese Ministry of Education, Global Center of Excellence (GCOE) Program, Tokyo Medical & Dental University