Variable results have been reported for the bonding of cervical lesion restorative materials to enamel and dentine. The effect of surface condition on bond strength was studied for two glass ionomer and one polycarboxylate cements and one composite resin material.Flat surfaces of human enamel and dentine, prepared by wet grinding on 600 grit sihcon carbide paper, were treated respectively with water, phosphoric acid, citric acid, EDTA and/or remineralizing solution. Using an improved bonding device the cements and the composite resin were bonded to the prepared enamel and dentine surfaces. After 24 h in water at 37°C a tensile bond strength was determined. The bond fracture surfaces were examined in the scanning electron microscope. The results showed good bonding of the materials to enamel after the recommended surface treatments with cohesive failure and values 60-120 kg/cm^.Bonding to dentine was more variable and was critically dependent on surface preparation.Caulk-ASPA bond strengths that were obtained after various treatments ranged from 34 kg/cm^ (untreated dentine) to 54 kg/cm^ (citric acid treatment).Fuji ionomer bond strengths that were obtained after various treatments ranged from 42 kg/cm^ (citric acid treated dentine) to 56 kg/cm^ (FDTA treated).Durelon bond strengths that were obtained after various treatments ranged from 24 kg/cm^ (citric acid treated dentine), to 69 kg/cm^ (remineralizing solution treated dentine).The bond strengths that were obtained with Cervident after various treatments ranged from 0 kg/cm^ (untreated dentine) to 30 kg/cm^ (phosphoric acid treated dentine plus the adhesion promoter).SEM examination showed micromechanical bonding through penetration into dentinal tubules for all materials.