Factors influencing the bond strength between glass polyalkenoate (ionomer) cements and dentine

A series of investigations have been performed to study some factors influencing the tensile bond strength of glass polyalkenoate cements to dentine. The measured bond strength was affected by the method of storage of the teeth prior to testing, the nature of the dentine and the type of cement used for the tests. The most consistent results for bond strength measurements were obtained with teeth stored in neutral buffered formalin for more than 1 month after extraction, and then stored in distilled water for 4 weeks prior to bond strength determinations. The mean value obtained with this storage regime (1.62 MPa) was not different from that obtained using freshly extracted teeth (1.74 MPa). The bond strength to deciduous dentine (0.72 MPa) was significantly less than that to permanent dentine (1.62 MPa). There were significant differences between the measured bond strengths of the three materials tested, with Ketac-Fil giving the lowest result (1.62 MPa), then Ketac-Silver (2.41 MPa), ChemFil II formed the strongest bonds (4.65 MPa).