Effects of sodium copper‐ and sodium iron‐chlorophyllin primers on resin bonding to dentin

This study evaluated the effects of two chlorophyll derivatives, sodium copper chlorophyllin (Cu‐Chl) and sodium iron chlorophyllin (Fe‐Chl), on the bond strength between a self‐curing luting agent (4‐META/MMA‐TBB resin) and dentin. Five aqueous primers containing 35% 2‐hydroxyethylmethacrylate with 0.007% Cu‐Chl, 0.07% Cu‐Chl, 0.007% Fe‐Chl, 0.07% Fe‐Chl, or neither Cu‐Chl nor Fe‐Chl (no‐Chl) were prepared. The extracted human dentin surfaces were etched with 10% phosphoric acid (10PA), primed, and bonded to a resin block using the 4‐META/MMA‐TBB resin. A conventional etching agent (10‐3) and 10PA without primer (PA/no‐primer) were used as controls. The microtensile bond strength was determined after 48 h. The arithmetic medians for 20 stick specimens were calculated and statistically analyzed using a nonparametric Steel‐Dwass test ( α = 0.05). The maximum bond strength was achieved in the 0.007% Cu‐Chl group, followed by those in the 0.07% Cu‐Chl, 0.07% Fe‐Chl, 10‐3, 0.007% Fe‐Chl, no‐Chl, and PA/no‐primer groups. No significant difference was observed between 0.007% Fe‐Chl, 0.07% Fe‐Chl, and 10‐3. The bond strength to dentin etched with 10PA was influenced by the type and concentration of the chlorophyll derivatives applied. Cu‐Chl rather than Fe‐Chl should be useful as a component of surface treatment agents for bonding 4‐META/MMA‐TBB resin to dentin.