Objective: To determine the tensile bond strengths of two adhesive resin cements in light- and self-cured modes to human enamel and superficial dentin at 10 m and 24 h.

Materials and Methods: Two adhesive resin cements [Bistite II DC, Tokuyama Dental (BDC); Panavia F, Kuraray America (PF)] were bonded as cones (3-mm bond diameter) to human enamel and dentin prepared with 600-grit surfaces. The cements were tested in light-cured (LC) and self-cured (SC) modes. Self-cured specimens were bonded using pre-cured composite cones (TPH Spectrum). Storage times before testing were 10 m and 24 h in water. Specimens were debonded in tension on Instron at crosshead speed of 0.5 mm/m. Results: Means (sd, n=8) of bond strength (MPa) and failure mode data are shown. Fisher's PLSD intervals (p<0.05) for cements, curing mode, substrates and time were each 2.0 MPa. Conclusions: Bond strengths of both cements increased with time. Self-cured polymerization resulted in higher bond strengths than the light-cured mode. Bond strength to enamel was higher than bond strength to dentin. BDC had equal or higher bond strengths to dentin than PF. Funded in part by Tokuyama Dental Corp.

	Enamel/LC		Enamel/SC
	10 min	24 hrs	10 min	24 hrs
BDC	13.9(4.5) 21A/79C*	20.1(6.7)  10A/90C	20.4(6.2) 15A/25CR/60I	23.2(7.9) 15A/73CR/12I
PF	13.9(3.7)    9A/91C	20.4(5.1)5A/83C/12T	20.2(7.5)28A/7CR/65I	26.7(7.9) 28A/44CR/12T/16I
	Dentin/LC		Dentin/SC
	10 min	24 hrs	10 min	24 hrs
BDC	10.7(4.1)  85A/15C	14.1(5.7)    94A/6C	14.3(5.5)    90A/10I	17.1(8.3)    89A/11I
PF	9.2(2.6)      95A/5C	11.8(3.1)    91A/9C	8.6(3.2)      89A/11I	11.2(4.8)78A/1C/21I

*A, adhesive failure between tooth and cement; C, cohesive failure in cement; CR, cohesive failure in composite; I, adhesive failure between composite and cement; T, cohesive failure in tooth